Light-emitting element and display device using same

Abstract

The present invention can be applied to the technical field related to a display device, and relates to a light-emitting element such as a light-emitting diode (LED), and a display device using same. The present invention may comprise: a support structure; a semiconductor structure which is positioned on the support structure, and which includes a first conductive semiconductor layer, a light-emitting layer that is positioned on the first conductive semiconductor layer, and a second conductive semiconductor layer that is positioned on the light-emitting layer and includes an expanded region with an area expanded to be larger than that of the light-emitting layer, the expanded region having a first surface that defines a light-emitting surface, and a second surface opposite to the first surface; a first electrode positioned on the first conductive semiconductor layer; a reflective electrode which is in contact with the first electrode and which has an extended area having a first contact part; a second electrode having a second contact part in contact with the second surface; and a passivation layer, which includes a region between the reflective electrode and the second electrode and is positioned on at least one surface of the semiconductor structure.

Description

Light-emitting element and display device using the same

[0001] The present invention is applicable to the technical field related to display devices, and relates to, for example, a light-emitting element such as an LED (Light Emitting Diode) and a display device using the same.

[0002] In recent years, display devices with superior characteristics, such as thinness and flexibility, have been developed in the field of display technology. Currently, the major commercially available displays are represented by LCD (Liquid Crystal Display) and OLED (Organic Light Emitting Diode).

[0003] Meanwhile, a light-emitting diode (LED) is a semiconductor light-emitting device that is well known for converting electric current into light. Starting with the commercialization of a red LED using GaAsP compound semiconductors in 1962, it has been used as a light source for display images in electronic devices, including information and communication devices, along with green LEDs of the GaP:N series.

[0004] Recently, these light-emitting diodes (LEDs) have been gradually miniaturized and manufactured into micrometer-sized LEDs, which are used as pixels in display devices.

[0005] Compared to other display devices / panels, this type of LED technology boasts low power consumption, high brightness, and high reliability, and can be applied to flexible devices. Therefore, research institutes and companies have been actively researching this technology recently.

[0006] In general, in order to secure the brightness of a display that uses a small light-emitting element, for example, a micro LED, as a subpixel, it is advantageous for the LED chip itself to have excellent luminous efficiency.

[0007] As the size of the device decreases, the area of ​​the side wall increases compared to the active area, which may increase current leakage and reduce light efficiency, making it difficult to achieve high brightness when the light-emitting device is used in a display.

[0008] Even if a method is adopted to increase light efficiency by forming roughness on the element itself, a lot of light escapes from the bottom and sides of the element, so a method to further increase light efficiency is required in displays where frontal brightness is important.

[0009] Additionally, since the red, green, and blue light-emitting elements are composed of different semiconductor thin film materials, their light emission distributions differ depending on the viewing angle, which can cause the problem of colors appearing different depending on the viewing angle on the display.

[0010] Meanwhile, there is a problem that makes it difficult to use a flip-chip structure in a structure that manufactures a display by connecting wiring to the upper part of the device. When connecting the lower wiring to use a flip-chip structure, bonding must be done using a solder material, but the spreading of the solder material during bonding can cause a short circuit defect between the two electrodes of the device. Therefore, when manufacturing a flip-chip structure into a display, it can be difficult to reduce the size of the device because a minimum distance between the two electrodes must be secured.

[0011] Therefore, a solution to this problem is required.

[0012] The technical problem to be solved by the present invention is to provide a light-emitting element and a display device using the same that can achieve a high-brightness light-emitting element and display by focusing light emitted from the lower portion of the light-emitting element toward the front of the light-emitting element.

[0013] In addition, it is intended to provide a light-emitting element capable of reducing the luminance deviation of the light-emitting element according to the viewing angle and a display device using the same.

[0014] In addition, the present invention aims to provide a light-emitting element and a display device using the same that can achieve high-definition display by reducing color-specific viewing angle deviation.

[0015] Meanwhile, it is an object of the present invention to provide a light-emitting element and a display device using the same that can prevent cracks from occurring in a 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 a wiring board.

[0016] In addition, the present invention aims to provide a light-emitting element and a display device using the same, wherein the light-emitting element is mounted on a wiring board and electrically connected to wiring is easily achieved on the upper part of the wiring board.

[0017] Meanwhile, it is intended to provide a light-emitting element capable of ohmic contact at room temperature and low temperature through a first contact portion and a second contact portion, and a display device using the same.

[0018] Furthermore, those skilled in the art will understand from the full intent of the specification and drawings that, according to other embodiments of the present invention, there may be additional technical problems not mentioned herein.

[0019] As a first viewpoint for achieving the above technical problem, the present invention may be configured to include a semiconductor structure including a support structure; a first conductive semiconductor layer positioned on the support structure, a light-emitting layer positioned on the first conductive semiconductor layer, and an extended region positioned on the light-emitting layer and having an area larger than that of the light-emitting layer, the extended region having a first surface defining a light-emitting surface and a second surface opposite to the first surface; a first electrode positioned on the first conductive semiconductor layer; a reflective electrode having an extended region in contact with the first electrode and having a first contact portion; a second electrode having a second contact portion in contact with the second surface; and a passivation layer positioned on at least one surface of the semiconductor structure including a region between the reflective electrode and the second electrode.

[0020] As an exemplary embodiment, the first surface may be a surface on the growth substrate side of the semiconductor structure.

[0021] As an exemplary embodiment, the semiconductor structure may include a nitride series semiconductor layer, and the second surface may be a gallium surface (Ga-face).

[0022] As an exemplary embodiment, the semiconductor structure may have an inverted mesa shape.

[0023] As an exemplary embodiment, the reflective electrode may cover at least a portion of the mesa shape.

[0024] As an exemplary embodiment, the support structure may include: a light-transmitting support layer; and an adhesive layer positioned between the support layer and the reflective electrode.

[0025] As an exemplary embodiment, the adhesive layer may include a reworkable adhesive layer.

[0026] As an exemplary embodiment, the first contact portion and the second contact portion may face the light-emitting surface.

[0027] As an exemplary embodiment, the first contact portion may be located on an opposite side of the second contact portion with respect to the light-emitting surface.

[0028] As an exemplary embodiment, the passivation layer may be formed to electrically isolate the first contact portion and the second contact portion.

[0029] As an exemplary embodiment, the first contact portion and the second contact portion may be formed to be exposed on a surface opposite to the support structure.

[0030] As a second viewpoint for achieving the above technical problem, the present invention may be configured to include: a support structure; a first conductive semiconductor layer positioned on the support structure; a light-emitting layer positioned on the first conductive semiconductor layer; and an extended region positioned on the light-emitting layer and having an area larger than that of the light-emitting layer, the extended region having a first surface of a first polarity defining a light-emitting surface and a second surface of a second polarity opposite to the first surface; a first electrode positioned on the first conductive semiconductor layer; a reflective electrode having an extended region in contact with the first electrode and having a first contact portion; a second electrode having a second contact portion in contact with the second surface; and a passivation layer positioned at least on a side surface of the light-emitting layer.

[0031] As an exemplary embodiment, the first polarity and the second polarity may be polarities that occur depending on the characteristics of the semiconductor growth surface.

[0032] As an exemplary embodiment, the second conductive semiconductor layer may include a nitride series semiconductor layer, and the second surface may be a gallium surface (Ga-face).

[0033] As an exemplary embodiment, the first side may be a side of the growth substrate on which the second conductive semiconductor layer is grown.

[0034] 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.

[0035] As a third aspect for achieving the above technical problem, the present invention may be configured to include a light-emitting element arranged on a wiring board to define individual pixels; and a molding layer positioned on the light-emitting element, wherein the light-emitting element comprises: a support structure; a semiconductor structure positioned on the support structure, the semiconductor structure including a first conductive semiconductor layer, a light-emitting layer positioned on the first conductive semiconductor layer, and an extension region positioned on the light-emitting layer and having an area larger than that of the light-emitting layer, the extension region having a first surface defining a light-emitting surface and a second surface opposite the first surface; a first electrode positioned on the first conductive semiconductor layer; a reflective electrode having an extension region in contact with the first electrode and having a first contact portion facing the first surface; a second electrode in contact with the second surface and having a second contact portion facing the first surface; and a passivation layer positioned on at least one surface of the semiconductor structure including a region between the reflective electrode and the second electrode.

[0036] As an exemplary embodiment, the wiring board may further include a first wiring connected to the first contact portion; and a second wiring connected to the second contact portion on the wiring board.

[0037] As an exemplary embodiment, the support structure may include an adhesive layer positioned between the upper surface of the wiring substrate and the reflective electrode.

[0038] As an exemplary embodiment, the passivation layer may be formed to electrically isolate the first contact portion and the second contact portion.

[0039] As an exemplary embodiment, the first contact portion and the second contact portion may be formed to be exposed on a surface opposite to the support structure.

[0040] First, according to one embodiment of the present invention, light emitted downward by a mesa structure and a reflective electrode structure is focused toward the front of a light-emitting element, thereby achieving a high-brightness light-emitting element and display.

[0041] Additionally, the luminance deviation by viewing angle can be reduced by the reflective electrode located on the obtuse mesa-shaped slope and the light extraction structure on the upper portion. In addition, the color viewing angle deviation by color can be reduced, thereby achieving a high-definition display.

[0042] Meanwhile, cracks can be prevented from occurring in thin portions 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 board.

[0043] In addition, although it has a flip-chip form overall, the first contact portion and the second contact portion extend left and right, so that the light-emitting element can be easily mounted on a wiring board and electrically connected to the wiring on the upper part of the wiring board.

[0044] Meanwhile, ohmic contact can be achieved at room temperature and low temperature through the first and second contact portions. This prevents damage to the heat-sensitive support layer.

[0045] Furthermore, according to another embodiment of the present invention, there are additional technical effects not mentioned herein. Those skilled in the art will understand these effects upon reading the specification and drawings.

[0046] Figure 1 is a plan view showing a light-emitting element according to one embodiment of the present invention.

[0047] Fig. 2 is a cross-sectional view showing a light-emitting element according to one embodiment of the present invention.

[0048] FIG. 3 is a cross-sectional view showing an example in which a light-emitting element according to one embodiment of the present invention is used as a pixel of a display device.

[0049] Figures 4 to 15 are cross-sectional views showing a manufacturing process of a light-emitting element according to one embodiment of the present invention.

[0050] Figures 16 to 21 are cross-sectional views showing a process of manufacturing a display device using a light-emitting element according to one embodiment of the present invention.

[0051] Fig. 22 is a cross-sectional view showing a unit pixel of a display device using a light-emitting element according to one embodiment of the present invention.

[0052] Fig. 23 is a plan view showing a unit pixel of a display device using a light-emitting element according to one embodiment of the present invention.

[0053] Hereinafter, embodiments disclosed in this specification will be described in detail with reference to the attached drawings. Regardless of the drawing numbers, identical or similar components will be given the same reference numbers, and redundant descriptions thereof will be omitted. The suffixes "module" and "part" used for components in the following description are assigned or used interchangeably only for the convenience of writing the specification, and do not in themselves have distinct meanings or roles. In addition, when describing the embodiments disclosed in this specification, if it is determined that a specific description of a related known technology may obscure the gist of the embodiments disclosed in this specification, a detailed description thereof will be omitted. In addition, it should be noted that the attached drawings are only intended to facilitate easy understanding of the embodiments disclosed in this specification, and should not be construed as limiting the technical ideas disclosed in this specification by the attached drawings.

[0054] Furthermore, although each drawing is described for convenience of explanation, it is also within the scope of the present invention for a person skilled in the art to implement another embodiment by combining at least two drawings.

[0055] Additionally, when an element such as a layer, region or substrate is referred to as existing "on" another element, it will be understood that this may be directly on the other element, or that there may be intermediate elements in between.

[0056] The display device described in this specification is a concept that includes all display devices that display information as a unit pixel or a set of unit pixels. Therefore, it can be applied not only to finished products but also to components. For example, a panel corresponding to a component of a digital TV is also a display device in this specification. Finished products may include mobile phones, smart phones, laptop computers, digital broadcasting terminals, personal digital assistants (PDAs), portable multimedia players (PMPs), navigation systems, slate PCs, tablet PCs, Ultrabooks, digital TVs, desktop computers, etc.

[0057] However, it will be readily apparent to those skilled in the art that the configuration according to the embodiments described herein may be applied to any device capable of displaying, even if it is a new product type developed in the future.

[0058] In addition, the semiconductor light-emitting device mentioned in the specification is a concept that includes LED, micro LED, etc., and may be used interchangeably.

[0059]

[0060] Fig. 1 is a plan view showing a light-emitting element according to one embodiment of the present invention. Fig. 2 is a cross-sectional view showing a light-emitting element according to one embodiment of the present invention.

[0061] Referring to FIGS. 1 and 2, in a light-emitting device (200) according to one embodiment, the first contact portion (242) and the second contact portion (251) may be positioned on the same surface with respect to the light-emitting surface (I). In addition, the first contact portion (242) and the second contact portion (251) may be positioned on opposite end sides with respect to the light-emitting surface (I). That is, the first contact portion (242) and the second contact portion (251) may be positioned on opposite sides with respect to the light-emitting surface (I). In FIG. 1, the light-emitting surface (I) is illustrated as being covered with a passivation layer (260).

[0062] As a specific example, a light emitting device (200) according to one embodiment may include a support structure (210) and a semiconductor structure (220) positioned on the support structure (210).

[0063] The semiconductor structure (220) may include a first conductive semiconductor layer (221), a light-emitting layer (222) positioned on the first conductive semiconductor layer (221), and a second conductive semiconductor layer (223) positioned on the light-emitting layer (222). For 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. Hereinafter, a case in which 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 will be described as an example.

[0064] The semiconductor structure (220) may have a light-emitting structure capable of emitting red, green, or blue light. In addition, the semiconductor structure (220) may form a mini LED having a size in the order of millimeters or a micro LED having a size in the order of micrometers.

[0065] This second conductive semiconductor layer (223) may include an extended area (E) that is larger than the light-emitting layer (222). Here, the extended area (E) may have a first surface (I) defining a light-emitting surface, and a second surface (II) that is the opposite surface of the first surface (I).

[0066] A first electrode (230) may be positioned on one surface of the first conductive semiconductor layer (221). The first conductive semiconductor layer (221) may form an ohmic contact with the first electrode (230). For example, the first electrode (230) may include a transparent conductive oxide layer such as ITO (indium tin oxide).

[0067] A reflective electrode (240) electrically connected to the first electrode (230) may be positioned on one side of the first electrode (230). The reflective electrode (240) may include an extension region (241) having a first contact portion (242). For example, the reflective electrode (240) may include at least one of aluminum (Al) and silver (Ag).

[0068] Meanwhile, a second electrode (250) may be positioned to contact the second surface (II) of the second conductive semiconductor layer (223). This second electrode (250) may include a second contact portion (251). For 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).

[0069] A passivation layer (260) may be positioned on at least one surface of the semiconductor structure (220). For example, the passivation layer (260) may be positioned on at least a side surface of the light-emitting layer (222). As another example, the passivation layer (260) may be positioned on a side surface of the semiconductor structure (220). The passivation layer (260) may include a first portion (261) positioned between the second electrode (250) and the support structure (210). In addition, the passivation layer (260) may include a second portion (262) positioned on the light-emitting surface (I).

[0070] As an exemplary embodiment, the semiconductor structure (220) may have an inverted mesa shape. For 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. For example, the reflective electrode (240) may be provided to surround the inverted mesa shape.

[0071] In addition, the side angle of the mesa shape or mesa structure is formed as an obtuse angle. At this time, the obtuse angle of the side can be set to a single preset angle, or can be formed at a different angle in consideration of the wavelength of light emitted from the light-emitting layer (e.g., light-emitting color such as R, G, B) or the luminance deviation according to the viewing angle.

[0072] In this case, the light-emitting surface (I) may be a surface that extends from the growth surface on which the semiconductor structure (220) is grown. In other words, the light-emitting surface (I) may be a surface facing the growth substrate on which the semiconductor structure (220) is grown. That is, the first surface (I) may 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) may be a nitrogen surface (N-face), and the second surface (II) may be a gallium surface (Ga-face).

[0073] Gallium nitride semiconductors can have polarity depending on the direction of atomic arrangement (Ga-N) along the growth direction. For example, the first side (I) can have the first polarity, and the second side (II) can have the second polarity. These first side (I) and second side (II) can have different states for ohmic contact. For example, the first side (I) and second side (II) can have different work functions.

[0074] Here, the second electrode (250) may be connected to the second surface (II) of the second conductive semiconductor (223). That is, when the second conductive semiconductor layer (223) includes a nitride series semiconductor layer, the second surface (II) may be a gallium surface (Ga-face). The second electrode (250) in contact with the second surface (II) may be formed through a room temperature process. For example, the second electrode (250) may form an ohmic contact on the second surface (II) through a room temperature or low temperature process.

[0075] A light extraction structure (270) may be formed on the first surface (I) forming the light-emitting surface. For example, a light extraction structure (270) having a rough surface or a rough structure (271) may be provided on the first surface (I). A second portion (262) of a passivation layer (260) may be positioned on the light extraction structure (270).

[0076] As an exemplary embodiment, the support structure (210) may include a light-transmitting support layer (211) and an adhesive layer (212) positioned between the support layer (211) and a reflective electrode (2400). The support layer (211) may be removed when mounted on a wiring board (100) forming a display device at a later time.

[0077] For 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) may be separated from the adhesive layer (212). The light-emitting element (200) from which the support layer (211) is separated in this manner may be mounted on the wiring board (100). At this time, the light-emitting element (200) may be attached to the wiring board (100) through the adhesive layer (212).

[0078] In general, in order to secure the brightness of a display that uses a small light-emitting element, for example, a micro LED, as a subpixel, it is advantageous for the LED chip itself to have excellent luminous efficiency.

[0079] As the size of the device decreases, the area of ​​the side wall increases compared to the active area, which may increase current leakage and reduce light efficiency, making it difficult to achieve high brightness when the light-emitting device is used in a display.

[0080] Even if a method is adopted to increase light efficiency by forming roughness on the element itself, a lot of light escapes from the bottom and sides of the element, so a method to further increase light efficiency is required in displays where frontal brightness is important.

[0081] Additionally, since the red, green, and blue light-emitting elements are composed of different semiconductor thin film materials, their light emission distributions differ depending on the viewing angle, which can cause the problem of colors appearing different depending on the viewing angle on the display.

[0082] Meanwhile, there is a problem that makes it difficult to use a flip-chip structure in a structure that manufactures a display by connecting wiring to the upper part of the device. When connecting the lower wiring to use a flip-chip structure, bonding must be done using a solder material, but the spreading of the solder material during bonding can cause a short circuit defect between the two electrodes of the device. Therefore, when manufacturing a flip-chip structure into a display, it can be difficult to reduce the size of the device because a minimum distance between the two electrodes must be secured.

[0083] However, according to an embodiment of the present invention, as described above, the first contact portion (242; P-contact) and the second contact portion (251; N-contact) can be positioned on the same surface, such as in a horizontal LED (light emitting diode) structure with an inverted structure, and the first contact portion (242) and the second contact portion (251) can be electrically separated by a passivation layer (262).

[0084] In addition, a reflective electrode (240) that surrounds the entire lower portion of the first contact portion (242), the second contact portion (251), and the semiconductor structure (220) may be provided. In addition, a support structure (210) including a bonding material (adhesive layer; 212) such as BCB may be positioned on the lower side of the reflective electrode (240). At this time, a separate bonding layer may be additionally provided between the reflective electrode (240) and the adhesive layer (212) to increase bonding strength.

[0085] Meanwhile, the first contact portion (242) and the second contact portion (251) extending from the first electrode (230) and the second electrode (250) may be positioned on the side of the light-emitting element (200) along the support structure (210). Accordingly, when the light-emitting element (100) is transferred onto the wiring board (100), the first contact portion (242) and the second contact portion (251) may be exposed on the side opposite to the support structure (210) so that wiring connection is possible from above.

[0086] The light emitting element according to the embodiment of the present invention as described above can achieve a high-brightness light emitting element and display by concentrating the light emitted downwards toward the front of the light emitting element through the mesa structure and the reflective electrode (240) structure.

[0087] In addition, the luminance deviation by viewing angle can be reduced by the reflective electrode (240) located on the obtuse mesa-shaped inclined portion and the light extraction structure (270) on the upper portion. In addition, the color viewing angle deviation by color can be reduced, so that a high-definition display can be achieved.

[0088] Meanwhile, it is possible to prevent cracks from occurring in a thin portion of the light-emitting element (200) due to pressure applied to the light-emitting element (200) during the process of transferring the light-emitting element (200) to the wiring board (100).

[0089] In addition, although it has a flip-chip shape overall, the first contact portion (242) and the second contact portion (251) extend left and right, so that the light emitting element (200) can be easily mounted on the wiring board (100) and electrically connected to the wiring on the upper part of the wiring board (100).

[0090] Meanwhile, ohmic contact can be achieved at room temperature and low temperature through the first contact portion (242) and the second contact portion (251). Accordingly, damage to the support layer (212), which is vulnerable to heat, can be prevented.

[0091]

[0092] FIG. 3 is a cross-sectional view showing an example in which a light-emitting element according to one embodiment of the present invention is used as a pixel of a display device.

[0093] Referring to Figure 3, a light-emitting element (200) is mounted on a wiring board (100) and wiring is performed.

[0094] The wiring board (100) may include a panel board (110), and a light emitting element (200) may be mounted on the upper surface of the panel board (110). At this time, the support layer (211) of the light emitting element (200) may be removed, and the light emitting element (200) may be installed on the upper surface of the panel board (110) by an adhesive layer (212). Accordingly, the support structure (210) may include an adhesive layer (212) positioned between the upper surface of the wiring board (100) and the reflective electrode (240).

[0095] At this time, the first contact portion (242) of the light-emitting element (200) on the wiring board (100) can be electrically connected by the first wiring (120), and the second contact portion (251) can be electrically connected by the second wiring (130). 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).

[0096] As described above, the light emitting element (100) may have a flip-chip shape as a whole. At this time, the first contact portion (242) and the second contact portion (251) may extend left and right, and may be electrically connected to the wiring board (100) by the first wiring (120) and the second wiring (130). In addition, since the first contact portion (242) and the second contact portion (251) face the upper surface (the opposite surface of the wiring board), the light emitting element (200) may be easily mounted on the wiring board (100) and electrically connected to the wiring on the upper side of the wiring board (100).

[0097] A display device using such a light-emitting element (100) will be described in detail later.

[0098]

[0099] Figures 4 to 15 are cross-sectional views showing a manufacturing process of a light-emitting element according to one embodiment of the present invention.

[0100] Hereinafter, with reference to each cross-sectional drawing, a manufacturing process of a light-emitting element according to one embodiment is described step by step.

[0101] First, referring to FIG. 4, a semiconductor thin film (220a) can be formed on a growth substrate (300). For example, this semiconductor thin film (220a) can include an N-type semiconductor layer (223), a light-emitting layer (222), and a P-type semiconductor layer (221).

[0102] The formation of this semiconductor thin film (220a) can be achieved over the entire area of ​​the wafer-shaped growth substrate (300).

[0103] Thereafter, referring to FIG. 5, a first electrode layer (231) can be formed on a semiconductor thin film (220a). As mentioned above, the first electrode layer (231) can be formed of a transparent conductive oxide such as ITO.

[0104] Next, referring to FIG. 6, a mesa shape (220b; mesa structure) can be formed. For example, mesa etching can be performed using a dry etching method to form the mesa shape (220b). Such mesa structures (220b) can be formed for each individual light-emitting element. For example, a plurality of mesa shapes (220b) can be formed on a growth substrate (300).

[0105] At this time, an opening (223a) may 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). This opening (223a) may form the expansion region (E) described above. For example, the expansion region (E) may be formed to form the second electrode (250). This expansion region (E) may include a first surface (I) and a second surface (II). Here, when forming a gallium nitride series semiconductor, the first surface (I) may form a gallium-surface, which is a growth surface, and the second surface (II) may form a nitrogen-surface.

[0106] Thereafter, referring to FIG. 7, a second electrode (250) can be formed in the opening (223a). As described above, the second electrode (250) can be formed on the second surface (II) forming the nitrogen surface in the second conductive semiconductor layer (223).

[0107] Next, referring to FIG. 8, a passivation layer (260) can be formed on the upper surface of the semiconductor structure (220) on which the first electrode (230) and the second electrode (250) are formed. This passivation layer (260) can be formed to cover the entire upper surface.

[0108] Thereafter, referring to FIG. 9, at least a portion of the passivation layer (260) covering the first electrode (230) and the second electrode (250) may be removed. For example, the first electrode (230) may be opened, and the second electrode (250) may not be opened.

[0109] Referring to FIG. 10, a reflective electrode (240) covering at least a mesa shape (220b) and a first electrode (230) can be formed. This reflective electrode (240) can be formed in an area excluding the extended area (E). This reflective electrode (240) can be electrically connected to the first electrode (230). A passivation layer (260) can be positioned between the reflective electrode (240) and the semiconductor structure (220).

[0110] Next, referring to FIG. 11, a support structure (210) can be bonded to the upper surface of the structure of FIG. 10. For example, the structure illustrated in FIG. 10 can be reversed and bonded 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 positioned on the support layer (211).

[0111] Accordingly, a mesa shape (220b) of an inverted shape may be positioned on the support structure (210). This mesa shape (220b) may be covered by a reflective electrode (240).

[0112] Thereafter, as shown in Fig. 12, the growth substrate (300) can be removed. During this process, the light-emitting surface (I) can be revealed.

[0113] Next, referring to FIG. 13, a separation process for separation into individual light emitting elements (200) can be performed. For example, a trench (T) that separates the areas of the individual light emitting elements (200) can be formed.

[0114] Thereafter, referring to FIG. 14, both sides of the semiconductor structure (220) may be etched to reveal at least a portion of the portion corresponding to the first contact portion (242) and the second contact portion (251).

[0115] By this etching process, the second contact portion (251) is exposed, and a portion of the passivation layer (260) corresponding to the first contact portion (242) is exposed.

[0116] Next, referring to FIG. 15, a passivation layer (262; second part) can be formed on the upper surface of the semiconductor structure (220) so as to cover the light-emitting surface.

[0117] Afterwards, if the passivation layer (260) corresponding to the first contact portion (242) and the second contact portion (251) is removed, a structure as shown in FIG. 2 can be formed.

[0118] Although not described separately above, when growing a semiconductor structure (220) on a growth substrate (300), a light extraction structure (270) may be formed in the process of removing the growth substrate (300) by using a patterned saphire substrate (PSS). Alternatively, the light extraction structure (270) may be formed through a separate etching process on the light-emitting surface (I).

[0119]

[0120] Figures 16 to 21 are cross-sectional views showing a process of manufacturing a display device using a light-emitting element according to one embodiment of the present invention.

[0121] First, referring to Fig. 16, a state in which a plurality of light-emitting elements (200) are manufactured on a support layer (211) is shown. Here, the plurality of light-emitting elements (200) may be light-emitting elements (200) having a semiconductor structure (220) that emits light of the same color.

[0122] Referring to Fig. 17, in order to transfer the light-emitting element (200) onto the wiring board (100), a temporary substrate (400) can first be attached to the light-emitting surface (I) side of the light-emitting element (200).

[0123] Thereafter, the support layer (211) can be removed. For example, by irradiating light through the support layer (211), the adhesive layer (212) can be deformed, thereby separating the support layer (211) and the adhesive layer (212).

[0124] Referring to Fig. 18, a unit light emitting element (200) can be transferred to one pixel area. For example, if the light emitting element (200) is a light emitting element (200) that emits blue light, one blue light emitting element (200) can be provided in one pixel area. Accordingly, one light emitting element (200) can be separated from the support layer (211) and transferred to a temporary substrate (400).

[0125] Thereafter, referring to FIG. 19, the light emitting element (200) transferred to the temporary substrate (400) can be transferred to the wiring substrate (100).

[0126] For example, a surface from which a support layer (211) has been removed can be bonded to a wiring board (100) having a bonding layer (120) on a panel substrate (110). That is, a light emitting element (200) can be transferred onto a wiring board (100) so that the adhesive layer (212) adheres to the bonding layer (120).

[0127] Next, referring to FIG. 20, a molding layer (132) can be formed at least to a height that covers the light emitting element (200). This molding layer (132) can flatten the height deviation caused by the light emitting element (200).

[0128] Thereafter, referring to FIG. 21, after removing a portion of the molding layer (132) so that the first contact portion (242) and the second contact portion (251) of the light emitting element (200) are exposed, the first wiring (121) and the second wiring (131) can be formed to be bonded to the first contact portion (242) and the second contact portion (251), respectively.

[0129] These first wiring (121) and second wiring (131) are each formed on the molding layer (132) and can be bent toward the light emitting element (200) to be electrically connected to the first contact portion (242) and the second contact portion (251).

[0130] Fig. 22 is a cross-sectional view showing a unit pixel of a display device using a light-emitting element according to one embodiment of the present invention. Fig. 23 is a plan view showing a unit pixel of a display device using a light-emitting element according to one embodiment of the present invention.

[0131] Referring to FIGS. 22 and 23, other light-emitting elements (201, 202) forming a unit pixel can be transferred and installed together by the same process as the process described above with reference to FIGS. 16 to 21. That is, a blue light-emitting element (200), a green light-emitting element (201), and a red light-emitting element (202) can be transferred adjacently on a wiring board (100) to form a unit pixel.

[0132] The light-emitting elements (200, 201, 202) forming these unit sub-pixel light sources can be installed electrically connected to each other by a first wiring (120) and a second wiring (130) on the upper portion of the molding layer (132). For example, the first contact portion (242) and the second contact portion (251) of the light-emitting elements (200, 201, 202) can be electrically connected to the first wiring (120) and the second wiring (130), respectively, to implement a unit pixel. It goes without saying that a plurality of such unit pixels can be provided on the display device.

[0133]

[0134] The above description is merely an example of the technical idea of ​​the present invention, and those skilled in the art will appreciate that various modifications and variations can be made without departing from the essential characteristics of the present invention.

[0135] Accordingly, the embodiments disclosed in the present invention are not intended to limit the technical idea of ​​the present invention but to explain it, and the scope of the technical idea of ​​the present invention is not limited by these embodiments.

[0136] The scope of protection of the present invention should be interpreted by the claims below, and all technical ideas within the scope equivalent thereto should be interpreted as being included in the scope of the rights of the present invention.

[0137] [Explanation of symbols]

[0138] 100: Wiring board 110: Panel board

[0139] 120, 121; 1st wiring 130, 131: 2nd wiring

[0140] 132: Molding layer

[0141] 200: Light-emitting element 210: Support structure

[0142] 220: Semiconductor structure 230: First electrode

[0143] 240: Reflective electrode 250: Second electrode

[0144] 260: Passivation layer 270: Light extraction structure

Claims

1. Support structure; A semiconductor structure including a first conductive semiconductor layer positioned on the support structure, a light-emitting layer positioned on the first conductive semiconductor layer, and an extended region positioned on the light-emitting layer and having an area larger than that of the light-emitting layer, wherein the extended region has a first surface defining a light-emitting surface and a second surface opposite to the first surface; A first electrode positioned on the first conductive semiconductor layer; A reflective electrode having an extended area in contact with the first electrode and having a first contact portion; A second electrode having a second contact portion in contact with the second surface; and A light emitting device characterized by comprising a passivation layer positioned on at least one surface of the semiconductor structure including a region between the reflective electrode and the second electrode.

2. A light-emitting device according to claim 1, characterized in that the first surface is a surface on the growth substrate side of the semiconductor structure.

3. A light-emitting device according to claim 1, wherein the semiconductor structure includes a nitride series semiconductor layer, and the second surface is a gallium surface (Ga-face).

4. A light-emitting device according to claim 1, characterized in that the semiconductor structure has an inverted mesa shape.

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

6. In the first paragraph, the support structure is a light-transmitting support layer; and A light-emitting device characterized by comprising an adhesive layer positioned between the support layer and the reflective electrode.

7. A light-emitting element according to claim 1, characterized in that the first contact portion and the second contact portion face the light-emitting surface.

8. A light-emitting element according to claim 1, characterized in that the first contact portion is located on the opposite side of the second contact portion with respect to the light-emitting surface.

9. A light emitting device 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. A light emitting element characterized in that in the first paragraph, the first contact portion and the second contact portion are formed to be exposed on a surface opposite to the support structure.

11. In paragraph 1, A light emitting device characterized in that the first side has a first polarity and the second side has a second polarity.

12. A light-emitting device according to claim 11, wherein the first polarity and the second polarity are polarities that occur depending on the characteristics of the semiconductor growth surface.

13. A light-emitting device according to claim 11, characterized in that the first surface is a surface on the side of the growth substrate on which the second conductive semiconductor layer is grown.

14. Light-emitting elements arranged on a wiring board to define individual pixels; and Including a molding layer positioned on the light emitting element, The above light emitting element, support structure; A semiconductor structure including a first conductive semiconductor layer positioned on the support structure, a light-emitting layer positioned on the first conductive semiconductor layer, and an extended region positioned on the light-emitting layer and having an area larger than that of the light-emitting layer, wherein the extended region has a first surface defining a light-emitting surface and a second surface opposite to the first surface; A first electrode positioned on the first conductive semiconductor layer; A reflective electrode having an extended area in contact with the first electrode and having a first contact portion facing the first surface; A second electrode having a second contact portion that contacts the second surface and faces the first surface; and A display device characterized in that it comprises a passivation layer positioned on at least one surface of the semiconductor structure including a region between the reflective electrode and the second electrode.

15. In paragraph 14, A first wiring connected to the first contact portion on the wiring board; and A display device characterized in that it further includes a second wiring connected to the second contact portion on the wiring board.

16. A display device according to claim 14, characterized in that the support structure includes an adhesive layer positioned between the upper surface of the wiring board and the reflective electrode.

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

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

19. A display device according to claim 14, characterized in that the passivation layer is formed to electrically isolate the first contact portion and the second contact portion.

20. A display device characterized in that, in claim 14, the first contact portion and the second contact portion are formed to be exposed on a surface opposite to the support structure.

Images