TWI864391B - Light-emitting element - Google Patents

Abstract

A light-emitting element is provided. The light emitting element includes a semiconductor-stack structure, a first electrode structure, a first pattern insulating layer and a second pattern insulating layer. The semiconductor-stack structure includes a first conductivity-type semiconductor layer having a first surface, a second conductivity-type semiconductor layer having a second surface, and an active region between the first conductivity- type semiconductor layer and the second conductivity-type semiconductor layer. The first electrode structure is formed on the first surface. The first pattern insulating layer is formed on the second surface. The second pattern insulating layer is formed on the second surface. The second pattern insulating layer surrounds and connects the first pattern insulating layer. The first pattern insulating layer and the second pattern insulating layer include different materials.

Description

Light-emitting element

This application relates to light-emitting devices, and in particular to semiconductor light-emitting devices.

Semiconductor light-emitting elements, such as light-emitting diodes, have been widely used in various lighting fields. Semiconductor light-emitting elements usually include a reflective structure, and the light emitted from the semiconductor light-emitting element toward the reflective structure will be reflected to the light-emitting surface to improve the light-emitting efficiency.

Therefore, how to adjust the reflective structure of semiconductor light-emitting elements to effectively improve the light extraction efficiency of semiconductor light-emitting elements is one of the key points of research and development.

According to one embodiment of the present application, the light-emitting element includes a semiconductor stack, a first electrode structure, a first patterned insulating layer, and a second patterned insulating layer. The semiconductor stack includes a first-type semiconductor layer having a first surface, a second-type semiconductor layer having a second surface, and an active region formed between the first-type semiconductor layer and the second-type semiconductor layer. The first electrode structure is formed on the first surface. The first patterned insulating layer is formed on the second surface. The second patterned insulating layer is formed on the second surface. The second patterned insulating layer surrounds and connects the first patterned insulating layer. The first patterned insulating layer and the second patterned insulating layer include different materials.

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:

1,2,3: Light-emitting element

11: Semiconductor stacking

12: First electrode structure

13: The first patterned insulating layer

13m: First insulating material layer

14: Second patterned insulating layer

14s: Insulation surface

14sw,16sw:outer edge

15: Patterned reflective layer

15’: Reflection layer

15A, 15A’: Adhesive layer

16: Reflection barrier

17: Barrier layer

18:Joint layer

19: Substrate

20: Second electrode structure

21: Protective layer

110: Type I semiconductor layer

110s: First surface

111: Type II semiconductor layer

111s: Second surface

112: Active area

131: Outer periphery

131s,132s:Surface

132: Long strips

151: Reflexology area

200: Luminescent package

201:Packaging substrate

205: Encapsulation wall

213,214: External electrode

230: Conductor

232: Fluorescent body

240:Packaging material

300: Light-emitting device

301: Lampshade

302: Reflector

303: Carrying part

304: Light-emitting unit

305: Light-emitting module

306: Lamp holder

307: Heat sink

308:Connection part

309: Electrical connection components

A-A’: section line

T1, T2, T3: thickness

X,Y,Z: Direction

FIG. 1 is a schematic diagram showing a perspective view of a light-emitting element 1 according to an embodiment; FIG. 2 is a schematic diagram showing a cross section of the light-emitting element 1 along the section line A-A' shown in FIG. 1; FIG. 3 is a diagram showing a simulated reflectivity curve of a reflective structure according to an embodiment; FIGS. 4-6 are schematic diagrams showing a part of the manufacturing steps of the light-emitting element 1 according to an embodiment from bottom views; FIG. 7 is a schematic diagram showing a cross section of the light-emitting element 2 according to an embodiment; FIG. 8 is a schematic diagram showing a cross-sectional view of a light-emitting element 3 according to an embodiment; FIG. 9 is a power curve diagram showing a light-emitting element of an embodiment and a light-emitting element of a comparative example; FIG. 10 is a power curve diagram showing light-emitting elements of different embodiments; FIG. 11 is a schematic diagram showing a cross-sectional view of a light-emitting package 200 according to an embodiment; and FIG. 12 is a schematic diagram showing a light-emitting device 300 according to an embodiment.

The ordinal numbers used in this manual, such as "first", "second", "third", etc., are used to modify the components. They do not imply or represent any previous ordinal numbers of the components, nor do they represent the order of one component and another component, or the order of the manufacturing method. These ordinal numbers are used only to make components with the same name clearly distinguishable. In addition, the drawings are simplified to facilitate the clear description of the contents of the embodiments, and the size ratios in the drawings are not drawn in proportion to the actual products. The same or similar component symbols are used to represent the same or similar components.

Please refer to Figures 1 and 2 at the same time. Figure 1 is a schematic top perspective view of a light-emitting element 1 according to an embodiment, and Figure 2 is a schematic cross-sectional view of the light-emitting element 1 along the section line A-A' shown in Figure 1. In order to facilitate understanding of the relative positional relationship among the semiconductor stack 11, the first electrode structure 12, the first patterned insulating layer 13, the second patterned insulating layer 14 and the patterned reflective layer 15, the top perspective schematic diagram of the light-emitting element 1 shown in FIG. 1 only shows the semiconductor stack 11, the first electrode structure 12, the first patterned insulating layer 13, the second patterned insulating layer 14, and the patterned reflective layer 15 partially covered by the first electrode structure 12 as seen from the semiconductor stack 11, and other elements are omitted, so it does not fully represent the actual structure. Referring to FIG. 2 , the light-emitting element 1 may include a substrate 19, a second electrode structure 20, and a semiconductor stack 11. The second electrode structure 20 and the semiconductor stack 11 are disposed on opposite sides of the substrate 19, respectively. The semiconductor stack 11 may include a first-type semiconductor layer 110, a second-type semiconductor layer 111, and an active region 112 formed between the first-type semiconductor layer 110 and the second-type semiconductor layer 111. As shown in FIG. 2 , the active region 112 and the first-type semiconductor layer 110 may be sequentially formed on the second-type semiconductor layer 111 along the positive Z direction. The first-type semiconductor layer 110 has a first surface 110s. The first surface 110s of the first-type semiconductor layer 110 is, for example, a light-emitting surface of the light-emitting element 1. The second type semiconductor layer 111 has a second surface 111s. The second surface 111s of the second type semiconductor layer 111 is, for example, a surface located on the opposite side of the light emitting surface of the light emitting element 1. In one embodiment, the first surface 110s of the first type semiconductor layer 110 may include a rough surface to improve light extraction efficiency.

In one embodiment, the substrate 19 includes a conductive material or a semiconductor material, and the substrate 19 can be transparent or opaque. The conductive transparent material includes but is not limited to a transparent conductive oxide (TCO), such as zinc oxide (ZnO); the conductive opaque material includes but is not limited to a metal material, such as aluminum (Al), copper (Cu), molybdenum (Mo), germanium (Ge) or tungsten (W) and other elements or alloys or stacks 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).

In one embodiment, the semiconductor stack 11 is a light-emitting stack, and the first type semiconductor layer 110 and the second type semiconductor layer 111 can be used as confinement layers, carrier supply layers, or contact layers. The active region 112 can be used as a light-emitting structure. The first type semiconductor layer 110 and the second type semiconductor layer 111 can include semiconductor materials of different doping types to supply carriers, for example, the first type semiconductor layer 110 includes an n-type semiconductor layer, and the second type semiconductor layer 111 includes a p-type semiconductor layer to provide electrons and holes, respectively, or the first type semiconductor layer 110 includes a p-type semiconductor layer, and the second type semiconductor layer 111 includes an n-type semiconductor layer to provide holes and electrons, respectively. The first type semiconductor layer 110, the active region 112 and the second type semiconductor layer 111 may include the same series of III-V compound semiconductor materials, such as AlInGaAs series, AlGaInP series, InGaAsP series or AlInGaN series. Among them, the AlInGaAs series can be expressed as (Al _x1 In _(1-x1) ) _1-x2 Ga _x2 As, the AlInGaP series can be expressed as (Al _x1 In _(1-x1) ) _1-x2 Ga _x2 P, the AlInGaN series can be expressed as (Al _x1 In _(1-x1) ) _1-x2 Ga _x2 N, and the InGaAsP series can be expressed as In _x1 Ga _1-x1 As _x2 P _1-x2 , wherein 0≦x1≦1, 0≦x2≦1. The light-emitting element 1 is, for example, a light-emitting diode, and the wavelength of the light emitted by the light-emitting element 1 depends on the material composition of the active region 112. Specifically, the material of the active region 112 may include AlInGaAs, InGaAsP, AlGaInP, InGaN or AlGaN. When the material of the active region 112 is an AlInGaP series material, red light with a wavelength between 610nm and 650nm or green light with a wavelength between 530nm and 570nm may be emitted. When the material of the active region 112 is an InGaN series material, blue light with a wavelength between 400nm and 490nm, cyan light with a wavelength between 490nm and 530nm, or green light with a wavelength between 530nm and 570nm may be emitted. When the material of the active region 112 is an AlGaN series or AlInGaN series material, ultraviolet light with a wavelength between 400nm and 250nm can be emitted. In one embodiment, the active region 112 may include a single heterostructure, a double heterostructure, or a multiple quantum well structure. In one embodiment, the active region 112 includes a multiple quantum well structure, and the active region 112 includes one or more quantum well layers and one or more barrier layers stacked alternately in the Z direction once or multiple times, and the energy barrier of the barrier layer is greater than that of the quantum well layer to limit carrier distribution. In addition, the multiple quantum well layers may have the same or different material compositions and energy barriers, and the present application is not limited thereto. In one embodiment, the material of the active region 112 can be i-type, p-type or n-type semiconductor.

The light-emitting element 1 may further include a first electrode structure 12, a first patterned insulating layer 13, a second patterned insulating layer 14, a patterned reflective layer 15, and a reflective barrier layer 16. The first electrode structure 12 may be disposed on the first surface 110s of the first type semiconductor layer 110. The first patterned insulating layer 13, the second patterned insulating layer 14, and the patterned reflective layer 15 may be disposed on the second surface 111s of the second type semiconductor layer 111. In one embodiment, the patterned reflective layer 15 directly contacts the second type semiconductor layer 111 to form an ohmic contact. In one embodiment, a transparent conductive layer (not shown) is further included between the patterned reflective layer 15 and the second type semiconductor layer 111, such as indium tin oxide (ITO), indium oxide (InO), tin oxide (SnO), cadmium tin oxide (CTO), antimony tin oxide (ATO), aluminum zinc oxide (AZO), zinc tin oxide (ZTO), gallium zinc oxide (GZO), or oxide. Indium tungsten oxide (IWO), zinc oxide (ZnO), aluminum gallium arsenide (AlGaAs), gallium nitride (GaN), gallium phosphide (GaP), gallium arsenide (GaAs), gallium arsenide phosphide (GaAsP), indium zinc oxide (IZO), diamond-like carbon film (DLC) or graphene, the transparent conductive layer directly contacts the second type semiconductor layer 111 to form an ohmic contact. The second patterned insulating layer 14 can surround the first patterned insulating layer 13 and the patterned reflective layer 15 on the XY plane. In some embodiments, the second patterned insulating layer 14 can be connected to the first patterned insulating layer 13. In some embodiments, the first patterned insulating layer 13 may be connected to the patterned reflective layer 15. In other embodiments, the first patterned insulating layer 13 may be disposed corresponding to the position of the first electrode structure 12. For example, the first electrode structure 12 may overlap the first patterned insulating layer 13 in the Z direction. The area of the first electrode structure 12 on the XY plane may be smaller than the area of the first patterned insulating layer 13 on the XY plane to prevent the excessive area of the first electrode structure 12 from shielding the light emitted from the active region 112. In addition, when the first type semiconductor layer 110 is an n-type semiconductor layer and the second type semiconductor layer 111 is a p-type semiconductor layer, the lateral diffusion speed of electrons in the first type semiconductor layer 110 is greater than the lateral diffusion speed of holes in the second type semiconductor layer 111. Therefore, the current (holes) injected from the second electrode structure 20 can be concentrated in the active area 112 through the larger first patterned insulating layer 13 with the electrons that diffuse faster laterally to avoid the first electrode structure 12 shielding area to emit light, thereby further reducing the light-shielding effect of the first electrode structure 12. The reflection barrier layer 16 can be disposed on the first patterned insulating layer 13, the second patterned insulating layer 14 and the patterned reflective layer 15. The reflection barrier layer 16 and the semiconductor stack 11 are disposed on opposite sides of the first patterned insulating layer 13, respectively.

Specifically, the first patterned insulating layer 13 may include an outer portion 131 and an inner portion, wherein the outer portion 131 surrounds the inner portion. The outer portion 131 may be a closed ring, such as a square ring or a circular ring. The pattern of the inner portion may be a geometric pattern, such as a rectangle or a circle. In one embodiment, the inner portion of the first patterned insulating layer 13 may be composed of a plurality of long strips 132, which may extend along the Y direction and be spaced apart from each other in the X direction. The plurality of long strips 132 may be connected to the outer portion 131 and surrounded by the outer portion 131. The patterned reflective layer 15 may include a plurality of reflective regions 151. The plurality of reflective regions 151 may extend along the Y direction and be spaced apart from each other in the X direction. The outer peripheral portion 131 of the first patterned insulating layer 13 may contact the second patterned insulating layer 14. The plurality of long strip portions 132 of the first patterned insulating layer 13 and the plurality of reflective regions 151 of the patterned reflective layer 15 may be arranged alternately along the X direction.

The reflection barrier layer 16 can cover the first patterned insulating layer 13, the second patterned insulating layer 14 and the patterned reflective layer 15. The reflection barrier layer 16 contacts the first patterned insulating layer 13 and forms an omni-directional reflector (ODR) with the first patterned insulating layer 13 to improve the light extraction efficiency of the light emitting element 1. The first patterned insulating layer 13 can be used as a current blocking layer. The external current injected through the second electrode structure 20 is blocked by the first patterned insulating layer 13 and then distributed and diffused into the second type semiconductor layer 111 through the patterned reflective layer 15. In one embodiment, the first patterned insulating layer 13 and/or the second patterned insulating layer 14 can increase the adhesion between the semiconductor stack 11 and the reflective barrier layer 16. The reflective barrier layer 16 can be used to prevent the material of the patterned reflective layer 15 from diffusing during the manufacturing process and destroying the electrical properties of the light-emitting element 1. In one embodiment, the patterned reflective layer 15 has a first reflectivity for the light of a specific wavelength emitted by the active region 112, such as ultraviolet light, and the reflective barrier layer 16 has a second reflectivity for the light of a specific wavelength emitted by the active region 112, and the first reflectivity is less than the second reflectivity. The patterned reflective layer 15 has good electrical contact with the semiconductor stack 11. Therefore, the patterned reflective layer 15 is not arranged on the entire surface, for example, it is dispersed between the patterned insulating layers 13, and then the large area of the reflective barrier layer 16 with high reflectivity, for example, it covers the entire surface, and then the omnidirectional reflective structure formed by the first patterned insulating layer 13 is used to increase the overall reflectivity, thereby improving the photoelectric characteristics of the light-emitting element 1.

In one embodiment, the second patterned insulating layer 14 includes an insulating surface 14s facing away from the semiconductor stack 11, the reflection barrier layer 16 can completely cover the insulating surface 14s of the second patterned insulating layer 14, and the outer edge 16sw of the reflection barrier layer 16 can be aligned with the outer edge 14sw of the second patterned insulating layer 14, for example, in the Z direction.

The first electrode structure 12 and the second electrode structure 20 may include conductive materials. The first electrode structure 12 and the second electrode structure 20 may include the same or different materials. The first electrode structure 12 and the second electrode structure 20 may include metal materials or transparent conductive materials; for example, the metal material may include but is not limited to aluminum (Al), chromium (Cr), copper (Cu), tin (Sn), gold (Au), nickel (Ni), titanium (Ti), platinum (Pt), palladium (Pd), silver (Ag), lead (Pb), zinc (Zn), cadmium (Cd), antimony (Sb), cobalt (Co) or alloys thereof; the transparent conductive material may include but is not limited to indium tin oxide (ITO). ), indium oxide (InO), tin oxide (SnO), cadmium tin oxide (CTO), antimony tin oxide (ATO), aluminum zinc oxide (AZO), zinc tin oxide (ZTO), gallium zinc oxide (GZO), indium tungsten oxide (IWO), zinc oxide (ZnO), aluminum gallium arsenide (AlGaAs), gallium nitride (GaN), gallium phosphide (GaP), gallium arsenide (GaAs), gallium arsenide phosphide (GaAsP), indium zinc oxide (IZO), diamond-like carbon film (DLC) or graphene. In one embodiment, the first electrode structure 12 and the second electrode structure 20 include a single layer or a multi-layer structure. The first electrode structure 12 and the second electrode structure 20 are disposed on opposite sides of the semiconductor stack 11 to form a vertical light-emitting element. In another embodiment, the first electrode structure 12 and the second electrode structure 20 can be disposed on the same side of the semiconductor stack 11 to form a horizontal light-emitting element. Both the first electrode structure 12 and the second electrode structure 20 can be used to connect to an external power source and evenly diffuse the current into the semiconductor stack 11. In this embodiment, the substrate 19 may include but is not limited to insulating materials, such as sapphire, diamond, glass, quartz, acrylic, epoxy, and aluminum nitride (AlN).

The first patterned insulating layer 13 and the second patterned insulating layer 14 may include the same or different materials. In one embodiment, the first patterned insulating layer 13 may include a first absorptivity for light of a specific wavelength emitted by the active region 112, and the second patterned insulating layer 14 may include a second absorptivity for light of a specific wavelength emitted by the active region 112, wherein the first absorptivity is less than the second absorptivity. In one embodiment, the light emitted by the active region 112 includes an ultraviolet light band, such as light with a peak wavelength of less than 380 nm, and the absorptivity of the first patterned insulating layer 13 for light with a wavelength less than about 380 nm is less than the absorptivity of the second patterned insulating layer 14 for light with a wavelength less than about 380 nm. In one embodiment, the first patterned insulating layer 13 has an absorption rate of less than 40% for light with a wavelength less than about 380 nm, and the second patterned insulating layer 14 has an absorption rate of more than 40% for light with a wavelength less than about 380 nm. In one embodiment, the refractive index of the first patterned insulating layer 13 is less than the refractive index of the second patterned insulating layer 14. The material of the first patterned insulating layer 13 may include a material with low light absorption rate, such as silicon dioxide (SiO ₂ ) or niobium pentoxide (Nb ₂ O ₅ ). The second patterned insulating layer 14 may include a material with high process tolerance, such as a material resistant to acid corrosion, such as titanium dioxide (TiO ₂ ) or niobium pentoxide (Nb ₂ O ₅ ). The above contents are merely examples of the present application and are not limited thereto. The material selection of the first patterned insulating layer 13 can be selected and adjusted according to the wavelength of the light emitted by the active region 112.

The patterned reflective layer 15 may include a metal material, such as silver (Ag), gold (Au), aluminum (Al), titanium (Ti), chromium (Cr), copper (Cu), nickel (Ni), platinum (Pt), ruthenium (Ru), tungsten (W), rhodium (Rh), or alloys or stacked layers thereof. In one embodiment, the patterned reflective layer 15 may include a multi-layer structure (not shown). For example, the patterned reflective layer 15 may include a multi-layer structure of a stacked first reflective metal layer, a second reflective metal layer, and a third reflective metal layer. The first reflective metal layer, the second reflective metal layer, and the third reflective metal layer may be stacked in sequence along the negative Z direction. The first reflective metal layer may include silver (Ag), the second reflective metal layer may include titanium tungsten (TiW), and the third reflective metal layer may include platinum (Pt). The patterned reflective layer 15 may form an ohmic contact with the second type semiconductor layer 111.

The reflection barrier layer 16 may include a metal material, such as aluminum (Al), chromium (Cr), platinum (Pt), titanium (Ti), tungsten (W), zinc (Zn), rhodium (Rh), or alloys or stacked layers thereof. In one embodiment, the reflection barrier layer 16 may include a multi-layer structure (not shown). For example, the reflection barrier layer 16 may include a multi-layer structure of a stacked first barrier metal layer, a second barrier metal layer, and a third barrier metal layer. The first barrier metal layer, the second barrier metal layer, and the third barrier metal layer may be stacked in sequence along the negative Z direction. The first barrier metal layer may include aluminum (Al), the second barrier metal layer may include titanium tungsten (TiW), and the third barrier metal layer may include platinum (Pt). In one embodiment, the portion of the reflection barrier layer 16 that contacts the first patterned insulating layer 13 includes aluminum (Al), platinum (Pt), or rhodium (Rh) with high reflectivity.

The light-emitting element 1 may further include a barrier layer 17 and a bonding layer 18 disposed between the reflective barrier layer 16 and the substrate 19. The barrier layer 17 and the bonding layer 18 may be disposed on the reflective barrier layer 16 in sequence along the negative Z direction. The light-emitting element 1 may further include a protective layer 21. The protective layer 21 may be disposed on the first surface 110s of the first type semiconductor layer 110 and cover a portion of the first surface 110s of the first type semiconductor layer 110, and extend to cover the side surface of the semiconductor stack 11. The protective layer 21 may further cover the second patterned insulating layer 14. The first electrode structure 12 may pass through the protective layer 21 and contact the first type semiconductor layer 110 of the semiconductor stack 11. In one embodiment, the first electrode structure 12 is located on the protective layer 21 and covers a portion of the protective layer 21. In one embodiment, the first electrode structure 12 does not cover the protective layer 21. In one embodiment, the protective layer 21 may conformably cover the rough surface of the first type semiconductor layer 110, so the upper surface of the protective layer 21 may include a concave-convex pattern. The barrier layer 17 can be used to prevent the material of the bonding layer 18 from diffusing into the reflective barrier layer 16 and/or the patterned reflective layer 15 during the manufacturing process, reacting to generate compounds or forming alloys, thereby affecting the reflectivity and conductive properties of the patterned reflective layer 15 and/or the reflective barrier layer 16. The bonding layer 18 can be used to bond the substrate 19 with the semiconductor stack 11 and the above-mentioned layers formed thereon.

The barrier layer 17 may include a metal material, such as chromium (Cr), platinum (Pt), titanium (Ti), tungsten (W), zinc (Zn), or an alloy or a stack of the above materials. In one embodiment, when the barrier layer 17 is a metal stack, the barrier layer 17 includes two or more layers of metal alternately stacked, such as Cr/Pt, Cr/Ti, Cr/TiW, Cr/W, Cr/Zn, Ti/Pt, Ti/W, Ti/TiW, Ti/Zn, TiW/Pt, Pt/W, Pt/Zn, TiW/W, TiW/Zn, or W/Zn. When the light-emitting element 1 is a vertical light-emitting element, the bonding layer 18 may include a transparent conductive material and a metal material; the transparent conductive material includes but is not limited to indium tin oxide (ITO), indium oxide (InO), tin oxide (SnO), cadmium tin oxide (CTO), antimony tin oxide (ATO), aluminum zinc oxide (AZO), zinc tin oxide (ZTO), gallium zinc oxide (GZO), zinc oxide (ZnO), gallium phosphide (GaP), indium caesium oxide (ICO), indium tungsten oxide (IWO), indium titanium oxide (ITO), and indium tungsten oxide (IWO). The bonding layer 18 may include a non-conductive material, such as silicon oxide (SiO 2 ), benzocyclobutene (BCB), silicon nitride (SiN _x ), bonding adhesive (such as epoxy resin, UV curing adhesive, _etc. ), or a combination of the above materials. The protection layer 21 may include an insulating material; the insulating material includes but is not limited to silicon oxide (SiO ₂ ), silicon nitride (SiN _x or Si ₃ N ₄ ) or a combination of the above materials.

The first patterned insulating layer 13 has a thickness T1 in the Z direction, the second patterned insulating layer 14 has a thickness T2 in the Z direction, and the patterned reflective layer 15 has a thickness T3 in the Z direction. The thickness T2 of the second patterned insulating layer 14 may be less than the thickness T1 of the first patterned insulating layer 13. The thickness T3 of the patterned reflective layer 15 may be less than or equal to the thickness T1 of the first patterned insulating layer 13. As shown in FIG. 2 , the thickness T3 of the patterned reflective layer 15 may be less than or equal to the thickness T1 of the first patterned insulating layer 13 , and the reflection barrier layer 16 may contact the first patterned insulating layer 13 and the patterned reflective layer 15 at the same time, thereby reducing the problem of poor adhesion of a single material to the interface. In one embodiment, the patterned reflective layer 15 does not completely cover the sidewall and the lower surface (the lower surface referred to herein refers to the surface facing the substrate 19) of the first patterned insulating layer 13, and the first patterned insulating layer 13 can contact the patterned reflective layer 15 and the reflection barrier layer 16 at the same time. The reflection barrier layer 16 has good adhesion to the patterned reflective layer 15 and the first patterned insulating layer 13, respectively, thereby enhancing the adhesion between the patterned reflective layer 15 and the first patterned insulating layer 13, so as to solve the problem of poor adhesion between the patterned reflective layer 15 and the first patterned insulating layer 13. In one embodiment, the lateral dimension (e.g., the width in the X direction) of the first electrode structure 12 may be smaller than the lateral dimension of the first patterned insulating layer 13, so as to avoid affecting the light emitted by the semiconductor stack 11.

Please refer to FIG. 3. FIG. 3 shows a reflectivity simulation curve of a reflective structure according to an embodiment of the present application and a reflective structure according to a comparative example, respectively, with incident light of different wavelengths and two incident angles (0 degrees and 45 degrees) for simulation. The reflective structure of the embodiment includes a material film layer with low light absorption rate as listed above, such as silicon dioxide and a metal material film layer with high reflection rate, such as aluminum. The reflective structure of the comparative example includes a silver film layer and a titanium dioxide film layer with high light absorption rate. As can be seen from Figure 3, the reflectivity of the reflective structure of the comparative example for light with a wavelength between about 380nm and about 600nm is greater than the reflectivity for light with a wavelength between about 200nm and about 380nm, and the reflectivity drops sharply in the wavelength range between about 200nm and about 380nm (for example, the reflectivity for light with a wavelength less than about 350nm is less than 60%). In other words, the light-emitting element using the reflective structure of the comparative example has poor brightness performance for light with a wavelength less than about 380nm. In contrast, the reflective structure of the embodiment has a reflectivity greater than 80% for light with a wavelength between about 200nm and about 380nm, and a reflectivity greater than 80% for light with a wavelength between about 380nm and about 600nm, indicating that the reflective structure has good reflectivity in the wavelength range between about 200nm and about 600nm. Therefore, the light-emitting element using the reflective structure of the embodiment still has good brightness performance for light with a wavelength less than about 380nm, and has a wider range of light-emitting wavelength band applications than the comparative example. For example, according to one embodiment, the light-emitting element can emit light with a wavelength between about 200nm and about 600nm. For example, according to one embodiment, the light-emitting element can emit light with a wavelength between about 360nm and about 550nm.

The following is an exemplary description of the manufacturing process of the light-emitting element 1 according to this application, but is not limited to this.

The semiconductor stack 11 can be grown on a growth substrate wafer (not shown), for example, by metal-organic chemical vapor deposition (MOCVD), molecular beam epitaxy (MBE), hydride vapor phase epitaxy (HVPE) or ion plating, such as sputtering or evaporation, to sequentially grow a first type semiconductor layer 110, an active region 112 and a second type semiconductor layer 111 on the growth substrate wafer. Next, a first insulating material layer 13m and a second patterned insulating layer 14 are formed on the second surface 111s of the second type semiconductor layer 111 (as shown in FIG. 4 ). In this step, the first insulating material layer 13m and the second patterned insulating layer 14 cover the second surface 111s, the second patterned insulating layer 14 surrounds the first insulating material layer 13m, and the first insulating material layer 13m has not been patterned. In this step, the first insulating material layer 13m can be used as a hard mask, and the second patterned insulating layer 14 can be formed by a lift-off process. In one embodiment, the first insulating material layer 13m and the second patterned insulating layer 14 are formed in the same yellow light process without the need for re-alignment, which helps to simplify the process and avoid pattern deviation. In this way, the second patterned insulating layer 14 can be connected to the first insulating material layer 13m.

Next, as shown in FIG. 5 , the first insulating material layer 13m is patterned, for example, by removing a portion of the first insulating material layer 13m through a wet etching or dry etching process to form a first patterned insulating layer 13, and exposing a portion of the second surface 111s. The first patterned insulating layer 13 includes a closed annular outer portion 131 and an inner portion surrounded by the outer portion 131. In one embodiment, the inner portion of the first patterned insulating layer 13 may be composed of a plurality of long strip portions 132. The exposed second surface 111s is between the outer portion 131 and the plurality of long strip portions 132. Next, as shown in FIG. 6 , a patterned reflective layer 15 can be formed on the exposed second surface 111s by a self-alignment process, so that the patterned reflective layer 15 and the second type semiconductor layer 111 are electrically connected. In one embodiment, the patterned reflective layer 15 directly contacts the second type semiconductor layer 111 to form an ohmic contact. In one embodiment, a transparent conductive layer (not shown) is further included between the patterned reflective layer 15 and the second type semiconductor layer 111, and the transparent conductive layer directly contacts the second type semiconductor layer 111 to form an ohmic contact. The second patterned insulating layer 14 can include acid-resistant corrosion resistance, so it can be used as an etch stop layer in subsequent processes. Next, a reflection barrier layer 16 and a barrier layer 17 are sequentially formed on the first patterned insulating layer 13, the second patterned insulating layer 14 and the patterned reflective layer 15, for example, by deposition, sputtering or evaporation.

A bonding layer 18 is formed on the barrier layer 17 to bond with the substrate 19 through the bonding layer 18. In one embodiment, the bonding layer 18 can be formed on the substrate 19, and then the substrate 19 is bonded to the barrier layer 17 through the bonding layer 18. In another embodiment, the bonding layer 18 can also be partially formed on the barrier layer 17 and partially formed on the substrate 19, and then the two parts of the bonding layer 18 are bonded to each other so that the substrate 19 is bonded to the barrier layer 17 through the bonding layer 18. In one embodiment, the barrier layer 17, the bonding layer 18 and the substrate 19 are bonded, for example, through a hot pressing process. Then, the second electrode structure 20 can be formed on the substrate 19 through deposition, sputtering or evaporation.

The growth substrate wafer on the semiconductor stack 11 can be removed by laser. In one embodiment, the semiconductor stack 11 includes an undoped semiconductor bottom layer (not shown), and the semiconductor bottom layer of the semiconductor stack 11 is exposed after the growth substrate wafer is removed. In one embodiment, the semiconductor bottom layer can be removed by a wet etching or dry etching process, and a portion of the first type semiconductor layer 110 is further removed to form a rough surface, such as the first surface 110s shown in FIG. 2. The chip separation area can be formed by patterning the semiconductor stack 11, removing a portion of the semiconductor stack 11 until the second patterned insulating layer 14 is exposed, wherein the chip separation area defines the periphery of the light-emitting element 1. The method of patterning the semiconductor stack 11 may include dry etching or wet etching. Then, a protective material layer (not shown) may be formed on the first surface 110s and the sidewall of the semiconductor stack 11 by deposition, sputtering or evaporation, and then a portion of the protective material layer may be removed by a wet etching or dry etching process to expose a portion of the first surface 110s and form a protective layer 21. Then, a first electrode structure 12 may be formed on the first type semiconductor layer 110 by deposition, sputtering or evaporation. Finally, the substrate 19 and the stack thereon are cut along the chip separation area to separate into a plurality of independent light-emitting elements 1. In one embodiment, the light-emitting element 1 as described in Figures 1-2 can be obtained by implementing the above method.

FIG. 7 and FIG. 8 are cross-sectional schematic diagrams of the light-emitting elements 2 and 3 of the embodiment, respectively. The manufacturing process and structure of the light-emitting elements 2 and 3 are similar to those of the light-emitting element 1. For similar manufacturing processes and structures, please refer to the description and drawings of the light-emitting element 1. The differences will be described later. Referring to FIG. 7, the difference between the light-emitting element 2 and the light-emitting element 1 is that the light-emitting element 2 further includes an adhesive layer 15A, and the reflective layer 15' of the light-emitting element 2 is different from the patterned reflective layer 15 of the light-emitting element 1. The adhesive layer 15A may be disposed on the second surface 111s of the second-type semiconductor layer 111, and may be extended to the surface 131s of the peripheral portion 131 and the surface 132s of the strip portion 132, the surface 131s of the peripheral portion 131 and the surface 132s of the strip portion 132 facing away from the semiconductor stack 11. In one embodiment, the adhesive layer 15A may cover the surface 131s of the peripheral portion 131 and the surface 132s of the strip portion 132. In another embodiment, the adhesive layer 15A may cover the surface 131s of the peripheral portion 131 and the surface 132s of the strip portion 132, and may further extend to cover the side walls of the peripheral portion 131 and the strip portion 132. The reflective layer 15' may be disposed between the adhesive layer 15A and the reflective barrier layer 16 and cover the first patterned insulating layer 13. The adhesive layer 15A may be used to enhance the adhesion between the first patterned insulating layer 13 and the reflective layer 15'. In one embodiment, the adhesive layer 15A may include metal oxide, metal nitride or metal. In one embodiment, the adhesive layer 15A may include indium tin oxide, and the thickness of the indium tin oxide in the Z direction is 10 to 300 Å. In one embodiment, the adhesive layer 15A may include titanium nitride, and the thickness of the titanium nitride in the Z direction is 10 to 50 Å. In one embodiment, the adhesive layer 15A may include chromium, and the thickness of the chromium in the Z direction is 10 to 50Å.

Please refer to Figure 8. The difference between the light-emitting element 3 and the light-emitting element 2 is that the adhesive layer 15A' of the light-emitting element 3 can be disposed on the first patterned insulating layer 13, and is not disposed on the second surface 111s of the second type semiconductor layer 111. The reflective layer 15' of the light-emitting element 3 can directly contact the second surface 111s of the second type semiconductor layer 111. In this embodiment, the adhesive layer 15A' is a patterned adhesive layer, which is only disposed on the first patterned insulating layer 13, and is not disposed on the second surface 111s of the second type semiconductor layer 111. Therefore, the absorption rate of the adhesive layer 15A' to the light emitted by the active area 112 can be reduced, and the light extraction efficiency can be improved.

Please refer to Figure 9. Figure 9 is a power curve diagram of the light-emitting elements of multiple embodiments and the light-emitting elements of multiple comparative examples. Multiple embodiments A-E have the structure shown in Figure 7 above, and the first patterned insulating layer 13 includes a material with a lower light absorption rate as listed above, such as silicon dioxide. Multiple comparative examples A-E include titanium dioxide with a higher light absorption rate. In Embodiment A, Embodiment C and Embodiment E, the thickness of the first patterned insulating layer 13 in the Z direction is between 700 and 2500Å. In Embodiment B and Embodiment D, the thickness of the first patterned insulating layer 13 in the Z direction is between 100 and 700Å. Comparative Examples A-E correspond to Examples A-E respectively and have the same thickness. As shown in FIG. 9, the power of the light-emitting elements of Examples A-E is higher than that of the light-emitting elements of Comparative Examples A-E. Therefore, the use of a reflective structure comprising a material with a low light absorption rate can effectively improve the brightness of the light-emitting element, for example, the brightness can be increased by 1% to 3%. In addition, as shown in FIG. 9, compared with Examples B and D, Examples A, C and E have higher brightness. Therefore, increasing the thickness of the first patterned insulating layer 13 in the Z direction within a certain range helps to improve the brightness of the light-emitting element, for example, the brightness can be increased by 0.8% to 2%. In one embodiment, the thickness T1 of the first patterned insulating layer 13 in the Z direction can be 100Å to 2500Å. In one embodiment, the thickness T1 of the first patterned insulating layer 13 in the Z direction may be 700Å to 2500Å.

Please refer to FIG. 10. FIG. 10 is a graph showing the power curves corresponding to the width variation of the first patterned insulating layer of the light-emitting element of different embodiments, wherein Embodiment A and Embodiment B have the structure shown in FIG. 7 above, and the first patterned insulating layer 13 comprises the material with a lower light absorption rate as listed above, such as silicon dioxide. The difference between Embodiment A and Embodiment B is that the thickness of the first patterned insulating layer 13 in Embodiment A in the Z direction is between 700 and 2500 Å; the thickness of the first patterned insulating layer 13 in Embodiment B in the Z direction is between 100 and 700 Å. As can be seen from Figure 10, in Embodiment A and Embodiment B, when the width of the first patterned insulating layer 13 in the X direction increases, the current dispersion and reflection efficiency of the corresponding light-emitting element are relatively improved, so the power and brightness of the light-emitting element are higher. Therefore, increasing the width of the first patterned insulating layer 13 in the X direction within a certain range of acceptable electrical properties of the light-emitting element helps to improve the brightness of the light-emitting element. In one embodiment, the width of the first patterned insulating layer 13 in the X direction can be 20μm to 80μm. In one embodiment, the width of the first patterned insulating layer 13 in the X direction can be 30μm to 80μm.

According to different applications, the light-emitting element 1, 2 or 3 may be packaged. Please refer to FIG. 11, which is a cross-sectional schematic diagram of a light-emitting package 200 according to an embodiment. The light-emitting device package 200 according to the embodiment may include a package wall 205, a package substrate 201, external electrodes 213 and 214 mounted on the package substrate 201, a light-emitting element 1, 2 or 3 mounted in the package wall 205 and electrically connected to the external electrodes 213 and 214, and a package material 240 (which includes a phosphor 232 to surround the light-emitting element 1). The external electrodes 213 and 214 are electrically insulated from each other, and provide power to the light-emitting element 1, 2 or 3 through the wire 230. In addition, the external electrodes 213 and 214 can reflect the light emitted from the light-emitting element 1, 2 or 3 to improve the light extraction efficiency, and discharge the heat emitted from the light-emitting element 1, 2 or 3 to the outside. The light-emitting package 200 can be applied to a backlight unit, a lighting unit, a display device, an indicator, a lamp, a street lamp, a lighting device for a vehicle, a display device for a vehicle, or a smart watch, but is not limited thereto.

FIG. 12 is a schematic diagram of a light-emitting device 300 according to an embodiment. The light-emitting device 300 includes a lampshade 301, a reflector 302, a light-emitting module 305, a lamp holder 306, a heat sink 307, a connecting portion 308, and an electrical connection element 309. The light-emitting module 305 includes a carrier 303, and a plurality of light-emitting units 304 are located on the carrier 303, wherein the plurality of light-emitting units 304 can be the light-emitting elements 1, 2, or 3 or the light-emitting package 200 in the aforementioned embodiments.

In many embodiments of the present disclosure, the light-emitting element includes a first patterned insulating layer 13 with a low light absorption rate, which improves the light extraction efficiency, light emission wavelength, brightness and application range of the light-emitting element. The reflectivity of the omnidirectional reflective structure formed by the first patterned insulating layer 13 and the high-reflectivity reflective barrier layer 16 for light with a wavelength between about 200nm and about 600nm is greater than 80%, so the reflectivity of the omnidirectional reflective structure formed by the first patterned insulating layer 13 and the reflective barrier layer 16 for light of various wavelengths can be improved. In addition, in many embodiments disclosed herein, the first patterned insulating layer 13 can simultaneously contact the adhesive layer 15A, the reflective layer 15' and the reflective barrier layer 16 comprising different materials, thereby improving the adhesion between the first patterned insulating layer 13 and other layers, effectively avoiding problems such as poor product yield and reduced durability of the light-emitting element caused by poor adhesion.

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

1: Light-emitting element

11: Semiconductor stacking

12: First electrode structure

13: The first patterned insulating layer

14: Second patterned insulating layer

14s: Insulation surface

14sw,16sw:outer edge

15: Patterned reflective layer

16: Reflection barrier

17: Barrier layer

18:Joint layer

19: Substrate

20: Second electrode structure

21: Protective layer

110: Type I semiconductor layer

110s: First surface

111: Type II semiconductor layer

111s: Second surface

112: Active area

131: Outer periphery

132: Long strips

151: Reflexology area

T1, T2, T3: thickness

X,Y,Z: Direction

Claims (22)

A light-emitting element comprises: a semiconductor stack, comprising a first-type semiconductor layer, a second-type semiconductor layer, and an active region formed between the first-type semiconductor layer and the second-type semiconductor layer, wherein the first-type semiconductor layer has a first surface, and the second-type semiconductor layer has a second surface; a first electrode structure formed on the first surface; a first patterned insulating layer formed on the second surface; and a second patterned insulating layer formed on the second surface, the second patterned insulating layer surrounding and connecting the first patterned insulating layer; wherein the first patterned insulating layer and the second patterned insulating layer comprise different materials. A light-emitting element as described in claim 1, wherein the first patterned insulating layer corresponds to the first electrode structure. A light-emitting element as described in claim 1, wherein the second patterned insulating layer has a thickness less than a thickness of the first patterned insulating layer. The light-emitting element as described in claim 1, wherein the first patterned insulating layer has a first absorptivity for light of a specific wavelength emitted by the active region, and the second patterned insulating layer has a second absorptivity for light of a specific wavelength emitted by the active region, and the first absorptivity is less than the second absorptivity. The light-emitting element as described in claim 4, wherein the absorption rate of the first patterned insulating layer for light with a wavelength less than about 380nm is less than 40%, and the absorption rate of the second patterned insulating layer for light with a wavelength less than about 380nm is greater than 40%. The light emitting device as described in claim 4, wherein the first patterned insulating layer comprises silicon dioxide (SiO ₂ ) or niobium pentoxide (Nb ₂ O ₅ ), and the second patterned insulating layer comprises titanium dioxide (TiO ₂ ). The light-emitting element as described in claim 1 further comprises a reflective layer formed on the second surface, wherein the reflective layer has a thickness equal to or less than a thickness of the first patterned insulating layer. A light-emitting element as described in claim 7, wherein the reflective layer comprises silver or aluminum. The light-emitting element as described in claim 7 further comprises a reflection barrier layer formed on the first patterned insulating layer, the second patterned insulating layer and the reflection layer, wherein the reflection barrier layer and the semiconductor stack are respectively located on opposite sides of the first patterned insulating layer, and the reflection barrier layer contacts the first patterned insulating layer and forms an omni-directional reflector (ODR). A light-emitting element as described in claim 9, wherein the reflectivity of the omnidirectional reflective structure for light with a wavelength between about 200 nanometers and about 380 nanometers is greater than 80%. The light-emitting element as described in claim 9, wherein the portion of the reflection barrier layer in contact with the first patterned insulating layer comprises aluminum, platinum or rhodium. The light-emitting element as described in claim 9, wherein the reflection barrier layer covers an insulating surface of the second patterned insulating layer, the insulating surface faces away from the semiconductor stack, and an outer edge of the reflection barrier layer is aligned with an outer edge of the second patterned insulating layer. A light-emitting element as described in claim 9, wherein the first patterned insulating layer contacts the reflective layer and the reflective barrier layer. The light-emitting element as described in claim 7, wherein the reflective layer is a patterned reflective layer, and is arranged alternately with the first patterned insulating layer. The light-emitting element as described in claim 7 further comprises an adhesive layer formed between the first patterned insulating layer and the reflective layer. The light-emitting element as described in claim 15, wherein the adhesive layer is a patterned adhesive layer, which is only disposed on the first patterned insulating layer. A light-emitting element as described in claim 15, wherein the adhesive layer comprises metal oxide, metal nitride or metal. A light-emitting device as described in claim 15, wherein the thickness of the adhesive layer is 10 to 300Å. The light-emitting element as described in claim 1, wherein the first patterned insulating layer includes an outer peripheral portion and a plurality of inner portions, the outer peripheral portion is in contact with the second patterned insulating layer, and the inner portions are surrounded by the outer peripheral portion. A light-emitting element as described in claim 1, wherein the light-emitting element has a light-emitting wavelength, and the light-emitting wavelength is between about 200nm and about 600nm. A light-emitting element as described in claim 1, wherein the thickness of the first patterned insulating layer is 100Å to 2500Å. A light-emitting element as described in claim 1, wherein the width of the first patterned insulating layer is 20 μm to 80 μm.

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