Semiconductor light emitting device and display device

Abstract

The semiconductor light emitting device includes: a light emitting layer; a passivation layer surrounding a side portion of the light emitting layer; a first electrode disposed below the light emitting layer; and a second electrode disposed on the light-emitting layer. The light emitting layer may have a first region and a second region surrounding the first region. The bottom surface of the first region of the light emitting layer may have a groove. The first electrode may include: an ohmic contact layer disposed in the recess; a reflective layer disposed below the second region of the light-emitting layer; and a magnetic layer disposed below the reflective layer. The area of the reflective layer may exceed 50% of the area of the lower side of the light emitting layer.

Description

Technical Field

[0001] The embodiment relates to a semiconductor light-emitting device and a display device. Background Art

[0002] Large-screen displays include liquid crystal displays (LCDs), OLED (organic light-emitting diode) displays, and micro-LED (micro light-emitting diode) displays (Micro-LED display), etc.

[0003] A micro-LED display is a display that uses micro-LEDs, which are semiconductor light-emitting devices with a diameter or cross-sectional area of 100 μm or less, as display devices.

[0004] Since a micro-LED display uses micro-LEDs as semiconductor light-emitting devices, it has excellent performance in many characteristics such as contrast ratio, response speed, color reproduction rate, viewing angle, brightness, resolution, lifespan, luminous efficiency, or luminance.

[0005] In particular, a micro-LED display can separate and combine images in a module manner, thus having the advantages of free adjustment of size or resolution and the ability to implement a flexible display.

[0006] However, a large-scale micro-LED display requires more than several million micro-LEDs, so there is a technical problem of difficulty in quickly and accurately transferring micro-LEDs to a display panel.

[0007] Recently developed transfer technologies include pick and place process, Laser Lift-off method, or self-assembly method, etc.

[0008] Among them, the self-assembly method, as a method in which semiconductor light-emitting devices find their assembly positions by themselves in a fluid, is a method that is beneficial for realizing a large-screen display device.

[0009] However, the current research on the technology of manufacturing a display by self-assembly of micro-LEDs is not yet perfect.

[0010] Especially in the prior art, in the case of quickly transferring more than several million semiconductor light-emitting devices to a large-scale display, although the transfer speed can be increased, the transfer error rate may increase, resulting in a technical problem of a decrease in transfer yield.

[0011] In the related art, although a transfer process using a dielectrophoresis (DEP) self-assembly method has been attempted, there is a problem of low self-assembly rate due to the non-uniformity of the dielectrophoretic force and the like.

[0012] On the other hand, since semiconductor light-emitting devices such as micro LEDs are small in size, there is a problem of low brightness. In particular, due to material characteristics, there is a problem that the brightness of red semiconductor light-emitting devices is lower than that of blue or green semiconductor light-emitting devices. Therefore, it is urgent to develop a technology capable of improving the brightness of semiconductor light-emitting devices.

[0013] According to non-disclosed internal technology, a solution is provided in which an ohmic contact layer is formed in the entire back region of a semiconductor light-emitting device in order to improve light efficiency (or light brightness). However, there is a problem that when heat treatment is performed to form the ohmic contact layer, the ohmic contact layer functions as a light absorption layer, resulting in a decrease in light efficiency.

[0014] On the other hand, in order for a semiconductor light-emitting device to immediately respond to a magnet used in a self-assembly method, a relatively large magnetization force of the semiconductor light-emitting device is required. However, since the size of the semiconductor light-emitting device is very small, it is limited to increase the magnetization force, and thus there is a problem of reducing the assembly rate during self-assembly. Summary of the Invention

[0015] Problems to be Solved

[0016] An object of an embodiment is to provide a semiconductor light-emitting device and a display device capable of improving light efficiency and light brightness.

[0017] Another object of the embodiment is to provide a semiconductor light-emitting device and a display device capable of increasing the assembly rate.

[0018] The object of the embodiment is not limited to the above object, and further includes problems that can be grasped through the description of the invention.

[0019] Technical Solutions for Solving the Problems

[0020] In order to achieve the above or other objects, according to one aspect of an embodiment, a semiconductor light-emitting device may include: a light-emitting layer; a passivation layer surrounding a side portion of the light-emitting layer; a first electrode disposed below the light-emitting layer; and a second electrode disposed on the light-emitting layer; the light-emitting layer may have a first region and a second region surrounding the first region; a bottom surface of the first region of the light-emitting layer may have a groove; the first electrode may include: an ohmic contact layer disposed in the groove; a reflective layer disposed below the second region of the light-emitting layer; and a magnetic layer disposed below the reflective layer; an area of the reflective layer may exceed 50% of an area of a lower side of the light-emitting layer.

[0021] The area of the ohmic contact layer may be 5% to 50% of the area of the lower side of the light-emitting layer.

[0022] The reflective layer may be disposed below the ohmic contact layer. The reflective layer may include a protruding portion, and the protruding portion surrounds the ohmic contact layer in the groove.

[0023] The bottom surface of the ohmic contact layer and the bottom surface of the second region of the light-emitting layer may be on the same horizontal line.

[0024] The bottom surface of the ohmic contact layer may be located at a position higher than the bottom surface of the second region of the light-emitting layer. The magnetic layer may have a second groove corresponding to the groove. The magnetic layer may be disposed below the reflective layer, and the bottom surface of the magnetic layer may be a flat plane.

[0025] The bottom surface of the ohmic contact layer may be located at a position lower than the bottom surface of the second region of the light-emitting layer. The magnetic layer may be disposed below the reflective layer, and the bottom surface of the magnetic layer may be a flat plane.

[0026] The depth of the groove is 1 / 2 or more of the thickness of the first conductive-type semiconductor layer of the light-emitting layer. The groove may have a bottom surface and an inclined surface, the ohmic contact layer may be disposed on the bottom surface, and the reflective layer may be disposed on the inclined surface.

[0027] The semiconductor light-emitting device may include irregularities on the surface of the groove, and the ohmic contact layer may be disposed on the irregularities.

[0028] The first electrode may include a contact electrode 154-4 disposed below the magnetic layer. At least one of the reflective layer, the magnetic layer, and the contact electrode may be disposed on the side portion of the light-emitting layer.

[0029] According to another aspect of the embodiment, the display device includes: a backplane substrate; a plurality of semiconductor light-emitting devices that emit lights of different colors from each other on the backplane substrate; connection electrodes disposed on sides of each of the plurality of semiconductor light-emitting devices; and electrode wirings disposed on upper sides of each of the plurality of semiconductor light-emitting devices; at least one of the plurality of semiconductor light-emitting devices includes: a light-emitting layer; a passivation layer surrounding sides of the light-emitting layer; a first electrode disposed below the light-emitting layer; and a second electrode disposed on the light-emitting layer; the light-emitting layer has a first region and a second region surrounding the first region; a bottom surface of the first region of the light-emitting layer has a groove; the first electrode includes: an ohmic contact layer disposed in the groove; a reflective layer disposed below the second region of the light-emitting layer; and a magnetic layer disposed below the reflective layer.

[0030] Advantages of the Invention

[0031] According to the embodiment, the area of the ohmic contact layer in the first electrode disposed on the lower side of the light-emitting layer can be minimized, while the area of the reflective layer can be maximized. That is, as Figures 7 to 9 shown, the ohmic contact layer 154-1 of the first electrode 154 can be disposed below the first region 150a of the light-emitting layers 151 to 153, and the reflective layer 154-2 can be disposed below the second region 150b surrounding the first region 150a of the light-emitting layers 151 to 153. At this time, the area A2 of the reflective layer 154-2 can exceed 50% of the area of the lower side of the light-emitting layers 151 to 153. Thus, the light efficiency and brightness can be improved by increasing the light reflectance based on the reflective layer 154-2.

[0032] In addition, by disposing the magnetic layer 154-3 below the reflective layer 154-2, the reaction speed of the semiconductor light-emitting device 150A to the magnet can be increased through the magnetic layer 154-3 during self-assembly, and thus the assembly rate can be improved.

[0033] As Figure 19 and Figure 20As shown, the depth d2 of the groove 158 formed on the bottom surface of the first region 150 of the light-emitting layers 151 to 153 is greater than the sum of the thicknesses of the ohmic contact layer 154-1, the reflective layer 154-2, and the magnetic layer 154-3. Thus, a groove 154-3a corresponding to the groove 158 can be formed in the magnetic layer 154-3. A display device 301 can be manufactured by disposing the semiconductor light-emitting device 150B having the groove 9154-3 as described above as the red semiconductor light-emitting device 150-1 on the substrate 310 and performing electrical connection through a post-process. At this time, the second insulating layer 335 is disposed not only between the lower side of the red semiconductor light-emitting device 150-1 and the first insulating layer 330 but also in the groove 154-3a. Therefore, the contact area between the red semiconductor light-emitting device 150-1 and the second insulating layer 335 increases, thereby strengthening the fixing property of the red semiconductor light-emitting device 150-1.

[0034] On the other hand, as Figure 25 and Figure 28 shown, the depths d4 and d5 of the groove 158 reach more than 1 / 2 of the thickness of the first conductive-type semiconductor layer 151. Thus, the ohmic contact layer 154-1 disposed in the groove 158 is maximally adjacent to the active layer 152. Therefore, the shortest current path is formed between the second electrode 155 and the ohmic contact layer 154-1 of the first electrode 154, so that more light can be generated by the driving current flowing through the shortest current path, and thus the light efficiency and brightness can be improved.

[0035] In addition, as Figure 29 shown, irregularities 159 can be formed on the inner surface of the groove 1580, and the ohmic contact layer 154-1 can be disposed on the irregularities 159. In this case, the light traveling from the active layer 152 to the ohmic contact layer 154-1 is diffusely reflected or scattered by the irregularities 159 before being absorbed by the ohmic contact layer 154-1, thereby improving the light efficiency or brightness.

[0036] Furthermore, as Figure 30 shown, at least one of the reflective layer 154-2, the magnetic layer 154-3, and the contact electrode 154-4 is disposed on the side of the light-emitting layers 151 to 153. Thus, the electrical characteristics can be improved by increasing the contact area with the connection electrode disposed on the side of the semiconductor light-emitting device 150H when manufacturing the display device. Therefore, the light efficiency and brightness can be improved, and low-voltage driving can be achieved, thereby reducing power consumption.

[0037] The additional scope applicable to the embodiments will become clearer through the following detailed description. However, those skilled in the art can clearly understand various changes and modifications within the spirit and scope of the embodiments. Therefore, it should be understood that the detailed description and specific embodiments such as the preferred embodiments are merely exemplary. Description of the Drawings

[0038] Figure 1 The living room of a house equipped with a display device according to an embodiment is shown.

[0039] Figure 2 It is a block diagram schematically showing the display device according to the embodiment.

[0040] Figure 3 It shows Figure 2 A circuit diagram of an example of the pixel.

[0041] Figure 4 It is Figure 1 An enlarged view of the first panel area in the display device.

[0042] Figure 5 It is Figure 4 An enlarged view of the A2 area.

[0043] Figure 6 It is a diagram showing an example in which a light-emitting device according to an embodiment is assembled to a substrate by a self-assembly method.

[0044] Figure 7 It is a cross-sectional view showing a semiconductor light-emitting device according to the first embodiment.

[0045] Figure 8 It is a top view showing a semiconductor light-emitting device according to the first embodiment.

[0046] Figure 9 It is a bottom view showing a semiconductor light-emitting device according to the first embodiment.

[0047] Figure 10 It is a bottom view showing the first conductive-type semiconductor layer of a semiconductor light-emitting device according to the first embodiment.

[0048] Figure 11 It shows Figure 7 An enlarged view of the C area in the semiconductor light-emitting device according to the embodiment.

[0049] Figure 12a It shows the light reflectance in a semiconductor light-emitting device of a comparative example.

[0050] Figure 12b It represents the reflectance before and after heat treatment.

[0051] Figure 13 It represents the light reflectance in a semiconductor light-emitting device according to the first embodiment.

[0052] Figure 14 Indicates the luminous efficiency of the comparative examples and the examples.

[0053] Figure 15 Indicates the luminance of the comparative examples and the examples.

[0054] Figure 16 Is a top view showing the display device of the first embodiment.

[0055] Figure 17 Is in Figure 16 The cross-sectional view taken along the line D1-D2 in the display device of the first embodiment of

[0056] Figure 18 Is a cross-sectional view showing the backplane substrate of the embodiment.

[0057] Figure 19 Is a cross-sectional view showing the semiconductor light-emitting device of the second embodiment.

[0058] Figure 20 Is a cross-sectional view showing the display device of the second embodiment.

[0059] Figure 21 Is a cross-sectional view showing the semiconductor light-emitting device of the third embodiment.

[0060] Figure 22 Is a cross-sectional view showing the semiconductor light-emitting device of the fourth embodiment.

[0061] Figure 23 Is a cross-sectional view showing the semiconductor light-emitting device for lighting and the semiconductor light-emitting device for display of the embodiment.

[0062] Figure 24 Is a bottom view showing the semiconductor light-emitting device for lighting and the semiconductor light-emitting device for display of the embodiment.

[0063] Figure 25 Is a cross-sectional view showing the semiconductor light-emitting device of the fifth embodiment.

[0064] Figure 26 Indicates the light reflection and current flow in the semiconductor light-emitting device of the fifth embodiment.

[0065] Figure 27 Is a cross-sectional view showing the display device of the third embodiment.

[0066] Figure 28 Is a cross-sectional view showing the semiconductor light-emitting device of the sixth embodiment.

[0067] Figure 29 Is a cross-sectional view showing the semiconductor light-emitting device of the seventh embodiment.

[0068] Figure 30 is a cross-sectional view showing a semiconductor light-emitting device of the eighth embodiment.

[0069] Figure 31 is a cross-sectional view showing a semiconductor light-emitting device of the ninth embodiment.

[0070] Figure 32 is a bottom view showing a semiconductor light-emitting device of the ninth embodiment.

[0071] The dimensions, shapes, numerical values, etc. of the plurality of constituent elements shown in the drawings may be different from the actual situation. Additionally, even if the same constituent elements are shown in different sizes, shapes, numerical values, etc. in each drawing, this is merely an example in the drawings, and the same constituent elements may have the same sizes, shapes, numerical values, etc. in each drawing. Detailed Description of the Embodiments

[0072] Hereinafter, the embodiments disclosed in this specification will be described in detail with reference to the drawings. Regardless of the drawing numbers, the same or similar constituent elements are given the same reference numerals, and repeated descriptions thereof are omitted. The suffixes "module" and "section" of the constituent elements used in the following description are given or mixed for ease of writing the specification, and they do not have distinct meanings or functions from each other. Also, the drawings are for facilitating understanding of the embodiments disclosed in this specification, and the technical ideas disclosed in this specification are not limited by the drawings. And when it is mentioned that an element such as a layer, region, or substrate exists "on" another constituent element, it should be understood that it may directly exist on the other element, or other intermediate elements may also exist between them.

[0073] The display device described in this specification may include a TV (television), a signboard, a mobile terminal such as a mobile phone or smartphone, a computer monitor such as a laptop or desktop computer, a head-up display for an automobile, a backlight unit for a display, a display for VR (virtual reality), AR (augmented reality), or MR (mixed reality), a light source, etc. However, even for newly developed products in the future, the configurations of the embodiments described in this specification can be similarly applied to displayable devices.

[0074] Figure 1 Shows the living room of a house equipped with a display device of an embodiment.

[0075] Refer to Figure 1, the display device 100 of the embodiment can display the states of various electronic products such as a washing machine 101, a floor cleaning robot 102, an air purifier 103, etc., can communicate with each electronic product based on IOT (Internet of Things), and can also control each electronic product based on the set data of the user.

[0076] The display device 100 of the embodiment can include a flexible display manufactured on a thin and flexible substrate. The flexible display can not only maintain the characteristics of the existing flat panel display, but also be bent or wound like paper.

[0077] In the flexible display, visual information can be realized by separately controlling the light emission of unit pixels arranged in a matrix form. A unit pixel refers to the smallest unit for realizing one color. The unit pixels of the flexible display can be implemented by light emitting devices. In the embodiment, the light emitting device can be a Micro-LED (micro light emitting diode) or a Nano-LED (nano light emitting diode), but is not limited thereto.

[0078] Figure 2 is a block diagram schematically showing the display device of the embodiment, Figure 3 shows Figure 2 a circuit diagram of an example of the pixel of.

[0079] Referring to Figure 2 and Figure 3 , the display device of the embodiment can include a display panel 10, a driving circuit 20, a scan driving unit 30, and a power supply circuit 50.

[0080] The display device 100 of the embodiment can drive the light emitting device in an active matrix (AM, Active Matrix) manner or a passive matrix (PM, Passive Matrix) manner.

[0081] The driving circuit 20 can include a data driving unit 21 and a timing control unit 22.

[0082] The display panel 10 can be formed in a rectangular shape, but is not limited thereto. That is, the display panel 10 can be formed in a circular or oval shape. At least one side of the display panel 10 can be formed to be bent with a specified curvature.

[0083] The display panel can include a display area DA. The display area DA is an area where pixels PX are formed to display an image. The display panel can include a non-display area NDA. The non-display area DNA can be an area other than the display area DA.

[0084] As an example, the display area DA and the non-display area NDA can be defined on the same surface. For example, the non-display area NDA can be on the same surface as the display area DA and surround the display area DA, but it is not limited thereto.

[0085] As another example, although not illustrated, the display area DA and the non-display area NDA can be defined on different surfaces. For example, the display area DA can be defined on the top surface of the substrate, and the non-display area NDA can be defined on the bottom surface of the substrate. For example, the non-display area NDA can also be defined on the entire area or a part of the area of the bottom surface of the substrate.

[0086] On the other hand, although the case where it is divided into the display area DA and the non-display area NDA is shown in the drawings, it may not be divided into the display area DA and the non-display area NDA. That is, only the display area DA can be provided on the top surface of the substrate, and there is no non-display area NDA. In other words, the entire area of the top surface of the substrate is the display area DA for displaying an image, and there may be no border area as the non-display area NDA.

[0087] The display panel 10 may include a plurality of data lines D1 to Dm (m is an integer of 2 or more), a plurality of scan lines S1 to Sn (n is an integer of 2 or more) intersecting the plurality of data lines D1 to Dm, a high potential voltage line VDDL supplied with a high potential voltage, a low potential voltage line VSSL supplied with a low potential voltage VSS, and a plurality of pixels PX connected to the plurality of data lines D1 to Dm and the plurality of scan lines S1 to Sn.

[0088] Each of the plurality of pixels PX may include a first sub-pixel PX1, a second sub-pixel PX2, and a third sub-pixel PX3. The first sub-pixel PX1 may emit first color light having a first main wavelength, the second sub-pixel PX2 may emit second color light having a second main wavelength, and the third sub-pixel PX3 may emit third color light having a third main wavelength. The first color light may be red light, the second color light may be green light, and the third color light may be blue light, but it is not limited thereto. In addition, Figure 2 The case where each of the plurality of pixels PX includes three sub-pixels is exemplified, but it is not limited thereto. That is, each of the plurality of pixels PX may include four or more sub-pixels.

[0089] Each of the first sub-pixel PX1, the second sub-pixel PX2, and the third sub-pixel PX3 may be connected to at least one of the plurality of data lines D1 to Dm, at least one of the plurality of scan lines S1 to Sn, and the high potential voltage line VDDL. As Figure 3As shown, the first sub-pixel PX1 may include a plurality of light-emitting devices LD, a plurality of transistors for supplying current to the plurality of light-emitting devices LD, and at least one capacitor Cst.

[0090] Although not shown, each of the first sub-pixel PX1, the second sub-pixel PX2, and the third sub-pixel PX3 may also include only one light-emitting device LD and at least one capacitor Cst.

[0091] Each of the plurality of light-emitting devices LD may be a semiconductor light-emitting diode including a first electrode, a plurality of conductive-type semiconductor layers, and a second electrode. Here, the first electrode may be an anode electrode, and the second electrode may be a cathode electrode, but is not limited thereto.

[0092] The light-emitting device LD may be one of a horizontal light-emitting device, a flip-chip light-emitting device, and a vertical light-emitting device.

[0093] As Figure 3 shown, the plurality of transistors may include: a driving transistor DT for supplying current to the plurality of light-emitting devices LD; and a scanning transistor ST for supplying a data voltage to the gate electrode of the driving transistor DT. The driving transistor DT may include: a gate electrode connected to the source electrode of the scanning transistor ST; a source electrode connected to a high-potential voltage line VDDL to which a high-potential voltage VDD is applied; and a drain electrode connected to the plurality of first electrodes of the plurality of light-emitting devices LD. The scanning transistor ST may include: a gate electrode connected to a scan line Sk (k is an integer satisfying 1 ≤ k ≤ n); a source electrode connected to the gate electrode of the driving transistor DT; and a drain electrode connected to a data line Dj (j is an integer satisfying 1 ≤ j ≤ m).

[0094] The capacitor Cst is formed between the gate electrode and the source electrode of the driving transistor DT. The storage capacitor Cst charges the difference between the gate voltage and the source voltage of the driving transistor DT.

[0095] The driving transistor DT and the scanning transistor ST may be formed of thin film transistors. Additionally, in Figure 3 it, the driving transistor DT and the scanning transistor ST are mainly described as being formed of P-type MOSFETs (Metal Oxide Semiconductor Field Effect Transistors), but the present invention is not limited thereto. The driving transistor DT and the scanning transistor ST may also be formed of N-type MOSFETs. In this case, the positions of the source electrodes and the drain electrodes of the driving transistor DT and the scanning transistor ST may be changed.

[0096] In addition, in Figure 3 it is illustrated that each of the first sub-pixel PX1, the second sub-pixel PX2, and the third sub-pixel PX3 includes a 2T1C (2 Transistor-1 capacitor, two transistors and one capacitor) having one driving transistor DT, one scanning transistor ST, and one capacitor Cst, but the present invention is not limited thereto. Each of the first sub-pixel PX1, the second sub-pixel PX2, and the third sub-pixel PX3 may include a plurality of scanning transistors ST and a plurality of capacitors Cst.

[0097] The second sub-pixel PX2 and the third sub-pixel PX3 may be represented by substantially the same circuit diagram as the first sub-pixel PX1, and thus a detailed description thereof is omitted.

[0098] The driving circuit 20 outputs a plurality of signals and a plurality of voltages for driving the display panel 10. To this end, the driving circuit 20 may include a data driving unit 21 and a timing control unit 22.

[0099] The data driving unit 21 receives digital video data DATA and a source control signal DCS from the timing control unit 22. The data driving unit 21 converts the digital video data DATA into a plurality of analog data voltages according to the source control signal DCS and supplies them to a plurality of data lines D1 to Dm of the display panel 10.

[0100] The timing control unit 22 receives digital video data DATA and a plurality of timing signals from the host system. The host system may be an application processor of a smart phone or a tablet PC, a display, a system on chip of a TV, etc.

[0101] The timing control unit 22 generates control signals for controlling the operation timing of the data driving unit 21 and the scan driving unit 30. The plurality of control signals may include: a source control signal DCS for controlling the operation timing of the data driving unit 21; and a scan control signal SCS for controlling the operation timing of the scan driving unit 30.

[0102] The driving circuit 20 may be disposed in a non-display area NDA provided on one side of the display panel 10. The driving circuit 20 is formed of an integrated circuit (IC) and may be mounted on the display panel 10 in a COG (chip on glass) manner, a COP (chip on plastic) manner, or an ultrasonic bonding manner, but the present invention is not limited thereto. For example, the driving circuit 20 may be mounted on a circuit board (not shown) instead of the display panel 10.

[0103] The data driving unit 21 can be mounted on the display panel 10 in a COG manner, a COP manner, or an ultrasonic bonding manner, and the timing control unit 22 can be mounted on a circuit board.

[0104] The scan driving unit 30 receives a scan control signal SCS from the timing control unit 22. The scan driving unit 30 generates a plurality of scan signals according to the scan control signal SCS and supplies them to a plurality of scan lines S1 to Sn of the display panel 10. The scan driving unit 30 includes a plurality of transistors and can be formed in the non-display area NDA of the display panel 10. Alternatively, the scan driving unit 30 can be formed by an integrated circuit, and in this case, it can be mounted on a gate flexible film attached to the other side of the display panel 10.

[0105] The power supply circuit 50 can generate a plurality of voltages required for driving the display panel 10 from a main power supply applied from a system board and supply them to the display panel 10. For example, the power supply circuit 50 can generate a high potential voltage VDD and a low potential voltage VSS for driving a plurality of light emitting devices LD of the display panel 10 from the main power supply and supply them to the high potential voltage line VDDL and the low potential voltage line VSSL of the display panel 10. In addition, the power supply circuit 50 can generate and supply a driving voltage for driving the driving circuit 20 and the scan driving unit 30 from the main power supply.

[0106] Figure 4 Yes Figure 3 is an enlarged view of the first panel area in the display device.

[0107] Refer to Figure 4 , the display device 100 of the embodiment can be manufactured by mechanically and electrically connecting a plurality of panel areas such as the first panel area A1 by tiling.

[0108] The first panel area A1 may include a plurality of semiconductor light emitting devices 150 arranged in unit pixels ( Figure 2 of PX).

[0109] Figure 5 Yes Figure 4 is an enlarged view of the A2 area.

[0110] Refer to Figure 5 , the display device 100 of the embodiment may include a substrate 200, assembly lines 201, 202, an insulating layer 206, and a plurality of semiconductor light emitting devices 150. More components may be included.

[0111] The assembly line may include a first assembly line 201 and a second assembly line 202 that are spaced apart from each other. The first assembly line 201 and the second assembly line 202 may generate a dielectrophoretic force (DEP force) for assembling the semiconductor light-emitting device 150. For example, the semiconductor light-emitting device 150 may be one of a horizontal semiconductor light-emitting device, a flip-chip semiconductor light-emitting device, and a vertical semiconductor light-emitting device.

[0112] To implement each unit pixel (sub-pixel), the semiconductor light-emitting device 150 may include a red semiconductor light-emitting device 150, a green semiconductor light-emitting device 150G, and a blue semiconductor light-emitting device 150B, but is not limited thereto, and may also have a red phosphor and a green phosphor, etc. to respectively implement red and green.

[0113] The substrate 200 may be a support member that supports a plurality of components disposed on the substrate 200, or a protection member that protects a plurality of components.

[0114] The substrate 200 may be a rigid substrate or a flexible substrate. The substrate 200 may be formed of sapphire, glass, silicon, or polyimide. In addition, the substrate 200 may include flexible materials such as PEN (Polyethylene Naphthalate) and PET (Polyethylene Terephthalate). In addition, the substrate 200 may be a transparent material, but is not limited thereto. The substrate 200 may function as a support substrate in the display panel, and may also function as an assembly substrate during the self-assembly of the light-emitting device.

[0115] The substrate 200 may be provided with Figure 2 and Figure 3 circuits such as transistors ST, DT, capacitors Cst, signal wirings, etc. in the sub-pixels PX1, PX2, PX3 shown, but is not limited thereto.

[0116] The insulating layer 206 may include organic materials having insulating properties and flexibility such as polyimide, PAC, PEN, PET, polymers, or inorganic materials such as silicon oxide (SiO 2 ) or silicon nitride-based (SiN x ), and may also be integrally formed with the substrate 200 to form a single substrate.

[0117] The insulating layer 206 may be a conductive adhesive layer having adhesiveness and conductivity. The conductive adhesive layer is flexible, thereby enabling the flexible function of the display device. For example, the insulating layer 206 may be an anisotropic conductive film (ACF), an anisotropic conductive medium, a solution containing conductive particles, or the like as a conductive adhesive layer. The conductive adhesive layer may be a layer having conductivity in a direction perpendicular to the thickness and electrical insulation in a direction parallel to the thickness.

[0118] The insulating layer 206 may include an assembly hole 203 for inserting the semiconductor light-emitting device 150. Thus, during self-assembly, the semiconductor light-emitting device 150 can be easily inserted into the assembly hole 203 of the insulating layer 206. The assembly hole 203 may be referred to as an insertion hole, a fixing hole, an alignment hole, etc. The assembly hole 203 may also be referred to as a hole.

[0119] The assembly hole 203 may be referred to as a hole, a groove, a trench, a recess, a pocket, etc.

[0120] The assembly hole 203 may vary according to the shape of the semiconductor light-emitting device 150. For example, a red semiconductor light-emitting device, a green semiconductor light-emitting device, and a blue semiconductor light-emitting device may each have a different shape, and the assembly hole 203 may have a shape corresponding to the shape of each of these semiconductor light-emitting devices. For example, the assembly hole 203 may include a first assembly hole 340H for assembling the red semiconductor light-emitting device 150-1, a second assembly hole 340H for assembling the green semiconductor light-emitting device, and a third assembly hole 340H for assembling the blue semiconductor light-emitting device. For example, the red semiconductor light-emitting device 150-1 may be circular, the green semiconductor light-emitting device may have a first ellipse including a first minor axis and a second major axis, and the blue semiconductor light-emitting device may have a second ellipse including a second minor axis and a second major axis, but is not limited thereto. The second major axis of the ellipse of the blue semiconductor light-emitting device may be greater than the second major axis of the ellipse of the green semiconductor light-emitting device, and the second minor axis of the ellipse of the blue semiconductor light-emitting device may be less than the first minor axis of the ellipse of the green semiconductor light-emitting device.

[0121] On the other hand, the method of mounting the semiconductor light-emitting device 150 on the substrate 200 may be, for example, a self-assembly method ( Figure 6 ), a transfer method, etc.

[0122] Figure 6 is a diagram showing an example in which a light-emitting device according to an embodiment is assembled to a substrate by a self-assembly method.

[0123] Based on Figure 6 An example of assembling a semiconductor light-emitting device according to an embodiment to a display panel by a self-assembly method using an electromagnetic field is described.

[0124] The assembled substrate 200, which will be described later, can function as the panel substrate 200a in the display device after the light-emitting device is assembled, but the embodiment is not limited thereto.

[0125] Referring to Figure 6 , the semiconductor light-emitting device 150 can be placed into the chamber 1300 filled with the fluid 1200. Through the magnetic field generated by the assembling device 1100, the semiconductor light-emitting device 150 can move to the assembled substrate 200. At this time, the light-emitting device 150 close to the assembling hole 207H of the assembled substrate 200 can be assembled into the assembling hole 207H by the dielectrophoretic force generated by the electric field of the assembly line. The fluid 1200 can be water, such as ultrapure water, etc., but is not limited thereto. The chamber can be referred to as a water tank, a vessel, a container, etc.

[0126] After the semiconductor light-emitting device 150 is placed into the chamber 1300, the assembled substrate 200 can be disposed on the chamber 1300. According to the embodiment, the assembled substrate 200 can also be placed into the chamber 1300.

[0127] As shown in the figure, the semiconductor light-emitting device 150 can be implemented as a vertical semiconductor light-emitting device, but is not limited thereto, and a horizontal light-emitting device can be adopted.

[0128] On the other hand, the first assembly line 201 and the second assembly line 202 can form an electric field when an alternating voltage is applied. Through the dielectrophoretic force generated by this electric field, the placed semiconductor light-emitting device 150 can be fixed to the assembling hole 207H. The interval between the first assembly line 201 and the second assembly line 202 can be smaller than the width of the semiconductor light-emitting device 150 and the width of the assembling hole 207H, so that the assembling position of the semiconductor light-emitting device 150 using the electric field can be fixed more precisely.

[0129] An insulating layer 215 is formed on the first assembly line 201 and the second assembly line 202, which can protect the first assembly line 201 and the second assembly line 202 from the influence of the fluid 1200 and can prevent the current flowing in the first assembly line 201 and the second assembly line 202 from leaking. For example, the insulating layer 215 can be formed of an inorganic insulator such as silicon dioxide or aluminum oxide or an organic insulator in a single layer or multiple layers. The insulating layer 215 can have the minimum thickness for preventing the first assembly line 201 and the second assembly line 202 from being damaged when assembling the semiconductor light-emitting device 150, and can have the maximum thickness for stably assembling the semiconductor light-emitting device 150.

[0130] On the upper part of the insulating layer 215, a partition wall 207 may be formed. A part of the partition wall 207 may be located above the first set of assembly lines 201 and the second set of assembly lines 202, and the remaining area may be located above the assembly substrate 200.

[0131] On the other hand, when manufacturing the assembly substrate 200, by removing a part of the partition wall 340 formed on the upper part of the insulating layer 215, an assembly hole 207H for each semiconductor light-emitting device 150 to be bonded and assembled to the assembly substrate 200 can be formed.

[0132] The assembly substrate 200 is formed with assembly holes 207H for bonding a plurality of semiconductor light-emitting devices 150, and the surface where the assembly holes 207H are formed may be in contact with the fluid 1200. The assembly holes 207H can guide the accurate assembly positions of the semiconductor light-emitting devices 150.

[0133] On the other hand, the assembly holes 207H may have shapes and sizes corresponding to the shapes of the semiconductor light-emitting devices 150 to be assembled to the corresponding positions. Thereby, it is possible to prevent other semiconductor light-emitting devices from being assembled into the assembly holes 207H, or a plurality of semiconductor light-emitting devices from being assembled into the assembly holes 207H.

[0134] Refer again to Figure 6 , after the assembly substrate 200 is disposed in the chamber, the assembly device 1100 applying a magnetic field may move along the assembly substrate 200. The assembly device 1100 may be a permanent magnet or an electromagnet.

[0135] In order to maximize the area affected by the magnetic field within the fluid 1200, the assembly device 1100 may move in a state of being in contact with the assembly substrate 200. According to an embodiment, the assembly device 1100 may include a plurality of magnetic bodies, or may also include a magnetic body having a size corresponding to the assembly substrate 200. In this case, the moving distance of the assembly device 1100 may also be limited within a specified range.

[0136] Under the action of the magnetic field generated by the assembly device 1100, the semiconductor light-emitting devices 150 in the chamber 1300 may move toward the assembly device 1100 and the assembly substrate 200.

[0137] During the process of moving toward the assembly device 1100, the semiconductor light-emitting devices 150 may enter the assembly holes 207H and be fixed under the action of dielectrophoretic force formed by the electric field between the assembly lines 201 and 202.

[0138] Specifically, the first set of assembly lines 201 and the second set of assembly lines 202 can use an AC power source to form an electric field, and can use this electric field to form a dielectrophoretic force between the assembly lines 201 and 202. Using this dielectrophoretic force, the semiconductor light-emitting device 150 can be fixed to the assembly hole 207H on the assembly substrate 200.

[0139] At this time, a predetermined solder layer (not shown) is formed between the light-emitting device 150 assembled in the assembly hole 207H of the assembly substrate 200 and the assembly lines 201 and 202, which can improve the bonding force of the light-emitting device 150.

[0140] In addition, after assembly, a molding layer (not shown) can be formed in the assembly hole 207H of the assembly substrate 200. The molding layer can be a transparent resin or a resin containing a reflective substance and a scattering substance.

[0141] Through the above-described self-assembly method using an electromagnetic field, the time required to assemble each semiconductor light-emitting device onto the substrate can be significantly shortened, so that a large-area high-pixel display can be realized more quickly and economically.

[0142] Hereinafter, with reference to Figures 7 to 32 , various embodiments for solving the above problems will be described. The following omitted descriptions can be easily understood through Figures 1 to 6 and the above descriptions related to the accompanying drawings.

[0143] The semiconductor light-emitting devices described below can have dimensions of less than a micron. As described above, there is a problem that the light brightness decreases as the size of the semiconductor light-emitting device decreases. Hereinafter, various embodiments capable of improving the light brightness will be described.

[0144] In addition, the semiconductor light-emitting devices described below are vertical semiconductor light-emitting devices in which current flows vertically.

[0145] In the following description, if the reference numeral of the backplane substrate is not marked in the corresponding drawings, it can be understood as the Figure 18 shown backplane substrate 300A.

[0146] [First Embodiment]

[0147] Figure 7 is a cross-sectional view showing the semiconductor light-emitting device of the first embodiment. Figure 8 is a top view showing the semiconductor light-emitting device of the first embodiment. Figure 9 is a bottom view showing the semiconductor light-emitting device of the first embodiment.

[0148] With reference to Figures 7 to 9, the semiconductor light-emitting device 150A of the first embodiment may include light-emitting layers 151 to 153, a passivation layer 157, a first electrode 154, and a second electrode 155.

[0149] The light-emitting layers 151 to 153 may emit light of a specific color. The specific color of the light depends on the semiconductor material of the light-emitting layers 151 to 153. For example, the specific color of the light may be red light, green light, or blue light. Hereinafter, the case where the light-emitting layers 151 to 153 emit red light will be described, but the light-emitting layers 151 to 153 of the embodiment may also emit green light or blue light.

[0150] The light-emitting layers 151 to 153 may include a plurality of semiconductor layers. For example, the light-emitting layers 151 to 153 may include at least one first-conductive-type semiconductor layer 151, an active layer 152, and at least one second-conductive-type semiconductor layer 153. The active layer 152 may be disposed on the first-conductive-type semiconductor layer 151, and the second-conductive-type semiconductor layer 153 may be disposed on the active layer 152. The first-conductive-type semiconductor layer 151 may include an n-type dopant, and the second-conductive-type semiconductor layer 153 may include a p-type dopant, but it is not limited thereto.

[0151] The light-emitting layers 151 to 153 may include a first region 150a and a second region 150b surrounding the first region 150a. A groove 158 having a predetermined depth d1 may be formed below the first region 150a of the light-emitting layers 151 to 153. For example, a groove 158 may be formed on the bottom surface of the first-conductive-type semiconductor layer 151 corresponding to the first region 150a of the light-emitting layers 151 to 153. The groove 158 may have a bottom surface 158-2 and an inner side surface. The inner side surface may have an inclined surface 158-1, but it may also have a vertical surface. The bottom surface 158-2 may be a straight plane, but it is not limited thereto. Although it will be described later, an ohmic contact layer 154-1 of the first electrode 154 may be disposed in the groove 158.

[0152] The passivation layer 157 is formed of a material having excellent insulating properties, thereby protecting the light-emitting layers 151 to 153 and preventing leakage current flowing on the side portions of the light-emitting layers 151 to 153. In addition, the passivation layer 157 exerts a repulsive force on the electrophoretic force during self-assembly, so that the lower side of the semiconductor light-emitting device 150A faces the bottom surface of the assembly hole 340H, enabling correct assembly.

[0153] The passivation layer 157 may surround the sides of the light-emitting layers 151 to 153. The passivation layer 157 may be disposed in the edge region of the light-emitting layers 151 to 153. The passivation layer 157 may have an opening 157H corresponding to the central region of the light-emitting layers 151 to 153. For example, the opening 157H corresponding to the central region of the light-emitting layers 151 to 153 may be formed by removing the passivation layer 157 corresponding to the central region of the light-emitting layers 151 to 153 after the passivation layer 157 is formed on the top surface of the second electrode 155, and the passivation layer 157 is formed on the second electrode 155 corresponding to the edge region of the light-emitting layers 151 to 153. Different from the drawings, the passivation layer 157 may also be formed on the top surface of the second electrode 155 without forming the opening 157H.

[0154] On the other hand, as described above, according to the non-disclosed internal technology (hereinafter referred to as the comparative example), the following solution is given, as Figure 12a shown, in order to improve the light efficiency (or light luminance), a solution of forming an ohmic contact layer 5 in the entire back region of the semiconductor light-emitting device. For example, in order to form the ohmic contact layer 5, a metal film such as AuGe is deposited on the back surface of the semiconductor light-emitting device and heat-treated, thereby having ohmic characteristics for the light-emitting layers 151 to 153, and thus the electrical characteristics can be improved.

[0155] However, as Figure 12b shown, it can be seen that the light reflectance of the ohmic contact layer 154-1 before and after the heat treatment is significantly different. For example, it can be known that based on the wavelength of 650 nm, the light reflectance of the ohmic contact layer 154-1 before the heat treatment is 74%, while the light reflectance of the ohmic contact layer 154-1 after the heat treatment is 22%, and the light reflectance significantly decreases.

[0156] Therefore, there is an urgent need for a solution to improve the light efficiency or luminance by increasing the light reflectance. In the following embodiments, embodiments capable of improving the light efficiency or luminance will be described.

[0157] Again, referring to Figures 7 to 9 , the first electrode 154 may be disposed below the light-emitting layers 151 to 153.

[0158] The first electrode 154 may include an ohmic contact layer 154-1, a reflective layer 154-2, and a magnetic layer 154-3. Although not shown, the first electrode 154 may include more layers. The ohmic contact layer 154-1 may contain Au, AuBe, AuGe, etc. The reflective layer 154-2 may contain Al, Ag, etc. The magnetic layer 154-3 may contain Ni, Co, etc. Although not shown, the first electrode 154 may also include an electrode layer (conductive layer) such as Cu, an antioxidant layer such as Mo, and an adhesion layer such as Cr, Ti.

[0159] According to an embodiment, the structure of the first electrode 154 can be designed such that the area of the ohmic contact layer 154-1 is minimized and the area of the reflective layer 154-2 is maximally expanded.

[0160] The ohmic contact layer 154-1 can be disposed below the first region 150a of the light-emitting layers 151 to 153. The ohmic contact layer 154-1 can be disposed in a groove 158 formed on the lower side of the first region 150a of the light-emitting layers 151 to 153. The ohmic contact layer 154-1 can be disposed in a groove 158 formed at a position corresponding to the first region 150a of the light-emitting layers 151 to 153 on the bottom surface of the first conductive semiconductor layer 151. The ohmic contact layer 154-1 can be disposed within a groove 158 formed at a position corresponding to the first region 150a of the light-emitting layers 151 to 153 on the bottom surface of the first conductive semiconductor layer 151. The ohmic contact layer 154-1 can be in contact with the bottom surface 158-2 of the groove 158. The ohmic contact layer 154-1 can be in contact with the inner side surface of the groove 158, but this is not limited thereto.

[0161] The ohmic contact layer 154-1 can be formed to improve the ohmic characteristics with the first conductive semiconductor layer 151. The ohmic contact layer 154-1 can be formed of a metal. For example, the ohmic contact layer 154-1 can include Au, AuBe, AuGe, etc.

[0162] The bottom surface of the ohmic contact layer 154-1 can be a flat plane. The bottom surface of the ohmic contact layer 154-1 can be on the same horizontal line as the bottom surface of the second region 150b of the light-emitting layers 151 to 153, but this is not limited thereto. For example, the thickness of the ohmic contact layer 154-1 can be the same as the depth d1 of the groove 158.

[0163] According to an embodiment, the ohmic contact layer 154-1 is only formed below the first region 150a, which is the central region of the light-emitting layers 151 to 153, thereby minimizing the probability that the light generated in the active layer 152 is incident and absorbed, and thus the light efficiency and brightness can be improved.

[0164] In addition, according to an embodiment, by making the area A1 of the ohmic contact layer 154-1 have the smallest area relative to the area of the lower side of the light-emitting layers 151 to 153, the light efficiency and brightness can be improved by preventing a decrease in the light reflectance caused by the ohmic contact layer 154-1. As Figure 9 shown, the area A1 of the ohmic contact layer 154-1 can be 5% to 50% of the area of the lower side of the light-emitting layers 151 to 153.

[0165] For example, the ohmic contact layer 154-1 can have a shape corresponding to the shape of the groove 158. As Figure 9As shown, when the groove 158 is circular, the ohmic contact layer 154-1 can be circular.

[0166] The reflective layer 154-2 can be disposed on the lower side of the second region 150b of the light-emitting layers 151 to 153. For example, the reflective layer 154-2 can be in contact with the bottom surface of the second region 150b of the light-emitting layers 151 to 153. For example, the reflective layer 154-2 can be in contact with a portion of the bottom surface of the first conductivity type semiconductor layer 151 corresponding to the second region 150b of the light-emitting layers 151 to 153.

[0167] In addition, the reflective layer 154-2 can be disposed below the first region 150a of the light-emitting layers 151 to 153. The reflective layer 154-2 can surround the ohmic contact layer 154-1. The reflective layer 154-2 can be disposed on the bottom surface of the ohmic contact layer 154-1. Although not shown, a part of the reflective layer 154-2, i.e., the protrusion 154-2a, can also be disposed between the inner side surface of the groove 158 and the side surface of the ohmic contact layer 154-1 within the groove 158. In this case, the protrusion 154-2a can be disposed along the peripheral edge of the side surface of the ohmic contact layer 154-1.

[0168] The reflective layer 154-2 can have a function of reflecting light. The reflective layer 154-2 can be formed of a metal. For example, the reflective layer 154-2 can contain silver (Ag), aluminum (Al), gold (Au), etc.

[0169] According to an embodiment, the reflective layer 154-2 can be formed below the second region 150b which is an edge region of the light-emitting layers 151 to 153, and occupies the largest area in the lower side area of the light-emitting layers 151 to 153, thereby maximizing the light reflectivity, and thus improving the light efficiency and brightness. As Figure 9 shown, the area A2 of the reflective layer 154-2 can exceed 50% of the area of the lower side of the light-emitting layers 151 to 153. Since the ohmic contact layer 154-1 and the reflective layer 154-2 are disposed in the entire region of the lower side of the light-emitting layers 151 to 153, the area of the reflective layer 154-2 can be maximized by minimizing the area of the ohmic contact layer 154-1. For example, in the lower side area of the light-emitting layers 151 to 153, the ohmic contact layer 154-1 can occupy 5% of the area A1, and the reflective layer 154-2 occupies the remaining area, i.e., 95% of the area A2. Therefore, the light efficiency and brightness of the light generated by the active layer 152 can be improved by maximizing the probability of being reflected by the reflective layer 154-2, rather than being absorbed by the ohmic contact layer 154-1.

[0170] As Figure 13As shown, the reflective layer 154-2 is disposed in the edge region of the light-emitting layers 151 to 153, that is, below the second region 150b. The area A2 of the reflective layer 154-2 exceeds 50% of the area of the lower side of the light-emitting layers 151 to 153. Thus, most of the light traveling in the downward direction from the active layer 152 is reflected in the upward direction, and therefore the light reflectivity can be improved.

[0171] As Figure 14 shown, the comparative example is a case where there is no reflective layer 154-2, and the example is a case where the area of the ohmic contact layer 154-1 is minimized and the area of the reflective layer 154-2 is maximized.

[0172] It can be seen that the external quantum efficiency of the example becomes very high compared with the comparative example. The external quantum efficiency is expressed as the ratio of the number of usable light particles to the number of injected charge particles, and can be the product of the internal quantum efficiency and the light extraction efficiency. In particular, it can be seen that as the drive current increases, the difference in the external quantum efficiency between the comparative example and the example becomes larger. For example, the inventor confirmed that at the 20 μA condition, the external quantum efficiency of the example is 4.7 times larger than that of the comparative example.

[0173] As Figure 15 shown, the comparative example is a case where there is no reflective layer 154-2, and the example is a case where the area of the ohmic contact layer 154-1 is minimized and the area of the reflective layer 154-2 is maximized.

[0174] It can be seen that at the 5 μA and 20 μA conditions, the light efficiency of the example is significantly higher than that of the comparative example. For example, the applicant confirmed that at the 5 μA condition, the light efficiency of the comparative example is 1.2 cd / A, while the light efficiency of the example is 5.3 cd / A, which is increased by approximately 4.4 times.

[0175] Above, the case where the reflective layer 154-2 is formed of a metal has been described. However, the reflective layer 154-2 can also be fabricated using a multi-refractive index difference.

[0176] As Figure 11 shown, the reflective layer 154-2 may include a plurality of first refractive index layers 154-21 and a plurality of second refractive index layers 154-22. For example, the first refractive index layers 154-21 and the second refractive index layers 154-22 may be alternately stacked with each other. For example, the first refractive index layer 154-21 is a layer having a low refractive index, and the second refractive index layer 154-22 may be a layer having a high refractive index, but they may also be opposite to each other. For example, the first refractive index layer 154-21 may be formed of SiO having a refractive index of 1.457 based on 632.nm 2 formed, and the second refractive index layer 154-22 may be formed of TiO having a refractive index of 2.493 based on 632.8 nm2 formed

[0177] Refer again to Figures 7 to 9 , the magnetic layer 154-3 is a member magnetized during self-assembly, and the magnetization force can be defined according to the degree of magnetization. For example, the greater the magnetization force of the magnetic layer 154-3, the greater the reaction speed of the semiconductor light-emitting element 150A to the magnet during self-assembly. The magnetization force of the magnetic layer 154-3.

[0178] The magnetic layer 154-3 can be disposed on the lower side of the light-emitting layers 151 to 153. The magnetic layer 154-3 can be disposed on the lower side of the first region 150a of the light-emitting layers 151 to 153. The magnetic layer 154-3 can be disposed below the reflection layer 154-2 corresponding to the first region 150a of the light-emitting layers 151 to 153. The magnetic layer 154-3 can be disposed on the lower side of the second region 150b of the light-emitting layers 151 to 153. The magnetic layer 154-3 can be disposed below the reflection layer 154-2 corresponding to the second region 150b of the light-emitting layers 151 to 153.

[0179] The magnetic layer 154-3 can be in contact with the bottom surface of the reflection layer 154-2, but this is not limited. The magnetic layer 154-3 can have the same size as the reflection layer 154-2, but this is not limited. The magnetic layer 154-3 can have a shape corresponding to the shape of the reflection layer 154-2. For example, when the reflection layer 154-2 is circular, the magnetic layer 154-3 can also be circular.

[0180] According to the embodiment, the magnetic layer 154-3 is disposed in the entire region on the lower side of the light-emitting layers 151 to 153, so that its disposed area is maximized, and thus the assembly rate can be improved by increasing the reaction speed of the semiconductor light-emitting device 150A to the magnet during self-assembly.

[0181] On the other hand, the second electrode 155 can be disposed on the light-emitting layers 151 to 153. The second electrode 155 can be disposed on the first region 150a of the light-emitting layers 151 to 153. The second electrode 155 can be disposed on the second region 150b of the light-emitting layers 151 to 153. The second electrode 155 can be in contact with the top surface of the second conductive-type semiconductor layer 153 of the light-emitting layers 151 to 153, but this is not limited. Although not shown, the size of the second electrode 155 can also be smaller than the size of the light-emitting layers 151 to 153. The second electrode 155 is a transparent conductive layer and can include ITO, IZO, etc.

[0182] On the other hand, the unillustrated label 150d is a multi-stage structure 150d, which can move the semiconductor light-emitting device 150A to a specified position during self-assembly without large up-and-down shaking or flipping, thereby preventing assembly defects.

[0183] Hereinafter, the display device of the first embodiment will be described.

[0184] Figure 16 is a top view showing the display device of the first embodiment. Figure 17 is in Figure 16 The cross-sectional view taken along the line D1 - D2 of the display device of the first embodiment. Figure 18 is a cross-sectional view showing the backplane substrate 300A of the embodiment.

[0185] Referring to Figure 16 , the display device 300 of the first embodiment may include a plurality of pixels PX, and each of the plurality of pixels PX may include a plurality of sub-pixels PX1, PX2, PX3.

[0186] For example, at least one semiconductor light-emitting device 150-1 to 150-3 may be arranged in each of the plurality of sub-pixels PX1, PX2, PX3. For example, at least one red semiconductor light-emitting element 150-1 may be arranged on the first sub-pixel PX1, at least one green semiconductor light-emitting device 150-2 may be arranged on the second sub-pixel PX2, and at least one blue semiconductor light-emitting device 150-3 may be arranged on the third sub-pixel PX3.

[0187] The red semiconductor light-emitting device 150-1 may be Figures 7 to 15 The semiconductor light-emitting device 150A shown in the first embodiment, and the green semiconductor light-emitting device 150-2 and / or the blue semiconductor light-emitting device 150-3 may also have the same shape, structure, and / or function as the semiconductor light-emitting device 150A of the first embodiment except for the semiconductor material of the light-emitting layers 151 to 153.

[0188] On the other hand, each of the plurality of sub-pixels PX1 to PX3 may include a first set of assembly lines 321 and a second set of assembly lines 322. During self-assembly, an electrophoresis force is formed by applying an alternating voltage to the first set of assembly lines 321 and the second set of assembly lines 322, and through this electrophoresis force, the semiconductor light-emitting devices 151-1 to 151-3 in the fluid can be assembled onto the corresponding sub-pixels PX1 to PX3.

[0189] To assist the assembly of the semiconductor light-emitting devices 151-1 to 151-3, each of the plurality of sub-pixels PX1 to PX3 may include an assembly hole 340H. Since a relatively large electrophoresis force is formed within the assembly hole 340H, the semiconductor light-emitting devices 150-1 to 150-3 moving in the fluid can be pulled by the relatively large electrophoresis force on the way through the assembly hole 340H and be assembled into the assembly hole 340H.

[0190] Reference Figure 17 and Figure 18 For Figure 17 and Figure 18 , the display device 300 of the first embodiment may include a backplane substrate 300A, a second insulating layer 335, a semiconductor light-emitting device 150-1, a connection electrode 370, a third insulating layer 350, and an electrode wiring 360.

[0191] The backplane substrate 300A may be preset. Thereafter, the semiconductor light-emitting device 150-1 may be assembled into the assembly hole 340H of the backplane substrate 300A by using a self-assembly process. Thereafter, the connection electrode 370, the third insulating layer 350, and the electrode wiring 360 may be formed through a post-process, thereby manufacturing the display device 300 of the first embodiment.

[0192] The backplane substrate 300A may include a substrate 310, a first set of assembly lines 321, a second set of assembly lines 322, a first insulating layer 330, and a partition wall 340.

[0193] The substrate 310 is a support substrate for supporting the components of the display device 300 of the first embodiment, that is, the semiconductor light-emitting device 150-1, the connection electrode 370, the third insulating layer 350, the electrode wiring 360, etc., and may be referred to as a lower substrate or a display substrate. Although not shown, an upper substrate may also be disposed on the electrode wiring 360, but this is not limited thereto.

[0194] The first set of assembly lines 321 may be disposed on the substrate 310. The second set of assembly lines 322 may be disposed on the substrate 310.

[0195] For example, the first set of assembly lines 321 and the second set of assembly lines 322 may each be disposed on the same layer. For example, the first set of assembly lines 321 and the second set of assembly lines 322 may be in contact with the top surface of the substrate 310, but this is not limited thereto. For example, the first set of assembly lines 321 and the second set of assembly lines 322 may be respectively disposed on the same layer. For example, the first set of assembly lines 321 and the second set of assembly lines 322 may be disposed side by side with each other. The first set of assembly lines 321 and the second set of assembly lines 322 each function to assemble the semiconductor light-emitting device 150-1 into the assembly hole 340H in a self-assembly manner. That is, during self-assembly, an electric field may be generated between the first set of assembly lines 321 and the second set of assembly lines 322 by the voltage applied to the first set of assembly lines 321 and the second set of assembly lines 322, and the moving semiconductor light-emitting device 150-1 may be assembled into the assembly hole 340H by the electrophoretic force formed by this electric field and using an assembly device ( Figure 10 1100) of. The assembly hole 340H may have a diameter larger than the diameter of the semiconductor light-emitting device 150-1.

[0196] The first set of assembly lines 321 and the second set of assembly lines 322 may each include a plurality of metal layers. Although not shown, the first set of assembly lines 321 and the second set of assembly lines 322 may each include a main wiring line and an auxiliary electrode. The main wiring lines of the first set of assembly lines 321 and the second set of assembly lines 322 may be arranged longitudinally in one direction of the substrate 310. The auxiliary electrodes of the first set of assembly lines 321 and the second set of assembly lines 322 may extend from the main wiring lines toward the assembly holes 340H. The auxiliary electrodes may be electrically connected to the main wiring lines. The main wiring lines may be disposed on the auxiliary wiring lines, and the bottom surface of the main wiring lines may contact the top surface of the auxiliary wiring lines, but this is not limited thereto.

[0197] On the other hand, although not shown, the first set of assembly lines 321 and the second set of assembly lines 322 may also be disposed on different layers from each other.

[0198] The first insulating layer 330 may be disposed on the first set of assembly lines 321 and the second set of assembly lines 322. For example, the first insulating layer 330 may be made of an inorganic material or an organic material. For example, the first insulating layer 330 may be formed of a material having a dielectric constant related to the electrophoretic force. For example, the greater the dielectric constant of the first insulating layer 330, the greater the electrophoretic force may be, but this is not limited thereto. The first insulating layer 330 may prevent the first set of assembly lines 321 or the second set of assembly lines 322 from coming into direct contact with the fluid and being corroded when self-assembling using the assembly holes 340H of the subsequently formed partition walls 340.

[0199] Although the drawings show the case where the first insulating layer 330 is removed within the assembly holes 340H, the backplane substrate 300A may remain in a state where the first insulating layer 330 within the assembly holes 340H is not removed. The process of removing the first insulating layer 330 within the assembly holes 340H may be performed after the semiconductor light-emitting device 150-1 is assembled into the corresponding assembly holes 340H. Removing the first insulating layer 330 within the assembly holes 340H is performed to electrically connect the electrode 370 to the first set of assembly lines 321 and / or the second set of assembly lines 322.

[0200] The partition walls 340 may be disposed on the first insulating layer 330. The first insulating layer 330 may have assembly holes 340H. The assembly holes 340H may be formed in each of a plurality of sub-pixels PX1, PX2, PX3 of a plurality of pixels PX. That is, one assembly hole 340H may be formed in each of the sub-pixels PX1, PX2, PX3, but this is not limited thereto. For example, the first insulating layer 330 may be exposed within the assembly holes 340H. For example, the bottom surface 158-2 of the assembly holes 340H may be the top surface of the first insulating layer 330.

[0201] The height (or thickness) of the partition walls 340 may be determined in consideration of the thickness of the semiconductor light-emitting device 150-1.

[0202] By performing a self-assembly process on the backplane substrate 300A as described above, a plurality of semiconductor light-emitting devices 150-1 to 150-3 can be assembled into a plurality of sub-pixels PX1, PX2, and PX3 of each of the plurality of pixels PX on the substrate 310.

[0203] As an embodiment, each of the plurality of red semiconductor light-emitting devices 150-1, the plurality of green semiconductor light-emitting devices 150-2, and the plurality of blue semiconductor light-emitting devices 150-3 can be sequentially assembled into a plurality of sub-pixels PX1, PX2, and PX3 of each of the plurality of pixels PX on the substrate 310.

[0204] As another example, the plurality of red semiconductor light-emitting devices 150-1, the plurality of green semiconductor light-emitting devices 150-2, and the plurality of blue semiconductor light-emitting devices 150-3 can be simultaneously assembled into a plurality of sub-pixels PX1, PX2, and PX3 of each of the plurality of pixels PX on the substrate 310. To this end, the plurality of red semiconductor light-emitting devices 150-1, the plurality of green semiconductor light-emitting devices 150-2, and the plurality of blue semiconductor light-emitting devices 150-3 can be put into and mixed in the fluid of the chamber. Then, by performing the same self-assembly process, the plurality of red semiconductor light-emitting devices 150-1, the plurality of green semiconductor light-emitting devices 150-2, and the plurality of blue semiconductor light-emitting devices 150-3 are simultaneously assembled into a plurality of sub-pixels PX1, PX2, and PX3 of each of the plurality of pixels PX on the substrate 310.

[0205] For simultaneous self-assembly, the red semiconductor light-emitting device 150-1, the green semiconductor light-emitting device 150-2, and the blue semiconductor light-emitting device 150-3 can be exclusive to each other. That is, the shapes or sizes of the red semiconductor light-emitting device 150-1, the green semiconductor light-emitting device 150-2, and the blue semiconductor light-emitting device 150-3 can be different. For example, the red semiconductor light-emitting device 150-1 can be circular, the green semiconductor light-emitting device 150-2 can be a first ellipse having a first minor axis and a first major axis, and the blue semiconductor light-emitting device 150-3 can be a second ellipse. At this time, the second ellipse can have a second minor axis shorter than the first minor axis and a second major axis longer than the first major axis.

[0206] As described above, a part of the first electrode 154, i.e., the ohmic contact layer 154-1, may be disposed below the first region 150a of the light-emitting layers 151 to 153. The reflective layer 154-2 may be disposed not only below the second region 150b of the light-emitting layers 151 to 153 but also below the ohmic contact layer 154-1. The magnetic layer 154-3 may be disposed below the reflective layer 154-2. At this time, since the ohmic contact layer 154-1 is disposed in the groove 158 formed on the lower side of the first region 150a of the light-emitting layers 151 to 153, the bottom surface of the reflective layer 154-2 and / or the bottom surface of the magnetic layer 154-3 disposed below the ohmic contact layer 154-1 may be a straight plane. Thus, since the lower side of the semiconductor light-emitting device 150-1 is a straight plane, the semiconductor light-emitting device 150-1 can be correctly assembled into the assembly hole 340H during self-assembly without swaying left and right or flipping in the fluid.

[0207] On the other hand, after the semiconductor light-emitting device 150-1 is assembled, a post-process may be used to form an electrical connection. That is, the connection electrode 370, the third insulating layer 350, and the electrode wiring 360 may be formed using a post-process.

[0208] The connection electrode 370 may be disposed in the assembly hole 340H. The connection electrode 370 may electrically connect the semiconductor light-emitting device 150-1 to the first set of assembly lines 321 and / or the second set of assembly lines 322. For example, the connection electrode 370 may electrically connect the electrode 154 of the semiconductor light-emitting device 150-1 to the first set of assembly lines 321 and / or the second set of assembly lines 322. For example, the connection electrode 370 may be electrically connected to the side surface of the reflective layer 154-2 and / or the side surface of the magnetic layer 154-3 of the first electrode 154.

[0209] The connection electrode 370 may be formed by electroplating or sputtering.

[0210] As an example, the connection electrode 370 may be formed using an electroplating process. That is, after an object to be gold-plated, such as the substrate 310, is immersed in an electrolyte, a voltage may be applied by connecting it to the cathode through the first set of assembly lines 321 and / or the second set of assembly lines 322, whereby a metal coating film may be formed on the first set of assembly lines 321 and / or the second set of assembly lines 322 to form the connection electrode 370.

[0211] As the metal coating film is coated on the first set of assembly lines 321 and / or the second set of assembly lines 322 and gradually thickens, the connection electrode 370 is formed not only on the lower side of the semiconductor light-emitting device 150-1 but also along the periphery of the semiconductor light-emitting device 150-1 in the assembly hole 340H.

[0212] As another example, a sputtering process can be utilized to form and pattern a metal film on the substrate 310, whereby connection electrodes 370 can be formed along the periphery of the semiconductor light-emitting device 150-1 in the assembly holes 340H. Additionally, a wider spaced-apart space equivalent to the sum of the thickness t4 of the first insulating layer 330 and the step d1 can be formed, and the metal film can also be formed in this spaced-apart space. Therefore, the formation of the connection electrodes 370 is easy and the contact area between the connection electrodes 370 and the first electrode 154 is maximized, whereby the luminous efficiency and light luminance can be significantly improved.

[0213] Although not shown, instead of the connection electrodes 370, another electrode wiring 360 spaced apart from the electrode wiring 360 can be connected to the side portion of the semiconductor light-emitting device 150-1 through the third insulating layer 350.

[0214] The second insulating layer 335 can be disposed between the semiconductor light-emitting device 150-1 and the first insulating layer 330 and fix the semiconductor light-emitting device 150-1 to the first insulating layer 330.

[0215] The second insulating layer 335 can have a shape corresponding to the shape of the semiconductor light-emitting device 150-1. For example, the diameter (or width) of the second insulating layer 335 can be the same as the diameter (or width) of the semiconductor light-emitting device 150-1, but this is not limited thereto. For example, the second insulating layer 335 can have a shape corresponding to the shape of the first conductive-type semiconductor layer 151 and / or the electrode 154 of the semiconductor light-emitting device 150-1. For example, the thickness of the second insulating layer 335 can be less than the thickness of the first insulating layer 330. For example, the thickness of the second insulating layer 335 can be less than the thickness of the electrode 154 of the semiconductor light-emitting device 150-1.

[0216] The third insulating layer 350 can be disposed on the partition wall 340. The third insulating layer 350 can be disposed on the semiconductor light-emitting device 150-1. The third insulating layer 350 can be disposed on the connection electrodes 370 disposed in the assembly holes 340H. The third insulating layer 350 can be a planarization layer for facilitating the formation of the electrode wiring 360 or other layers. Therefore, the top surface of the third insulating layer 350 can be a straight plane. The first insulating layer 330 and the third insulating layer 350 can be made of an organic material or an inorganic material. For example, at least one of the first insulating layer 330 and the third insulating layer 350 can be made of an organic material.

[0217] The electrode wiring 360 can be disposed on the third insulating layer 350 and be electrically connected to the semiconductor light-emitting device 150-1 through the third insulating layer 350. For example, the electrode wiring 360 can be electrically connected to the upper side of the light-emitting layers 151 to 153 through the third insulating layer 350 and the passivation layer 157 of the semiconductor light-emitting device 150-1.

[0218] Therefore, the semiconductor light-emitting device 150-1 can emit light by using the voltage applied to the first set of assembly lines 321 and / or the second set of assembly lines 322 and the electrode wiring 360.

[0219] [Second Embodiment]

[0220] Figure 19 FIG. is a cross-sectional view showing the semiconductor light-emitting device of the second embodiment.

[0221] The second embodiment is the same as the first embodiment except for the depth d2 of the groove 158. For the components having the same shape, structure, and / or function as those in the first embodiment in the second embodiment, the same reference numerals are given and detailed descriptions are omitted.

[0222] Refer to Figure 19 , the semiconductor light-emitting device 150B of the second embodiment may include a light-emitting layer 151 to 153, a passivation layer 157, a first electrode 154, and a second electrode 155. The semiconductor light-emitting device 150B of the second embodiment may be a red semiconductor light-emitting device ( Figure 16 of 150-1). The basic structure of the green semiconductor light-emitting device 150-2 or the blue semiconductor light-emitting device 150-3 may also be the same as that of the semiconductor light-emitting device 150B of the second embodiment, except that the materials of the light-emitting layers 151 to 153 are different.

[0223] A groove 158 may be formed on the lower side of the first region 150a of the light-emitting layers 151 to 153. The depth d2 of the groove 158 in the second embodiment may be greater than the depth d1 of the groove 158 in the first embodiment ( Figure 7 ).

[0224] The first electrode 154 may be disposed on the lower side of the light-emitting layers 151 to 153, and the second electrode 155 may be disposed on the upper side of the light-emitting layers 151 to 153. The first electrode 154 may include an ohmic contact layer 154-1, a reflective layer 154-2, and a magnetic layer 154-3. Although not shown, the first electrode 154 may include more layers.

[0225] The groove 158 may have a bottom surface 158-2 and an inclined surface 158-1. The greater the depth d2 of the groove 158, the greater the length or area of the inclined surface 158-1 may be.

[0226] The ohmic contact layer 154-1 may be disposed in the groove 158. At this time, the thickness of the ohmic contact layer 154-1 may be the same as that of the ohmic contact layer 154-1 in the first embodiment ( Figure 7 ), but this is not limited thereto.

[0227] In the second embodiment, the thickness of the ohmic contact layer 154-1 may be less than the depth d2 of the groove 158. Accordingly, the bottom surface of the ohmic contact layer 154-1 may be positioned higher than the bottom surface of the second region 150b of the light-emitting layers 151 to 153. The ohmic contact layer 154-1 may be disposed on the bottom surface 158-2 of the groove 158.

[0228] On the other hand, the reflective layer 154-2 may be disposed on the lower side of the light-emitting layers 151 to 153, and the magnetic layer 154-3 may be disposed below the reflective layer 154-2. The reflective layer 154-2 may be disposed below the second region 150b of the light-emitting layers 151 to 153. The reflective layer 154-2 may be disposed below the ohmic contact layer 154-1. The reflective layer 154-2 may surround the ohmic contact layer 154-1.

[0229] The reflective layer 154-2 and the magnetic layer 154-3 may be disposed in the groove 158. The reflective layer 154-2 and the magnetic layer 154-3 may be disposed below the ohmic contact layer 154-1 within the groove 158. The reflective layer 154-2 may be disposed on the inclined surface 158-1 of the groove 158. A part of the reflective layer 154-2, i.e., the protruding portion 154-2a, may surround the ohmic contact layer 154-1 within the groove 158. The depth d2 of the groove 158 may be greater than the sum of the thicknesses of the ohmic contact layer 154-1, the reflective layer 154-2, and the magnetic layer 154-3. Accordingly, the magnetic layer 154-3 may form a groove 154-3a corresponding to the groove 158 formed on the lower side of the light-emitting layers 151 to 153.

[0230] According to the second embodiment, since the depth d2 of the groove 158 is large, the ohmic contact layer 154-1 may be disposed on the bottom surface 158-2 of the groove 158, and the reflective layer 154-2 may be disposed on the inner side surface of the groove 158. Accordingly, compared with the first embodiment ( Figure 7 ), the area A2 of the reflective layer 154-2 in the second embodiment is larger, and thus the light efficiency and brightness can be improved by an increase in the light reflectance.

[0231] According to the second embodiment, since the magnetic layer 154-3 is also disposed on the reflective layer 154-2 disposed on the inner side surface of the groove 158, the area of the magnetic layer 154-3 is also larger than that in the first embodiment ( Figure 7 ), and thus the reaction speed with respect to the magnet during self-assembly can be increased, and the assembly rate can be improved.

[0232] Figure 20 is a cross-sectional view showing the display device of the second embodiment.

[0233] Refer to Figure 20, the display device 301 of the second embodiment may include a backplane substrate 300A, a second insulating layer 335, a semiconductor light-emitting device 150-1, a connection electrode 370, a third insulating layer 350, and an electrode wiring 360.

[0234] The backplane substrate 300A may include a substrate 310, a first set of assembly lines 321, a second set of assembly lines 322, a first insulating layer 330, and a partition wall 340.

[0235] After performing self-assembly on the backplane substrate 300A to assemble the semiconductor light-emitting device 150-1 into the assembly hole 340H, the second insulating layer 335, the semiconductor light-emitting device 150-1, the connection electrode 370, the third insulating layer 350, and the electrode wiring 360 may be sequentially formed by performing post-processing.

[0236] The semiconductor light-emitting device 150-1 is a red semiconductor light-emitting device and may be the semiconductor light-emitting device ( Figure 19 of 150B) of the second embodiment.

[0237] Since the depth d2 of the semiconductor light-emitting device 150-1 is greater than the sum of the thicknesses of the ohmic contact layer 154-1, the reflective layer 154-2, and the magnetic layer 154-3, a groove 154-3a of the magnetic layer 154-3 may be formed in the groove 158.

[0238] As Figure 20 shown, since the second insulating layer 335 is disposed not only between the lower side of the semiconductor light-emitting device 150-1 and the first insulating layer 330 but also in the groove 154-3a of the magnetic layer 154-3, the contact area between the magnetic layer 154-3 and the second insulating layer 335, that is, the contact area between the semiconductor light-emitting device 150-1 and the second insulating layer 335 increases. Thus, the semiconductor light-emitting device 150-1 is more tightly fixed to the first insulating layer 330, thereby preventing the separation of the semiconductor light-emitting device 150-1.

[0239] [Third Embodiment]

[0240] Figure 21 is a cross-sectional view showing the semiconductor light-emitting device of the third embodiment.

[0241] The third embodiment is the same as the second embodiment except that the entire area of the bottom surface of the magnetic layer 154-3 is a straight plane.

[0242] Referring to Figure 21 , the semiconductor light-emitting device 150C of the third embodiment may include a light-emitting layer 151 to 153, a passivation layer 157, a first electrode 154, and a second electrode 155. The semiconductor light-emitting device 150C of the third embodiment may be a red semiconductor light-emitting device (Figure 16 of 150-1). The basic structure of the green semiconductor light-emitting device 150-2 or the blue semiconductor light-emitting device 150-3 can also be the same as that of the semiconductor light-emitting device 150C of the third embodiment, except that the materials of the light-emitting layers 151 to 153 are different.

[0243] A groove 158 can be formed on the lower side of the first region 150a of the light-emitting layers 151 to 153. The depth d2 of the groove 158 of the third embodiment can be greater than the depth d1 of the groove 158 of the first embodiment ( Figure 7 ).

[0244] The first electrode 154 can be disposed on the lower side of the light-emitting layers 151 to 153, and the second electrode 155 can be disposed on the upper side of the light-emitting layers 151 to 153. The first electrode 154 can include an ohmic contact layer 154-1, a reflective layer 154-2, and a magnetic layer 154-3. Although not shown, the first electrode 154 can include more layers.

[0245] The ohmic contact layer 154-1, the reflective layer 154-2, and the magnetic layer 154-3 can be disposed in the groove 158. The depth d2 of the groove 158 can be equal to the sum of the thicknesses of the ohmic contact layer 154-1, the reflective layer 154-2, and the magnetic layer 154-3. Specifically, within the groove 158, the bottom surface of the ohmic contact layer 154-1 can be located at a position higher than the bottom surface of the second region 150b of the light-emitting layers 151 to 153. Within the groove 158, the bottom surface of the reflective layer 154-2 can be located at a position higher than the bottom surface of the second region 150b of the light-emitting layers 151 to 153. Within the groove 158, the bottom surface of the magnetic layer can be located at a position lower than the bottom surface of the second region 150b of the light-emitting layers 151 to 153. In other words, in the second region 150b, the bottom surface of the magnetic layer 154-3 can be on the same horizontal line as the light-emitting layers 151 to 153. That is, the magnetic layer 154-3 can include a first magnetic region 154-31 corresponding to the first region 150a of the light-emitting layers 151 to 153 and a second magnetic region 154-32 corresponding to the second region 150b of the light-emitting layers 151 to 153. In this case, the thickness t1 of the first magnetic region 154-31 can be greater than the thickness t2 of the second magnetic region 154-32.

[0246] According to the third embodiment, even if the depth d2 of the groove 158 is large as in the second embodiment ( Figure 19 ), since the bottom surface of the light-emitting layers 151 to 153, that is, the bottom surface of the magnetic layer 154-3 of the first electrode 154, is a straight plane, the semiconductor light-emitting device 150C will not sway or flip left and right in the fluid during self-assembly.

[0247] [Fourth Embodiment]

[0248] Figure 22 This is a cross-sectional view showing a semiconductor light-emitting device according to a fourth embodiment.

[0249] The fourth embodiment is the same as the first to third embodiments except that the thickness T1 of the ohmic contact layer 154-1 is greater than the depth d3 of the groove 158. For components having the same shape, structure, and / or function as those in the first to third embodiments in the fourth embodiment, the same reference numerals are given and detailed descriptions are omitted.

[0250] Referring to Figure 22 , the semiconductor light-emitting device 150D according to the fourth embodiment may include light-emitting layers 151 to 153, a passivation layer 157, a first electrode 154, and a second electrode 155. The semiconductor light-emitting device 150D according to the fourth embodiment may be a red semiconductor light-emitting device ( Figure 16 150-1). The basic structure of a green semiconductor light-emitting device 150-2 or a blue semiconductor light-emitting device 150-3 may also be the same as that of the semiconductor light-emitting device 150D according to the fourth embodiment, except that the materials of the light-emitting layers 151 to 153 are different.

[0251] A groove 158 may be formed on the lower side of the first region 150a of the light-emitting layers 151 to 153.

[0252] The first electrode 154 may be disposed on the lower side of the light-emitting layers 151 to 153, and the second electrode 155 may be disposed on the upper side of the light-emitting layers 151 to 153. The first electrode 154 may include an ohmic contact layer 154-1, a reflective layer 154-2, and a magnetic layer 154-3. Although not shown, the first electrode 154 may include more layers.

[0253] The ohmic contact layer 154-1, the reflective layer 154-2, and the magnetic layer 154-3 may be disposed in the groove 158. Here, the depth d3 of the groove 158 may be less than the thickness T1 of the ohmic contact layer 154-1. When the ohmic contact layer 154-1 is disposed in the groove 158, the bottom surface of the ohmic contact layer 154-1 may be located at a position lower than the bottom surface of the second region 150b of the light-emitting layers 151 to 153. In other words, the ohmic contact layer 154-1 may protrude more downward than the second region 150b of the light-emitting layers 151 to 153.

[0254] The reflective layer 154-2 may be disposed on the ohmic contact layer 154-1 and the second region 150b of the light-emitting layers 151 to 153. Since the thickness of the reflective layer 154-2 is less than the thickness of the ohmic contact layer 154-1, the reflective layer 154-2 disposed below the ohmic contact layer 154-1 may also protrude in the lower direction.

[0255] The magnetic layer 154-3 may be disposed below the reflective layer 154-2. At this time, the entire area of the bottom surface of the magnetic layer 154-3 may be a flat plane. The magnetic layer 154-3 may include a first magnetic region 154-31 corresponding to the first region 150a of the light-emitting layers 151 to 153 and a second magnetic region 154-32 corresponding to the second region 150b of the light-emitting layers 151 to 153. In this case, the thickness t1 of the first magnetic region 154-31 may be smaller than the thickness t2 of the second magnetic region 154-32.

[0256] [Fifth Embodiment]

[0257] The fifth embodiment is the same as the first to fourth embodiments except that the groove 158 has a very deep conical shape. The same reference numerals are given to the components having the same shape, structure, and / or function as those in the first to fourth embodiments in the fifth embodiment, and detailed descriptions thereof are omitted.

[0258] Before describing the semiconductor light-emitting device ( Figure 25 150E) of the fifth embodiment, the related background art will be described first.

[0259] Figure 23 a and Figure 24 a show the size of the semiconductor light-emitting device for illumination, Figure 23 b and Figure 24 b show the size of the semiconductor light-emitting device of the embodiment.

[0260] Generally, the diameter D1 of the semiconductor light-emitting device for illumination is several hundred micrometers to several millimeters, while the diameter D2 of the semiconductor light-emitting device of the embodiment used as a sub-pixel of a high-resolution or ultra-high-resolution display device is 10 micrometers or less, and in recent years, it has reached several nanometers or several tens of nanometers.

[0261] On the other hand, as a semiconductor light-emitting device, in order to emit light, it needs to be composed of a plurality of semiconductor layers, which is independent of whether it is used for illumination or for display. For the sake of convenience of description, generally, the semiconductor light-emitting device for illumination may be composed of a first conductive-type semiconductor layer 7, an active layer 8, and a second conductive-type semiconductor layer 9, and the semiconductor light-emitting device of the embodiment may be composed of a first conductive-type semiconductor layer 151, an active layer 152, and a second conductive-type semiconductor layer 153. Thus, the height H1 of the semiconductor light-emitting device for illumination and the height H2 of the semiconductor light-emitting device of the embodiment are the same. As a result, from the semiconductor light-emitting device for illumination to the semiconductor light-emitting device of the embodiment, the reduction in diameter is more significant than the change in height.

[0262] On the other hand, as is well known, after depositing a large number of semiconductor layers using a deposition process, a mesa etching process is performed to separate them in units of chips. In this case, since the mesa etching process is a physical etching process using plasma, the etched surface during the mesa etching process, that is, the outer side surface and a part of the inside of each of the plurality of semiconductor layers, may be damaged, resulting in non-light-emitting regions 6 and 150e that do not emit light.

[0263] In a semiconductor light-emitting device for lighting, since the area occupied by the non-light-emitting region 6 is small compared to the entire area, there is a possibility that a relatively large area of the active layer 152 is used as a light-emitting region. Thus, the semiconductor light-emitting device for lighting generates light in a relatively spacious space of the active layer 152 by changing the current-dispersing structure.

[0264] On the contrary, in the semiconductor light-emitting device of the embodiment, the area occupied by the non-light-emitting region 150e is very large compared to the entire area. That is, most of the region of the active layer 152 belongs to the non-light-emitting region 150e, so there are not many regions in the active layer 152 that can generate light by changing the current-dispersing structure or the like. Therefore, in the semiconductor light-emitting device of the embodiment, changing the current-dispersing structure or the like is not very helpful for improving the light efficiency or brightness.

[0265] Referring to this background art, the applicant proposed a solution for improving the light efficiency and / or brightness improvement in a semiconductor light-emitting device of an embodiment used as a sub-pixel of a high-resolution or ultra-high-resolution display device, rather than changing the current-dispersing structure. Figure 25 ).

[0266] Figure 25 It is a cross-sectional view showing a semiconductor light-emitting device of the fifth embodiment.

[0267] Referring to Figure 25 , the semiconductor light-emitting device 150E of the fifth embodiment may include light-emitting layers 151 to 153, a passivation layer 157, a first electrode 154, and a second electrode 155. The semiconductor light-emitting device 150E of the fifth embodiment may be a red semiconductor light-emitting device ( Figure 16 of 150-1). The basic structure of the green semiconductor light-emitting device 150-2 or the blue semiconductor light-emitting device 150-3 may also be the same as that of the semiconductor light-emitting device 150E of the fifth embodiment, only the materials of the light-emitting layers 151 to 153 are different.

[0268] A groove 158 may be formed below the first region 150a of the light-emitting layers 151 to 153. The groove 158 may have a conical shape with a very deep depth d4. The depth d4 of the groove 158 may be defined by the distance between the peak P of the groove 158 and the bottom surface of the second region 150b of the light-emitting layers 151 to 153. For example, the depth d4 of the groove 158 may be more than 1 / 2 of the thickness of the first conductive-type semiconductor layer 151 of the light-emitting layers 151 to 153. For example, the peak P of the groove 158 may be located at a position higher than the step region in the multi-segment structure 150d. The peak P of the groove 158 may be adjacent to the active layer 152 without contacting the active layer 152. The groove 158 may have an inclined surface 158-1. The length or area of the inclined surface 158-1 may increase as the depth d4 becomes larger.

[0269] The first electrode 154 may be disposed on the lower side of the light-emitting layers 151 to 153, and the second electrode 155 may be disposed on the upper side of the light-emitting layers 151 to 153. The first electrode 154 may include an ohmic contact layer 154-1, a reflective layer 154-2, and a magnetic layer 154-3. Although not shown, the first electrode 154 may include more layers.

[0270] The ohmic contact layer 154-1, the reflective layer 154-2, and the magnetic layer 154-3 may be disposed in the groove 158. The ohmic contact layer 154-1 may be disposed at the peak P of the groove 158 and its periphery. Since the ohmic contact layer 154-1 is disposed at the peak P of the groove 158 and its periphery, the ohmic contact layer 154-1 may be disposed at a position very close to the active layer 152. That is, as Figure 26 shown, when a driving current I flows in the semiconductor light-emitting device 150E, the shortest current path may be formed between the second electrode 155 and the ohmic contact layer 154-1 with the active layer 152 interposed therebetween. Since the shorter the current path, the smaller the current loss, more light can be generated by the driving current flowing through the shortest current path, thereby improving the light efficiency and brightness. In addition, since the driving current starting from the second electrode 155 flows toward the ohmic contact layer 154-1 disposed at the peak P of the groove 158 and its periphery, not only the shortest current path is formed in the central region of the second electrode 155, but also the shortest current path is formed between the edge region and the ohmic contact layer 154-1, so that more light is generated in the corresponding region of the active layer 152 via each of the shortest current paths, and thus the light efficiency and brightness can be significantly improved.

[0271] The reflective layer 154-2 may be disposed below the second region 150b of the light-emitting layers 151 to 153. Additionally, the reflective layer 154-2 may be disposed on the inclined surface 158-1 of the groove 158. The reflective layer 154-2 may be in contact with the inclined surface 158-1 of the groove 158, but this is not limited thereto. The magnetic layer 154-3 may be disposed below the reflective layer 154-2.

[0272] As Figure 26 shown, since the depth d4 of the groove 158 is very large, the length or area of the inclined surface 158-1 of the groove 158 can also be significantly increased. Therefore, the area of the reflective layer 154-2 disposed on the inclined surface 158-1 of the groove 158 is also greatly increased and inclined. In addition, the reflective layer 154-2 is also disposed below the second region 150b of the light-emitting layers 151 to 153. Therefore, the light traveling from the active layer 152 in the downward direction is reflected not only by the reflective layer 154-2 disposed below the second region 150b of the light-emitting layers 151 to 153, but also by the reflective layer 154-2 disposed on the inclined surface 158-1 of the groove 158, thereby further improving the light efficiency and brightness.

[0273] On the other hand, the magnetic layer 154-3 is disposed not only below the second region 150b of the light-emitting layers 151 to 153, but also on the inclined surface 158-1 of the groove 158 having a very large depth d4 or below the ohmic contact layer 154-1. Thus, the area of the magnetic layer 154-3 can be maximized, thereby significantly increasing the reaction speed to the magnet during self-assembly, and further improving the assembly rate.

[0274] Figure 27 is a cross-sectional view showing a display device of the third embodiment.

[0275] Referring Figure 27 , the display device 302 of the third embodiment may include a backplane substrate 300A, a second insulating layer 335, a semiconductor light-emitting device 150-1, a connection electrode 370, a third insulating layer 350, and an electrode wiring 360.

[0276] The semiconductor light-emitting device 150-1 is a red semiconductor light-emitting device and may be the semiconductor light-emitting element of the fifth embodiment ( Figure 25 150E). The basic structure of the green semiconductor light-emitting device 150-2 or the blue semiconductor light-emitting device 150-3 provided in the display device 302 of the third embodiment is the same as or similar to the structure of the semiconductor light-emitting element of the fifth embodiment ( Figure 25 150E), only the semiconductor materials are different.

[0277] As described above, the depth d4 of the groove 158 is set to be more than 1 / 2 of the thickness of the first conductive semiconductor layer 151 of the light-emitting layers 151 to 153. An ohmic contact layer 154-1 may be disposed at the apex P of the groove 158 and its periphery. The reflective layer 154-2 is disposed not only below the second region 150b of the light-emitting layers 151 to 153 but also on the inclined surface 158-1 of the groove 158 or below the ohmic contact layer 154-1. A magnetic layer 154-3 may be disposed below the reflective layer 154-2. By the above-described structural change, not only the shortest current path is formed, but also the area of the reflective layer 154-2 is maximized, thereby significantly improving the light efficiency or brightness. Therefore, by providing the semiconductor light-emitting device 50-1 having the above-described structure in the display device 302 of the third embodiment, the image quality can be improved by increasing the contrast.

[0278] On the other hand, since the depth d4 of the groove 158 is very large, even if the reflective layer 154-2 and the magnetic layer 154-3 are disposed in the groove 158, a second insulating layer 335 having a very large depth can be formed corresponding to the groove 158 in the groove 154-3a of the magnetic layer 154-3 formed on the lower side of the light-emitting layers 151 to 153. In this case, since the second insulating layer 335 is disposed not only between the lower side of the semiconductor light-emitting device 150E and the first insulating layer 330 but also in the groove 154-3a of the magnetic layer 154-3, the fixing property of the semiconductor light-emitting device 150-1 can be further enhanced by the second insulating layer 335.

[0279] [Sixth Embodiment]

[0280] Figure 28 FIG. is a cross-sectional view showing a semiconductor light-emitting device according to the sixth embodiment.

[0281] The sixth embodiment is the same as the fifth embodiment except for the shape of the groove 158. For the components having the same shape, structure, and / or function as those in the fifth embodiment in the sixth embodiment, the same reference numerals are given and detailed descriptions are omitted.

[0282] Referring to Figure 27 , the semiconductor light-emitting device 150F according to the sixth embodiment may include light-emitting layers 151 to 153, a passivation layer 157, a first electrode 154, and a second electrode 155. The semiconductor light-emitting device 150F according to the sixth embodiment may be a red semiconductor light-emitting device 150-1. The basic structure of the green semiconductor light-emitting device 150-2 or the blue semiconductor light-emitting device 150-3 may also be the same as that of the semiconductor light-emitting device 150F according to the sixth embodiment, except that the materials of the light-emitting layers 151 to 153 are different.

[0283] A groove 158 may be formed below the first region 150a of the light-emitting layers 151 to 153. The groove 158 has a very deep depth d5 and may have a cylindrical shape with a smaller diameter closer to the upper side. The groove 158 may have an inclined surface 158-1 and a bottom surface 158-2. In this case, the diameter D2 of the bottom surface 158-2 of the groove 158 may be 1 / 3 or less of the diameter D1 of the lowermost side of the groove 158.

[0284] The depth d5 of the groove 158 may be defined by the distance between the bottom surface 158-2 of the groove 158 and the bottom surface of the second region 150b of the light-emitting layers 151 to 153. For example, the depth d5 of the groove 158 may be 1 / 2 or more of the thickness of the first conductive semiconductor layer 151 of the light-emitting layers 151 to 153. For example, the vertex P of the groove 158 may be located at a position higher than the step region of the multi-segment structure 150d. The bottom surface 158-2 of the groove 158 may be adjacent to the active layer 152 without contacting the active layer 152. The groove 158 may have an inclined surface 158-1. The length or area of the inclined surface 158-1 may increase as the depth d5 increases.

[0285] The first electrode 154 may be disposed below the light-emitting layers 151 to 153, and the second electrode 155 may be disposed above the light-emitting layers 151 to 153. The first electrode 154 may include an ohmic contact layer 154-1, a reflective layer 154-2, and a magnetic layer 154-3. Although not shown, the first electrode 154 may include more layers.

[0286] The ohmic contact layer 154-1, the reflective layer 154-2, and the magnetic layer 154-3 may be disposed in the groove 158. The ohmic contact layer 154-1 may be disposed on the bottom surface 158-2 of the groove 158. Since the ohmic contact layer 154-1 is disposed on the bottom surface 158-2 of the groove 158, the ohmic contact layer 154-1 may be disposed very close to the active layer 152. Therefore, as described above, when a driving current flows through the semiconductor light-emitting device 150F, the shortest current path is formed between the second electrode 155 and the ohmic contact layer 154-1 across the active layer 152, so that more light can be generated in the active layer 152. In addition, the reflective layer 154-2 is disposed not only below the second region 150b of the light-emitting layers 151 to 153 but also on the inclined surface 158-1 of the groove 158 whose area increases as the depth d5 of the groove 158 increases, thereby improving the light reflectivity. As described above, by changing the structure of the lower layer of the semiconductor light-emitting device 150F to form the shortest current path and increase the light reflectivity, the light efficiency and light luminance can be significantly improved.

[0287] [Seventh Embodiment]

[0288] Figure 29This is a cross-sectional view showing a semiconductor light-emitting device according to a seventh embodiment.

[0289] The seventh embodiment is the same as the first to sixth embodiments except for the unevenness 159 formed in the groove 158. For components having the same shape, structure, and / or function as those in the first to sixth embodiments in the seventh embodiment, the same reference numerals are given and detailed descriptions are omitted.

[0290] Referring to Figure 29 , the semiconductor light-emitting device 150G according to the seventh embodiment may include light-emitting layers 151 to 153, a passivation layer 157, a first electrode 154, and a second electrode 155. The semiconductor light-emitting device 150G according to the seventh embodiment may be a red semiconductor light-emitting device 150-1. The basic structure of a green semiconductor light-emitting device 150-2 or a blue semiconductor light-emitting device 150-3 may also be the same as that of the semiconductor light-emitting device 150G according to the seventh embodiment, except that the materials of the light-emitting layers 151 to 153 are different.

[0291] A groove 158 may be formed on the lower side of the first region 150a of the light-emitting layers 151 to 153. Unevenness 159 may be formed on the inner surface of the groove 158. Unevenness 159 may be formed on the inclined surface 158-1 of the groove 158. Unevenness 159 may be formed on the bottom surface 158-2 of the groove 158. By first forming the groove 158 and then performing an additional etching process, unevenness 159 may be formed on the surface of the groove 158. The roughness of the unevenness 159 may be as follows.

[0292] The first electrode 154 may be disposed on the lower side of the light-emitting layers 151 to 153, and the second electrode 155 may be disposed on the upper side of the light-emitting layers 151 to 153. The first electrode 154 may include an ohmic contact layer 154-1, a reflective layer 154-2, and a magnetic layer 154-3. Although not shown, the first electrode 154 may include more layers.

[0293] The ohmic contact layer 154-1, the reflective layer 154-2, and the magnetic layer 154-3 may be disposed in the groove 158. The ohmic contact layer 154-1 may be disposed on the unevenness 159. The ohmic contact layer 154-1 may be disposed on the unevenness 159 formed on the inclined surface 158-1 of the groove 158. The ohmic contact layer 154-1 may be disposed on the unevenness 159 formed on the bottom surface 158-2 of the groove 158. The thickness of the ohmic contact layer 154-1 may be the same as the depth of the groove 158, but this is not limited thereto.

[0294] The reflective layer 154-2 can be disposed not only under the second region 150b of the light-emitting layers 151 to 153, but also under the ohmic contact layer 154-1. The magnetic layer 154-3 can be disposed under the reflective layer 154-2.

[0295] According to the seventh embodiment, the ohmic contact layer 154-1 can be disposed on the unevenness 159 formed in the groove 158. As described above, when heat treatment is performed to form the ohmic contact layer 154-1, the light reflectivity of the ohmic contact layer 154-1 decreases. However, since the unevenness 159 is formed in contact with the ohmic contact layer 154-1 disposed in the groove 158, the light traveling from the active layer 152 to the lower ohmic contact layer 154-1 is diffusely reflected or scattered by the unevenness 159, so that it does not enter the ohmic contact layer 154-1, thereby reducing the reduction of light reflection caused by the ohmic contact layer 154-1. In addition, since the light diffusely reflected or scattered by the unevenness 159 contributes to the light extraction effect, the light efficiency or brightness can be improved.

[0296] [Eighth Embodiment]

[0297] Figure 30 FIG. is a cross-sectional view showing a semiconductor light-emitting device according to the eighth embodiment.

[0298] The eighth embodiment is the same as the first to seventh embodiments except for the contact electrode 154-4 included in the first electrode 154. The same reference numerals are given to the constituent elements of the eighth embodiment that are the same as those of the first to seventh embodiments, and detailed descriptions thereof are omitted.

[0299] Refer to Figure 30 , the semiconductor light-emitting device 150H according to the eighth embodiment may include light-emitting layers 151 to 153, a passivation layer 157, a first electrode 154, and a second electrode 155. The semiconductor light-emitting device 150H according to the eighth embodiment may be a red semiconductor light-emitting device 150-1. The basic structures of the green semiconductor light-emitting device 150-2 or the blue semiconductor light-emitting device 150-3 may also be the same as those of the semiconductor light-emitting device 150H according to the eighth embodiment, except that the materials of the light-emitting layers 151 to 153 are different.

[0300] A groove 158 may be formed on the lower side of the first region 150a of the light-emitting layers 151 to 153.

[0301] The first electrode 154 may be disposed on the lower side of the light-emitting layers 151 to 153, and the second electrode 155 may be disposed on the upper side of the light-emitting layers 151 to 153. The first electrode 154 may include an ohmic contact layer 154-1, a reflective layer 154-2, a magnetic layer 154-3, and a contact electrode 154-4. Although not shown, the first electrode 154 may include more layers.

[0302] An ohmic contact layer 154-1 may be disposed in the groove 158. A reflective layer 154-2 may be disposed below the second region 150b of the light-emitting layer. A magnetic layer 154-3 may be disposed below the reflective layer 154-2. A contact electrode 154-4 may be disposed below the magnetic layer 154-3. The reflective layer 154-2, the magnetic layer 154-3, and the contact electrode 154-4 may be disposed below the ohmic contact layer 154-1.

[0303] The contact electrode 154-4 may be formed of a metal having excellent contact characteristics. For example, the contact electrode 154-4 may have a multilayer structure such as Mo / Al / Mo.

[0304] In an embodiment, the contact electrode 154-4 may be disposed on the side portions of the light-emitting layers 151 to 153. After the semiconductor light-emitting device 150H of the eighth embodiment having the above-described structure is assembled into the assembly hole 340H of the backplane substrate ( Figure 18 of 300A), a connection electrode 370 may be formed. In this case, when the connection electrode 370 is formed along the peripheral edge of the side portion of the semiconductor light-emitting device 150H in the assembly hole 340H, the contact area between the contact electrode 154-4 disposed on the side portions of the light-emitting layers 151 to 153 and the connection electrode 370 becomes larger, thereby improving the electrical characteristics. Therefore, the light efficiency and brightness can be improved, and low-voltage driving can be performed, thereby reducing power consumption.

[0305] Although not shown, the reflective layer 154-2 and / or the magnetic layer 154-3 may also be disposed on the side portions of the light-emitting layers 151 to 153.

[0306] [Ninth Embodiment]

[0307] Figure 31 is a cross-sectional view showing a semiconductor light-emitting device of the ninth embodiment. Figure 32 is a bottom view showing a semiconductor light-emitting device of the ninth embodiment.

[0308] The ninth embodiment is the same as the first to seventh embodiments except for the partial disposition of the ohmic contact layer 154-1 of the first electrode 154 below the second region 150b of the light-emitting layers 151 to 153.

[0309] Refer to Figure 31 and Figure 32, the semiconductor light-emitting device 150I of the ninth embodiment may include light-emitting layers 151 to 153, a passivation layer 157, a first electrode 154, and a second electrode 155. The semiconductor light-emitting device 150I of the ninth embodiment may be a red semiconductor light-emitting device 150-1. The basic structure of the green semiconductor light-emitting device 150-2 or the blue semiconductor light-emitting device 150-3 may also be the same as that of the semiconductor light-emitting device 150I of the ninth embodiment, except that the materials of the light-emitting layers 151 to 153 are different.

[0310] A first groove 158a may be formed on the lower side of the first region 150a of the light-emitting layers 151 to 153. The first groove 158a may have a shape corresponding to the shape of the first region 150a. The first groove 158a may have the same size as the first region 150a of the light-emitting layers 151 to 153.

[0311] At least one second groove 158b may be formed on the lower side of the second region 150b of the light-emitting layer. The second groove 158b may be locally formed on the lower side of the second region 150b of the light-emitting layers 151 to 153. The second groove 158b may have a size smaller than the size of the second region 150b of the light-emitting layers 151 to 153. The second groove 158b may be in the shape of a closed loop. Although not shown, the second groove 158b may also be in the shape of a loop and composed of a plurality of sub-grooves separated from each other. The width of the second groove 158b may be smaller than the diameter of the first groove 158a, but this is not limited thereto.

[0312] The first electrode 154 may be disposed on the lower side of the light-emitting layers 151 to 153, and the second electrode 155 may be disposed on the upper side of the light-emitting layers 151 to 153. The first electrode 154 may include an ohmic contact layer 154-1, a reflective layer 154-2, a magnetic layer 154-3, and a contact electrode 154-4. Although not shown, the first electrode 154 may include more layers.

[0313] The ohmic contact layer 154-1 may include a first ohmic contact layer 154-11 disposed in the first groove 158a and a second ohmic contact layer 154-12 disposed in at least one second groove 158b. The first ohmic contact layer 154-11 may have a shape corresponding to the shape of the first groove 158a. The second ohmic contact layer 154-12 may have a shape corresponding to the shape of the second groove 158b. The width of the second ohmic contact layer 154-12 disposed in the second groove 158b may be smaller than the diameter of the first ohmic contact layer 154-11 disposed in the first groove 158a, but this is not limited thereto.

[0314] The reflective layer 154-2 may be disposed on the lower side of the light-emitting layers 151 to 153. The reflective layer 154-2 may be disposed on the lower side of the first region 150a and the second region 150b of the light-emitting layers 151 to 153. The reflective layer 154-2 may surround the first ohmic contact layer 154-11 and / or the second ohmic contact layer 154-12. The reflective layer 154-2 may be in contact with the remaining bottom surfaces of the bottom surfaces of the light-emitting layers 151 to 153 except for the bottom surface of the second region 150b that is in contact with the second ohmic contact layer 154-12. The magnetic layer 154-3 may be disposed below the reflective layer 154-2.

[0315] According to the ninth embodiment, the ohmic contact layer 154-1 is disposed not only below the first region 150a of the light-emitting layers 151 to 153 but also locally on the bottom surface of the second region 150b of the light-emitting layers 151 to 153, thereby not only improving the electrical characteristics based on the ohmic contact layer 154-1 but also increasing the light reflectance based on the reflective layer 154-2 to improve the light efficiency and brightness.

[0316] On the other hand, the above-described display device may be a display panel. That is, in the embodiment, the display device and the display panel may be understood to have the same meaning. In the embodiment, the actual display device may include a display panel and a controller (or a processor) capable of controlling the display panel for displaying an image.

[0317] The above-described detailed description should not be construed as restrictive in all aspects, but should be understood as exemplary. The scope of the embodiment should be determined by a reasonable interpretation of the appended claims, and all changes within the equivalent scope of the embodiment are included in the scope of the embodiment.

[0318] Industrial Applicability

[0319] The embodiment can be applied to the display field for displaying images or information. The embodiment can be applied to the display field for displaying images or information using semiconductor light-emitting devices. The semiconductor light-emitting device may be a micron-scale semiconductor light-emitting device or a nano-scale semiconductor light-emitting device.

[0320] For example, the embodiment can be applied to TVs, signs, mobile terminals such as mobile phones or smart phones, computer monitors such as laptop computers or desktop computers, automotive head-up displays, backlight units for displays, VR, AR, or MR (mixed reality) displays, light sources, and the like.

Claims

1. A semiconductor light-emitting device, wherein, comprising: a light-emitting layer; a passivation layer surrounding the side portion of the light-emitting layer; a first electrode disposed below the light-emitting layer; and a second electrode disposed on the light-emitting layer; the light-emitting layer has a first region and a second region surrounding the first region; the bottom surface of the first region of the light-emitting layer has a groove; the first electrode includes: an ohmic contact layer disposed in the groove; a reflective layer disposed below the second region of the light-emitting layer; and a magnetic layer disposed below the reflective layer; the area of the reflective layer exceeds 50% of the area of the lower side of the light-emitting layer.

2. The semiconductor light-emitting device according to claim 1, wherein, the area of the ohmic contact layer is 5% to 50% of the area of the lower side of the light-emitting layer.

3. The semiconductor light-emitting device according to claim 1, wherein, the reflective layer is disposed below the ohmic contact layer.

4. The semiconductor light-emitting device according to claim 3, wherein, the reflective layer includes a protruding portion that surrounds the ohmic contact layer in the groove.

5. The semiconductor light-emitting device according to claim 1, wherein, the bottom surface of the ohmic contact layer and the bottom surface of the second region of the light-emitting layer are on the same horizontal line.

6. The semiconductor light-emitting device according to claim 1, wherein, the bottom surface of the ohmic contact layer is at a higher position than the bottom surface of the second region of the light-emitting layer.

7. The semiconductor light-emitting device according to claim 6, wherein, the magnetic layer has a second groove corresponding to the groove.

8. The semiconductor light-emitting device according to claim 6, wherein, the magnetic layer is disposed below the reflective layer, the bottom surface of the magnetic layer is a straight plane.

9. The semiconductor light-emitting device according to claim 1, wherein, the bottom surface of the ohmic contact layer is at a lower position than the bottom surface of the second region of the light-emitting layer.

10. The semiconductor light-emitting device according to claim 9, wherein, the magnetic layer is disposed below the reflective layer, the bottom surface of the magnetic layer is a straight plane.

11. The semiconductor light-emitting device according to claim 1, wherein, the depth of the groove is 1 / 2 or more of the thickness of the first conductive type semiconductor layer of the light-emitting layer.

12. The semiconductor light-emitting device according to claim 11, wherein, the groove has a bottom surface and an inclined surface, the ohmic contact layer is disposed on the bottom surface, the reflective layer is disposed on the inclined surface.

13. The semiconductor light-emitting device according to claim 1, wherein, the surface of the groove includes irregularities; the ohmic contact layer is disposed on the irregularities.

14. The semiconductor light-emitting device according to claim 1, wherein, the first electrode includes a contact electrode disposed below the magnetic layer.

15. The semiconductor light-emitting device according to claim 14, wherein, at least one of the reflective layer, the magnetic layer, and the contact electrode is disposed on the side portion of the light-emitting layer.

16. A display device, wherein, comprising: a backplane substrate; A plurality of semiconductor light-emitting devices that emit light of different colors from each other on the backplane substrate; Connecting electrodes disposed on the sides of each of the plurality of semiconductor light-emitting devices; And Electrode wirings disposed on the upper sides of each of the plurality of semiconductor light-emitting devices; At least one of the plurality of semiconductor light-emitting devices includes: A light-emitting layer; A passivation layer surrounding the side of the light-emitting layer; A first electrode disposed below the light-emitting layer; and A second electrode disposed on the light-emitting layer; The light-emitting layer has a first region and a second region surrounding the first region; The bottom surface of the first region of the light-emitting layer has a groove; The first electrode includes: An ohmic contact layer disposed in the groove; A reflective layer disposed below the second region of the light-emitting layer; and A magnetic layer disposed below the reflective layer.

Images