Light emitting element and display device using the same

Abstract

This invention is applicable to the technical field related to display devices, such as light-emitting elements (LEDs) and display devices utilizing such light-emitting elements. The invention includes: a support structure; a semiconductor structure disposed on the support structure, comprising: a first conductive semiconductor layer; a light-emitting layer disposed on the first conductive semiconductor layer; and a second conductive semiconductor layer disposed on the light-emitting layer and including an enlarged region larger than the area of ​​the light-emitting layer, the enlarged region including a first surface and a second surface defining the light-emitting surface, wherein the second surface is the opposite surface of the first surface; a first electrode disposed on the first conductive semiconductor layer; a reflective electrode contacting the first electrode and having an extended region including a first contact portion; a second electrode contacting the second surface and having a second contact portion; and a passivation layer including the region between the reflective electrode and the second electrode and disposed on at least one surface of the semiconductor structure.

Description

Technical Field

[0001] This invention is applicable to the technical field related to display devices, such as to light-emitting elements like LEDs (Light Emitting Diodes) and display devices utilizing such light-emitting elements. Background Technology

[0002] In recent years, display devices with excellent characteristics such as thinness and flexibility have been developed in the field of display technology. As the main displays that have been commercialized, the representative ones are LCD (Liquid Crystal Display) and OLED (Organic Light Emitting Diodes).

[0003] On the other hand, light-emitting diodes (LEDs), as well-known semiconductor light-emitting elements that convert electric current into light, have been used as light sources for displaying images in electronic devices, such as information and communication equipment, since the commercialization of red LEDs using GaAsP compound semiconductors in 1962, together with green LEDs of the GaP:N series.

[0004] In recent years, such light-emitting diodes (LEDs) have been gradually miniaturized and manufactured into micron-sized LEDs, which are used as pixels in display devices.

[0005] Compared to other display elements / panels, this LED technology features low power consumption, high brightness, and high reliability, and is also applicable to flexible components. Therefore, it has been actively researched by research institutions and companies in recent years.

[0006] Typically, the excellent luminous efficiency of the LED chip itself helps ensure the brightness of a display that uses small light-emitting elements, such as a micro LED used as a subpixel.

[0007] As the size of the components decreases, the area ratio of the sidewalls relative to the active area increases, resulting in greater current leakage and a decrease in luminous efficiency. Therefore, it may be difficult to achieve high brightness when using light-emitting components in displays.

[0008] Even when methods are used to improve light efficiency by creating roughness in the component itself, further methods to improve light efficiency are still needed in displays where front brightness is crucial because more light leaks to the bottom and sides of the component.

[0009] In addition, since the semiconductor thin film materials that make up the red, green and blue light-emitting elements are different from each other, the light emission distribution is different depending on the viewing angle, which can cause the problem of different colors being seen from different viewing angles in a display.

[0010] On the other hand, there is a problem with using flip-chip structures in displays where wiring is connected to the top of components. When connecting the bottom wiring using a flip-chip structure, bonding is required using solder material. During bonding, solder spreading can cause defects due to short circuits between the two electrodes of the component. Therefore, when configuring a flip-chip structure in a display, a minimum distance between the two electrodes must be ensured, which may make it difficult to reduce component size.

[0011] Therefore, a solution is needed to address such problems. Summary of the Invention

[0012] Technical issues

[0013] The technical problem to be solved by the present invention is to provide a light-emitting element that can concentrate light emitted towards the lower part of the light-emitting element onto the front of the light-emitting element to obtain a high-brightness light-emitting element and a display, and a display device using the light-emitting element.

[0014] In addition, a light-emitting element that can reduce the brightness deviation of the light-emitting element from different viewing angles is provided, and a display device utilizing the light-emitting element is also provided.

[0015] In addition, a light-emitting element that can reduce the color viewing angle deviation of different colors, thereby obtaining a high-definition display, and a display device utilizing the light-emitting element are provided.

[0016] On the other hand, a light-emitting element and a display device utilizing the light-emitting element are provided, which can prevent cracks from occurring in the thin portion of the light-emitting element due to pressure applied to the light-emitting element during the process of transferring the light-emitting element to the wiring substrate.

[0017] In addition, a light-emitting element that is easy to mount on a wiring substrate and electrically connected to wiring on the upper part of the wiring substrate is provided, as well as a display device using the light-emitting element.

[0018] On the other hand, a light-emitting element that can achieve ohmic contact at room temperature and low temperature through a first contact portion and a second contact portion is provided, and a display device utilizing the light-emitting element is provided.

[0019] Furthermore, according to another embodiment of the present invention, those skilled in the art will understand from the gist of the specification and drawings that there may be other technical issues not mentioned herein.

[0020] Methods for solving problems

[0021] As a first perspective for addressing the aforementioned technical problem, the present invention includes: a support structure; a semiconductor structure disposed on the support structure, comprising: a first conductive semiconductor layer; a light-emitting layer disposed on the first conductive semiconductor layer; and a second conductive semiconductor layer disposed on the light-emitting layer and including an enlarged region larger than the area of ​​the light-emitting layer, the enlarged region including a first surface defining a light-emitting surface and a second surface being the opposite surface of the first surface; a first electrode disposed on the first conductive semiconductor layer; a reflective electrode in contact with the first electrode and having an extended region including a first contact portion; a second electrode in contact with the second surface and having a second contact portion; and a passivation layer including a region between the reflective electrode and the second electrode and disposed on at least one surface of the semiconductor structure.

[0022] As an illustrative embodiment, the first surface may be the surface on the growth substrate side of the semiconductor structure.

[0023] As an exemplary embodiment, the above semiconductor structure includes a nitride series semiconductor layer, and the second surface may be a gallium surface (Ga-face).

[0024] As an illustrative embodiment, the semiconductor structure described above may have an inverted mesa shape.

[0025] As an illustrative embodiment, the reflective electrode described above may cover at least a portion of the aforementioned mesa shape.

[0026] As an exemplary embodiment, the above-mentioned support structure may include: a light-transmitting support layer; and an adhesive layer disposed between the support layer and the reflective electrode.

[0027] As an illustrative embodiment, the adhesive layer described above may include a reworkable adhesive layer.

[0028] As an exemplary embodiment, the first contact portion and the second contact portion may face the light-emitting surface.

[0029] As an exemplary embodiment, the first contact portion may be disposed on the opposite side of the second contact portion relative to the light-emitting surface.

[0030] As an exemplary embodiment, the passivation layer can electrically isolate the first contact portion and the second contact portion.

[0031] As an illustrative embodiment, the first contact portion and the second contact portion described above may be exposed on the surface opposite to the support structure described above.

[0032] As a second perspective for addressing the aforementioned technical problem, the present invention includes: a support structure; a first conductive semiconductor layer disposed on the support structure; a light-emitting layer disposed on the first conductive semiconductor layer; a second conductive semiconductor layer disposed on the light-emitting layer and including an enlarged region larger than the area of ​​the light-emitting layer, the enlarged region having a first surface defining a first polarity of the light-emitting surface and a second surface being the opposite surface of the first surface with a second polarity; a first electrode disposed on the first conductive semiconductor layer; a reflective electrode in contact with the first electrode and having an extended region including a first contact portion; a second electrode in contact with the second surface and having a second contact portion; and a passivation layer disposed at least on a side surface of the light-emitting layer.

[0033] As an illustrative embodiment, the first polarity and the second polarity described above are polarities generated along the characteristics of the semiconductor growth surface.

[0034] As an exemplary embodiment, the second conductive semiconductor layer includes a nitride series semiconductor layer, and the second surface may be a gallium surface (Ga-face).

[0035] As an exemplary embodiment, the first surface may be the surface of the growth substrate on which the second conductive semiconductor layer is grown.

[0036] As an exemplary embodiment, at least a portion of the first conductive semiconductor layer, the light-emitting layer, and the second conductive semiconductor layer may have an inverted mesa shape.

[0037] As a third perspective for addressing the aforementioned technical problem, the present invention includes: light-emitting elements arranged on a wiring substrate to define individual pixels; and a molding layer disposed on the light-emitting elements, wherein the light-emitting elements include: a support structure; a semiconductor structure disposed on the support structure and including: a first conductive semiconductor layer; a light-emitting layer disposed on the first conductive semiconductor layer; and a second conductive semiconductor layer disposed on the light-emitting layer and including an enlarged region larger than the area of ​​the light-emitting layer, the enlarged region including a first surface defining a light-emitting surface and a second surface being the opposite surface of the first surface; a first electrode disposed on the first conductive semiconductor layer; a reflective electrode contacting the first electrode and having an extended region, the extended region including a first contact portion facing the first surface; a second electrode contacting the second surface and having a second contact portion facing the first surface; and a passivation layer including a region between the reflective electrode and the second electrode and disposed on at least one surface of the semiconductor structure.

[0038] As an exemplary embodiment, it may further include: a first wiring connected to the first contact portion on the wiring substrate; and a second wiring connected to the second contact portion on the wiring substrate.

[0039] As an exemplary embodiment, the support structure may include an adhesive layer disposed between the upper surface of the wiring substrate and the reflective electrode.

[0040] As an exemplary embodiment, the passivation layer can electrically isolate the first contact portion and the second contact portion.

[0041] As an illustrative embodiment, the first contact portion and the second contact portion described above may be exposed on the surface opposite to the support structure described above.

[0042] Invention Effects

[0043] First, according to one embodiment of the present invention, light emitted downwards can be focused onto the front of the light-emitting element through a platform structure and a reflective electrode structure, thereby obtaining a high-brightness light-emitting element and a display.

[0044] Furthermore, by using reflective electrodes located on the obtuse-angled, inclined portion of the platform and the upper light extraction structure, brightness deviations at different viewing angles can be reduced. Additionally, color viewing angle deviations for different colors can be reduced, thereby achieving a high-definition display.

[0045] On the other hand, during the process of transferring the light-emitting element to the wiring substrate, it is possible to prevent cracks from occurring in the thin parts of the light-emitting element due to the pressure applied to it.

[0046] In addition, it has a flip-chip shape overall, but the first contact portion and the second contact portion extend to the left and right, which facilitates the mounting of the light-emitting element on the wiring substrate and the electrical connection with the wiring on the upper part of the wiring substrate.

[0047] On the other hand, ohmic contact can be achieved at both room temperature and low temperature through the first and second contact portions. This prevents damage to the heat-sensitive support layer.

[0048] Furthermore, according to yet another embodiment of the present invention, additional technical effects not mentioned herein may also be achieved. Those skilled in the art will understand these other effects from the gist of the specification and drawings. Attached Figure Description

[0049] Figure 1 This is a top view showing a light-emitting element according to an embodiment of the present invention.

[0050] Figure 2This is a cross-sectional view showing a light-emitting element according to an embodiment of the present invention.

[0051] Figure 3 This is a cross-sectional view showing an example of using a light-emitting element of one embodiment of the present invention as a pixel in a display device.

[0052] Figures 4 to 15 This is a cross-sectional view illustrating the manufacturing process of a light-emitting element according to an embodiment of the present invention.

[0053] Figures 16 to 21 This is a cross-sectional view illustrating the process of manufacturing a display device using a light-emitting element according to an embodiment of the present invention.

[0054] Figure 22 This is a cross-sectional view of a unit pixel of a display device using a light-emitting element according to an embodiment of the present invention.

[0055] Figure 23 This is a top view of a unit pixel of a display device using a light-emitting element according to an embodiment of the present invention. Detailed Implementation

[0056] The embodiments disclosed in this specification will now be described in detail with reference to the accompanying drawings. Regardless of the drawing numbers, the same or similar reference numerals are used for the same or similar components, and repeated descriptions are omitted. The terms "module" and "part" used to describe components in the following description are assigned or used interchangeably only for ease of writing and do not inherently distinguish one from another. Furthermore, when describing the embodiments disclosed in this specification, detailed descriptions are omitted where specific explanations of related well-known technologies would obscure the essence of the embodiments disclosed in this specification. Additionally, the accompanying drawings are used to aid in understanding the embodiments disclosed in this specification, and the technical ideas disclosed in this specification are not limited to the content shown in the drawings.

[0057] Furthermore, the accompanying drawings are described for ease of explanation, but those skilled in the art can combine at least two or more drawings to implement another embodiment, which also falls within the scope of the present invention.

[0058] Furthermore, when referring to elements such as layers, regions, or substrates as existing "on" other constituent elements, it should be understood as either existing directly on the other elements or having intermediate elements in between.

[0059] The display device described in this specification is a concept encompassing all display devices that display information per unit pixel or set of units pixels. Therefore, it is not limited to finished products but can also apply to components. For example, a panel equivalent to a component of a digital TV also independently corresponds to the display device described in this specification. Finished products may include mobile phones, smartphones, laptop computers, digital broadcasting terminals, PDAs (personal digital assistants), PMPs (portable multimedia players), navigation devices, Slate PCs, tablet PCs, Ultrabooks, digital TVs, desktop computers, etc.

[0060] However, those skilled in the art will readily understand that the structure of the embodiments described in this specification can also be applied to displayable devices, even in new product forms developed later.

[0061] In addition, the semiconductor light-emitting elements mentioned in this specification include concepts such as LED and micro-LED, and can be used interchangeably.

[0062] Figure 1 This is a top view showing a light-emitting element according to an embodiment of the present invention. Figure 2 This is a cross-sectional view showing a light-emitting element according to an embodiment of the present invention.

[0063] Reference Figure 1 and Figure 2 In one embodiment of the light-emitting element 200, the first contact portion 242 and the second contact portion 251 may be disposed on the same plane relative to the light-emitting surface I. Furthermore, the first contact portion 242 and the second contact portion 251 may be located at opposite ends relative to the light-emitting surface I. That is, the first contact portion 242 and the second contact portion 251 may be located on opposite sides of each other relative to the light-emitting surface I. Figure 1 The image shows the state in which the light-emitting surface I is covered by the passivation layer 260.

[0064] As a specific example, the light-emitting element 200 of one embodiment may include a support structure 210 and a semiconductor structure 220 disposed on the support structure 210.

[0065] The semiconductor structure 220 may include a first conductive semiconductor layer 221, a light-emitting layer 222 disposed on the first conductive semiconductor layer 221, and a second conductive semiconductor layer 223 disposed on the light-emitting layer 222. As an example, the first conductive semiconductor layer 221 may be a P-type semiconductor layer, and the second conductive semiconductor layer 223 may be an N-type semiconductor layer. The following is an illustrative description of the case where the first conductive semiconductor layer 221 is a P-type semiconductor layer and the second conductive semiconductor layer 223 is an N-type semiconductor layer.

[0066] The semiconductor structure 220 may have a light-emitting structure that emits red, green, or blue light. Furthermore, the semiconductor structure 220 may be configured as a miniature LED with a millimeter-sized dimension or a micro-LED with a micrometer-sized dimension.

[0067] Such a second conductive semiconductor layer 223 may include an enlarged region E whose area is larger than that of the light-emitting layer 222. Here, the enlarged region E may have a first surface I that defines the light-emitting surface and a second surface II that is the opposite surface of the first surface I.

[0068] A first electrode 230 may be disposed on one surface of the first conductive semiconductor layer 221. Such a first conductive semiconductor layer 221 can achieve ohmic contact with the first electrode 230. As an example, the first electrode 230 may include a transparent conductive oxide layer such as ITO (Indium Tin Oxide).

[0069] A reflective electrode 240 electrically connected to the first electrode 230 may be disposed on one surface of the first electrode 230. The reflective electrode 240 may include an extension region 241 having a first contact portion 242. As an example, the reflective electrode 240 may include at least one of aluminum (Al) and silver (Ag).

[0070] On the other hand, a second electrode 250 may be provided that contacts the second surface II of the second conductive semiconductor layer 223. Such a second electrode 250 may include a second contact portion 251. As an example, the second electrode 250 may include gold (Au). As a specific example, the second electrode 250 may include at least one of chromium (Cr), platinum (Pt), and gold (Au).

[0071] A passivation layer 260 may be disposed on at least one surface of the semiconductor structure 220. As one example, the passivation layer 260 may be disposed on at least one side of the light-emitting layer 222. As another example, the passivation layer 260 may be disposed on one side of the semiconductor structure 220. The passivation layer 260 may include a first portion 261 located between the second electrode 250 and the support structure 210. Additionally, the passivation layer 260 may include a second portion 262 disposed on the light-emitting surface I.

[0072] As an exemplary embodiment, the semiconductor structure 220 may have an inverted mesa shape. As an example, the semiconductor structure 220 may have an inverted horizontal light-emitting element structure. As an exemplary embodiment, the reflective electrode 240 may cover at least a portion of the mesa shape. As an example, the reflective electrode 240 may be configured to surround such an inverted mesa shape.

[0073] In addition, the side angles of the tabletop shape or structure are formed as obtuse angles. In this case, the obtuse angles of the sides can not only be formed as a preset single angle, but also can be formed as different angles by taking into account the wavelength of the light emitted from the light-emitting layer (e.g., light emission colors such as R, G, B) or the brightness deviation from different viewing angles.

[0074] In this case, the light-emitting surface I can be a surface extending on the growth surface on which the semiconductor structure 220 is grown. In other words, the light-emitting surface I can be a surface facing the growth substrate on which the semiconductor structure 220 is grown. That is, the first surface I can be a surface on the side of the growth substrate on which the semiconductor structure 220 is grown. As an exemplary embodiment, the semiconductor structure 220 may include a nitride-based semiconductor layer such as gallium nitride (GaN). In this case, the first surface I can be a nitrogen-based surface (N-face), and the second surface II can be a gallium-based surface (Ga-face).

[0075] Gallium nitride semiconductors can have polarity based on the atomic configuration (Ga-N) orientation according to the growth direction. For example, a first surface I can have a first polarity, and a second surface II can have a second polarity. The states of the first surface I and the second surface II for achieving ohmic contact can be different from each other. For example, the first surface I and the second surface II can have different work functions.

[0076] Here, the second electrode 250 can be connected to the second surface II of the second conductive semiconductor 223. That is, if the second conductive semiconductor layer 223 includes a nitride-based semiconductor layer, the second surface II can be a gallium-face. The second electrode 250 in contact on such a second surface II can be formed by a room-temperature process. As an example, the second electrode 250 can form an ohmic contact on the second surface II by a room-temperature or low-temperature process.

[0077] A light extraction structure 270 may be formed on the first surface I constituting the light-emitting surface. As an example, a light extraction structure 270 having a rough surface or uneven structure 271 may be provided on the first surface I. A second portion 262 of a passivation layer 260 may be provided on such a light extraction structure 270.

[0078] As an exemplary embodiment, the support structure 210 may include a light-transmitting support layer 211 and an adhesive layer 212 located between the support layer 211 and the reflective electrode 2400. The support layer 211 may be removed during subsequent mounting to the wiring substrate 100 constituting the display device.

[0079] As an example, the adhesive layer 212 of the support structure 210 may include a reworkable adhesive layer. That is, when light is irradiated through the light-transmitting support layer 211, the support layer 211 can be separated from the adhesive layer 212. In this way, the light-emitting element 200 separated from the support layer 211 can be mounted onto the wiring substrate 100. At this time, the light-emitting element 200 can be attached to the wiring substrate 100 through the adhesive layer 212.

[0080] Typically, the excellent luminous efficiency of the LED chip itself helps ensure the brightness of a display that uses small light-emitting elements, such as a micro LED used as a subpixel.

[0081] As the size of the components decreases, the area ratio of the sidewalls relative to the active area increases, resulting in greater current leakage and a decrease in luminous efficiency. Therefore, it may be difficult to achieve high brightness when using light-emitting components in displays.

[0082] Even when methods are used to improve light efficiency by creating roughness in the component itself, further methods to improve light efficiency are still needed in displays where front brightness is crucial because more light leaks to the bottom and sides of the component.

[0083] In addition, since the semiconductor thin film materials that make up the red, green and blue light-emitting elements are different from each other, the light emission distribution is different depending on the viewing angle, which can cause the problem of different colors being seen from different viewing angles in a display.

[0084] On the other hand, there is a problem with using flip-chip structures in displays where wiring is connected to the top of components. When connecting the bottom wiring using a flip-chip structure, bonding is required using solder material. During bonding, solder spreading can cause defects due to short circuits between the two electrodes of the component. Therefore, when configuring a flip-chip structure in a display, a minimum distance between the two electrodes must be ensured, which may make it difficult to reduce component size.

[0085] However, according to an embodiment of the present invention, as described above, in a horizontal LED (Light Emitting Diode) structure with an inverted structure, a first contact portion 242 (P-contact) and a second contact portion 251 (N-contact) can be provided on the same plane, and such a first contact portion 242 and a second contact portion 251 can be electrically isolated by a passivation layer 262.

[0086] Additionally, a reflective electrode 240 may be provided that surrounds the first contact portion 242, the second contact portion 251, and the entire lower portion of the semiconductor structure 220. Furthermore, a support structure 210 comprising a bonding material (adhesive layer 212) such as BCB may be provided below the reflective electrode 240. In this case, an additional bonding layer may be provided to improve the bonding force between the reflective electrode 240 and the adhesive layer 212.

[0087] On the other hand, the first contact portion 242 and the second contact portion 251, extending from the first electrode 230 and the second electrode 250, can be disposed along the side of the light-emitting element 200 along the support structure 210. Therefore, when the light-emitting element 100 is transferred onto the wiring substrate 100, the first contact portion 242 and the second contact portion 251 can be exposed on the surface opposite to the support structure 210, so that wiring connection can be realized at the top.

[0088] As described above, the light-emitting element of the embodiment of the present invention uses a mesa structure and a reflective electrode 240 structure to focus the light emitted downwards onto the front side of the light-emitting element, thereby obtaining a high-brightness light-emitting element and a display.

[0089] Furthermore, the reflective electrode 240, which is provided in the inclined portion formed with an obtuse-angled platform shape, and the light extraction structure 270 at the top, can reduce brightness deviation at different viewing angles. In addition, since the color viewing angle deviation of different colors can be reduced, a high-definition display can be obtained.

[0090] On the other hand, during the process of transferring the light-emitting element 200 to the wiring substrate 100, it is possible to prevent cracks from occurring in the thin portion of the light-emitting element 200 due to the pressure applied to it.

[0091] In addition, it has a flip-chip shape overall, but the first contact portion 242 and the second contact portion 251 extend to the left and right, which facilitates the mounting of the light-emitting element 200 on the wiring substrate 100 and its electrical connection with the wiring on the upper part of the wiring substrate 100.

[0092] On the other hand, ohmic contact can be achieved at both room temperature and low temperature through the first contact portion 242 and the second contact portion 251. This prevents damage to the heat-sensitive support layer 212.

[0093] Figure 3 This is a cross-sectional view showing an example of using a light-emitting element of one embodiment of the present invention as a pixel in a display device.

[0094] Reference Figure 3 This shows the state in which the light-emitting element 200 is mounted on the wiring substrate 100 to achieve wiring.

[0095] The wiring substrate 100 includes a panel substrate 110, on which a light-emitting element 200 can be mounted. In this case, the support layer 211 of the light-emitting element 200 is removed, and the light-emitting element 200 can be disposed on the upper surface of the panel substrate 110 via an adhesive layer 212. Therefore, the support structure 210 may include an adhesive layer 212 located between the upper surface of the wiring substrate 100 and the reflective electrode 240.

[0096] At this time, on the wiring substrate 100, the first contact portion 242 of the light-emitting element 200 is electrically connected through the first wiring 120, and the second contact portion 251 is electrically connected through the second wiring 130. Thus, the first wiring 120 and the second wiring 130 can each be connected to the light-emitting element 200 through the upper surface of the light-emitting element 200.

[0097] As explained above, the light-emitting element 100 can have a flip-chip configuration. In this case, the first contact portion 242 and the second contact portion 251 extend to the left and right, and can be electrically connected to the wiring substrate 100 through the first wiring 120 and the second wiring 130. In addition, the first contact portion 242 and the second contact portion 251 face the upper surface (the surface opposite to the wiring substrate), which facilitates the mounting of the light-emitting element 200 on the wiring substrate 100 and its electrical connection with the wiring on the upper part of the wiring substrate 100.

[0098] The display device utilizing such a light-emitting element 100 will be described in detail later.

[0099] Figures 4 to 15 This is a cross-sectional view illustrating the manufacturing process of a light-emitting element according to an embodiment of the present invention.

[0100] The manufacturing process of a light-emitting element according to an embodiment will now be described with reference to the cross-sectional views and following the steps.

[0101] First, refer to Figure 4A semiconductor thin film 220a can be formed on the growth substrate 300. As an example, such a semiconductor thin film 220a may include an N-type semiconductor layer 223, a light-emitting layer 222, and a P-type semiconductor layer 221.

[0102] Such a semiconductor thin film 220a can be formed over the entire area of ​​a wafer-shaped growth substrate 300.

[0103] Then, refer to Figure 5 A first electrode layer 231 may be formed on the semiconductor thin film 220a. As described above, the first electrode layer 231 may be formed of a transparent conductive oxide such as ITO.

[0104] Then, refer to Figure 6 A mesa shape 220b (mesa structure) can be formed. For example, the mesa shape 220b can be formed by performing mesa etching using a dry etching method. Such mesa structures 220b can be formed on individual light-emitting elements. For example, multiple mesa shapes 220b can be formed on the growth substrate 300.

[0105] At this time, an opening 223a can be formed to expose a portion of the second conductive semiconductor layer 223 (N-type semiconductor layer) in order to form the second electrode 250. Such an opening 223a can constitute the enlarged region E as described above. As an example, the enlarged region E can be formed to form the second electrode 250. Such an enlarged region E may include a first surface I and a second surface II. Here, in the case of forming a gallium nitride series semiconductor, the first surface I can be a gallium surface as a growth surface, and the second surface II can be a nitrogen surface.

[0106] Then, refer to Figure 7 A second electrode 250 may be formed at the opening 223a. As described above, a second electrode 250 may be formed on the second surface II constituting the nitrogen surface of the second conductive semiconductor layer 223.

[0107] Then, refer to Figure 8 A passivation layer 260 may be formed on the upper surface of the semiconductor structure 220 on which the first electrode 230 and the second electrode 250 are formed. Such a passivation layer 260 is formed to cover the entire upper surface.

[0108] Then, refer to Figure 9 At least one portion can be removed from the passivation layer 260 covering the first electrode 230 and the second electrode 250. As an example, the first electrode 230 may have an opening, while the second electrode 250 may not have an opening.

[0109] Reference Figure 10A reflective electrode 240 can be formed that at least covers the mesa shape 220b and the first electrode 230. This reflective electrode 240 can be formed in a region other than the enlarged region E. This reflective electrode 240 can be electrically connected to the first electrode 230. A passivation layer 260 can be disposed between the reflective electrode 240 and the semiconductor structure 220.

[0110] Then, refer to Figure 11 ,exist Figure 10 The upper surface of the structure can be joined to the support structure 210. As an example, it can be... Figure 10 The structure shown in the diagram is inverted and joined to the support structure 210. At this time, a portion of the reflective electrode 240 and the passivation layer 260 are bonded to the adhesive layer 212 and disposed on the support layer 211.

[0111] Thus, an inverted mesa shape 220b can be formed on the support structure 210. This mesa shape 220b can be covered by the reflective electrode 240.

[0112] After that, as Figure 12 As shown, the growth substrate 300 can be removed. During this process, the light-emitting surface I can be exposed.

[0113] Then, refer to Figure 13 This allows for the separation process of individual light-emitting elements 200. As an example, trenches T can be formed to distinguish the regions of each light-emitting element 200.

[0114] Then, refer to Figure 14 Both sides of the semiconductor structure 220 can be etched to expose at least a portion of the portions corresponding to the first contact portion 242 and the second contact portion 251.

[0115] Through this etching process, the second contact portion 251 is exposed, as well as a portion of the passivation layer 260 corresponding to the area of ​​the first contact portion 242.

[0116] Then, refer to Figure 15 A passivation layer 262 (second part) can be formed on the upper surface of the semiconductor structure 220 to cover the light-emitting surface.

[0117] Subsequently, when the passivation layer 260 corresponding to the portions of the first contact portion 242 and the second contact portion 251 is removed, a configuration can be formed. Figure 2 The structure shown.

[0118] Although not described separately on the upper surface, when growing the semiconductor structure 220 on the growth substrate 300, if a patterned sapphire substrate (PSS) is used, the light extraction structure 270 can be formed during the removal of the growth substrate 300. Alternatively, the light extraction structure 270 can also be formed on the light-emitting surface I through another etching process.

[0119] Figures 16 to 21 This is a cross-sectional view illustrating the process of manufacturing a display device using a light-emitting element according to an embodiment of the present invention.

[0120] First, refer to Figure 16 The diagram shows a state in which multiple light-emitting elements 200 are fabricated on a support layer 211. Here, the multiple light-emitting elements 200 may be light-emitting elements 200 having a semiconductor structure 220 that emits light of the same color.

[0121] Reference Figure 17 In order to transfer such a light-emitting element 200 onto the wiring substrate 100, a temporary substrate 400 can first be attached to the light-emitting surface I side of the light-emitting element 200.

[0122] The support layer 211 can then be removed. As an example, light is irradiated through the support layer 211, thereby deforming the adhesive layer 212, thereby separating the support layer 211 and the adhesive layer 212.

[0123] Reference Figure 18 The unit light-emitting element 200 can be transferred to a pixel area. As an example, when the light-emitting element 200 is a blue light-emitting element 200, a blue light-emitting element 200 can be provided in a pixel area. Thus, a light-emitting element 200 can be separated from the support layer 211 and transferred to the temporary substrate 400.

[0124] Then, refer to Figure 19 The light-emitting element 200 transferred to the temporary substrate 400 can be transferred to the wiring substrate 100.

[0125] As an example, the surface from which the support layer 211 has been removed can be bonded to the wiring substrate 100 on which the bonding layer 120 is disposed on the panel substrate 110. That is, the light-emitting element 200 can be transferred to the wiring substrate 100 and bonded to the bonding layer 120 by the adhesive layer 212.

[0126] Then, refer to Figure 20 A molding layer 132 can be formed that at least covers the height of the light-emitting element 200. Such a molding layer 132 can flatten the height deviation caused by the light-emitting element 200.

[0127] Then, refer to Figure 21After removing a portion of the molding layer 132 to expose the first contact portion 242 and the second contact portion 251 of the light-emitting element 200, a first wiring 121 and a second wiring 131 can be formed and respectively joined to the first contact portion 242 and the second contact portion 251.

[0128] Such first wiring 121 and second wiring 131 can each be formed on the molding layer 132 and bent toward the light-emitting element 200 to be electrically connected to the first contact portion 242 and the second contact portion 251.

[0129] Figure 22 This is a cross-sectional view of a unit pixel of a display device using a light-emitting element according to an embodiment of the present invention. Figure 23 This is a top view of a unit pixel of a display device using a light-emitting element according to an embodiment of the present invention.

[0130] Reference Figure 22 and Figure 23 By referring to the above Figures 16 to 21 The same process described above can be used to transfer different light-emitting elements 201 and 202 that constitute a unit pixel. That is, the blue light-emitting element 200, the green light-emitting element 201, and the red light-emitting element 202 can be transferred adjacently to the wiring substrate 100 to constitute a unit pixel.

[0131] The light-emitting elements 200, 201, and 202 constituting such a unit sub-pixel light source can be electrically connected on the upper part of the molding layer 132 via a first wiring 120 and a second wiring 130, respectively. As an example, the light-emitting elements 200, 201, and 202 can realize a unit pixel by being electrically connected to the first wiring 120 and the second wiring 130 via a first contact portion 242 and a second contact portion 251, respectively. Of course, multiple such unit pixels can be provided on the display device.

[0132] The above description provides an illustrative explanation of the technical concept of the present invention. Those skilled in the art can make various modifications and variations without departing from the essential characteristics of the present invention.

[0133] Therefore, the embodiments disclosed in this invention are not intended to limit the technical concept of the invention, but rather to illustrate the technical concept of the invention. The scope of the technical concept of the invention is not limited to such embodiments.

[0134] The scope of protection of this invention should be interpreted through the following claims, and all technical ideas within the same scope should be included in the scope of the invention.

[0135] Explanation of reference numerals in the attached figures

[0136] 100: Wiring substrate; 110: Panel substrate; 120, 121: First wiring; 130, 131: Second wiring; 132: Molding layer; 200: Light-emitting element; 210: Support structure; 220: Semiconductor structure; 230: First electrode; 240: Reflective electrode; 250: Second electrode; 260: Passivation layer; 270: Light extraction structure.

Claims

1. A light emitting element characterized by comprising: It includes: Support structure; A semiconductor structure disposed on the aforementioned support structure includes: a first conductive semiconductor layer; a light-emitting layer disposed on the first conductive semiconductor layer; and a second conductive semiconductor layer disposed on the light-emitting layer and including an enlarged region that is larger than the area of ​​the light-emitting layer, the enlarged region including a first surface and a second surface defining the light-emitting surface, wherein the second surface is the opposite surface of the first surface. The first electrode is disposed on the first conductive semiconductor layer; A reflective electrode that is in contact with the first electrode and has an extended region including the first contact portion; The second electrode, which is in contact with the aforementioned second surface and has a second contact portion; and A passivation layer, which includes the region between the aforementioned reflective electrode and the aforementioned second electrode, and is disposed on at least one surface of the aforementioned semiconductor structure.

2. The light-emitting element according to claim 1, characterized in that, The first surface mentioned above is the surface on the growth substrate side of the semiconductor structure mentioned above.

3. The light-emitting element according to claim 1, characterized in that, The aforementioned semiconductor structure includes a nitride-based semiconductor layer, and the second surface is a gallium surface.

4. The light-emitting element according to claim 1, characterized in that, The aforementioned semiconductor structure has an inverted mesa shape.

5. The light-emitting element according to claim 4, characterized in that, The aforementioned reflective electrode covers at least a portion of the aforementioned mesa shape.

6. The light-emitting element according to claim 1, characterized in that, The aforementioned support structure includes: Translucent support layer; and An adhesive layer is disposed between the support layer and the reflective electrode.

7. The light-emitting element according to claim 1, characterized in that, The first contact portion and the second contact portion are oriented toward the light-emitting surface.

8. The light-emitting element according to claim 1, characterized in that, The first contact portion is disposed on the opposite side of the second contact portion relative to the light-emitting surface.

9. The light-emitting element according to claim 1, characterized in that, The passivation layer is formed to electrically isolate the first contact portion and the second contact portion.

10. The light-emitting element according to claim 1, characterized in that, The first contact portion and the second contact portion are formed to be exposed on the surface opposite to the support structure.

11. The light-emitting element according to claim 1, characterized in that, The first surface mentioned above has a first polarity, and the second surface mentioned above has a second polarity.

12. The light-emitting element according to claim 11, characterized in that, The aforementioned first polarity and the aforementioned second polarity are polarities generated based on the characteristics of the semiconductor growth surface.

13. The light-emitting element according to claim 11, characterized in that, The first surface mentioned above is the surface on the growth substrate where the second conductive semiconductor layer is grown.

14. A display device comprising: It includes: Light-emitting elements are arranged on a wiring substrate to define each pixel; and A molding layer is disposed on the aforementioned light-emitting element. The above-mentioned light-emitting elements include: Support structure; A semiconductor structure disposed on the aforementioned support structure includes: a first conductive semiconductor layer; a light-emitting layer disposed on the first conductive semiconductor layer; and a second conductive semiconductor layer disposed on the light-emitting layer and including an enlarged region that is larger than the area of ​​the light-emitting layer, the enlarged region including a first surface and a second surface defining the light-emitting surface, wherein the second surface is the opposite surface of the first surface. The first electrode is disposed on the first conductive semiconductor layer; A reflective electrode that contacts the first electrode and has an extended region, the extended region including a first contact portion facing the first surface; The second electrode, which is in contact with the second surface and has a second contact portion facing the first surface; and A passivation layer, which includes the region between the aforementioned reflective electrode and the aforementioned second electrode, and is disposed on at least one surface of the aforementioned semiconductor structure.

15. The display device of claim 14, wherein, The display device also includes: A first wiring, which is connected to the first contact portion on the wiring substrate; and The second wiring is connected to the second contact portion on the wiring substrate.

16. The display device according to claim 14, characterized in that, The aforementioned support structure includes an adhesive layer located between the upper surface of the aforementioned wiring substrate and the aforementioned reflective electrode.

17. The display device according to claim 14, characterized in that, The aforementioned semiconductor structure has an inverted mesa shape.

18. The display device according to claim 14, characterized in that, The aforementioned reflective electrode covers at least a portion of the aforementioned mesa shape.

19. The display device according to claim 14, characterized in that, The passivation layer electrically isolates the first contact portion and the second contact portion.

20. The display device according to claim 14, characterized in that, The first contact portion and the second contact portion are exposed on the side opposite to the support structure.

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