Semiconductor light-emitting element and display device

Abstract

The semiconductor light emitting element includes a light emitting layer, a passivation layer surrounding the light emitting layer, a first electrode on the light emitting layer, a second electrode under the light emitting layer, and an adhesion promoting layer under the light emitting layer. An interior angle between the side surface and the lower surface of the light emitting layer may be an obtuse angle. The adhesion promoting layer has a size corresponding to a size of the first conductive type semiconductor layer of the light emitting layer, and may surround a side portion of the second conductive type semiconductor layer. The first conductive type semiconductor layer may include an overlapping region that vertically overlaps each of the active layer and the second conductive type semiconductor layer, and a non-overlapping region that does not vertically overlap each of the active layer and the second conductive type semiconductor layer and surrounds the overlapping region. The first electrode may be disposed on an upper surface of a non-overlapping region in a first side of the overlapping region.

Description

Technical Field

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

[0002] Large-area displays include liquid crystal displays (LCDs), OLED displays, and micro-LED displays (Micro-LED displays).

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

[0004] Micro-LED displays use micro-LEDs, which are semiconductor light-emitting elements, as display elements, so they have excellent performance in many characteristics such as contrast, response speed, color reproduction rate, viewing angle, brightness, resolution, lifespan, luminous efficiency or brightness.

[0005] In particular, micro-LED displays can separate or combine images in a modular manner, so they have the advantages of being able to freely adjust the size or resolution and being able to realize flexible displays.

[0006] On the other hand, the uses of LEDs for lighting and micro LEDs for display are different.

[0007] like Figure 1 (a) shows that the light is emitted in all directions from the lighting LED 1, and has uniform brightness in a wide area. Figure 1 (b) shows that the display micro-LED 3 itself is used as a sub-pixel, so it is preferred to emit forward light and suppress side light. Side light refers to light emitted in the side direction, and forward light refers to light emitted in the front direction. The more forward light there is, the greater the brightness, thereby improving the contrast, so it is preferred to suppress side light in the display micro-LED 3 and maximize the amount of forward light. However, compared with the lighting LED 1, the display micro-LED 3 is only smaller in size, and light is still emitted in all directions, so there is less forward light and there is a problem of weak brightness.

[0008] On the other hand, in the manufacturing process of LEDs, a non-luminous region corresponding to a predetermined depth is formed from the side surface of the LED due to the etching process, and no light is generated.

[0009] Figure 2 (a) and Figure 2 (b) is a cross-sectional view of each of the lighting LED and the display LED as viewed from above.

[0010] like Figure 2As shown in (a), the illumination LED 1 has a width ranging from several hundred microns to several millimeters. Therefore, the non-luminous region 1b formed along its outer edge accounts for approximately 3% of the total area. Consequently, the luminous region 1a accounts for 97% of the total area, making the illumination LED 1 largely unaffected by the non-luminous region 1b. In other words, even if the non-luminous region 1b does not produce light, the brightness of the illumination LED 1 is not reduced.

[0011] On the contrary, Figure 2 (b) shows that the display micro-LED 3 has a width of about 10 micrometers or less. In the display micro-LED 3, the narrower the width becomes, the larger the area occupied by the non-luminous region 3b in the entire area.

[0012] The thickness of the non-luminous regions 1b and 3b is approximately the same in the illumination LED 1 and the display micro-LED 3. Therefore, as the size of the display micro-LED 3 becomes significantly smaller than that of the illumination LED 1, the area of the luminous regions 1a and 3a in the display micro-LED 3 becomes even smaller than that of the illumination LED 1.

[0013] For example, if the horizontal and vertical widths are 5 microns each, the thickness (or depth) of non-luminous region 3b is 2 microns, and the area of non-luminous region 3b accounts for 96% of the total area. Consequently, the area of luminous region 3a is only 4% of the total area, a very small amount. Therefore, light is generated only in this 4% of luminous region 3a, resulting in very low brightness.

[0014] As can be seen from this, the brightness of display micro-LEDs is significantly lower than that of lighting LEDs 1. However, high-brightness light must be emitted to achieve high-definition displays. Therefore, there is an urgent need to develop display micro-LEDs that can emit high-brightness light.

[0015] On the other hand, the semiconductor material of each color in the semiconductor light emitting element is different. For example, the red semiconductor light emitting element is made of a semiconductor material such as GaP, while the green or blue semiconductor light emitting element is made of a semiconductor material such as GaN.

[0016] Therefore, the semiconductor material of each color in the semiconductor light-emitting element is different. Consequently, the refractive index difference between the semiconductor material of each color and air in the semiconductor light-emitting element is also different, resulting in a different light distribution for each color in the semiconductor light-emitting element. This different light distribution for each color in the semiconductor light-emitting element leads to different viewing angles.

[0017] On the other hand, after transferring the micro-LEDs to the backplane, electrical wiring connections are performed as a subsequent process. However, as the LED size decreases, the likelihood of short circuits increases, making electrical wiring connections more difficult. Therefore, there is an urgent need to develop technologies that can facilitate electrical wiring and connections. Summary of the Invention

[0018] Technical issues

[0019] Embodiments are directed to solving the above-referenced problems and other problems.

[0020] Another object of the embodiment is to provide a semiconductor light emitting element and a display device capable of achieving high brightness.

[0021] Furthermore, another object of the embodiment is to provide a semiconductor light emitting element and a display device capable of improving the viewing angle.

[0022] Furthermore, another object of the embodiment is to provide a display device that facilitates electrical wiring or connection thereof.

[0023] The technical problems of the embodiment are not limited to the technical problems described in this claim, but include all technical problems that can be understood from the description of the invention.

[0024] Means of solving technical problems

[0025] In order to achieve the above-mentioned purpose or other purposes, according to one aspect of the embodiment, a semiconductor light-emitting element includes: a light-emitting layer; a passivation layer surrounding the light-emitting layer; a first electrode on the light-emitting layer; a second electrode below the light-emitting layer; and an adhesion promotion layer below the light-emitting layer, the inner angle between the side surface of the light-emitting layer and the lower surface is an obtuse angle, the light-emitting layer includes: an active layer; a first conductive semiconductor layer on the active layer; and a second conductive semiconductor layer below the active layer, the size of the adhesion promotion layer corresponds to the size of the first conductive semiconductor layer, and the adhesion promotion layer surrounds the side of the second conductive semiconductor layer, the first conductive semiconductor layer includes: an overlapping area, which vertically overlaps with each of the active layer and the second conductive semiconductor layer; and a non-overlapping area, which does not vertically overlap with each of the active layer and the second conductive semiconductor layer but surrounds the overlapping area, and the first electrode is arranged on the upper surface of the non-overlapping area on the first side of the overlapping area.

[0026] The side surface of the light emitting layer may have polygonal slopes having different obtuse angles.

[0027] The side surface of the first conductive semiconductor layer may include a vertical surface connected to the upper surface of the light emitting layer, a horizontal surface connected to the vertical surface, and an inclined surface connected to the horizontal surface, wherein the vertical surface is an outer side surface of the non-overlapping region.

[0028] The inclined surface may have a critical angle relative to the surface of the active layer that constitutes a total reflection condition. The side surface of the active layer may have an inclined surface that is connected to the inclined surface of the first conductive type semiconductor layer, and the side surface of the second conductive type semiconductor layer may have a vertical surface that is connected to the inclined surface of the active layer.

[0029] The light-emitting layer may have a recess below the non-overlapping region, and the adhesion promoting layer includes a first adhesion promoting layer disposed in the recess and a second adhesion promoting layer disposed below the second electrode.

[0030] The lower surface of the first adhesion promoting layer and the lower surface of the second adhesion promoting layer may be located on the same horizontal line.

[0031] The passivation layer may include: a first passivation layer on the upper surface of the light emitting layer; a second passivation layer on the lower surface of the light emitting layer; and a third passivation layer surrounding the side surface of the light emitting layer.

[0032] The first electrode may be in contact with the upper surface of the first conductive type semiconductor layer through the first passivation layer, and the second electrode may be in contact with the lower surface of the second conductive type semiconductor layer through the second passivation layer.

[0033] The second electrode may include a first connection electrode extending from a lower surface of the second conductive semiconductor layer along a surface of each of the second passivation layer and the third passivation layer.

[0034] The second electrode may include a second connection electrode disposed on an upper surface of the non-overlapping region on a second side opposite to the first side of the overlapping region.

[0035] The second connection electrode may extend from the first connection electrode through the first conductive type semiconductor layer to the upper surface of the non-overlapping region.

[0036] The second electrode may include a reflective metal layer.

[0037] According to another aspect of the embodiment, the display device may include: a back panel; the above-mentioned semiconductor light-emitting element according to the first item on the above-mentioned back panel; a first electrode wiring connected to the above-mentioned first electrode of the above-mentioned semiconductor light-emitting element; and a second electrode wiring connected to the above-mentioned second electrode of the above-mentioned semiconductor light-emitting element.

[0038] The adhesion promoting layer of the semiconductor light emitting element may be bonded to the adhesive layer on the back plate.

[0039] Effects of the Invention

[0040] According to the embodiment, even if a semiconductor light emitting element having a size of less than one micrometer is used as a sub-pixel of a display, high brightness can be obtained.

[0041] For this reason, Figure 7 as well as Figure 8 As shown, the first electrode 154 and the second electrode 155 can be arranged in the non-overlapping region 151b of the first conductive semiconductor layer 151 of the light-emitting layer 150a. This allows the overlapping region 151a, which vertically overlaps the active layer 152, to function solely as a light-emitting region, thereby improving light efficiency. Furthermore, the first and second electrodes 154, 155 are arranged in the non-overlapping region 151b so that they do not obstruct the propagation of light, thereby improving light efficiency. This increases brightness, enabling a high-brightness display.

[0042] Furthermore, the internal angle θ1 between the side surface 150a3 of the light-emitting layer 150a and the lower surface 150a2 can be an obtuse angle. Thus, the side surface 150a3 of the light-emitting layer 150a can have an inclined surface. In this case, the obtuse angle can be an angle for causing the inclined surface to have a critical angle θc. Therefore, light traveling from the active layer 152 toward the side surface 150a3 of the light-emitting layer 150a at an incident angle greater than the critical angle θc is totally reflected, thereby converging the light in front of the semiconductor light-emitting element 150A, thereby achieving high brightness.

[0043] The first semiconductor light emitting element 150R, the second semiconductor light emitting element 150G, and the third semiconductor light emitting element 150B disposed in each of the first sub-pixel PX1, the second sub-pixel PX2, and the third sub-pixel PX3 constituting the pixel have Figure 7 as well as Figure 8 The structure of the semiconductor light-emitting element 150A shown in the figure allows the first semiconductor light-emitting element 150R, the second semiconductor light-emitting element 150G, and the third semiconductor light-emitting element 150B to emit light with high brightness, thereby improving the wide viewing angle. In other words, by significantly increasing the brightness, the difference in wide viewing angle between the first sub-pixel PX1, the second sub-pixel PX2, and the third sub-pixel PX3 can be compensated.

[0044] On the other hand, the semiconductor light emitting element can have many variations. For example, Figure 7 as well as Figure 8 As shown, the first electrode 154 and the second electrode 155 are both disposed on the upper surface 150a1 of the first conductive semiconductor layer 151, so that the connection of electrical wiring in subsequent processes can be facilitated. Figure 21 as well as Figure 22 As shown, the first electrode 154 is disposed on the upper surface 150a1 of the first conductive semiconductor layer 151, and the second electrode 155 is exposed on the side of the light emitting layer 150a, thereby eliminating the need to form a through hole 420 in the first conductive semiconductor layer 151. This simplifies the process and solves the difficulty of forming the through hole 420. Figure 35 As shown, the second electrode 155 is connected to the entire region of the second conductive type semiconductor layer 153 , thereby improving electrical and optical characteristics.

[0045] On the other hand, Figure 24 As shown, the side surface 150a3 of the light-emitting layer 150a has polygonal inclined surfaces with different obtuse angles. At least one of the polygonal inclined surfaces 151-3 can be inclined to have a critical angle θc. As a result, light traveling from the active layer 152 is totally reflected by the inclined surface 151-3, while light that is not totally reflected and travels toward the second passivation layer 157-2 can be reflected by the second electrode 155. Therefore, the light generated in the active layer 152 travels forward rather than sideways, thereby emitting light in a concentrated manner forward, significantly increasing the brightness and achieving high brightness.

[0046] Other applicable scopes of the embodiments will be clearly understood from the following description. However, those skilled in the art will clearly understand various changes and modifications within the concept and scope of the embodiments, and therefore, the detailed description and specific embodiments such as the preferred embodiments should be interpreted as only examples. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Figure 1 (a) and Figure 1 (b) shows the direction of light emitted from each of the lighting LED and the display micro LED.

[0048] Figure 2 (a) and Figure 2 (b) shows the light-emitting area and the non-light-emitting area of each of the lighting LED and the display micro LED.

[0049] Figure 3 A residential living room equipped with a display device according to an embodiment is shown.

[0050] Figure 4 is a block diagram briefly showing a display device according to an embodiment.

[0051] Figure 5 It shows Figure 4 A circuit diagram of an example of a pixel.

[0052] Figure 6 yes Figure 3 An enlarged view of the first panel area in the display device.

[0053] Figure 7 is a plan view showing the semiconductor light emitting element according to the first embodiment.

[0054] Figure 8 yes Figure 7 FIG. 1 shows a cross-sectional view taken along line B1 - B2 of the semiconductor light emitting element according to the first embodiment.

[0055] Figure 9 The figure shows how light travels in the light-emitting layer of the embodiment.

[0056] Figure 10 FIG. 1 shows how the semiconductor light emitting element according to the first embodiment is transferred onto a backplane.

[0057] Figures 11 to 18 A manufacturing process of the semiconductor light emitting element according to the first embodiment is shown.

[0058] Figure 19 is a top view showing a display device according to an embodiment.

[0059] Figure 20 It shows Figure 19 FIG. 1 shows a cross-sectional view of a first sub-pixel cut along line C1 - C2 in a display device according to an embodiment.

[0060] Figure 21 is a plan view showing a semiconductor light emitting element according to a second embodiment.

[0061] Figure 22 yes Figure 21 FIG. 1 shows a cross-sectional view taken along line D1 - D2 of the semiconductor light emitting element according to the second embodiment.

[0062] Figure 23 is a cross-sectional view showing a first sub-pixel of a display device including a semiconductor light emitting element according to the second embodiment.

[0063] Figure 24 is a cross-sectional view showing a semiconductor light emitting element according to a third embodiment.

[0064] Figures 25 to 33 A manufacturing process of the semiconductor light emitting element according to the third embodiment is shown.

[0065] Figure 34 is a cross-sectional view showing a first sub-pixel of a display device including the semiconductor light emitting element according to the third embodiment.

[0066] Figure 35 is a cross-sectional view showing a semiconductor light emitting element according to a fourth embodiment.

[0067] The sizes, shapes, and numerical values of the components shown in the drawings may differ from the actual sizes, shapes, and numerical values. Furthermore, if the same component is shown with different sizes, shapes, and numerical values in different drawings, these are merely examples, and the same component may have the same sizes, shapes, and numerical values across different drawings. DETAILED DESCRIPTION

[0068] The embodiments disclosed in this specification are described in detail below with reference to the accompanying drawings, and for the same or similar constituent elements, the same figure numbers are marked in different figure numbers, and repeated descriptions thereof are omitted. The suffixes "module" and "section" of the constituent elements used in the following description are added or mixed for the convenience of writing the specification, and do not have different meanings or functions in themselves. The accompanying drawings are used to help understand the embodiments disclosed in this specification, and the technical ideas disclosed in this specification are not limited to the accompanying drawings. In addition, when an element such as a layer, a region or a substrate is recorded as being "on" other constituent elements, it includes being directly above other elements or there may be other intermediate elements between them.

[0069] The display devices described in this specification may include TVs, signage, mobile terminals such as mobile phones and smartphones, computer monitors such as laptops and desktops, automotive HUDs (head-up displays), display backlight units, and displays and light sources for XR (Extended Reality) such as AR, VR, and MR (mixed reality). However, even for new product forms developed in the future, the configurations described in this specification according to the embodiments can be similarly applied to devices capable of displaying.

[0070] Figure 3 A living room of a house equipped with a display device according to an embodiment is shown.

[0071] Reference Figure 3 The display device 100 of the embodiment can display the status of various electronic products such as a washing machine 101, a robot vacuum cleaner 102, and an air purifier 103, can communicate with each electronic product based on IOT, and can control each electronic product based on data set by the user.

[0072] The display device 100 according to the embodiment may include a flexible display formed on a thin and flexible substrate. The flexible display can be bent or rolled like a piece of paper while maintaining the characteristics of a conventional flat panel display.

[0073] In flexible displays, visual information can be achieved by individually controlling the light emission of unit pixels arranged in a matrix. A unit pixel represents the smallest unit used to achieve a color. Unit pixels in flexible displays can be implemented using light-emitting elements. In embodiments, the light-emitting elements can be micro-LEDs or nano-LEDs, but are not limited thereto.

[0074] Figure 4 is a block diagram briefly showing a display device according to an embodiment, Figure 5 It shows Figure 4 A circuit diagram of an example of a pixel.

[0075] Reference Figure 4 as well as Figure 5 The display device according to the embodiment may include a display panel 10 , a driving circuit 20 , a scan driving part 30 , and a power supply circuit 50 .

[0076] The display device 100 of the embodiment can drive the light emitting elements in an active matrix (AM) method or a passive matrix (PM) method.

[0077] The driving circuit 20 may include a data driving section 21 and a timing control section 22 .

[0078] The display panel 10 may be configured as a rectangular quadrilateral, but is not limited thereto. That is, the display panel 10 may be formed in a circular or elliptical shape. At least one side of the display panel 10 may be formed to be bent with a predetermined curvature.

[0079] The display panel may include a display area DA. The display area DA is a region where a plurality of pixels PX are formed to display an image. The display panel may include a non-display area NDA. The non-display area DNA may be a region other than the display area DA.

[0080] As an example, the display area DA and the non-display area NDA may be defined on the same surface. For example, the non-display area DNA may surround the display area DA on the same surface as the display area DA, but this is not limited thereto.

[0081] As another example, although not shown in the drawings, the display area DA and the non-display area NDA may be defined on different surfaces. For example, the display area DA may be defined on the upper surface of the substrate, and the non-display area NDA may be defined on the lower surface of the substrate. For example, the non-display area NDA may also be defined on the entire area or a portion of the lower surface of the substrate.

[0082] On the other hand, while the drawings illustrate division into a display area DA and a non-display area NDA, this division into the display area DA and the non-display area NDA is not required. That is, only the display area DA may exist on the upper surface of the substrate, with no non-display area NDA. In other words, the entire upper surface of the substrate may be the display area DA for displaying images, with no border area serving as the non-display area NDA.

[0083] The display panel 10 may include a plurality of data lines D1 to Dm (m is an integer greater than or equal to 2), a plurality of scan lines S1 to Sn (n is an integer greater than or equal to 2) intersecting the plurality of data lines D1 to Dm, a high-potential voltage line VDDL supplied with a high-potential voltage VDD, 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.

[0084] 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 a first color light of a first main wavelength, the second sub-pixel PX2 may emit a second color light of a second main wavelength, and the third sub-pixel PX3 may emit a third color light of 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 is not limited thereto. Furthermore, in Figure 4 , each of the plurality of pixels PX includes three sub-pixels, but the present invention is not limited thereto. That is, each of the plurality of pixels PX may include four or more sub-pixels.

[0085] Each of the first sub-pixel PX1, the second sub-pixel PX2 and the third sub-pixel PX3 can 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. Figure 5 As shown, the first sub-pixel PX1 may include a plurality of light emitting elements LD, a plurality of transistors for supplying current to the plurality of light emitting elements LD, and at least one capacitor Cst.

[0086] Although not shown in the drawings, each of the first sub-pixel PX1 , the second sub-pixel PX2 , and the third sub-pixel PX3 may further include only one light emitting element LD and at least one capacitor Cst.

[0087] Each of the plurality of light emitting elements LD may be a semiconductor light emitting diode including a first electrode, a plurality of conductive semiconductor layers, and a second electrode, wherein the first electrode may be an anode electrode and the second electrode may be a cathode electrode, but this is not limited thereto.

[0088] The light emitting element LD may be one of a horizontal light emitting element, a flip-chip light emitting element, and a vertical light emitting element.

[0089] like Figure 5 As shown, the multiple transistors may include a driving transistor DT that supplies current to the multiple light-emitting elements LD, and a scanning transistor ST that supplies a data voltage to the gate of the driving transistor DT. The driving transistor DT may include a gate connected to the source of the scanning transistor ST, a source connected to a high-potential voltage line VDDL to which a high-potential voltage VDD is applied, and a drain connected to the first electrodes of the multiple light-emitting elements LD. The scanning transistor ST may include a gate connected to a scanning line Sk (k is an integer satisfying 1≤k≤n), a source connected to the gate of the driving transistor DT, and a drain connected to a data line Dj (j is an integer satisfying 1≤j≤m).

[0090] The capacitor Cst is formed between the gate and source of the driving transistor DT. The storage capacitor Cst can charge the difference between the gate voltage and the source voltage of the driving transistor DT.

[0091] The driving transistor DT and the scanning transistor ST may be formed as thin film transistors. Figure 5 While the example in which the drive transistor DT and the scan transistor ST are formed as P-type MOSFETs (Metal Oxide Semiconductor Field Effect Transistors) is primarily described, the present invention is not limited thereto. The drive transistor DT and the scan transistor ST can also be formed as N-type MOSFETs. In this case, the positions of the source and drain of each of the drive transistor DT and the plurality of scan transistors ST can be changed.

[0092] And, in Figure 5 2T1C (2Transistor-1Capacitor) example is shown in the figure, in which each of the first subpixel PX1, the second subpixel PX2, and the third subpixel PX3 includes one driving transistor DT, one scanning transistor ST, and one capacitor Cst, but the present invention is not limited thereto. Each of the first subpixel PX1, the second subpixel PX2, and the third subpixel PX3 may include multiple scanning transistors ST and multiple capacitors Cst.

[0093] The second subpixel PX2 and the third subpixel PX3 can be represented by substantially the same circuit diagram as the first subpixel PX1 , and thus detailed descriptions of these pixels are omitted.

[0094] 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 part 21 and a timing control part 22.

[0095] The data driver 21 receives digital video data DATA and a source control signal DCS from the timing controller 22 , converts the digital video data DATA into analog data voltages according to the source control signal DCS, and supplies the analog data voltages to the data lines D1 to Dm of the display panel 10 .

[0096] The timing control unit 22 receives digital video data DATA and a timing signal from a host system, which may be an application processor of a smartphone or tablet PC, a monitor, or a system-on-chip of a TV system.

[0097] The timing control unit 22 generates a plurality of control signals for controlling the operation timings of the data driver 21 and the scan driver 30. The plurality of control signals may include a source control signal DCS for controlling the operation timing of the data driver 21 and a scan control signal SCS for controlling the operation timing of the scan driver 30.

[0098] The driver circuit 20 can be disposed in a non-display area (NDA) provided on one side of the display panel 10. The driver circuit 20 can be formed as an integrated circuit (IC) and mounted on the display panel 10 using a COG (chip on glass) method, a COP (chip on plastic) method, or an ultrasonic bonding method, but the present invention is not limited thereto. For example, the driver circuit 20 can be mounted on a circuit board (not shown) instead of the display panel 10.

[0099] The data driving unit 21 may be mounted on the display panel 10 by a COG (chip on glass) method, a COP (chip on plastic) method, or an ultrasonic bonding method, and the timing control unit 22 may be mounted on a circuit board.

[0100] The scan driver 30 receives a scan control signal SCS from the timing control unit 22. Based on the scan control signal SCS, the scan driver 30 generates a plurality of scan signals and supplies them to the plurality of scan lines S1 to Sn of the display panel 10. The scan driver 30 may include a plurality of transistors formed in the non-display area (NDA) of the display panel 10. Alternatively, the scan driver 30 may be formed as an integrated circuit, in which case it may be mounted on a gate flexible film attached to the other side of the display panel 10.

[0101] The power supply circuit 50 can generate the voltages required to drive the display panel 10 based on the main power applied from the system board, and then supply the voltages to the display panel 10. For example, the power supply circuit 50 can generate the high potential voltage VDD and the low potential voltage VSS for driving the plurality of light-emitting elements LD of the display panel 10 based on the main power, and then supply the voltages to the high potential voltage line VDDL and the low potential voltage line VSSL of the display panel 10. Furthermore, the power supply circuit 50 can generate and supply a plurality of driving voltages for driving the driving circuit 20 and the scan driving unit 30 based on the main power.

[0102] Figure 6 yes Figure 3 An enlarged view of the first panel area in the display device.

[0103] Reference Figure 6 The display device 100 of the embodiment is manufactured such that a plurality of panel areas such as the first panel area A1 are structurally and electrically connected by dividing the panels into blocks.

[0104] The first panel area A1 may include a pixel for each unit pixel ( Figure 4 Multiple semiconductor light emitting elements 150 are configured with PX).

[0105] Below, refer to Figures 7 to 35 Various embodiments for solving the above problems are described. Figures 3 to 6 As well as the above contents related to the corresponding drawings, it is easy to understand the description omitted in the following description.

[0106] The overlapping region described below is the region of the first conductive semiconductor layer that overlaps with the active layer. This region, defined in the first conductive semiconductor layer, may also be referred to as a light-emitting region. The first conductive semiconductor layer may further define a non-overlapping region surrounding the overlapping region in addition to the overlapping region. The non-overlapping region may be a region of the first conductive semiconductor layer that does not vertically overlap with the active layer.

[0107] [First embodiment]

[0108] Figure 7 is a plan view showing the semiconductor light emitting element according to the first embodiment. Figure 8 yes Figure 7 FIG. 1 shows a cross-sectional view taken along line B1 - B2 of the semiconductor light emitting element according to the first embodiment.

[0109] Reference Figure 7 as well as Figure 8 The semiconductor light emitting element 150A according to the first embodiment may include a light emitting layer 150 a , a passivation layer 157 , a first electrode 154 , a second electrode 155 , and an adhesion promoting layer 158 .

[0110] The light-emitting layer 150a can emit light of a specific color. The specific color can be determined by the semiconductor material of the light-emitting layer 150a. The specific color can be, for example, red, green, or blue. The following description assumes that the light-emitting layer 150a emits red light. However, in the embodiments, the light-emitting layer 150a can also emit green or blue light.

[0111] The light-emitting layer 150a may include multiple semiconductor layers. For example, the light-emitting layer 150a may include at least one first-conductivity-type semiconductor layer 151, an active layer 152, and at least one second-conductivity-type semiconductor layer 153. The active layer 152 may be disposed below the first-conductivity-type semiconductor layer 151, and the second-conductivity-type semiconductor layer 153 may be disposed below the active layer 152. The first-conductivity-type semiconductor layer 151 may include an n-type dopant, and the second-conductivity-type semiconductor layer 153 may include a p-type dopant, but this is not limited to this. For example, the first-conductivity-type semiconductor layer 151 may include a p-type dopant, and the second-conductivity-type semiconductor layer 153 may include an n-type dopant.

[0112] On the other hand, in the embodiment, the light emitting layer 150a may have a rectangular shape when viewed from above, but this is not limited to the above. That is, when viewed from above, the light emitting layer 150a may have a circular, elliptical, polygonal, or other shape.

[0113] On the other hand, in an embodiment, when the light-emitting layer 150a is observed from the side, it may have an inverted trapezoidal shape. That is, the size (or diameter) of the upper surface 150a1 of the light-emitting layer 150a may be larger than the size (or diameter) of the lower surface 150a2. In this case, the side surface 150a3 of the light-emitting layer 150a may have an inclined surface that is inclined relative to the lower surface 150a2 (or the upper surface 150a1). For example, the internal angle θ1 between the side surface 150a3 of the light-emitting layer 150a and the lower surface 150a2 may be an obtuse angle. An obtuse angle refers to an angle greater than 90° and less than 180°.

[0114] For example, the side surface 150a3 of the light emitting layer 150a may have an oblique angle inclined in such a manner as to have a critical angle θc. Figure 9 As shown, when light generated by active layer 152 is incident on side surface 150a3 of light-emitting layer 150a, if the incident angle of the corresponding light is greater than the critical angle θc, the corresponding light is totally reflected and is not refracted by side surface 150a3 of light-emitting layer 150a. In other words, the corresponding light is totally reflected and can be emitted to the outside through upper surface 150a1 of first conductive semiconductor layer 151. Therefore, light generated by active layer 152 and then incident on side surface 150a3 of light-emitting layer 150a, i.e., side light, is emitted forward through total reflection, thereby increasing brightness and improving contrast.

[0115] For example, in each of the red, green, and blue semiconductor light-emitting elements, the side surface 150a3 of the light-emitting layer 150a can be inclined at a critical angle θc. In this case, even though the semiconductor materials included in the light-emitting layer 150a of each of the red, green, and blue semiconductor light-emitting elements are different, the luminance is significantly increased, thereby improving the wide viewing angle. In other words, this significant increase in luminance can compensate for the difference in wide viewing angles between the red, green, and blue semiconductor light-emitting elements.

[0116] On the other hand, the first conductive type semiconductor layer 151 may include an overlapping region 151a and a non-overlapping region 151b. The drawings show that the overlapping region 151a also has a rectangular shape corresponding to the shape of the light emitting layer 150a, but it can also have a right rectangular shape, a circle, an ellipse, etc.

[0117] The overlapping region 151a may vertically overlap each of the active layer 152 and the second conductive type semiconductor layer 153. That is, a region of the first conductive type semiconductor layer 151 vertically overlapping each of the active layer 152 and the second conductive type semiconductor layer 153 may be defined as the overlapping region 151a.

[0118] The non-overlapping region 151b may not vertically overlap with either the active layer 152 or the second conductive semiconductor layer 153. That is, the region of the first conductive semiconductor layer 151 that does not vertically overlap with either the active layer 152 or the second conductive semiconductor layer 153 may be defined as the non-overlapping region 151b. For example, the non-overlapping region 151b may be a region of the first conductive semiconductor layer 151 excluding the overlapping region 151a. For example, the non-overlapping region 151b may surround the overlapping region 151a.

[0119] The size or area of each of the active layer 152 and the second conductive semiconductor layer 153 can be smaller than the size or area of the first conductive semiconductor layer 151. For example, after the first conductive semiconductor layer 151, the active layer 152, and the second conductive semiconductor layer 153 are formed to the same size, the edge region of the first conductive semiconductor layer 151, namely, the active layer 152 and the second conductive semiconductor layer 153 corresponding to the non-overlapping region 151b, can be removed. In other words, by removing the edge regions of each of the active layer 152 and the second conductive semiconductor layer 153 corresponding to the non-overlapping region 151b of the first conductive semiconductor layer 151, the recess 160 can be formed. Therefore, the light emitting layer 150a can be formed below the non-overlapping region 151b of the first conductive semiconductor layer 151. The shape of the recess 160 can correspond to the shape of each of the removed active layer 152 and the second conductive semiconductor layer 153.

[0120] On the other hand, after removing the second conductive semiconductor layer 153 and the active layer 152 to form the recess 160, the first conductive semiconductor layer 151 can also be removed. For example, at least half the thickness of the first conductive semiconductor layer 151 can be removed. The removal of the second conductive semiconductor layer 153, the active layer 152, and the first conductive semiconductor layer 151 can be performed through a Mesa etching process. As a result, the side surfaces of the second conductive semiconductor layer 153, the active layer 152, and the first conductive semiconductor layer 151, i.e., the side surface 150a3 of the light-emitting layer 150a, can have an inclined surface relative to the lower surface 150a2. As described above, the side surface 150a3 of the light-emitting layer 150a can have an inclined angle that is inclined so as to have a critical angle θc.

[0121] On the other hand, the passivation layer 157 is made of a material with excellent insulation properties, protects the light emitting layer 150 a , and can prevent leakage current from flowing through the side of the light emitting layer 150 a .

[0122] For example, the passivation layer 157 may include a first passivation layer 157-1 on the upper surface of the light emitting layer 150a, a second passivation layer 157-2 on the lower surface 150a2 of the light emitting layer 150a, and a third passivation layer 157-3 surrounding the side surface 150a3 of the light emitting layer 150a. The third passivation layer 157-3 may be disposed along the periphery of the side surface 150a3 of the light emitting layer 150a.

[0123] The first passivation layer 157-1, the second passivation layer 157-2, and the third passivation layer 157-3 may be formed of the same insulating material, but this is not limited to the above. For example, the second passivation layer 157-2 and the third passivation layer 157-3 may be formed of the same insulating material, and the first passivation layer 157-1 may be formed of a different material from the second passivation layer 157-2.

[0124] The first passivation layer 157-1, the second passivation layer 157-2, and the third passivation layer 157-3 can be formed to the same thickness, but this is not limited to this. For example, the second passivation layer 157-2 and the third passivation layer 157-3 can be formed to the same thickness, while the first passivation layer 157-1 and the second passivation layer 157-2 can be formed to different thicknesses. The first passivation layer 157-1 should have excellent light transmittance to facilitate the emission of light from the light-emitting layer 150a to the outside, so its thickness is preferably as thin as possible. The second and third passivation layers 157-3 need to prevent leakage current from flowing through the sides of the light-emitting layer 150a, so their thickness can be formed relatively thick.

[0125] On the other hand, the first electrode 154 can be arranged on the light-emitting layer 150a. For example, the first electrode 154 can be arranged on the upper surface of the non-overlapping region 151b. For example, the first electrode 154 can be arranged on the upper surface of the non-overlapping region 151b on the first side of the overlapping region 151a. The first electrode 154 can be formed in the non-overlapping region 151b in a long shape along one direction, but this is not limited to this. The first electrode 154 is a cathode electrode and can have a multilayer structure including multiple layers. For example, the first electrode 154 can be grounded or a negative (-) voltage can be applied to the first electrode 154.

[0126] Although not shown, the first electrode 154 may be disposed on the upper surface of the non-overlapping region 151b along the outer edge of the overlapping region 151a. The overlapping region 151a has a first side, a second side, a third side, and a fourth side. The first and second sides may face each other, and the third and fourth sides may face each other. The second side may be located opposite the first side, and the fourth side may be located opposite the third side.

[0127] The first electrode 154 may be disposed on an upper surface of the non-overlap region 151 b in a first side of the overlap region 151 a , and the second electrode 155 may be disposed on an upper surface of the non-overlap region 151 b in a second side of the overlap region 151 a .

[0128] Although not shown, the first electrode 154 can be arranged on the upper surface of the non-overlapping region 151b on the third side and / or the fourth side in addition to the first side. The second electrode 155 can also be arranged on the upper surface of the non-overlapping region 151b on the third side and / or the fourth side in addition to the second side. In this case, the configuration area of the first electrode 154 and / or the second electrode 154 becomes wider, which can improve the electrical or optical properties. That is, the smoother flow of current in the light-emitting layer 150a increases the production of electrons and holes, thereby improving the light efficiency and increasing the brightness. The light efficiency and brightness can be values measured in front of the semiconductor light-emitting element 150A.

[0129] For example, the first electrode 154 may be in contact with the upper surface 150a1 of the first conductive semiconductor layer 151 through the passivation layer 157. For example, the first electrode 154 may be in contact with the upper surface 150a1 of the first conductive semiconductor layer 151 through the first passivation layer 157-1.

[0130] For example, the first electrode 154 does not vertically overlap the active layer 152. Thus, light generated in the active layer 152 and emitted forward is not blocked by the first electrode 154, thereby increasing light brightness by improving light efficiency.

[0131] On the other hand, the second electrode 155 can be arranged below the light-emitting layer 150a. The second electrode 155 can be arranged on the side of the light-emitting layer 150a. The second electrode 155 can be arranged on the upper side of the light-emitting layer 150a. The second electrode 155 is an anode electrode and can have a multilayer structure including multiple layers. A positive (+) voltage can be applied to the second electrode 155.

[0132] The second electrode 155 is in contact with the lower surface of the conductive layer 155c below the light-emitting layer 150a through the passivation layer 157. If the conductive layer 155c is omitted, the first electrode 154 may be in contact with the second conductive semiconductor layer 153. For example, the second electrode 155 is in contact with the lower surface of the conductive layer 155c below the light-emitting layer 150a through the second passivation layer 157-2.

[0133] The second electrode 155 may include a first connection electrode 155a and a second connection electrode 155b. The first connection electrode 155a may extend from the lower surface of the conductive layer 155c along the surface of each of the second passivation layer 157-2 and the third passivation layer 157-3. That is, the first connection electrode 155a may be disposed on the surface of the second passivation layer 157-2 and the surface of the third passivation layer 157-3. A portion of the first connection electrode 155a may be exposed to the outside. That is, the side surface of the first electrode 154 and the side surface of the adhesion promoting layer 158 are located on the same vertical line 172, so that the side surface of the first electrode 154 can be exposed to the outside.

[0134] Although not shown, the side surface of the first connection electrode 155a is not located on the same vertical line 172 as the side surface of the adhesion-promoting layer 158, thereby preventing the side surface of the first connection electrode 155a from being exposed to the outside. By positioning the side surface of the first connection electrode 155a a predetermined distance inward from the end of the non-overlapping region 151b of the first conductive semiconductor layer 151, the side surface of the first connection electrode 155a is covered by the adhesion-promoting layer 158. Thus, the side surface of the first connection electrode 155a is covered by the adhesion-promoting layer 158 and is not exposed to the outside.

[0135] The second connection electrode 155b can be connected to the first connection electrode 155a. The second connection electrode 155b can be integrally formed with the first connection electrode 155a. The second connection electrode 155b can extend from the first connection electrode 155a through the first conductive semiconductor layer 151 to the upper surface of the non-overlapping region 151b. The second electrode 155 can be arranged on the non-overlapping region 151b on the second side, where the second side is opposite to the first side of the overlapping region 151a. Thus, in an embodiment, the first electrode 154 and the second electrode 155 can be arranged on the same surface. That is, the first electrode 154 and the second electrode 155 can be arranged on the upper surface 150a1 of the first conductive semiconductor layer 151. The first electrode 154 and the second electrode 155 are arranged on the non-overlapping region 151b surrounding the overlapping region 151a, so they do not hinder the travel of light emitted from the overlapping region 151a, thereby preventing a decrease in light efficiency and contributing to increased brightness.

[0136] The second electrode 155 may include a plurality of metal layers including a reflective metal layer. For example, the reflective metal layer may include aluminum (Al), silver (Ag), copper (Au), etc. The reflective metal layer reflects light that has passed through the third passivation layer 157-3 at the active layer 152 and is emitted forward through the upper surface 150a1 of the first conductive semiconductor layer 151, thereby increasing light brightness.

[0137] On the other hand, the second electrode 155 may include a transparent conductive layer 155 c such as ITO.

[0138] The conductive layer 155c can be a current diffusion layer. Current diffuses laterally through the conductive layer 155c, so that current is injected into the second conductive type semiconductor layer 153 over the entire area of the conductive layer 155c, thereby increasing the amount of hole generation and improving light efficiency.

[0139] The conductive layer 155c may be a transmissive layer. Light generated by the active layer 152 is transmitted through the conductive layer 155c and can be incident on the second electrode 155. In this case, the corresponding light is reflected by the second electrode 155 and again transmitted through the conductive layer 155c before being emitted forward through the upper surface 150a1 of the first conductive type semiconductor layer 151, thereby improving light efficiency.

[0140] On the other hand, the first electrode 154 and / or the second electrode 155 exposed on the first passivation layer 157-1 may be a contact pad. The contact pad is a component connected to an external power source and may include a metal having low contact resistance and excellent conductivity, such as copper (Cu).

[0141] On the other hand, adhesion-promoting layer 158 may be disposed below light-emitting layer 150a. Adhesion-promoting layer 158 may be disposed below passivation layer 157. Adhesion-promoting layer 158 may be disposed below second passivation layer 157-2. Adhesion-promoting layer 158 may be in contact with the lower surface of second passivation layer 157-2. Adhesion-promoting layer 158 may be disposed below second electrode 155. Adhesion-promoting layer 158 may be in contact with the lower surface of second electrode 155.

[0142] The size of the adhesion promoting layer 158 may correspond to the size of the first conductive type semiconductor layer 151. The adhesion promoting layer 158 may surround the side of the second conductive type semiconductor layer 153. The adhesion promoting layer 158 may surround the side of the active layer 152.

[0143] like Figure 10 As shown, adhesion promoting layer 158 can secure semiconductor light emitting element 150A in the correct position without tilting when attached to back plate 300A. To this end, the lower surface of adhesion promoting layer 158 can have a straight plane. In this case, the lower surface of adhesion promoting layer 158 is adhesive surface 158a, which can be the surface that contacts adhesive layer 310 when adhesion promoting layer 158 is attached to adhesive layer 310 on back plate 300A.

[0144] First, the semiconductor light-emitting element 150A is placed on the backplane 300A and aligned. This alignment allows the semiconductor light-emitting element 150A to align with the sub-pixels on the backplane 300A. Then, the semiconductor light-emitting element is pressed, allowing the adhesion-promoting layer 158 of the semiconductor light-emitting element 150A to adhere to the adhesive layer 310 of the backplane 300A.

[0145] If the semiconductor light emitting element 150A does not have the adhesion promoting layer 158, the semiconductor light emitting element 150A may be attached to the back plate 300A in an inclined state. In this case, when the electrical wiring is connected in the subsequent process, the electrical wiring may be disconnected, resulting in failure to light up or an electrical short circuit.

[0146] However, in the embodiment, when the lower surface 150a2 of the semiconductor light-emitting element 150A is provided with a straight, flat adhesion-promoting layer 158, when the semiconductor light-emitting element 150A is attached to the backplate 300A, the semiconductor light-emitting element 150A is fixed in the correct position and does not wobble or tilt. This allows the electrode wiring to be accurately connected to each of the first electrode 154 and the second electrode 155 of the semiconductor light-emitting element 150A in subsequent steps, preventing electrical disconnection or short circuits, thereby improving yield. Furthermore, since the semiconductor light-emitting element 150A is attached to the backplate 300A in a non-tilted state, electrical wiring can be easily connected.

[0147] On the other hand, the adhesion promoting layer 158 may include a first adhesion promoting layer 1581 - 1 and a second adhesion promoting layer 158 - 2 .

[0148] A first adhesion-promoting layer 1581-1 may be disposed below the non-overlapping region 151b. The first adhesion-promoting layer 1581-1 may be disposed below the third passivation layer 157-3. The first adhesion-promoting layer 1581-1 may be in contact with the lower surface of the third passivation layer 157-3. The first adhesion-promoting layer 1581-1 may be disposed in the recess 160. The first adhesion-promoting layer 1581-1 may surround the sides of each of the second conductive semiconductor layer 153 and / or the active layer 152.

[0149] Second adhesion-promoting layer 158-2 may be disposed below overlap region 151a. Second adhesion-promoting layer 158-2 may be disposed below second passivation layer 157-2. Second adhesion-promoting layer 158-2 may be in contact with the lower surface of second passivation layer 157-2. Second adhesion-promoting layer 158-2 may be disposed below second electrode 155. Second adhesion-promoting layer 158-2 may be in contact with the lower surface of second electrode 155.

[0150] The lower surface of the first adhesion promoting layer 1581-1 and the lower surface of the second adhesion promoting layer 158-2 can be located on the same horizontal line. To this end, the thickness of the first adhesion promoting layer 1581-1 and the second adhesion promoting layer 158-2 can be different. For example, the thickness of the first adhesion promoting layer 1581-1 can be thicker than the thickness of the second adhesion promoting layer 158-2.

[0151] The adhesion promoting layer 158 may include, for example, a high molecular organic substance, but is not limited thereto. The adhesion promoting layer 158 may be formed of an insulating substance having excellent adhesion properties. For example, the adhesion promoting layer 158 may include BCB (benzocyclobutene) or the like. The adhesion promoting layer 158 may be used for bonding with the temporary substrate 410 when manufacturing the semiconductor light emitting element 150A according to the first embodiment. At this time, the adhesion promoting layer 158 is not removed but retained, thereby being used as a constituent element of the semiconductor light emitting element 150A according to the first embodiment. That is, the adhesion promoting layer 158 is not only used in the manufacturing process but also retained on the product, and a composite technical effect having respective technical effects can be achieved.

[0152] Figures 11 to 18 FIG1 shows a manufacturing process of the semiconductor light emitting element according to the first embodiment. Figures 11 to 18 Unlabeled reference numerals in the figure may be the same reference numerals as those labeled for the same constituent elements in the previous drawings.

[0153] like Figure 11As shown, a light-emitting layer 150a can be evaporated on a growth substrate 400. The growth substrate 400 can be formed of sapphire, GaN, glass, silicon, ceramic, or the like. The light-emitting layer 150a can include at least one first-conductivity-type semiconductor layer 151, an active layer 152, and at least one second-conductivity-type semiconductor layer 153. The first-conductivity-type semiconductor layer 151 can include an n-type dopant, and the second-conductivity-type semiconductor layer 153 can include a p-type dopant.

[0154] A conductive layer 155c may be formed on the light emitting layer 150a. The conductive layer 155c may be made of a transparent material such as ITO.

[0155] like Figure 12 As shown, a PR pattern (not shown) can be formed on the conductive layer 155c. Using the PR pattern as a mask, an etching process is performed to remove the conductive layer 155c and the light-emitting layer 150a, thereby forming a plurality of unit chips 150a' separated from each other. The number of unit chips 150a' can be formed to the same number as the PR pattern. The etching process is a dry etching process, etching obliquely rather than vertically, thereby forming a plurality of unit chips 150a' having a Mesa structure.

[0156] Although not shown in the drawings, the PR pattern can be omitted and the conductive layer 155c can be used as a mask. Specifically, the conductive layer 155c can be formed into a pattern corresponding to the unit chips 150a', and each pattern of the conductive layer 155c can be used as a mask for the etching process. The etching process removes the light-emitting layer 150a, thereby forming a plurality of separate unit chips 150a'.

[0157] like Figure 13 As shown, the second passivation layer 157-2 and the third passivation layer 157-3 may be formed on the outer edge of the unit chip 150a'. That is, the second passivation layer 157-2 may be formed on the conductive layer 155c, and the third passivation layer 157-3 may be formed on the outer edge of the side of the light emitting layer 150a.

[0158] Afterwards, after the second passivation layer 157 - 2 is removed to expose the conductive layer 155 c , the first connection electrode 155 a may be formed on the second passivation layer 157 - 2 and the third passivation layer 157 - 3 .

[0159] like Figure 14 As shown, the unit chip 150a' can be bonded to the temporary substrate 410 via the adhesion promoting layer 158. In this case, the adhesion promoting layer 158 can function as a bonding layer. To this end, the adhesion promoting layer 158 is made of a material with excellent bonding strength, such as BCB.

[0160] The upper surface of the temporary substrate 410 has a linear plane, so the lower surface of the adhesion promoting layer 158 bonded to the upper surface of the temporary substrate may also have a linear plane.

[0161] like Figure 15 As shown, the growth substrate 400 may be removed through an LLO process.

[0162] Then, an etching process is performed on the non-overlapping region 151b of the first conductive semiconductor layer 151 to remove the first conductive semiconductor layer 151 and the third passivation layer 157-3. By removing the first conductive semiconductor layer 151 and the third passivation layer 157-3, a through hole 420 is formed to expose a portion of the upper surface of the first connection electrode 155a.

[0163] like Figure 16 As shown, a first passivation layer 157-1 can be formed on the exposed first conductive type semiconductor layer 151. Thus, the passivation layer 157 can be composed of the first passivation layer 157-1, the second passivation layer 157-2, and the third passivation layer 157-3. The first passivation layer 157-1 can also be formed on the inner side surface of the through hole 420. By forming the first passivation layer 157-1 on the inner side surface of the through hole 420, the width of the through hole 420 can be reduced.

[0164] like Figure 17 As shown, a second connection electrode 155b may be formed in the through hole 420. The second connection electrode 155b may be connected to the first connection electrode 155a through the through hole 420. The second connection electrode 155b may be formed on the upper surface 150a1 of the first conductive semiconductor layer 151 through the through hole 420. Thus, the first connection electrode 155a and the second connection electrode 155b may constitute the second electrode 155.

[0165] On the other hand, the first electrode 154 can be formed on the non-overlapping region 151b located on the opposite side of the second connection electrode 155b. That is, the first passivation layer 157-1 on the non-overlapping region 151b located on the opposite side of the second connection electrode 155b is removed, thereby forming a through hole. The first electrode 154 can be formed through the through hole. The first electrode 154 can be formed on the first conductive type semiconductor layer 151. The above-mentioned through hole can be formed in Figure 14 The through hole 420 is shown to be formed, but this is not limiting.

[0166] The drawings show an example in which the first electrode 154 and the second electrode 155 are formed separately. However, the first electrode 154 and the second electrode 155 may be formed simultaneously, that is, the second connection electrode 155 b may be formed simultaneously.

[0167] like Figure 18As shown, by removing the temporary substrate 410 , the semiconductor light emitting element 150A can be manufactured.

[0168] Figure 19 is a plan view showing a display device according to a first embodiment.

[0169] like Figure 19 As shown, the display device 301 according to the first embodiment may include a plurality of pixels PX, and the plurality of pixels PX respectively include a plurality of sub-pixels PX1 , PX2 , and PX3 .

[0170] For example, the pixel PX may include a first sub-pixel PX1 , a second sub-pixel PX2 , and a third sub-pixel PX3 , but this is not limited.

[0171] The multiple sub-pixels PX1, PX2, and PX3 may include multiple semiconductor light-emitting elements 150R, 150G, and 150B. For example, the first sub-pixel PX1 may include at least one first semiconductor light-emitting element 150R, which may emit a first color light. For example, the second sub-pixel PX2 may include at least one second semiconductor light-emitting element 150G, which may emit a second color light. For example, the third sub-pixel PX3 may include at least one third semiconductor light-emitting element 150B, which may emit a third color light. For example, the first color light may be red, the second color light may be green, and the third color light may be blue, but this is not limited to this.

[0172] Each of the plurality of sub-pixels may include a pair of electrode wirings 321-1 to 321-3 and 322-1 to 322-3. The pair of electrode wirings 321-1 to 321-3 and 322-1 to 322-3 may be arranged in parallel with each other in a longitudinal direction.

[0173] For example, the first subpixel PX1 may include a pair of electrode wirings 321 - 1 and 322 - 1 , the second subpixel PX2 may include a pair of electrode wirings 321 - 2 and 322 - 2 , and the third subpixel PX3 may include a pair of electrode wirings 321 - 3 and 322 - 3 .

[0174] Specifically, in the first subpixel PX1, a pair of electrode wires 321-1 and 322-1 can be connected to the first electrode 154-1 and the second electrode 155-1 of the first semiconductor light emitting element 150R, respectively. Because the first electrode 154-1 and the second electrode 155-1 are located above the first semiconductor light emitting element 150R, the pair of electrode wires 321-1 and 322-1 can be connected to the first electrode 154-1 and the second electrode 155-1 above the first semiconductor light emitting element 150R. A portion of each of the pair of electrode wires 321-1 and 322-1 extends toward the top of the first semiconductor light emitting element 150R, thereby connecting to the first electrode 154-1 and the second electrode 155-1. A portion of each of the pair of electrode wires 321-1 and 322-1 can vertically overlap the first electrode 154-1 and the second electrode 155-1 above the first semiconductor light emitting element 150R.

[0175] In the second subpixel PX2, a pair of electrode wires 321-2 and 322-2 can be connected to the first electrode 154-2 and the second electrode 155-2 of the second semiconductor light emitting element 150G, respectively. Because the first electrode 154-2 and the second electrode 155-2 are located above the second semiconductor light emitting element 150G, the pair of electrode wires 321-2 and 322-2 can be connected to the first electrode 154-2 and the second electrode 155-2 above the second semiconductor light emitting element 150G. A portion of each of the pair of electrode wires 321-2 and 322-2 extends above the second semiconductor light emitting element 150G, thereby connecting to the first electrode 154-2 and the second electrode 155-2. A portion of each of the pair of electrode wires 321-2 and 322-2 can vertically overlap the first electrode 154-2 and the second electrode 155-2 above the second semiconductor light emitting element 150G.

[0176] In the third subpixel PX3, a pair of electrode wires 321-3 and 322-3 can be connected to the first electrode 154-3 and the second electrode 155-3 of the third semiconductor light emitting element 150B, respectively. The first electrode 154-3 and the second electrode 155-3 are disposed on the upper side of the third semiconductor light emitting element 150B. Therefore, the pair of electrode wires 321-3 and 322-3 can be connected to the first electrode 154-3 and the second electrode 155-3 on the upper side of the third semiconductor light emitting element 150B. A portion of each of the pair of electrode wires 321-3 and 322-3 extends toward the upper side of the third semiconductor light emitting element 150B, thereby being connected to the first electrode 154-3 and the second electrode 155-3. A portion of each of the pair of electrode wires 321-3 and 322-3 can vertically overlap the first electrode 154-3 and the second electrode 155-3 on the upper side of the third semiconductor light emitting element 150B.

[0177] For example, the first electrode 154 wiring 321-1 of the first subpixel PX1, the first electrode 154 wiring 321-2 of the second subpixel PX2, and the first electrode 154 wiring 321-3 of the third subpixel PX3 may be connected to a common wiring. In this case, the same voltage may be applied to the first electrode 154 wiring 321-1 of the first subpixel PX1, the first electrode 154 wiring 321-2 of the second subpixel PX2, and the first electrode 154 wiring 321-3 of the third subpixel PX3 via the common wiring. For example, the first electrode 154 wiring 321-1 of the first subpixel PX1, the first electrode 154 wiring 321-2 of the second subpixel PX2, and the first electrode 154 wiring 321-3 of the third subpixel PX3 may be grounded via the common wiring. For example, a negative (-) voltage may be applied to the first electrode 154 wiring 321-1 of the first subpixel PX1, the first electrode 154 wiring 321-2 of the second subpixel PX2, and the first electrode 154 wiring 321-3 of the third subpixel PX3 through a common wiring.

[0178] Figure 20 It shows Figure 19 The cross-sectional view of the first subpixel PX1 is shown in FIG.

[0179] Reference Figure 20 The first subpixel PX1 of the display device 301 according to the embodiment may include a back panel 300A, a first semiconductor light emitting element 150R, first electrode 154 wirings 321 - 1 to 321 - 3 , and second electrode 155 wirings 322 - 1 to 322 - 3 .

[0180] The backplane 300A may be referred to as a circuit board, a supporting substrate, a lower substrate, etc. A plurality of signal lines may be arranged in the backplane 300A, wherein the plurality of signal lines are electrically connected to the plurality of sub-pixels PX1, PX2, and PX3 included in each of the plurality of pixels PX. Although not shown, each of the plurality of sub-pixels may include a driver for driving the corresponding sub-pixel.

[0181] An adhesive layer 310 may be disposed on the upper side of the backplane 300A. The first semiconductor light-emitting element 150R may be bonded to the adhesive layer 310 on the backplane 300A. After the first semiconductor light-emitting element 150R is placed on the first subpixel PX1 of the backplane 300A, alignment may be performed to ensure accurate positioning of the first subpixel PX1. Subsequently, a pressurizing device such as a die or a hot plate may be used to apply downward pressure to the first semiconductor light-emitting element 150R, thereby bonding the first semiconductor light-emitting element 150R to the adhesive layer 310 on the first subpixel PX1.

[0182] If the adhesive layer 310 is made of a material whose adhesive strength increases with heating, heat can be applied to the first semiconductor light emitting element 150R when the first semiconductor light emitting element 150R is pressed. This heat increases the adhesive strength of the adhesive layer 310, making it easier for the first semiconductor light emitting element 150R to adhere to the first subpixel PX1.

[0183] For example, when the first semiconductor light emitting element 150R is transferred to the back plate 300A using a transfer substrate, the adhesive force of the first semiconductor light emitting element 150R adhering to the adhesive layer 310 on the back plate 300A is greater than the adhesive force of the first semiconductor light emitting element 150R adhering to the transfer substrate. As a result, there is a possibility that the first semiconductor light emitting element 150R on the transfer substrate will separate from the transfer substrate and then adhere to the adhesive layer 310 on the back plate 300A.

[0184] An adhesion-promoting layer 158 may be provided on the lower side of the first semiconductor light-emitting element 150R. The adhesion-promoting layer 158 is a material that can improve adhesion to the adhesive layer 310 and can be formed, for example, from BCB. Therefore, the adhesion-promoting layer 158 of the first semiconductor light-emitting element 150R adheres to the adhesive layer 310 on the backplane 300A, allowing the first semiconductor light-emitting element 150R to be more securely bonded to the backplane 300A. In particular, the lower surface of the adhesion-promoting layer 158, serving as the adhesive surface 158a, has a straight plane, enabling a more secure bond to the adhesive layer 310 on the backplane 300A.

[0185] Although not shown, the adhesive surface 158 a has projections and depressions formed thereon. These projections and depressions allow the first semiconductor light emitting element 150R to be more firmly adhered to the adhesive layer 310 on the back plate 300A.

[0186] On the other hand, although not shown, the adhesive layer 310 may be omitted. In this case, the adhesion promoting layer 158 of the first semiconductor light emitting element 150R can function as the adhesive layer 310. That is, when the first semiconductor light emitting element 150R is pressurized, heat is applied, and the adhesion promoting layer 158 is vitrified. After the adhesion promoting layer 158 is cooled, the first semiconductor light emitting element 150R can be bonded or adhered to the upper surface of the backplane 300A.

[0187] The first electrode 154 wirings 321-1 to 321-3 may be connected to the first electrode 154 on the first region of the upper side of the first semiconductor light emitting element 150R, and the second electrode 155 wirings 322-1 to 322-3 may be connected to the second electrode 155 on the second region of the upper side of the first semiconductor light emitting element 150R. As described above, the first region and the second region may be included in the non-overlapping region 151b surrounding the overlapping region 151a.

[0188] For example, the first electrode 154 may be connected to the first electrode 154 on the upper side of the first semiconductor light emitting element 150R via the first side of the first semiconductor light emitting element 150R on the upper side of the back plate 300A. For example, the second electrode 155 may be connected to the second electrode 155 on the upper side of the first semiconductor light emitting element 150R via the first side of the first semiconductor light emitting element 150R on the upper side of the back plate 300A. The second side is the opposite side of the first side, and the first side and the second side may face each other.

[0189] [Second embodiment]

[0190] Figure 21 is a plan view showing a semiconductor light emitting element according to a second embodiment. Figure 22 yes Figure 21 FIG. 1 shows a cross-sectional view taken along line D1 - D2 of the semiconductor light emitting element according to the second embodiment.

[0191] Except for the configuration structure of the second electrode 155, the second embodiment is similar to the first embodiment ( Figure 7 as well as Figure 8 In the second embodiment, the same reference numerals are given to the constituent elements having the same structure, shape and / or function as those in the first embodiment, and detailed description thereof is omitted.

[0192] Reference Figure 21 as well as Figure 22 The semiconductor light emitting element 150B according to the second embodiment may include a light emitting layer 150 a , a passivation layer 157 , a first electrode 154 , a second electrode 155 , and an adhesion promoting layer 158 .

[0193] The light emitting layer 150a is a component that generates light, and can generate red light, green light, blue light, or light of other colors.

[0194] In an embodiment, the passivation layer 157 may surround the light emitting layer 150a. For example, the passivation layer 157 may be disposed on the upper surface 150a1, the lower surface 150a2, and the side surface 150a3 of the light emitting layer 150a. The passivation layer 157 may be disposed along the outer edge of the side surface 150a3 of the light emitting layer 150a.

[0195] The first electrode 154 can be connected to the first conductive semiconductor layer 151 of the light-emitting layer 150a, and the second electrode 155 can be connected to the second conductive semiconductor layer 153 of the light-emitting layer 150a. To this end, the first electrode 154 can be disposed on the first conductive semiconductor layer 151, and the second electrode 155 can be disposed below the second conductive semiconductor layer 153. The first electrode 154 can be disposed on the upper surface 150a1 of the first conductive semiconductor layer 151, which corresponds to the first region of the non-overlapping region 151b. The first electrode 154 can be in contact with the upper surface 150a1 of the first conductive semiconductor layer 151 via a first passivation layer 157-1, which serves as a passivation layer 157. The second electrode 155 can be in contact with the lower surface of the conductive layer 155c via a second passivation layer 157-2, which serves as a passivation layer 157.

[0196] On the other hand, compared with the first embodiment ( Figure 7 as well as Figure 8 ), in the second embodiment, the second electrode 155 is not disposed on the non-overlapping region 151b. That is, in the first embodiment, the second connecting electrode 155b of the second electrode 155 is disposed on the non-overlapping region 151b through the through hole 420 of the first conductive type semiconductor layer 151. In contrast, in the second embodiment, the second connecting electrode 155b of the second electrode 155 can be omitted.

[0197] Therefore, in the second embodiment, only the first connection electrode 155a of the second electrode 155 can be arranged along the surface of the second passivation layer 157-2 and the third passivation layer 157-3, which serve as the passivation layer 157. In this case, a portion of the connection electrode can be exposed to the outside. In other words, the side surface of the first electrode 154 and the side surface of the adhesion promoting layer 158 are located on the same vertical line 172, so that the side surface of the first electrode 154 can be exposed to the outside.

[0198] To summarize, in the second embodiment, the first electrode 154 can be disposed on the upper surface 150a1 of the first conductive semiconductor layer 151 of the light-emitting layer 150a, which corresponds to the non-overlapping region 151b, and the second electrode 155 can be disposed below the first conductive semiconductor layer 151 of the light-emitting layer 150a. In this case, the first electrode 154 can be exposed to the outside on the upper side of the light-emitting layer 150a, and the second electrode 155 can be exposed to the outside on the side of the light-emitting layer 150a.

[0199] Figure 23 The figure shows a cross-sectional view of a first subpixel of a display device including a semiconductor light emitting element according to the second embodiment. The figure shows a cross-sectional view of the first subpixel PX1, and the cross-sectional view of the second subpixel PX2 or the third subpixel PX3 is the same as that of the first subpixel PX1.

[0200] Reference Figure 23 The first subpixel PX1 of the display device 301 according to the embodiment may include a back panel 300A, a first semiconductor light emitting element 150R, first electrode 154 wirings 321 - 1 to 321 - 3 , and second electrode 155 wirings 322 - 1 to 322 - 3 .

[0201] The structure of each of the back plate 300A and the first electrode 154 wiring 321-1 to 321-3 is the same as Figure 20 The illustrated back plate 300A and each of the first electrode 154 wirings 321 - 1 to 321 - 3 have the same structure, so detailed description is omitted.

[0202] The first semiconductor light emitting element 150R may be the semiconductor light emitting element according to the second embodiment ( Figure 21 as well as Figure 22 150B).

[0203] On the other hand, the second electrode 155 wiring 322-1 to 322-3 can be connected to the second electrode 155 exposed from the side of the light-emitting layer 150a. The second electrode 155 wiring 322-1 to 322-3 can be arranged on the upper surface of the backplane 300A and can be arranged on the side of the first semiconductor light-emitting element 150R. As described above, the second electrode 155 can be connected to the second conductive type semiconductor layer 153 of the light-emitting layer 150a and extend along the surface of each of the second passivation layer 157-2 and the third passivation layer 157-3 to be exposed to the outside. The exposed second electrode 155 can be connected to the second electrode 155 wiring 322-1 to 322-3. The second electrode 155 wiring 322-1 to 322-3 can be in contact with the side surface of the second electrode 155.

[0204] Although not shown, the second electrode 155 wirings 322 - 1 to 322 - 3 may be arranged on the upper side of the first semiconductor light emitting element 150R, ie, on the non-overlapping region 151 b of the first conductive type semiconductor layer 151 , via the side of the first semiconductor light emitting element 150R.

[0205] In this way, the second electrode 155 will not be configured on the non-overlapping area 151a of the first conductive semiconductor layer 151 through the through hole 420 of the first conductive semiconductor layer 151, so the through hole 420 or the second electrode 155 configured in the through hole 420 is prevented from obstructing light, thereby improving light efficiency and increasing light brightness.

[0206] [Third embodiment]

[0207] Figure 24 is a cross-sectional view showing a semiconductor light emitting element according to a third embodiment.

[0208] The third embodiment is identical to the first embodiment, except that the side surface 150a3 of the light-emitting layer 150a has polygonal slopes with different obtuse angles, and the second electrode 155 is disposed on the lower side and side of the light-emitting layer 150a. The third embodiment is also applicable to the second embodiment. In the third embodiment, components having the same structure, shape, and / or function as the first embodiment are denoted by the same reference numerals, and detailed descriptions are omitted.

[0209] Reference Figure 24 The semiconductor light emitting element 150C according to the third embodiment may include a light emitting layer 150 a , a passivation layer 157 , a first electrode 154 , a second electrode 155 , and an adhesion promoting layer 158 .

[0210] exist Figure 24 For ease of explanation, the example in which the side surface 150a3 of the light-emitting layer 150a has a single obtuse-angled slope is shown. However, the side surface 150a3 of the light-emitting layer 150a may have multiple obtuse-angled slopes. Alternatively, the side surface 150a3 of the light-emitting layer 150a may have multiple obtuse-angled slopes with at least one obtuse angle and at least one acute angle positioned in parallel or alternately. The obtuse angle or acute angle may refer to an angle in the internal angle θ1 between the side surface 150a3 of the light-emitting layer 150a and the lower surface 150a2.

[0211] The side surface 150a3 of the light emitting layer 150a has a polygonal slope, thereby increasing the amount of light emitted forward, thereby increasing the brightness.

[0212] The light emitting layer 150a may include at least one first conductive semiconductor layer 151, an active layer 152, and at least one second conductive semiconductor layer 153. The first conductive semiconductor layer 151 may include an n-type dopant, and the second conductive semiconductor layer 153 may include a p-type dopant.

[0213] The side surface 150a3 of the first conductive semiconductor layer 151 can include a vertical surface 151-1 where the light-emitting layer 150a contacts the upper surface 150a1, a horizontal surface 151-2 contacting the vertical surface 151-1, and an inclined surface 151-3 contacting the horizontal surface 151-2. The vertical surface 151-1 can be the outer side surface of the non-overlapping region 151b of the first conductive semiconductor layer 151. The horizontal surface 151-2 and the inclined surface 151-3 can be the lower surface of the first conductive semiconductor layer 151. Specifically, during the manufacturing process, when a portion of the first conductive semiconductor layer 151 is etched through a Mesa etching process, the Mesa-etched surface can be used. Thus, the Mesa-etched surfaces, namely the horizontal surface 151-2 and the inclined surface 151-3, can form a recess 160.

[0214] On the other hand, the inclined surface 151-3 may have a critical angle θc of total reflection condition for the active layer 152. The total reflection condition refers to a condition in which when the incident angle of light from a medium with a high refractive index to a medium with a low refractive index is greater than the critical angle θc, the corresponding light is completely reflected without being refracted.

[0215] The first conductive semiconductor layer 151 and the third passivation layer 157-3 meet at the inclined surface 151-3. The refractive index of GaN in the first conductive semiconductor layer 151 is approximately 2.38, while the refractive index of SiO2 in the third passivation layer 157-3 is approximately 1.965. Therefore, light enters the third passivation layer 157-3, which has a lower refractive index, from the first conductive semiconductor layer 151, which has a higher refractive index. This satisfies the total internal reflection condition. In this case, the critical angle θc can be the minimum angle of incidence at which total internal reflection occurs. The angle of refraction varies depending on the angle of incidence of light on the boundary surface, i.e., the inclined surface 151-3. For example, the greater the angle of incidence, the closer the refraction angle is likely to be to 90°. In this case, the critical angle θc can be set to the angle of incidence at which the refraction angle is 90°.

[0216] The incident angle can be set based on the boundary surface, i.e., the normal 171 of the inclined surface 151-3. Therefore, when light enters the inclined surface 151-3 at an incident angle greater than the critical angle θc, the corresponding light is not refracted by the third passivation layer 157-3 and is totally reflected by the inclined surface 151-3, thereby traveling toward the first conductive type semiconductor layer 151. Therefore, when the internal angle θ1 between the inclined surface 151-3 and the surface of the active layer 152 is obtuse, so that the inclined surface 151-3 has the critical angle θc, the light incident on the inclined surface 151-3 from the surface of the active layer 152 is totally reflected and is more directly reflected than the side light, thereby significantly improving the light efficiency and brightness, thereby achieving a high-brightness display.

[0217] The inclined surface 151-3 may have an obtuse angle with respect to the surface of the active layer 152. The angle between the normal line 171 and the active layer 152 may have a critical angle θc. The angle between the inclined surface 151-3 and the vertical line 172 may have the same angle as the critical angle θc.

[0218] On the other hand, the side surface 150a3 of the active layer 152 may have an inclined surface connected to the inclined surface of the first conductive semiconductor layer 151, and the side surface 150a3 of the second conductive semiconductor layer 153 may have a vertical surface connected to the inclined surface of the active layer 152, but this is not limited.

[0219] On the other hand, the second electrode 155 may be disposed on the lower side and the side of the light emitting layer 150 a .

[0220] In the first embodiment ( Figure 7 as well as Figure 8 ) is configured on a portion of the lower side and a portion of the side of the light-emitting layer 150a. In contrast, in the second embodiment, it can be configured on both the lower side and the side of the light-emitting layer 150a.

[0221] The second electrode 155 may include a first connection electrode 155 a and a second connection electrode 155 b .

[0222] The first connection electrode 155a may be disposed under the entire lower surface 150a2 of the second conductive semiconductor layer 153. In this case, the first connection electrode 155a may be connected to a portion of the lower surface of the conductive layer 155c through the second passivation layer 157-2.

[0223] On the other hand, the first connection electrode 155a can be disposed on a side portion of the light-emitting layer 150a. The first connection electrode 155a can be disposed along the outer edge of the side portion of the light-emitting layer 150a. The first connection electrode 155a can be in contact with the lower surface of the conductive layer 155c on the lower side of the light-emitting layer 150a and can extend along the surface of the third passivation layer 157-3. A portion of the first connection electrode 155a, namely the side surface, can be exposed to the outside. In other words, the side surface of the first connection electrode 155a and the side surface of the adhesion-promoting layer 158 can be located on the same vertical line 172. Therefore, the side surface of the first connection electrode 155a is not obstructed by the adhesion-promoting layer 158 and can be exposed to the outside.

[0224] Although not shown, the side surface of the first connection electrode 155a is not located on the same vertical line 172 as the side surface of the adhesion-promoting layer 158, thereby preventing the side surface of the first connection electrode 155a from being exposed to the outside. By positioning the side surface of the first connection electrode 155a a predetermined distance inward from the end of the non-overlapping region 151b of the first conductive semiconductor layer 151, the side surface of the first connection electrode 155a can be covered by the adhesion-promoting layer 158. Thus, the side surface of the first connection electrode 155a is covered by the adhesion-promoting layer 158 and is not exposed to the outside.

[0225] The second connection electrode 155 b may be disposed on the non-overlapping region 151 b of the first conductive semiconductor layer 151 through the through hole 420 formed in the first conductive semiconductor layer 151 .

[0226] Therefore, the second electrode 155 is disposed on the lower side and all sides of the light-emitting layer 150a. The second electrode 155 includes a reflective layer, so light traveling laterally from the active layer 152 can be totally reflected by the polygonal oblique surfaces having a critical angle θc. The angle of incidence from the active layer 152 to the oblique surface 151-3 of the first conductive semiconductor layer 151 is less than the critical angle θc, so that light traveling toward the third passivation layer 157-3 can be reflected by the second electrode 155. Furthermore, light traveling downward from the active layer 152 can be reflected by the second electrode 155 and emitted forward. As a result, more light is concentrated and emitted forward through the forward beam, significantly improving light efficiency and significantly increasing brightness.

[0227] Figures 25 to 33 FIG. 2 shows a manufacturing process of a semiconductor light emitting element according to the third embodiment. Figures 25 to 33 Unlabeled reference numerals in the figure may be the same reference numerals as those labeled for the same constituent elements in the previous drawings.

[0228] Figure 25 as well as Figure 26 and Figure 11 as well as Figure 12 The details are similar, so the detailed description is omitted.

[0229] like Figure 27 As shown, a secondary etching process is performed using the PR pattern as a mask to remove the light-emitting layer 150a, so that the side surface of the light-emitting layer 150a has multiple inclined surfaces with different obtuse angles θ1. The obtuse angle θ1 can be an angle in the internal angle between the inclined surface and the surface of the active layer 152. At this time, at least one inclined surface 151-3 of the polygonal inclined surfaces can be inclined to a critical angle θc.

[0230] like Figure 28 As shown, a second passivation layer 157 - 2 and a third passivation layer 157 - 3 may be formed on the outer edge of the unit chip 150 a ′.

[0231] After removing the second passivation layer 157-2 to expose a portion of the conductive layer 155c, the first connection electrode 155a can be disposed on the light-emitting layer 150a. The first connection electrode 155a can be connected to the upper surface of the conductive layer 155c of the light-emitting layer 150a through the second passivation layer 157-2 and can extend along the surface of each of the second passivation layer 157-2 and the third passivation layer 157-3. In this case, the side surface of one side of the first connection electrode 155a is located on the same vertical line 172 as the side surface 150a3 of the first conductive semiconductor layer 151, but the side surface of the other side of the first connection electrode 155a is not located on the same vertical line 172 as the side surface 150a3 of the first conductive semiconductor layer 151. In other words, the side surface of the other side of the first connection electrode 155a can be located a predetermined distance inward from the side surface 150a3 of the first conductive semiconductor layer 151. This is to prevent an electrical short circuit from occurring when electrical wiring, ie, electrode wiring, is connected to the back plate 300A later in order to manufacture a display device.

[0232] like Figure 29 As shown, an adhesion promoting layer 158 can be formed on the first connection electrode 155a, and the unit chip 150a' is bonded to the temporary substrate 410 via the adhesion promoting layer 158. In this case, the adhesion promoting layer 158 can function as a bonding layer. While the temporary substrate 410 is placed on the adhesion promoting layer 158, heat is applied to vitrify the adhesion promoting layer 158, and then the adhesion promoting layer 158 is cooled, so that the adhesion promoting layer 158 can be bonded to the temporary substrate 410.

[0233] The upper surface of the temporary substrate 410 has a linear plane, so the lower surface of the adhesion promoting layer 158 bonded to the upper surface of the temporary substrate may also have a linear plane.

[0234] Thereafter, the growth substrate 400 or the temporary substrate 410 may be rotated 180°.

[0235] Figures 30 to 33 and Figures 15 to 18 Similar, so detailed description is omitted.

[0236] Figure 34 is a cross-sectional view showing a first sub-pixel of a display device including the semiconductor light emitting element according to the third embodiment.

[0237] Reference Figure 34 The first subpixel PX1 of the display device 301 according to the embodiment may include a back panel 300A, a first semiconductor light emitting element 150R, first electrode 154 wirings 321 - 1 to 321 - 3 , and second electrode 155 wirings 322 - 1 to 322 - 3 .

[0238] The structure of each of the back plate 300A, the first electrode 154 wiring 321-1 to 321-3 and the second electrode 155 wiring 322-1 to 322-3 is the same as that of the back plate 300A. Figure 20 The illustrated backplane 300A, the first electrode 154 wirings 321 - 1 to 321 - 3 , and the second electrode 155 wirings 322 - 1 to 322 - 3 each have the same structure, so detailed description is omitted.

[0239] The first semiconductor light emitting element 150R may be the semiconductor light emitting element according to the third embodiment ( Figure 24 of 150C).

[0240] As described above, in the first semiconductor light-emitting element 150R according to the third embodiment, the second electrode 155 is disposed on the lower side and all sides of the light-emitting layer 150a. The second electrode 155 includes a reflective layer, so light traveling laterally from the active layer 152 can be configured to be totally reflected by a polygonal oblique surface having a critical angle θc. The angle of incidence from the active layer 152 onto the oblique surface of the first conductive semiconductor layer 151 is less than the critical angle θc, so that light traveling toward the third passivation layer 157-3 can be reflected by the second electrode 155. Furthermore, light traveling downward from the active layer 152 is reflected by the second electrode 155 and can be emitted forward. As a result, more light is concentrated and emitted forward by forward light, significantly improving light efficiency and significantly increasing brightness.

[0241] According to the embodiment, the structure of the first semiconductor light-emitting element 150R is modified to focus light forward rather than side-lighting, thereby improving light efficiency and brightness. Therefore, there is no need to provide a separate reflector on the back panel 300A, thus saving costs. Furthermore, the need to provide a reflector on the back panel 300A is eliminated, which can prevent the thickness of the display device 301 from increasing.

[0242] [Fourth embodiment]

[0243] Figure 35is a cross-sectional view showing a semiconductor light emitting element according to a fourth embodiment.

[0244] The fourth embodiment is similar to the third embodiment ( Figure 24 ). In the fourth embodiment, the same reference numerals are added to the constituent elements having the same structure, shape, and / or function as the third embodiment, and detailed descriptions are omitted. The fourth embodiment can also be applied to the first embodiment or the second embodiment.

[0245] Reference Figure 35 , the semiconductor light emitting element 150D according to the fourth embodiment may include a light emitting element The light emitting layer 150 a , the passivation layer 157 , the first electrode 154 , the second electrode 155 and the adhesion promoting layer 158 .

[0246] The light emitting layer 150 a , the passivation layer 157 , the first electrode 154 , and the adhesion promoting layer 158 have been described in detail above, and thus detailed description thereof will be omitted.

[0247] The second electrode 155 may include a first connection electrode 155 a and a second connection electrode 155 b .

[0248] The first connection electrode 155a can extend from the lower surface 150a2 of the second conductive semiconductor layer 153 of the light emitting layer 150a along the surface of each of the second passivation layer 157-2 and the third passivation layer 157-3. The second connection electrode 155b can be disposed on the non-overlapping region 151b of the first conductive semiconductor layer 151 through the through hole 420 formed in the first conductive semiconductor layer 151 of the light emitting layer 150a.

[0249] The first connection electrode 155a can be connected to the entire area of the lower surface 150a2 of the second conductive semiconductor layer 153. Specifically, the first connection electrode 155a is in contact with the entire area of the lower surface of the conductive layer 155c, thereby being connected to the entire area of the lower surface 150a2 of the second conductive semiconductor layer 153. The size of the conductive layer 155c can correspond to the size of the second conductive semiconductor layer 153. The size of the conductive layer 155c can be the same as the size of the second conductive semiconductor layer 153, but this is not limited to this. To this end, after removing the second passivation layer 157-2 corresponding to the second conductive semiconductor layer 153 to expose the entire area of the lower surface of the conductive layer 155c, the entire area of the exposed lower surface of the conductive layer 155c can be connected to the entire area of the first connection electrode 155a.

[0250] The first connection electrode 155 a is connected to the entire lower surface 150 a 2 of the second conductive semiconductor layer 153 , thereby improving electrical and optical characteristics.

[0251] On the other hand, when the first connection electrode 155a is connected to the entire area of the lower surface 150a2 of the second conductive semiconductor layer 153, the conductive layer 155c can be omitted. In this case, the first connection electrode 155a can be in contact with the entire area of the lower surface 150a2 of the second conductive semiconductor layer 153.

[0252] On the other hand, the display device described above may be a display panel. That is, in the embodiment, the display device and the display panel may be understood as having the same meaning. In the embodiment, the display device in the substantive sense may include a display panel and a controller (or processor) that controls the display panel to display an image.

[0253] The above detailed description should not be interpreted as limiting in all aspects and should be regarded as illustrative. The scope of the embodiments should be determined based on the reasonable interpretation of the claims, and all changes within the scope of equivalence of the embodiments are included within the scope of the embodiments.

[0254] Industrial applicability

[0255] The embodiments can be applied to the field of displays that display images or information. The embodiments can be applied to the field of displays that display images or information using semiconductor light-emitting elements. The semiconductor light-emitting elements can be micro-scale semiconductor light-emitting elements or nano-scale semiconductor light-emitting elements.

[0256] For example, the embodiments can be used in TVs, signs, mobile terminals such as mobile phones or smart phones, computer displays such as laptops or desktops, HUDs (head-up displays) for cars, backlight units for displays, displays and light sources for XR (Extended Reality) such as AR, VR, and MR (mixed reality).

Claims

1. A semiconductor light emitting element, comprising: a luminescent layer; a passivation layer surrounding the light-emitting layer; a first electrode on the light-emitting layer; a second electrode below the light-emitting layer; as well as The adhesion promoting layer below the light emitting layer, The inner angle between the side surface of the light-emitting layer and the lower surface is an obtuse angle. The light-emitting layer includes: active layer; a first conductive type semiconductor layer on the active layer; and The second conductive type semiconductor layer below the active layer, The size of the adhesion promoting layer corresponds to the size of the first conductive type semiconductor layer, and the adhesion promoting layer surrounds the side of the second conductive type semiconductor layer. The first conductive type semiconductor layer includes: an overlapping region vertically overlapping each of the active layer and the second conductive type semiconductor layer; and a non-overlapping region that does not vertically overlap with the active layer and the second conductive type semiconductor layer, and surrounds the overlapping region; The first electrode is disposed on an upper surface of the non-overlapping region on a first side of the overlapping region.

2. The semiconductor light emitting element according to claim 1, wherein The side surface of the light emitting layer has polygonal slopes having different obtuse angles.

3. The semiconductor light emitting element according to claim 2, wherein The side surface of the first conductive type semiconductor layer has a vertical surface connected to the upper surface of the light emitting layer, a horizontal surface connected to the vertical surface, and an inclined surface connected to the horizontal surface. The vertical surface is the outer side surface of the non-overlapping area.

4. The semiconductor light emitting element according to claim 3, wherein The inclined surface has a critical angle that constitutes a total reflection condition relative to the surface of the active layer. The semiconductor light emitting element according to claim 3 , wherein: The side surface of the active layer has an inclined surface connected to the inclined surface of the first conductive type semiconductor layer. A side surface of the second conductive type semiconductor layer has a vertical surface in contact with the inclined surface of the active layer. The semiconductor light emitting element according to claim 1 , wherein: The light emitting layer has a depression below the non-overlapping region. The adhesion promoting layer comprises: A first adhesion promoting layer is disposed in the depression; and The second adhesion promoting layer is disposed below the second electrode.

7. The semiconductor light emitting element according to claim 6, wherein The lower surface of the first adhesion promoting layer and the lower surface of the second adhesion promoting layer are located on the same horizontal line.

8. The semiconductor light emitting element according to claim 1, wherein The passivation layer includes: a first passivation layer on the upper surface of the light-emitting layer; a second passivation layer on the lower surface of the light-emitting layer; and a third passivation layer surrounding the side surface of the light emitting layer; 9. The semiconductor light emitting element according to claim 8, wherein The first electrode is in contact with the upper surface of the first conductive type semiconductor layer through the first passivation layer. The second electrode is in contact with the lower surface of the second conductive type semiconductor layer through the second passivation layer.

10. The semiconductor light emitting element according to claim 9, wherein The second electrode comprises: A first connecting electrode extends from a lower surface of the second conductive type semiconductor layer along a surface of each of the second passivation layer and the third passivation layer. The semiconductor light emitting element according to claim 10 , wherein: The second electrode comprises: The second connection electrode is arranged on the upper surface of the non-overlapping region on a second side, the second side being an opposite side to the first side of the overlapping region.

12. The semiconductor light emitting element according to claim 11, wherein The second connection electrode extends from the first connection electrode through the first conductive type semiconductor layer to the upper surface of the non-overlapping region.

13. The semiconductor light emitting element according to claim 1, wherein The second electrode includes a reflective metal layer.

14. A display device comprising: Back panel; The semiconductor light emitting element according to claim 1 on the back plate; a first electrode wiring connected to the first electrode of the semiconductor light emitting element; as well as A second electrode wiring is connected to the second electrode of the semiconductor light emitting element.

15. The display device according to claim 14, wherein The adhesion promoting layer of the semiconductor light emitting element is adhered to the adhesive layer on the back plate.

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