TWI849421B - Light-emitting element, light-emitting device having the same, and method for manufacturing light-emitting element - Google Patents

Abstract

A light-emitting element is provided. The light-emitting element includes: a substrate; a first semiconductor layer disposed on the substrate and including a first portion and a second portion connected with the first portion; a semiconductor stack disposed on the first portion and including: an active area disposed on the first semiconductor layer, and a second semiconductor layer disposed on the active area and having a conductive type different from that of the first semiconductor layer; a first protective layer disposed on the semiconductor stack with one or multiple first protective layer openings on the second semiconductor layer; a transparent conductive oxide layer disposed on the first protective layer and filling into the first protective layer openings to provide a flat surface; and a metal reflection layer disposed on the flat surface and through the transparent conductive oxide layer to electrically connected to the second semiconductor layer.

Description

Light-emitting element, light-emitting device having the same, and method for manufacturing the light-emitting element

This application is about a light-emitting element, a light-emitting device having the same, and a method for manufacturing the light-emitting element. This application is particularly about a light-emitting element including a metal reflective layer, a light-emitting device having the same, and a method for manufacturing the light-emitting element.

A reflective structure is often provided in a light-emitting device to concentrate the light. For example, in a flip-chip light-emitting diode (LED) component, a reflective layer is provided on the side opposite to the light-emitting surface, thereby reflecting the light emitted to the side opposite to the light-emitting surface back to the light-emitting surface, thereby concentrating the light source and increasing the brightness. However, during the manufacturing process of the flip-chip light-emitting diode component, the structure below the reflective layer has obvious ups and downs, so the reflective layer is also quite uneven. The uneven reflective surface will cause the reflected light to be diffused, and part of the light will not leave the light-emitting surface directly, but will be reflected multiple times inside the structure, causing light loss.

This application provides a light-emitting element, a light-emitting device having the same, and a method for manufacturing the light-emitting element. In the light-emitting element of some embodiments of this application, the reflective layer is formed on a relatively flat surface, thereby avoiding the problem caused by the reflective surface being not flat enough.

The light-emitting element according to the embodiment includes a substrate, a first semiconductor layer, a semiconductor stack, a first protective layer, a transparent conductive oxide layer, and a metal reflective layer. The first semiconductor layer is disposed on the substrate. The first semiconductor layer includes a first part and a second part connected to the first part. The semiconductor stack is disposed on the first part. The semiconductor stack includes an active region and a second semiconductor layer. The active region is disposed on the first semiconductor layer. The second semiconductor layer is disposed on the active region. The conductivity type of the second semiconductor layer is different from the conductivity type of the first semiconductor layer. The first protective layer is disposed on the semiconductor stack. The first protective layer has one or more first protective layer openings on the second semiconductor layer. The transparent conductive oxide layer is disposed on the first protective layer and fills the opening of the first protective layer to provide a flat surface. The metal reflective layer is disposed on the flat surface and electrically connected to the second semiconductor layer through the transparent conductive oxide layer. The transparent conductive oxide layer is not covered by the first protective layer.

The light-emitting device according to the embodiment includes the light-emitting element according to the embodiment, which is arranged in the light-emitting device in a flip-chip manner.

The manufacturing method of the light-emitting element according to the embodiment includes the following steps. First, a substrate is provided. A first semiconductor layer is formed on the substrate, including a first portion and a second portion connected to the first portion. A semiconductor stack is formed on the first portion, including forming an active region on the first portion and forming a second semiconductor layer on the active region. The conductivity type of the second semiconductor layer is different from the conductivity type of the first semiconductor layer. A first protective layer is formed on the semiconductor stack and one or more first protective layer openings are formed on the second semiconductor layer. A transparent conductive oxide layer is formed on the first protective layer and the first protective layer openings are filled to provide a flat surface. Afterwards, a metal reflective layer is formed on the flat surface and contacts the transparent conductive oxide layer to electrically connect to the second semiconductor layer.

In order to better understand the above and other aspects of this application, the following is a specific example, and the attached drawings are explained in detail as follows:

1A, 2A, 3A, 4A: Light-emitting device

1P, 2P, 3P: luminescent package

100, 200, 300, 400, 500, 1000: light-emitting element

101P: Translucent body

102: Substrate

102P: Reflector

102w: side surface

103a, 103b: metal bumps

104: First semiconductor layer

104A: Part 1

104B: Part 2

106: Semiconductor stacking

108: Active area

110: Second semiconductor layer

112: First protective layer

114, 214, 314, 414, 514: Transparent conductive oxide layer

116, 516: Metal reflective layer

118: Ohm contact layer

120, 520: Barrier layer

122: Second protective layer

124: Conductive layer

124A: First conduction part

124B: Second conduction part

126: The third protective layer

128:Pad layer

128A: First pad

128B: Second pad

201P: Reflection structure

202P:Packaging substrate

203P: First gasket

204P: Second gasket

205P: Insulation Department

300P: Support substrate

301: First pad

302: Second solder pad

303: First bump

304: Second bump

305: Wavelength converter

306: Lens

401A: Lampshade

402A: Reflector

403A: Carrier Department

404A: Light-emitting unit

405A: Light-emitting module

406A: Lamp holder

407A: Heat sink

408A:Connection part

409A: Electrical connection components

500A, 600: Display panel

501: Bottom cover

502, 606: reflective sheet

503:Diffusion plate

504, 605: Optical film

505: Lens

514A: first transparent conductive part

514B: Second transparent conductive part

516A: First reflection part

516B: Second reflection part

520A: First barrier section

520B: Second barrier section

601:Framework

602, 603: Cover

604: Light guide plate

607, 701: carrier board

700: Light body

702: Cover lens

703: Heat dissipation unit

704: Support ribs

705: Connecting parts

706: Heat sink

707: Cooling fan

C: Depression

h: height difference

O1: Opening of the first protective layer

O2: Second protective layer opening

O3: Opening of protective layer

O4: First welding pad opening

O5: Second welding pad opening

S: Flat surface

S1~S12, S31, S32: Steps

Figure 1 is a schematic cross-sectional view of a light-emitting element according to an embodiment.

Figure 2 is a schematic cross-sectional view of a light-emitting element according to an embodiment.

Figure 3 is a schematic cross-sectional view of a light-emitting element according to an embodiment.

Figure 4 is a schematic cross-sectional view of a light-emitting element according to an embodiment.

Figure 5 is a schematic cross-sectional view of a light-emitting element according to an embodiment.

Figure 6 is a flow chart showing a method for manufacturing a light-emitting element according to an embodiment.

Figure 7 is a schematic diagram of a light-emitting package according to an embodiment.

Figure 8 is a schematic diagram of a light-emitting package according to an embodiment.

Figure 9 is a schematic diagram of a light-emitting package according to an embodiment.

Figure 10 is a schematic diagram of a light-emitting device according to an embodiment.

Figure 11 is a schematic diagram of a light-emitting device according to an embodiment.

Figure 12 is a schematic diagram of a light-emitting device according to an embodiment.

Figure 13 is a schematic diagram of a light-emitting device according to an embodiment.

The following will be described in more detail with the accompanying drawings for various different embodiments. For the sake of clarity, the elements in the drawings may not be drawn according to the actual scale. In addition, some elements and/or symbols may be omitted in some drawings. In the drawings, similar symbols are used to indicate similar elements. The following content and the accompanying drawings are provided for illustration only and are not intended to be limiting. It is expected that the elements and features of one embodiment can be advantageously incorporated into another embodiment without further elaboration.

One aspect of this application is a light-emitting element. Please refer to Figure 1, which is a cross-sectional schematic diagram of a light-emitting element 100 according to an embodiment.

The light-emitting element 100 includes a substrate 102, a first semiconductor layer 104, a semiconductor stack 106, a first protective layer 112, a transparent conductive oxide layer 114, and a metal reflective layer 116. The first semiconductor layer 104 is disposed on the substrate 10. The first semiconductor layer 104 includes a first portion 104A and a second portion 104B connected to the first portion 104A. The semiconductor stack 106 is disposed on the first portion 104A. The semiconductor stack 106 includes an active region 108 and a second semiconductor layer 110. The active region 108 is disposed on the first semiconductor layer 104. The second semiconductor layer 110 is disposed on the active region 108. The conductivity type of the second semiconductor layer 110 is different from the conductivity type of the first semiconductor layer 104. The first protective layer 112 is disposed on the semiconductor stack 106. The first protective layer 112 has one or more first protective layer openings O1 on the second semiconductor layer 110. The transparent conductive oxide layer 114 is disposed on the first protective layer 112 and fills the first protective layer openings O1 to provide a flat surface S. The metal reflective layer 116 is disposed on the flat surface S and is electrically connected to the second semiconductor layer 110 through the transparent conductive oxide layer 114.

More specifically, the substrate 102 may be a growth substrate for epitaxially growing semiconductor stacks such as the first semiconductor layer 104 and the semiconductor stack 106, including a gallium arsenide (GaAs) substrate and a gallium phosphide (GaP) substrate for growing gallium indium phosphide (AlGaInP), or a sapphire ( _Al2O3 ) substrate, a gallium nitride (GaN) substrate, a silicon carbide ( _SiC ) substrate, and an aluminum nitride (AlN) substrate for growing gallium indium nitride (InGaN) or aluminum gallium nitride (AlGaN). The substrate 102 may also be a carrier substrate, and the semiconductor stack crystal formed by epitaxial growth of the growth substrate is bonded to the carrier substrate by a process such as wafer transfer, and then the growth substrate is removed to continue the subsequent process. The carrier substrate includes a conductive material or a semiconductor material, and the carrier substrate may be light-transmissive or light-opaque. The conductive light-transmissive material includes but is not limited to a transparent conductive oxide (TCO), such as zinc oxide (ZnO); the conductive light-opaque material includes but is not limited to a metal material, such as aluminum (Al), copper (Cu), molybdenum (Mo), germanium (Ge) or tungsten (W) or an alloy or stack of the above materials; the semiconductor material includes silicon (Si), silicon carbide (SiC), gallium arsenide (GaAs), gallium nitride (GaN), aluminum nitride (AlN), gallium phosphide (GaP), gallium arsenide phosphide (GaAsP), zinc selenide (ZnSe), zinc selenide (ZnSe) or indium phosphide (InP). The substrate 102 may be a patterned substrate, that is, the upper surface of the substrate has a patterned structure (not shown). In one embodiment, light emitted from the active region 108 can be refracted or reflected by the patterned structure of the substrate 102, thereby improving the light extraction efficiency of the light emitting element. In one embodiment, when the substrate 102 is used as a growth substrate, its patterned structure reduces or suppresses the misalignment caused by lattice mismatch between the substrate 102 and the first semiconductor layer 104, the active region 108, and the second semiconductor layer 110, thereby improving the epitaxial quality.

In one embodiment, before forming the first semiconductor layer 104 on the substrate 102, a buffer structure (not shown) may be formed first. The buffer structure may further alleviate the above-mentioned lattice mismatch and suppress dislocation, thereby improving the epitaxial quality. The material of the buffer layer includes a material suitable for the above-mentioned semiconductor stack epitaxial growth, such as GaN, AlGaN or AlN. The method for forming the buffer structure includes metal organic chemical vapor deposition (MOCVD), molecular beam epitaxy (MBE), hydrogen vapor phase epitaxy (HVPE) or ion plating, such as sputtering or evaporation. In one embodiment, the buffer structure includes a plurality of sub-layers (not shown). The sub-layers include the same material or different materials. In one embodiment, the buffer structure includes two sublayers, wherein the growth method of the first sublayer is sputtering, and the growth method of the second sublayer is MOCVD. In one embodiment, the buffer layer further includes a third sublayer. The growth method of the third sublayer is MOCVD, and the growth temperature of the second sublayer is higher or lower than the growth temperature of the third sublayer. In one embodiment, the first, second and third sublayers include the same material, such as AlN, or different materials, such as AlN, GaN, or AlGaN. In one embodiment of the present application, the first semiconductor layer 104 and the second semiconductor layer 110, such as a cladding layer or a confinement layer, have different conductivity types, electrical properties, polarities, or doping elements for providing electrons or holes. For example, the first semiconductor layer 104 is an n-type semiconductor, and the second semiconductor layer 110 is a p-type semiconductor. The active region 108 is formed between the first semiconductor layer 104 and the second semiconductor layer 110. Electrons and holes combine in the active region 108 under current drive, converting electrical energy into light energy to emit light. The wavelength of light emitted by the light-emitting element 100 can be adjusted by changing the physical properties and chemical composition of one or more of the layers.

x，y

1；x+y

1。根據主動區域108的材料，當主動區域108的材料是AlInGaP系列時，可以發出波長介於610nm和650nm之間的紅光或波長介於550nm和570nm之間的黃光。當主動區域108的材料是InGaN 系列時，可以發出波長介於400nm和490nm之間的藍光或深藍光或波長介於490nm和550nm之間的綠光。當主動區域108的材料是AlGaN系列時，可以發出波長介於400nm和250nm之間的UV光。主動區域108可以是單異質結構(single heterostructure；SH)、雙異質結構(double heterostructure；DH)、雙面雙異質結構(double-side double heterostructure；DDH)、多重量子井(multi-quantum well；MQW)。主動區域108的材料可以是i型、p型或n型半導體。 The materials of the first semiconductor layer 104, the active region 108 and the second _{semiconductor} layer 110 include III-V semiconductor materials of _{AlxInyGa (1-xy)} N or _AlxInyGa (1- _{xy )} P, wherein 0

x,y

1; x+y

1. According to the material of the active region 108, when the material of the active region 108 is AlInGaP series, red light with a wavelength between 610nm and 650nm or yellow light with a wavelength between 550nm and 570nm can be emitted. When the material of the active region 108 is InGaN series, blue light or deep blue light with a wavelength between 400nm and 490nm or green light with a wavelength between 490nm and 550nm can be emitted. When the material of the active region 108 is AlGaN series, UV light with a wavelength between 400nm and 250nm can be emitted. The active region 108 may be a single heterostructure (SH), a double heterostructure (DH), a double-side double heterostructure (DDH), or a multi-quantum well (MQW). The material of the active region 108 may be an i-type, p-type, or n-type semiconductor.

According to some embodiments, the light emitting element 100 may further include an ohmic contact layer 118 disposed between the semiconductor stack 106 and the first protective layer 112, covering an upper surface of the second semiconductor layer 110, and electrically contacting the second semiconductor layer 110. In this embodiment, the edge of the ohmic contact layer 118 is formed inwardly on the second semiconductor layer 110, and is spaced a distance from the edge of the adjacent second semiconductor layer 110. The ohmic contact layer 118 can be a metal or a transparent conductive material, wherein the metal can be selected from a thin metal layer with light transmittance, such as gold (Au), aluminum (Al), titanium (Ti), nickel (Ni), chromium (Cr) or an alloy or stack of the above materials. The transparent conductive material is transparent to the light emitted by the active region 108, and includes materials such as graphene, indium tin oxide (ITO), aluminum zinc oxide (AZO), gallium zinc oxide (GZO), zinc oxide (ZnO) or indium zinc oxide (IZO). In one embodiment, the material of the ohmic contact layer 118 is the same as or different from the material of the transparent conductive oxide layer 114.

The first protective layer 112 is formed on the second semiconductor layer 110. In one embodiment, the first protective layer 112 is formed on an upper surface of the ohmic contact layer 118, extending to cover a portion of the second semiconductor layer 110, a side surface of the first portion 104A of the first semiconductor layer 104, and an upper surface of the second portion 104B. The first protective layer 112 includes one or more first protective layer openings O1 located on the second semiconductor layer 110, exposing a portion of the second semiconductor layer 110 and/or the ohmic contact layer 118. The first protective layer 112 is transparent to the light emitted by the active area 108, and its material is a non-conductive material, including an organic material or an inorganic material. The organic materials include Su8, benzocyclobutene (BCB), perfluorocyclobutane (PFCB), epoxy, acrylic resin, cycloolefin polymer (COC), polymethyl methacrylate (PMMA), polyethylene terephthalate (PET), polycarbonate (PC), polyetherimide, polyimide or fluorocarbon polymer. The inorganic materials include silicone, glass or dielectric materials. Dielectric materials include: silicon-containing materials, such as silicon oxide ( _SiNx ), silicon nitride ( _SiOx ), silicon oxynitride ( _SiOxNy ); metal oxides, such as niobium oxide ( _Nb2O5 ), _tantalum oxide ( _Ta2O5 ), _ferrous oxide ( _HfO2 ), titanium oxide ( _TiOx ), aluminum oxide ( _Al2O3 ); metal fluorides, _such as _magnesium fluoride ( _MgF2 ). The first protection layer 112 can be formed by stacking multiple sub-layers. In one embodiment, the multiple sub-layers are formed by dielectric materials. The dielectric material includes: silicon-containing materials, such as silicon oxide ( _SiOx ), silicon nitride ( _SiNx ), or silicon oxynitride ( _SiOxNy ); metal oxides, such as _tantalum oxide ( _Ta2O5 ), niobium oxide ( _Nb2O5 ), _niobium oxide ( _HfO2 ), titanium oxide ( _TiOx ), or aluminum oxide ( _Al2O3 ); metal fluorides, such as _magnesium fluoride ( _MgF2 ). In one embodiment, the first protective layer 112 is stacked into _a material stack by selecting materials with different refractive indices and designing their thicknesses to form a reflective structure, which provides a reflective function for light in a specific wavelength range emitted by the active region 108, such as a distributed Bragg reflector (DBR).

In the light-emitting element 100, the transparent conductive oxide layer 114 is disposed on the first protective layer 112. An upper surface of the transparent conductive oxide layer 114 is higher than an upper surface of the first protective layer 112, and the upper surface of the transparent conductive oxide layer 114 constitutes a flat surface S. According to some embodiments, the material selection conditions of the transparent conductive oxide layer 114 may be a light transmittance greater than 90% and a resistivity less than or equal to 1×10 ^-3 ohmm. cm. For example, the material of the transparent conductive oxide layer 114 may be indium tin oxide (ITO), indium zinc oxide (IZO), aluminum zinc oxide (AZO), gallium zinc oxide (GZO) or zinc oxide (ZnO), but is not limited thereto. In one embodiment, when the thickness of the first protective layer 112 is relatively large, for example, greater than 200 nm, the material of the transparent conductive oxide layer 114 may be selected from materials with higher light transmittance, such as IZO or ZnO, so that when the thickness reaches a thickness close to that of the first protective layer 112, the material of the transparent conductive oxide layer 114 can still take into account high light transmittance to improve the brightness of the light-emitting element. In the formation method of the conductive oxide layer 114, after depositing the material of the transparent conductive oxide layer 114, a planarization process, such as chemical mechanical planarization (CMP) treatment, may be performed to improve the surface flatness. In some embodiments, the width of the transparent conductive oxide layer 114 may be greater than the width of the second semiconductor layer 110. In some embodiments, the transparent conductive oxide layer 114 may extend beyond the edge of the second semiconductor layer 110 and be formed on the sidewall of the semiconductor stack 106 , and be electrically insulated from the semiconductor stack 106 by the first protection layer 112 .

In the light-emitting element 100, only the transparent conductive oxide layer 114 provides a flat surface S on which the metal reflective layer 116 is to be formed. It is understandable that the so-called "flatness" in this application still allows for some errors or defects caused by the process. According to some embodiments, the height difference between the highest point and the lowest point of the flat surface S is less than 5nm. According to some embodiments, the surface roughness Ra of the flat surface S is less than 1nm.

The metal reflective layer 116 is disposed on the flat surface S, thereby forming a flat layer without obvious ups and downs, thereby providing a flat reflective surface. The metal reflective layer 116 is electrically connected to the second semiconductor layer 110 via the transparent conductive oxide layer 114. The external injection current passes through the metal reflective layer 116, and then electrically connects to the second semiconductor layer 110 via the first protective layer opening O1 to achieve the effect of uniform current distribution. In one embodiment, the metal reflective layer 116 may include a single metal layer or a stacked layer formed by a plurality of metal layers, and the first protective layer 112 may include a single layer or a stacked layer formed by multiple layers, such as a distributed Bragg reflector. In one embodiment, the metal reflective layer 116, the transparent conductive oxide layer 114 and the first protective layer 112 form an omnidirectional reflector (ODR) to enhance the reflection of light and the brightness of the light-emitting element 100. The metal reflective layer 116 may include a metal material having a high reflectivity for the light emitted by the active area 108, such as silver (Ag), gold (Au), aluminum (Al), titanium (Ti), chromium (Cr), copper (Cu), nickel (Ni), platinum (Pt), ruthenium (Ru), tungsten (W) or alloys or stacks of the above materials.

According to some embodiments, the light emitting element 100 may further include a barrier layer 120 disposed on the metal reflective layer 116. The barrier layer 120 may be made of metal, such as chromium (Cr), aluminum (Al), platinum (Pt), titanium (Ti), tungsten (W), zinc (Zn), or alloys or stacks thereof. In one embodiment, when the barrier layer 120 is a metal stack, the barrier layer 120 is formed by alternately stacking two or more metal layers, such as Cr/Pt, Cr/Ti, Cr/TiW, Cr/W, Cr/Zn, Ti/Al, Ti/Pt, Ti/W, Ti/TiW, Ti/Zn, Pt/TiW, Pt/W, Pt/Zn, TiW/W, TiW/Zn, or W/Zn. In one embodiment, the material of the barrier layer 120 may include a transparent conductive material, including graphene, indium tin oxide (ITO), aluminum zinc oxide (AZO), gallium zinc oxide (GZO), zinc oxide (ZnO), or indium zinc oxide (IZO). In one embodiment, the edge of the metal reflective layer 116 is inwardly contracted to the edge of the adjacent second semiconductor layer 110, and the edge of the ohmic contact layer 118 is inwardly contracted to the edge of the adjacent metal reflective layer 116. In other words, there is a gap between the edge of the metal reflective layer 116 and the edge of the adjacent second semiconductor layer 110, and there is a gap between the edge of the ohmic contact layer 118 and the edge of the adjacent metal reflective layer 116. In one embodiment, the edge of the metal reflective layer 116 is indented to the edge of the adjacent transparent conductive oxide layer 114, and the edge of the ohmic contact layer 118 is indented to the edge of the adjacent metal reflective layer 116. In other words, the edge of the metal reflective layer 116 is located between the edge of the adjacent transparent conductive oxide layer 114 and the edge of the adjacent ohmic contact layer 118.

According to some embodiments, the light emitting device 100 may further include a second protective layer 122 disposed on the barrier layer 120. The second protective layer 122 extends from the barrier layer 120 to cover the sidewall of the first protective layer 112. In one embodiment, the second protective layer 122 is formed on the barrier layer 120. In one embodiment, the second protective layer 122 includes one or more second protective layer openings O2 located on the barrier layer 120 and exposing the barrier layer 120. The first protective layer 112 and the second protective layer 122 further include one or more protective layer openings (not shown) located on the second portion 104B of the first semiconductor layer 104 and exposing the second portion 104B of the first semiconductor layer 104. In one embodiment, the protective layer openings of the first protective layer 112 and the second protective layer 122 on the second portion 104B of the first semiconductor layer 104 have an overlapping protective layer opening O3. The second protective layer 122 is transparent to the light emitted by the active area 108 and is made of a non-conductive material, including an organic material or an inorganic material. The organic materials include Su8, benzocyclobutene (BCB), perfluorocyclobutane (PFCB), epoxy, acrylic resin, cycloolefin polymer (COC), polymethyl methacrylate (PMMA), polyethylene terephthalate (PET), polycarbonate (PC), polyetherimide, polyimide or fluorocarbon polymer. The inorganic materials include silicone, glass or dielectric materials. Dielectric materials include silicon-containing materials, such as silicon oxide ( _SiNx ), silicon nitride ( _SiNx ), silicon oxynitride ( _SiOxNy ) _, metal oxides, such as niobium oxide ( _Nb2O5 ), _tantalum oxide ( _Ta2O5 ), helium oxide ( _HfO2 ), titanium oxide ( _TiOx ), aluminum oxide ( _Al2O3 ), and metal fluorides, such as _magnesium fluoride ( _MgF2 ). The second protection layer 122 can be formed _by stacking multiple sub-layers. In one embodiment, the plurality of sub-layers are formed of a dielectric material, the dielectric material comprising: a silicon-containing material, such as silicon oxide ( _SiOx ), silicon nitride ( _SiNx ), or silicon oxynitride ( _SiOxNy ); a metal oxide, such as _{niobium oxide (Nb2O5 )} , _tantalum oxide ( _Ta2O5 ), helium oxide _{( HfO2} ), titanium oxide ( _TiOx ), or aluminum oxide ( _Al2O3 ); a metal fluoride, such as _magnesium fluoride ( _MgF2 ). In one embodiment, the second protective layer 122 is stacked into a material layer to form a reflective structure by selecting materials with different refractive indices and designing their thicknesses, and provides a reflective function for light in a specific wavelength range emitted by the active area 108, such as a distributed Bragg reflector (DBR).

According to some embodiments, the light-emitting element 100 may further include a conductive layer 124 disposed on the second protective layer 122. The conductive layer 124 includes a first conductive portion 124A and a second conductive portion 124B separated from each other. The first conductive portion 124A covers the first protective layer 112 and the second protective layer 122 and contacts the second portion 104B of the first semiconductor layer 104 through the protective layer opening O3 to electrically connect the first semiconductor layer 104. The second conductive portion 124B contacts the barrier layer 120 through the second protective layer opening O2 to electrically connect the second semiconductor layer 110. In one embodiment, the conductive layer 124 includes a metal material, such as silver (Ag), aluminum (Al), chromium (Cr), platinum (Pt), gold (Au), titanium (Ti), tungsten (W), zinc (Zn), or an alloy or a stack of the above materials.

According to some embodiments, the light-emitting element 100 may further include a third protective layer 126, a first pad opening O4, and a second pad opening O5, which are disposed on the conductive layer 124. The third protective layer 126 extends from the conductive layer 124 to cover the sidewall of the second protective layer 122, and further extends to cover the second portion 104B of the first semiconductor layer 104 and/or the upper surface of the substrate at the periphery of the substrate 102. The first pad opening O4 exposes the first conductive portion 124A, and the second pad opening O5 exposes the second conductive portion 124B. The third protective layer 126 is transparent to the light emitted by the active region 108, and its material is a non-conductive material, including an organic material or an inorganic material. The organic materials include Su8, benzocyclobutene (BCB), perfluorocyclobutane (PFCB), epoxy, acrylic resin, cycloolefin polymer (COC), polymethyl methacrylate (PMMA), polyethylene terephthalate (PET), polycarbonate (PC), polyetherimide, polyimide or fluorocarbon polymer. The inorganic materials include silicone, glass or dielectric materials. Dielectric materials include: silicon-containing materials, such as silicon oxide ( _SiNx ), silicon nitride ( _SiNx ), silicon oxynitride ( _SiOxNy ); metal oxides, such as niobium oxide ( _Nb2O5 ), _tantalum oxide ( _{Ta2O5 )} , helium oxide ( _HfO2 ), titanium oxide ( _TiOx ), aluminum oxide ( _Al2O3 ); metal fluorides, such as _magnesium fluoride ( _MgF2 ). The third protection layer 126 can be formed _by stacking multiple sub-layers. In one embodiment, the plurality of sub-layers are formed of a dielectric material, the dielectric material comprising: a silicon-containing material, such as silicon oxide ( _SiOx ), silicon nitride ( _SiNx ), or silicon oxynitride ( _SiOxNy ); a metal oxide, such as niobium oxide ( _Nb2O5 ), _tantalum oxide ( _Ta2O5 ), helium oxide _{( HfO2} ), titanium oxide ( _TiOx ), or aluminum oxide ( _Al2O3 ); a metal fluoride, such as _magnesium fluoride ( _MgF2 ). In one embodiment, the third protective layer 126 is stacked into a material layer to form a reflective structure by selecting materials with different refractive indices and designing their thicknesses, and provides a reflective function for light in a specific wavelength range emitted by the active area 108, such as a distributed Bragg reflector (DBR).

According to some embodiments, the light emitting device 100 may further include a pad layer 128 disposed on the third protective layer 126. The pad layer 128 includes a first pad 128A and a second pad 128B, and is electrically connected to the first semiconductor layer 104 and the second semiconductor layer 110 by contacting the first conductive portion 124A and the second conductive portion 124B, respectively. In one embodiment, the first pad 128A and/or the second pad 128B may be covered on the third protective layer 126 to increase the area of the first pad 128A and the second pad 128B, and further increase the bonding area when bonding to the outside in the subsequent packaging process. The first pad 128A and the second pad 128B include metal materials, such as chromium (Cr), titanium (Ti), tungsten (W), gold (Au), aluminum (Al), indium (In), tin (Sn), nickel (Ni), platinum (Pt), or a stack or alloy of the above materials. The first pad 128A and the second pad 128B may be composed of a single layer or multiple layers. For example, the first pad 128A and the second pad 128B may include Ti/Al, Ti/Au, Ti/Pt/Au, Cr/Au, Cr/Pt/Au, Ni/Au, Ni/Pt/Au, or Cr/Al/Cr/Ni/Au. In one embodiment, the surfaces of the first pad 128A and the second pad 128B have a plurality of recesses (not shown) corresponding to the openings of the first protective layer 112, the second protective layer 122, and the third protective layer 126. Through the plurality of recesses, the bonding force between the pad and the carrier can be enhanced in the subsequent packaging process to improve the process yield.

Without violating the spirit of the present application, the structure of the light-emitting element can be adjusted in various ways. For example, please refer to FIG. 2, which is a cross-sectional schematic diagram of a light-emitting element 200 according to an embodiment. The process and structure of the light-emitting element 200 are similar to those of the light-emitting element 100. For similar processes and structures, please refer to the description and drawings of the light-emitting element 100, and will not be repeated here. The differences will be described later. The light-emitting element 200 is different from the light-emitting element 100 in that an upper surface of the transparent conductive oxide layer 214 is substantially flush with the upper surface of the first protective layer 112, and the upper surface of the transparent conductive oxide layer 114 and the upper surface of the first protective layer 112 together constitute a flat surface S. Furthermore, the metal reflective layer 116 is formed on the flat surface S provided by the transparent conductive oxide layer 114 and the first protective layer 112. Such a structure can be achieved by, for example, adjusting the CMP process parameters of the transparent conductive oxide layer 114. Other components and features of the light-emitting element 200 are similar to those of the light-emitting element 100 and will not be described again here.

Please refer to FIG. 3, which is a schematic cross-sectional view of a light-emitting element 300 according to an embodiment. The manufacturing process and structure of the light-emitting element 300 are similar to those of the light-emitting element 100. For similar manufacturing processes and structures, please refer to the description and drawings of the light-emitting element 100, and will not be repeated here. The differences will be described later. The light-emitting element 300 is different from the light-emitting element 100 in that, due to factors such as the manufacturing process, the transparent conductive oxide layer 314 may be slightly concave at the position corresponding to the first protective layer opening O. Therefore, the flat surface S has one or more depressions C at the positions corresponding to one or more first protective layer openings O. In one embodiment, the metal reflective layer 116 forms a smooth convex surface corresponding to the position of one or more depressions C. The light emitted by the active area 108 is reflected by the convex surface and the plane of the metal reflective layer 116, which can further improve the light extraction efficiency. In one embodiment, even if there is a depression C, the height difference h between the highest point and the lowest point of the flat surface S is still less than 5nm. In one embodiment, the flat surface S includes a lowest point located at one or more depressions C, and the height difference between the highest point and the lowest point of the flat surface S is less than 5nm. Compared with traditional flip-chip LED components, the problem caused by the uneven reflective surface can still be greatly improved. Other components and features of the light-emitting element 300 are similar to those of the light-emitting element 100 and will not be repeated here.

Please refer to FIG. 4, which is a schematic cross-sectional view of a light-emitting element 400 according to an embodiment. The manufacturing process and structure of the light-emitting element 400 are similar to those of the light-emitting element 100. For similar manufacturing processes and structures, please refer to the description and drawings of the light-emitting element 100, and no further description will be given. The differences will be described later. The light-emitting element 400 is different from the light-emitting element 100 in that an upper surface of the transparent conductive oxide layer 414 is substantially flush with the upper surface of the first protective layer 112, and the upper surface of the transparent conductive oxide layer 414 and the upper surface of the first protective layer 112 together form a flat surface S. In addition, affected by factors such as the manufacturing process, the flat surface S has one or more recesses C corresponding to one or more first protective layer openings O. In one embodiment, the metal reflective layer 116 forms a smooth convex surface corresponding to one or more depressions C. The light emitted from the active area 108 is reflected by the convex surface and the plane of the metal reflective layer 116, which can further improve the light extraction efficiency. In one embodiment, even if there is a depression C, the height difference h between the highest point and the lowest point of the flat surface S is still less than 5nm. In one embodiment, the flat surface S includes a lowest point located at one or more depressions C, and the height difference between the highest point and the lowest point of the flat surface S is less than 5nm. Compared with traditional flip-chip LED components, the problem caused by the uneven reflective surface can still be greatly improved. Other components and features of the light-emitting element 400 are similar to those of the light-emitting element 100 and will not be repeated here.

Please refer to FIG. 5, which is a schematic cross-sectional view of a light-emitting device 500 according to an embodiment. The manufacturing process and structure of the light-emitting device 500 are similar to those of the light-emitting device 100. For similar manufacturing processes and structures, please refer to the description and drawings of the light-emitting device 100, and no further description will be given. The differences will be described later. The light-emitting device 500 is different from the light-emitting device 100 in that the transparent conductive oxide layer 514 includes a first transparent conductive portion 514A disposed above the semiconductor stack 106, and a second transparent conductive portion 514B is located on the second portion 104B of the first semiconductor layer 104. In one embodiment, the metal reflective layer 516 includes a first reflective portion 516A disposed on the first transparent conductive portion 514A, and a second reflective portion 516B disposed on the second transparent conductive portion 514B, the barrier layer 520 includes a first barrier portion 520A disposed on the first reflective portion 516A, and a second barrier portion 520B disposed on the second reflective portion 516B, the second protective layer 122 is not only located on the first barrier portion 520A, but also on the second barrier portion 520B, and the third protective layer 126 is not only located on the first barrier portion 520A, but also extends to cover the second barrier portion 520B. According to some embodiments, an upper surface of the first transparent conductive portion 514A is flush with an upper surface of the second transparent conductive portion 514B, thereby making an upper surface of the first reflective portion 516A and an upper surface of the first barrier portion 520A flush with an upper surface of the second reflective portion 516B and an upper surface of the second barrier portion 520B, respectively. By forming the transparent conductive oxide layer 514 and the metal reflective layer 516 on the second portion 104B of the first semiconductor layer 104, the light emitted from the sidewall of the semiconductor stack 106 can be reflected, thereby improving the forward light extraction.

In the light-emitting element of the present application, the transparent conductive oxide layer provides a flat surface for the metal reflective layer to be formed thereon, thereby providing a flat reflective surface to reduce or avoid light loss caused by diffusion in the structure. The first protective layer, the transparent conductive oxide layer, and the flat metal reflective layer can further form an ODR structure to obtain excellent optical reflection. It is understood that the light-emitting element of the present application can be appropriately adjusted and modified according to needs, as long as it does not deviate from the spirit of the present application.

Another aspect of the present application is a method for manufacturing a light-emitting element, which is used to manufacture a light-emitting element according to an embodiment. Please refer to FIG. 6, which is a flow chart of a method for manufacturing a light-emitting element according to an embodiment. You can also refer to FIG. 1 at the same time to understand the manufacturing method more clearly.

First, in step S1, a substrate 102 is provided. In step S2, a first semiconductor layer 104 is formed on the substrate 102. The first semiconductor layer 104 includes a first portion 104A and a second portion 104B connected to the first portion 104A.

In step S3, a semiconductor stack 106 is formed on the first portion 104A. This step includes steps S31 and S32. In step S31, an active region 108 is formed on the first semiconductor layer 104. In step S32, a second semiconductor layer 110 is formed on the active region 108. The conductivity type of the second semiconductor layer 110 is different from the conductivity type of the first semiconductor layer 104. In one embodiment, two regions of the first portion 104A and the second portion 104B of the first semiconductor layer 104 are defined, and the second semiconductor layer 110 and the active region 108 on the second portion 104B are removed downward from an upper surface of the second semiconductor layer 110, or a portion of the first semiconductor layer 104 is further etched to a depth to expose the upper surface of the first semiconductor layer 104, and the active region 108 and the second semiconductor layer 110 that are not removed on the first portion 104A form a semiconductor stack 106. In one embodiment, the method of removing the second semiconductor layer 110 and the active region 108 on the second portion 104B includes defining the first portion 104A and the second portion 104B by a mask, and then removing the second semiconductor layer 110 and the active region 108 on the second portion 104B by etching and developing. In one embodiment of the present application, the method of forming the first semiconductor layer 104, the active region 108 and the second semiconductor layer 110 on the substrate 102 includes metal organic chemical vapor deposition (MOCVD), molecular beam epitaxy (MBE), hydrogenated vapor phase epitaxy (HVPE) or ion plating, such as sputtering or evaporation.

In the optional step S4, an ohmic contact layer 118 may be formed on the semiconductor stack. The ohmic contact layer 118 may be formed by a deposition process or a sputtering process, an evaporation process, and a yellow light developing etching or a lift-off process, but is not limited thereto.

In step S5, a first protection layer 112 is formed on the semiconductor stack 106, one or more first protection layer openings O1 are formed on the second semiconductor layer 110, and one or more protection layer openings (not shown) are located on the second portion 104B of the first semiconductor layer 104 and expose the second portion 104B of the first semiconductor layer 104. In one embodiment, in the step of forming the first protective layer 112, the first protective layer opening O1 and the protective layer opening, a first insulating material layer may be formed by atomic layer deposition (ALD), sputtering, evaporation and spin-coating, and then the first protective layer opening O and one or more protective layer openings may be formed in the first insulating material layer by yellow light etching or lift-off to form the first protective layer 112.

In step S6, a transparent conductive oxide layer 114 is formed on the first protective layer 112 and fills the first protective layer opening O1 to provide a flat surface S. For example, the transparent conductive oxide layer 114 can be formed by a deposition process or a sputtering process, an evaporation process, and a yellow light development etching or lift-off process, and then a planarization process is performed, such as a chemical mechanical planarization (CMP) process, to improve the surface flatness. In some embodiments, as shown in FIG. 2 and FIG. 4, CMP parameters can be adjusted so that the upper surface of the transparent conductive oxide layer 214/414 can be substantially flush with the upper surface of the first protective layer 112, and the upper surface of the transparent conductive oxide layer 214/414 and the upper surface of the first protective layer 112 together constitute a flat surface S on which the metal reflective layer 116 is formed. In some embodiments, as shown in FIG. 5, the transparent conductive oxide layer 514 can be patterned by yellow light etching or lift-off, and the first transparent conductive portion 514A is formed on the semiconductor stack 106 and the second transparent conductive portion 514B is formed on the second portion 104B, wherein the second portion 104B is not covered by the semiconductor stack 106.

In step S7, a metal reflective layer 116 is formed on the flat surface S and contacts the transparent conductive oxide layer 114 to electrically connect the second semiconductor layer 110. The metal reflective layer 116 is formed, for example, by a deposition process or a sputtering process, an evaporation process, and yellow light development etching or lift-off, but is not limited thereto. In some embodiments, as shown in FIG. 5, the metal reflective layer 516 can be patterned by yellow light development etching or lift-off, and the first reflective portion 516A is formed on the first transparent conductive portion 514A and the second reflective portion 516B is formed on the second transparent conductive portion 514B.

In the optional step S8, a barrier layer 120 may be formed on the metal reflective layer 116. The barrier layer 120 may be formed, for example, by a deposition process or an evaporation sputtering process and yellow light photolithography or lift-off, but is not limited thereto. In some embodiments, as shown in FIG. 5, the barrier layer 520 may be patterned by yellow light photolithography or lift-off, and the first barrier portion 520A may be formed on the first reflective portion 516A and the second barrier portion 520B may be formed on the second reflective portion 516B.

In step S9, a second protective layer 122, one or more second protective layer openings O2 may be formed on the barrier layer 120, and one or more protective layer openings may be formed on the second portion 104B of the first semiconductor layer 104. In one embodiment, in the step of forming the second protective layer 122, the second protective layer openings O2, and the protective layer openings, a second insulating material layer may be first formed by atomic deposition, sputtering, evaporation, spin coating, etc., and then the second protective layer openings O2 and the protective layer openings may be formed in the second insulating material layer by photolithography or lift-off to form the second protective layer 122. In one embodiment, the protective layer openings of the first protective layer 112 and the second protective layer 122 can be formed by forming a first and a second insulating material layer, and then using the same process of yellow light development etching or lift-off to form an overlapping protective layer opening O3.

In step S10, a conductive layer 124 can be formed on the second protective layer 122. The conductive layer 124 includes a first conductive portion 124A and a second conductive portion 124B, the first conductive portion 124A is electrically connected to the first semiconductor layer 104, and the second conductive portion 124B is electrically connected to the second semiconductor layer 110. The conductive layer 124 is formed by, for example, a deposition process or evaporation, sputtering process, yellow light development etching or lift-off, but is not limited thereto.

In step S11, a third protective layer 126, a first pad opening O4 and a second pad opening O5 can be formed on the conductive layer 124. In the step of forming the third protective layer 126, an insulating material layer can be formed by atomic deposition, sputtering, evaporation and spin coating, and then the first pad opening O4 can be formed by yellow light etching or lift-off to expose the first conductive part 124A, and the second pad opening O5 can be formed to expose the second conductive part 124B.

In step S12, a pad layer 128 may be formed on the third protective layer 126. The pad layer 128 includes a first pad 128A and a second pad 128B, the first pad 128A is electrically connected to the first conductive portion 124A, and the second pad 128B is electrically connected to the second conductive portion 124B. The pad layer 128 is formed, for example, by a deposition process or evaporation, sputtering process, yellow light development etching or lift-off, but is not limited thereto.

So far, a sufficient description has been provided for the manufacturing method of the light-emitting element of the present application. It can be understood that the light-emitting element of the present application can be appropriately adjusted and changed as needed, as long as it does not deviate from the spirit of the present application. Figure 7 is a schematic diagram of a light-emitting package 1P according to an embodiment. As shown in Figure 7, the light-transmitting body 101P covers the side surface 102w of the substrate 102. The metal bumps 103a and 103b are respectively provided corresponding to the first pad 128A and the second pad 128B. In detail, the metal bump 103a is connected to the first pad 128A. The metal bump 103b is connected to the second pad 128B. The reflector 102P covers a portion of the side walls of the metal bumps 103a and 103b. In one embodiment, the reflector 102P also covers a portion of the sidewalls of the first pad 128A and the second pad 128B.

The metal bump (103a, 103b) comprises a lead-free solder, which comprises at least one material selected from the group consisting of tin, copper, silver, bismuth, indium, zinc and antimony. The height of the metal bump is between 20 and 150 μm. In one embodiment, the metal bump is formed by a reflow soldering process. The solder paste is placed on the bonding pad and then heated in a reflow soldering furnace to melt the solder paste and produce a joint. The solder paste may contain tin-silver-copper, tin-antimony or gold-tin and have a melting point greater than 215°C, or greater than 220°C, or between 215~240°C (e.g. 217°C, 220°C, 234°C). In addition, the peak temperature during the reflow process (the peak temperature usually occurs in the reflow zone) is greater than 250°C, or greater than 260°C, or between 250~270°C (e.g. 255°C, 265°C).

The reflector 102P is an electrical insulator and includes a first matrix and a plurality of reflective particles mixed in the matrix (not shown). The first matrix has a silicone-based material or an epoxy-based material and has a refractive index (n) between 1.4 and 1.6 or 1.5 and 1.6. The reflective particles include titanium dioxide, silicon dioxide, aluminum oxide, zinc oxide, or zirconium dioxide. In one embodiment, when light emitted by the semiconductor stack 106 hits the reflector 102P, the light is reflected and this reflection is called diffuse reflection. In addition to the reflective function, the reflector 102P can also serve as a mechanical load and withstand the stress generated by the light-emitting package 1P during operation.

The light-transmitting body 101P includes a base material of a silicon substrate or a base material of an epoxy resin substrate. Furthermore, the light-transmitting body 101P may include a plurality of wavelength conversion particles (not shown) or/and diffusion powder particles dispersed therein to absorb the first light emitted by the light-emitting element 1000 and convert it into a second light of a different frequency spectrum from the first light, wherein the light-emitting element 1000 may be the light-emitting element in the aforementioned embodiment. If the first light is mixed with the second light, a third light will be generated. In this embodiment, the third light has a color point coordinate (x, y) in the CIE1931 chromaticity diagram, wherein 0.27≦x≦0.285; 0.23≦y≦0.26. In another embodiment, the first light is mixed with the second light to generate a third light, such as white light. According to the weight percentage concentration and type of the wavelength conversion particles, the light-emitting package can have a white light in a thermally stable state, with a relative color temperature (CCT) of 2200K~6500K (for example: 2200K, 2400K, 2700K, 3000K, 5000k, 5700K, 6500K), a color point coordinate (x, y) in the CIE1931 chromaticity diagram that falls within the range of seven MacAdam ellipses, and a color rendering index (CRI) greater than 80 or greater than 90. In another embodiment, the first light and the second light are mixed to produce purple light, amber light, green light, yellow light or other non-white light.

The wavelength conversion particles have a particle size of 10nm~100μm and may include one or more types of inorganic phosphors, organic fluorescent colorants, semiconductor materials, or a combination of the above materials. The inorganic fluorescent powder material includes but is not limited to yellow-green phosphors or red phosphors. The components of the yellow-green phosphors are, for example, aluminum oxide (YAG or TAG), silicates, vanadates, alkali earth metal selenides, or metal nitrides. The red fluorescent powder is composed of, for example, fluoride (K ₂ TiF ₆ :Mn ⁴⁺ , K ₂ SiF ₆ :Mn ⁴⁺ ), silicate, vanadate, alkaline earth metal sulfide (CaS), metal oxynitride, or tungsten-molybdenum salt mixture. The weight percentage concentration (w/w) of the wavelength conversion particles in the matrix is between 50 and 70%. The semiconductor material includes a semiconductor material of nano crystal, such as a quantum-dot luminescent material. The quantum dot luminescent material can be selected from zinc sulfide (ZnS), zinc selenide (ZnSe), zinc telluride (ZnTe), zinc oxide (ZnO), cadmium sulfide (CdS), cadmium selenide (CdSe), cadmium telluride (CdTe), gallium nitride (GaN), gallium phosphide (GaP), gallium selenide (GaSe), gallium antimonide (GaSb), gallium arsenide (GaAs), aluminum nitride (Al The light emitting element 1000 is a group consisting of: aluminum phosphide (AlP), aluminum arsenide (AlAs), indium phosphide (InP), indium arsenide (InAs), tellurium (Te), lead sulfide (PbS), indium antimonide (InSb), lead telluride (PbTe), lead selenide (PbSe), antimony telluride (SbTe), zinc cadmium selenide sulfide (ZnCdSeS), copper indium sulfide (CuInS), lead chloride (CsPbCl ₃ ), lead bromide (CsPbBr ₃ ), and lead iodide (CsPbI ₃ ). The diffusion powder includes titanium dioxide, zirconium oxide, zinc oxide or aluminum oxide, and is used to scatter the light emitted by the light emitting element 1000.

FIG. 8 is a schematic diagram of a light-emitting package 2P according to an embodiment. The light-emitting element 1000 is mounted on the first pad 203P and the second pad 204P of the package substrate 202P in the form of a flip chip. The first pad 203P and the second pad 204P are electrically insulated by an insulating portion 205P containing an insulating material. The flip chip mounting is to place the side of the substrate 102 opposite to the pad forming surface upward so that the substrate side is the main light extraction surface. In order to increase the light extraction efficiency of the light-emitting element, a reflective structure 201P can be set around the light-emitting element 1000, wherein the light-emitting element 1000 can be the light-emitting element in the aforementioned embodiment.

FIG. 9 is a schematic diagram of a light-emitting package 3P according to an embodiment. The light-emitting package 3P includes a supporting substrate 300P, a light-emitting element 1000, a wavelength converter 305, and a lens 306. The light-emitting element 1000 is flip-chip bonded to the supporting substrate 300P having a first pad 301 and a second pad 302 by using a first bump 303 and a second bump 304. The supporting substrate 300P may be, for example, a printed circuit board. On the other hand, the lens 306 is disposed above the light-emitting element 1000. The lens 306 is a diffusion lens that disperses light, but is not limited thereto. Lenses 306 of various shapes can be combined with the light-emitting element 1000 to realize various light patterns, wherein the light-emitting element 1000 can be the light-emitting element in the aforementioned embodiment.

FIG. 10 is a schematic diagram of a light-emitting device 1A according to an embodiment. The light-emitting device 1A includes a lampshade 401A, a reflector 402A, a light-emitting module 405A, a lamp holder 406A, a heat sink 407A, a connecting portion 408A, and an electrical connection element 409A. The light-emitting module 405A includes a carrier 403A, and a plurality of light-emitting units 404A located on the carrier 403A, wherein the plurality of light-emitting units 404A may be the light-emitting elements and light-emitting packages in the aforementioned embodiments.

FIG. 11 is a schematic diagram of a light-emitting device 2A according to an embodiment. The light-emitting device 2A includes a display panel 500A and a backlight unit. The backlight unit includes a light-emitting element 1000, a bottom cover 501, a reflective sheet 502, a diffusion plate 503, and an optical sheet 504. The bottom cover 501 can be opened upward to accommodate the light-emitting element 1000, the reflective sheet 502, the diffusion plate 503, and the optical sheet 504. The light-emitting element 1000 can be a light-emitting element or a light-emitting package in the aforementioned embodiment. In one embodiment, a lens 505 is provided on each light-emitting element 1000 to improve the uniformity of light emitted from the plurality of light-emitting elements 1000. The diffusion plate 503 and the optical sheet 504 are located on the light-emitting element 1000. The light emitted from the light-emitting element 1000 can be supplied to the display panel 500A in the form of a surface light source through the diffusion plate 503 and the optical sheet 504.

FIG. 12 is a schematic diagram of a light-emitting device 3A according to an embodiment. The light-emitting device 3A includes a display panel 600 and a backlight unit disposed below the display panel 600. Furthermore, the light-emitting device 3A includes: a frame 601 that supports the display panel 600 and accommodates the backlight unit, and covers 602 and 603 of the display panel 600. The display panel 600 can be fixed by the covers 602 and 603 located above and below it, and the cover 603 located below can be combined with the backlight unit. The backlight unit includes a light guide plate 604, an optical sheet 605, a reflective sheet 606, a carrier 607, and a plurality of light-emitting elements 1000. The optical sheet 605 is located on the light guide plate 604 to diffuse the light, the reflective sheet 606 is arranged below the light guide plate 604 to reflect the light traveling below the light guide plate 604 toward the display panel 600, and the light-emitting elements 1000 are arranged at certain intervals on the carrier 607. In one embodiment, the carrier 607 can be a printed circuit substrate. The light-emitting element 1000 can be the light-emitting element or light-emitting package in the aforementioned embodiment.

FIG. 13 is a schematic diagram of a light-emitting device 4A according to an embodiment. The light-emitting device 4A includes a lamp body 700, a carrier 701, a light-emitting element 1000, a cover lens 702, a heat sink 703, a support rib 704, and a connecting component 705. The carrier 701 is fixed by the support rib 704 and is spaced apart from the lamp body 700. The carrier 701 can be a substrate having a conductive pattern such as a printed circuit substrate. The light-emitting element 1000 is located on the carrier 701 and can be electrically connected to an external power source through the conductive pattern of the carrier 701. The light-emitting element 1000 can be the light-emitting element or light-emitting package in the aforementioned embodiments. The cover lens 702 is located on the light path emitted from the light-emitting element 1000, and the light directional angle and/or color emitted by the light-emitting device 4A to the outside can be adjusted through the cover lens 702. The connecting component 705 surrounds the light-emitting element 1000 and has a light-guiding function while fixing the cover lens 702 to the carrier 701. In one embodiment, the connecting component 705 can be formed of a light-reflective material, or coated with a light-reflective material. The heat dissipation portion 703 can include a heat sink 706 and/or a heat dissipation fan 707 to discharge the heat generated when the light-emitting element 1000 is driven to the outside.

In summary, although this application has been disclosed as above by the embodiments, it is not used to limit this application. Those with common knowledge in the technical field to which this application belongs can make various changes and embellishments without departing from the spirit and scope of this application. Therefore, the scope of protection of this application shall be subject to the scope of the attached patent application.

100: Light-emitting element

102: Substrate

104: First semiconductor layer

104A: Part 1

104B: Part 2

106: Semiconductor stacking

108: Active area

110: Second semiconductor layer

112: First protective layer

114: Transparent conductive oxide layer

116:Metal reflective layer

118: Ohm contact layer

120: Barrier layer

122: Second protective layer

124: Conductive layer

124A: First conduction part

124B: Second conduction part

126: The third protective layer

128:Pad layer

128A: First pad

128B: Second pad

O1: Opening of the first protective layer

O2: Second protective layer opening

O3: Opening of protective layer

O4: First welding pad opening

O5: Second welding pad opening

S: Flat surface

Claims (10)

A light-emitting element comprises: a substrate; a first semiconductor layer disposed on the substrate, comprising a first portion and a second portion connected to the first portion; a semiconductor stack disposed on the first portion, the semiconductor stack comprising: an active region disposed on the first semiconductor layer; and a second semiconductor layer disposed on the active region, the conductivity type of the second semiconductor layer being different from the conductivity type of the first semiconductor layer; a first protective layer; A protective layer is disposed on the semiconductor stack and has one or more first protective layer openings on the second semiconductor layer; a transparent conductive oxide layer is disposed on the first protective layer and fills the one or more first protective layer openings to provide a flat surface, the transparent conductive oxide layer is not covered by the first protective layer; and a metal reflective layer is disposed on the flat surface and electrically connected to the second semiconductor layer through the transparent conductive oxide layer. The light-emitting element as described in claim 1, wherein the surface roughness Ra of the flat surface is less than 1nm. The light-emitting element as described in claim 1, wherein the transparent conductive oxide layer is disposed on the first protective layer, an upper surface of the transparent conductive oxide layer is higher than an upper surface of the first protective layer, and the upper surface of the transparent conductive oxide layer constitutes the flat surface. The light-emitting element as described in claim 1, wherein an upper surface of the transparent conductive oxide layer is substantially flush with an upper surface of the first protective layer, and the upper surface of the transparent conductive oxide layer and the upper surface of the first protective layer together constitute the flat surface. The light-emitting element as described in claim 1, wherein the flat surface has one or more depressions at the openings corresponding to the one or more first protective layers, the flat surface includes a lowest point located at one of the one or more depressions, and the height difference between a highest point and the lowest point of the flat surface is less than 5nm. A light-emitting element as described in claim 1, wherein the second portion is not covered by the semiconductor stack, wherein the transparent conductive oxide layer includes a first transparent conductive portion located above the semiconductor stack, and a second transparent conductive portion located on the second portion, and an upper surface of the first transparent conductive portion is flush with an upper surface of the second transparent conductive portion. The light-emitting element as described in claim 1, wherein the material of the transparent conductive oxide layer is indium zinc oxide (IZO) or zinc oxide (ZnO). The light-emitting element as described in claim 1 further includes an ohmic contact layer disposed between the semiconductor stack and the first protective layer. A light-emitting device, comprising: a light-emitting element as described in any one of claim 1 to claim 8, which is arranged in the light-emitting device in a flip-chip manner. A method for manufacturing a light-emitting element, comprising: providing a substrate; forming a first semiconductor layer on the substrate, comprising a first portion and a second portion connected to the first portion; forming a semiconductor stack on the first portion, comprising: forming an active region on the first portion; and forming a second semiconductor layer on the active region, wherein the conductivity type of the second semiconductor layer is different from the conductivity type of the first semiconductor layer; forming a A first protective layer is formed on the semiconductor stack and one or more first protective layer openings are formed on the second semiconductor layer; a transparent conductive oxide layer is formed on the first protective layer and fills the one or more first protective layer openings to provide a flat surface, the transparent conductive oxide layer is not covered by the first protective layer; and a metal reflective layer is formed on the flat surface and contacts the transparent conductive oxide layer to electrically connect the second semiconductor layer.

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