CN116344699A

CN116344699A - Light-emitting element

Info

Publication number: CN116344699A
Application number: CN202111542712.2A
Authority: CN
Inventors: 谢冰璋; 陈俊昌
Original assignee: Epistar Corp
Current assignee: Epistar Corp
Priority date: 2021-12-16
Filing date: 2021-12-16
Publication date: 2023-06-27
Also published as: TW202345419A

Abstract

The invention discloses a light-emitting element, comprising: a semiconductor stack; an electrode on and electrically connected to the semiconductor stack, the electrode comprising a lower electrode and an upper electrode on the lower electrode; and a protective layer covering the semiconductor stack and the lower electrode, including an opening on the lower electrode and exposing the upper electrode; the lower electrode comprises a first main body structure and a first metal bonding layer, wherein the first metal bonding layer is positioned on the upper surface and the side surface of the first main body structure and is connected with the upper electrode.

Description

Light-emitting element

Technical Field

The present invention relates to a light emitting element, and more particularly, to a light emitting element having a multi-layered electrode structure.

Background

The light-emitting device has the advantages of low power consumption, high brightness, high color rendering, small size, etc., and has been widely used in various lighting and display devices. For example, the light emitting element can be used as a pixel or a backlight of a display device, and a display effect with higher image quality can be achieved. The conventional light emitting device includes a p-type electrode and an n-type electrode respectively provided on a p-type semiconductor layer and an n-type semiconductor layer, and a protective layer provided on a surface of the light emitting device, the protective layer having an opening exposing the p-type electrode and the n-type electrode, and the exposed p-type electrode and n-type electrode can be used as a portion for wire bonding (wire bond).

However, the existing light emitting element may have the following problems: in the wire bonding manufacturing process or after the manufacturing process of the light-emitting element, stress exists above the electrode, so that cracks can possibly occur between the protective layer and the electrode, and the protective layer cannot provide an effective protective function, so that environmental moisture, oxygen or pollutants invade the light-emitting element to cause failure; or the p and n electrodes are subjected to the electric field application, and the metal components in the electrodes are subjected to diffusion and migration (migration) phenomenon, so that the electrode structure is damaged or degenerated to cause the failure of the light-emitting element.

Disclosure of Invention

The invention also discloses a light-emitting element package, comprising: a main body; a cavity located in the body; the wire terminal is positioned at the bottom of the cavity; a light emitting element located at the bottom; the wire and the metal solder ball are positioned in the cavity; and an encapsulation material disposed in the cavity and covering the light emitting element; wherein the light emitting element comprises: a semiconductor stack; an electrode on and electrically connected to the semiconductor stack, comprising a lower electrode and an upper electrode on the lower electrode; and a protective layer covering the semiconductor stack and the lower electrode, including an opening on the lower electrode and exposing the upper electrode; the lower electrode comprises a first main body structure and a first metal bonding layer, and the first metal bonding layer is positioned on the upper surface and the side surface of the first main body structure and is connected with the upper electrode; wherein, the metal solder ball is located on the upper electrode, and the wire is connected with the metal solder ball and the wire terminal.

Drawings

Fig. 1A is a cross-sectional view of a light emitting device 1 according to an embodiment of the present invention;

FIG. 1B is an enlarged view of a portion of region R1 of FIG. 1A;

FIG. 1C is an enlarged view of a portion of region R2 of FIG. 1A;

fig. 2 is a partial enlarged view of a region R1 in a light emitting element 1 according to another embodiment of the present invention;

fig. 3 is a partial enlarged view of a region R1 in a light emitting element 1 according to another embodiment of the present invention;

fig. 4 is a partial enlarged view of a region R1 in a light emitting element 1 according to another embodiment of the present invention;

fig. 5 is a partial enlarged view of a light emitting element 1 according to another embodiment of the present invention;

fig. 6 is a partial enlarged view of a light emitting element 1 according to another embodiment of the present invention;

fig. 7 is a cross-sectional view of a light emitting element 2 according to another embodiment of the present invention;

fig. 8 is a schematic diagram of a light emitting device package 100 according to an embodiment of the invention.

Symbol description

1. 2 light emitting element

100. Light emitting device package

10. Substrate board

12. Semiconductor laminate

121. First semiconductor layer

121a first surface

122. Second semiconductor layer

123. Active layer

14. Conducting wire

16. Main body

160. Cavity body

18. Transparent conductive layer

20. First electrode

30. Second electrode

20a, 30a lower electrode

20b, 30b upper electrode

201. 301 first body structure

202. 302 second body structure

203. 303 first metal adhesion layer

204. 304 second metal adhesion layer

305. First metal base layer

307. Barrier layer

309. Reflective layer

23. Encapsulating material

50. Protective layer

501. A first opening

502. A second opening

60a first wire terminal

60b second wire terminal

70. Metal solder ball

PAD portion of PAD

FR extension

R1 and R2 regions

Thickness T1, T2

S1 and S2 first upper surface and second upper surface

S3, S4 side surface first portion, side surface second portion

S5, S6 upper surface

h1 Height of (1)

Detailed Description

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the drawings so that those skilled in the art of the present invention can fully understand the spirit of the present invention. The present invention is not limited to the following embodiments, but may be embodied in other forms. The dimensions, materials, shapes, relative arrangements, and the like of the constituent parts described in the embodiments are not limited to those described in the specification, and the scope of the present invention is not limited thereto but only by a simple description. And the sizes, positional relationships, etc. of the members shown in the drawings are exaggerated for the sake of clarity. Furthermore, other layers/structures or steps may be incorporated in the following embodiments. For example, the description of "forming a second layer/structure on a first layer/structure" may include embodiments in which the first layer/structure directly contacts the second layer/structure, or embodiments in which the first layer/structure indirectly contacts the second layer/structure, i.e., other layers/structures exist between the first layer/structure and the second layer/structure. In addition, the spatial relative relationship between the first layer/structure and the second layer/structure may vary depending on the operation or use of the device, the first layer/structure itself is not limited to a single layer or a single structure, the first layer may include a plurality of sub-layers, and the first structure may include a plurality of sub-structures. In this description, there are some common symbols that represent elements of the same or similar structure, function, and principle, and will be apparent to those skilled in the art in light of the teachings of this specification. Elements of the same symbols will not be repeated for brevity of description.

Fig. 1A shows a cross-sectional view of a light emitting device 1 according to an embodiment of the invention, fig. 1B shows a partially enlarged view of a region R1 in fig. 1A, and fig. 1C shows a partially enlarged view of a region R2 in fig. 1A. As shown in fig. 1A, the light-emitting element 1 includes a semiconductor stack 12, a transparent conductive layer 18, a first electrode 20, a second electrode 30, and a protective layer 50. In one embodiment, the light emitting device 1 includes a substrate 10, and the semiconductor stack 12 is disposed on an upper surface of the substrate 10, wherein the semiconductor stack 12 includes a first semiconductor layer 121, an active layer 123 and a second semiconductor layer 122 sequentially disposed on the upper surface of the substrate 10, and the first semiconductor layer 121 has a first surface 121a not covered by the active layer 123 and the second semiconductor layer 122. The transparent conductive layer 18 is disposed on the second semiconductor layer 122, and the second electrode 30 is disposed on the transparent conductive layer 18 and electrically connected to the second semiconductor layer 122. The first electrode 20 is located on the first surface 121a of the first semiconductor layer and is electrically connected to the first semiconductor layer 121. The protective layer 50 is located on the semiconductor stack 12, the first electrode 20 and the second electrode 30, and includes a first opening 501 and a second opening 502, where the first opening 501 and the second opening 502 expose a portion of the first electrode 20 and a portion of the second electrode 30, respectively.

The substrate 10 may be a growth substrate including gallium arsenide (GaAs) substrate for growing gallium indium phosphide (AlGaInP), gallium phosphide (GaP) substrate, or sapphire (Al) substrate for growing indium gallium nitride (InGaN) or aluminum gallium nitride (AlGaN) ₂ O ₃ ) A substrate, a gallium nitride (GaN) substrate, a silicon carbide (SiC)) A substrate, and an aluminum nitride (AlN) substrate. The substrate 10 may be a patterned substrate, i.e. the substrate 10 has patterned structures (not shown) on its first surface 10 a. In one embodiment, light emitted from the semiconductor stack 12 may be refracted by the patterned structure of the substrate 10, thereby improving the brightness of the light emitting element. In addition, the patterned structure mitigates or inhibits misalignment between the substrate 10 and the semiconductor stack 12 due to lattice mismatch, thereby improving the epitaxial quality of the semiconductor stack 12.

In one embodiment of the present invention, the method of forming the semiconductor stack 12 on the substrate 10 includes Metal Organic Chemical Vapor Deposition (MOCVD), molecular Beam Epitaxy (MBE), hydride Vapor Phase Epitaxy (HVPE), or ion plating, such as sputtering or evaporation.

The semiconductor stack 12 further includes a buffer structure (not shown) between the upper surface of the substrate and the first semiconductor layer 121. The buffer structure, the first semiconductor layer 121, the active layer 123 and the second semiconductor layer 122 constitute the semiconductor stack 12. The buffer structure can reduce the lattice mismatch and suppress dislocation, thereby improving the epitaxial quality. The material of the buffer layer includes GaN, alGaN, or AlN. In one embodiment, the buffer structure includes a plurality of sub-layers (not shown). The sublayers comprise the same material or different materials. In an embodiment, the buffer structure includes two sub-layers, wherein the first sub-layer is grown by sputtering and the second sub-layer is grown by MOCVD. In one embodiment, the buffer layer further comprises a third sub-layer. The growth mode of the third sub-layer is MOCVD, and the growth temperature of the second sub-layer is higher or lower than that of the third sub-layer. In one embodiment, the first, second and third sublayers comprise the same material, such as AlN, or different materials, such as AlN, gaN, alGaN. In an embodiment of the present invention, the first semiconductor layer 121 and the second semiconductor layer 122, such as a capping layer or a confinement layer (confinement layer), have different conductivity types, electrical properties, polarities, or doping elements for providing electrons or holes. For example, the first semiconductor layer 121 is an n-type semiconductor, and the second semiconductor layer 122 is a p-type semiconductor. The active layer 123 is formed between the first semiconductor layer 121 and the second semiconductor layer 122. The electrons and holes are combined in the active layer 123 under current driving, and convert electric energy into light energy to emit light. The wavelength of the light emitted by the light emitting element 1 or the semiconductor stack 12 can be tuned by changing the physical properties and chemical composition of one or more layers in the semiconductor stack 12.

The material of the semiconductor stack 12 includes Al _x In _y Ga _(1-x-y) N or Al _x In _y Ga _(1-x-y) Group III-V semiconductor material of P, wherein 0.ltoreq.x, y.ltoreq.1; x+y is less than or equal to 1. Depending on the material of the active layer, red light having a wavelength between 570nm and 780nm or yellow light having a wavelength between 550nm and 570nm may be emitted when the material of the semiconductor stack 12 is AlInGaP-series. When the material of the semiconductor stack 12 is InGaN series, blue or deep blue light having a wavelength between 380nm and 490nm or green light having a wavelength between 490nm and 550nm may be emitted. The active layer 123 may be a single heterostructure (single heterostructure; SH), a double heterostructure (double heterostructure; DH), a double-sided double heterostructure (double-side double heterostructure; DDH), a Multiple Quantum Well (MQW). The material of the active layer 123 may be an i-type, p-type or n-type semiconductor.

The transparent conductive layer 18 is electrically contacted with the second semiconductor layer 122 to laterally disperse the current. The transparent conductive layer 18 may be a metal or a transparent conductive material, wherein the metal may be selected from a thin metal layer with light transmittance, and the transparent conductive material is transparent to the light emitted by the active layer 123, and includes graphene, indium Tin Oxide (ITO), aluminum Zinc Oxide (AZO), gallium Zinc Oxide (GZO), zinc oxide (ZnO), or Indium Zinc Oxide (IZO). In one embodiment, as shown in fig. 1A, the transparent conductive layer 18 includes an opening below the second electrode 30, exposing the second semiconductor layer 122, and the second electrode 30 may contact the second semiconductor layer 122 through the opening of the transparent conductive layer 18. In an embodiment, the width of the opening of the transparent conductive layer 18 is smaller than the width of the second opening 502 of the protection layer. In another embodiment, transparent conductive layer 18 may not include openings. In another embodiment, the light emitting element 1 does not have the transparent conductive layer 18. In another embodiment, a current blocking layer (not shown) is further included between the transparent conductive layer 18 and the second semiconductor layer 122 and/or between the second electrode 30 and the second semiconductor layer 122, so as to block most of the current from being directly injected from the electrode 30 to the underlying second semiconductor layer 122, thereby further enhancing the lateral dispersion current. Similarly, a current blocking layer (not shown) may be included between the first electrode 20 and the first semiconductor layer 121.

The material of the protective layer 50 is an insulating material containing an organic material such as Su8, benzocyclobutene (BCB), perfluorocyclobutane (PFCB), epoxy (Epoxy), acrylic Resin (Acrylic Resin), cyclic olefin polymer (COC), polymethyl methacrylate (PMMA), polyethylene terephthalate (PET), polycarbonate (PC), polyetherimide (polyethylenimide) or fluorocarbon polymer (Fluorocarbon Polymer), or an inorganic material such as silica gel (Silicone), glass (Glass) or a dielectric material such as silicon oxide (SiO) _x ) Silicon nitride (SiN) _x ) Silicon oxynitride (SiO) _x N _y ) Niobium oxide (Nb) ₂ O ₅ ) Hafnium oxide (HfO) ₂ ) Titanium oxide (TiO) _x ) Magnesium fluoride (MgF) ₂ ) Alumina (Al) ₂ O ₃ ) Etc. The protective layer 50 may have a single-layer structure or a multi-layer structure composed of different materials. For example, the protective layer 50 includes a dense layer (not shown) directly covering the semiconductor stack 12 and another insulating layer on the dense layer, wherein the dense layer is an insulating layer formed on the surfaces of the transparent conductive layer 18 and the semiconductor stack 20 by, for example, atomic deposition. In another embodiment, the protection layer 50 is formed by alternately stacking one or more pairs of materials with different refractive indexes, and the thickness of the materials with different refractive indexes is selected to match the design, so that the protection layer 50 forms a reflective structure to provide a reflective function for light with a specific wavelength range, for example, a distributed Bragg reflector.

The first electrode 20 and the second electrode 30 respectively include a pad portion for bonding wires. In fig. 1A, the pad portions of the first electrode 20 and the second electrode 30 are only exemplarily shown. Fig. 1B shows a detailed structure of the second electrode 30, and fig. 1C shows a detailed structure of the first electrode 20. The second electrode 30 includes a lower electrode 30a and an upper electrode 30b on the lower electrode 30 a. The protective layer 50 covers the side surface and a part of the upper surface of the lower electrode 30a, the second opening 502 of the protective layer 50 is located above the lower electrode 30a, and the protective layer 50 surrounds the upper electrode 30b, exposing the upper electrode 30b through the second opening 502. The first electrode 20 includes a lower electrode 20a and an upper electrode 20b on the lower electrode 20 a. The protective layer 50 covers the side surface and a part of the upper surface of the lower electrode 20a, the first opening 501 of the protective layer 50 is located above the lower electrode 20a, and the protective layer 50 surrounds the upper electrode 20b, exposing the upper electrode 20b through the first opening 501. In the subsequent wire bonding process of the light emitting device, the

upper electrodes

30b and 20b are mainly carried and connected to a metal ball (not shown). Referring to fig. 1B, the lower electrode 30a includes a first body structure 301, and a first metal adhesion layer 303 is disposed on an upper surface and a side surface of the first body structure 301, wherein the first metal adhesion layer 303 contacts the protection layer 50. In one embodiment, the upper electrode 30b includes a second body structure 302, and a second metal adhesion layer 304 is located under the second body structure 302. The first metal bonding layer 303 is connected to the upper electrode 30b, and more specifically, the first metal bonding layer 303 is connected to the second metal bonding layer 304. Referring to fig. 1C, the lower electrode 20a includes a first body structure 201, and a first metal adhesion layer 203 is disposed on an upper surface and a side surface of the first body structure 201, wherein the first metal adhesion layer 203 contacts the protection layer 50. In one embodiment, the upper electrode 20b includes a second body structure 202, and a second metal adhesion layer 204 is located under the second body structure 202. The first metal bonding layer 203 is connected to the upper electrode 20b, and more specifically, the first metal bonding layer 203 is connected to the second metal bonding layer 204. In another embodiment (not shown), the upper electrode 30b (20 b) does not include the second metal adhesion layer 304 (204), and the upper electrode 30b and the lower electrode 30a can be bonded directly to the second body structure 302 (202) by selecting a suitable adhesion layer material, i.e., through the first metal adhesion layer 303 (203).

For the sake of brevity and clarity of the present disclosure, the following descriptions of the first electrode 20 and the second electrode 30 are presented by way of example with respect to the second electrode 30, and those skilled in the art will appreciate from the disclosure herein that the first electrode 20 and the second electrode 30 may comprise the same materials, structures, functions and implementation.

The material of the first body structure 301 and the second body structure 302 may be selected from metals such as chromium (Cr), titanium (Ti), gold (Au), aluminum (Al), copper (Cu), silver (Ag), tin (Sn), nickel (Ni), rhodium (Rh), or platinum (Pt), or alloys or laminates of the above materials. The first metal adhesion layer 303 is used to increase adhesion between metal and insulating material, and the second metal adhesion layer 304 can increase adhesion between different metals, such as adhesion between the first metal adhesion layer 303, thereby improving adhesion between the upper electrode 30b and the lower electrode 30a, and improving reliability of the device. The materials of the first metal bonding layer 303 and the second metal bonding layer 304 may be selected from chromium (Cr), tungsten (W), titanium (Ti), nickel (Ni), molybdenum (Mo), tantalum (Ta), rhodium (Rh), tin (Sn), or a stack or alloy of the above materials, respectively. The first metal adhesion layer 303 and the second metal adhesion layer 304 may be the same material or different materials; in one embodiment, the first metal bonding layer 303 and the second metal bonding layer 304 are made of the same material and are connected to form a metal bonding structure, as shown in fig. 1B and 1C, which has a first upper surface S1 and a second upper surface S2 higher than the first upper surface S1, wherein the first upper surface S1 is covered by the protection layer 50.

In the present embodiment, the bottom width of the upper electrode 30b is smaller than or equal to the width of the second opening 502, and the upper surface area of the upper electrode 30b is smaller than or equal to the area of the second opening 502. In one embodiment, the ratio of the upper surface area of the upper electrode 30b to the upper surface area of the lower electrode 30a is between 50% and 96%. In one embodiment, the thickness T1 of the lower electrode 30a is between 0.5 and 2.0 μm, and the thickness T2 of the upper electrode 30b is between 0.5 and 2.5 μm. In one embodiment, the ratio of T2 to T1 is between 0.8 and 3. In one embodiment, the thickness of the first metal bonding layer 303 and the thickness of the second metal bonding layer 304 are respectively between

。

In another embodiment, the first metal adhesion layer 303, which is disposed on the upper surface of the first main body structure 301 and is covered by the protection layer 50 and is not covered by the protection layer 50, has different thicknesses; for example, as shown in fig. 2, when the first metal adhesion layer 303 not covered by the protection layer 50 is formed in the protection layer second opening 502, the first metal adhesion layer 303 not covered by the protection layer 50 may be unintentionally etched by an etchant, so that the first metal adhesion layer 303 not covered by the protection layer 50 has a smaller thickness than the first metal adhesion layer 303 covered by the protection layer 50.

In one embodiment, as shown in fig. 3, the first metal adhesion layer 303 does not cover all side surfaces of the first body structure 301. The side surface of the first body structure 301 includes a first portion S3 covered by the first metal adhesion layer 303, and a second portion S4 not covered by the first metal adhesion layer 303. Preferably, the height h1 of the first metal bonding layer 303 in the thickness direction is greater than or equal to 40% of the thickness T1 of the lower electrode 30a, so that a sufficient contact area between the protective layer 50 and the first metal bonding layer 303 can be provided. In an embodiment, the first portion S3 and the second portion S4 have different slopes, the slope of the first portion S3 is smaller than that of the second portion S4, and the first metal adhesion layer 303 covers the first portion S3 with the smaller slope. In another embodiment, when the electrode thickness is larger, the thickness of the outermost metal material on the electrode side surface is easier to be gradually reduced as the electrode is further away from the electrode upper surface, so that the outermost metal material is incompletely present on the electrode side surface or cannot cover all the electrode side surfaces, the first metal bonding layer 303 only covers the upper portion (the first portion S3) of the side surface of the first body structure 301, and the lower portion (the second portion S4) of the side surface is not covered by the first metal bonding layer 303. In the above embodiment, the first metal bonding layer 303 covers the first portion S3 of the side surface of the first main body structure 301, so that a sufficient contact area and good adhesion between the protection layer 50 and the first metal bonding layer 303 can be achieved without completely covering the side surface of the first main body structure 301 by the first metal bonding layer 303, and environmental moisture, oxygen or other pollutants are prevented from entering the light emitting device through the gap between the electrode and the protection layer. In the embodiment of the present invention, the electrodes are configured as an upper electrode and a lower electrode, and the upper electrode is used as a main bonding site, and in an embodiment, the thickness T1 of the lower electrode 30a may be designed to be less than or equal to 1.5 μm, and the height h1 is greater than or equal to 40% of the thickness T1, and preferably the height h1 is greater than or equal to 60% of the thickness T1. By adjusting the thickness T1 of the lower electrode 30a, the side metal material can have a sufficient height h1 and thickness to cover the sidewall of the first main structure 301, so that good adhesion between the lower electrode 30a and the passivation layer 50 can be achieved, and environmental moisture, oxygen or other pollutants can be prevented from entering the light emitting device 1 through the gap between the electrode and the passivation layer. In addition, the uppermost surface of the lower electrode 30a is in contact with the upper electrode 30b by the first metal bonding layer 303, and the upper electrode 30b may further include the second metal bonding layer 304 in contact with the first metal bonding layer 303, so that the adhesion between the lower electrode 30a and the upper electrode 30b may be increased. When diffusion migration (migration) of the metal components in the electrodes occurs, the first metal adhesion layer 303 and/or the second metal adhesion layer 304 between the lower electrode 30a and the upper electrode 30b can provide a function of blocking the metal diffusion by selecting the material of the metal adhesion layer, so as to avoid the failure of the light emitting element 1.

Fig. 4 shows a cross-sectional view of a second electrode 30 in another embodiment. The first body structure 301 comprises a stack of different metal layers. For example, the first body structure 301 includes a functional structure and the first metal base layer 305 is located between the first metal adhesion layer 303 and the functional structure. In one embodiment, the functional structure includes a reflective layer 309 that reflects or redirects light directed to the electrode, increasing light extraction. In another embodiment, the functional structure includes a barrier layer 307 that blocks diffusion and migration of metal components. In another embodiment, an adhesion layer (not shown) may be included between the layers in the functional structure to enhance adhesion between the layers or between the layers and the semiconductor stack. In this embodiment, as shown in fig. 4, the functional structure includes a reflective layer 309 and a barrier layer 307 covering the reflective layer 309. The material of the reflective layer 309 includes a metal material having high reflectivity for light emitted by the semiconductor stack 12, such as silver (Ag), gold (Au), aluminum (Al), titanium (Ti), chromium (Cr), copper (Cu), nickel (Ni), platinum (Pt), ruthenium (Ru), or an alloy or stack of the above materials. The barrier layer 307 may prevent migration, diffusion, or oxidation of metal elements of the reflective layer 309, and its material includes chromium (Cr), molybdenum (Mo), platinum (Pt), titanium (Ti), tungsten (W), zinc (Zn), rhodium (Rh), or an alloy or a laminate of the above materials. In one embodiment, when the barrier layer 307 is a metal stack, the barrier layer 307 is formed by alternately stacking two or more metal layers, such as Cr/Pt, cr/Ti, cr/TiW, cr/W, cr/Zn, ti/Pt, ti/W, ti/TiW, ti/Zn, pt/TiW, pt/W, pt/Zn, tiW/W, tiW/Zn, or W/Zn. The first metal base 305 is used for conducting current, and its material may include gold (Au), aluminum (Al), copper (Cu), silver (Ag), or the like. The second body structure 302 of the upper electrode 30b includes a second metal base layer (not shown) for wire bonding, optionally a chemically stable metal material such as gold (Au). In one embodiment, the first metal base layer 305 and the second metal base layer are made of the same material. In one embodiment, the thickness of the first metal base layer 305 is less than the thickness of the second metal base layer. In another embodiment (not shown), like the first body structure 301, the second body structure 302 may include a functional structure between a second metal base layer and a second metal adhesion layer 304.

Fig. 5 shows a cross-sectional view of the first electrode 20 or the second electrode 30 in another embodiment. The difference from the foregoing embodiment is that the first metal adhesion layer 203 (303) extends from the side surface of the lower electrode 20b (30 b) to cover the upper surface S5. In one embodiment, the electrode shown in fig. 5 is the first electrode 20, and S5 is the upper surface 121a of the first semiconductor layer 121. In another embodiment, the electrode shown in fig. 5 is the second electrode 30, and S5 is the upper surface of the transparent conductive layer 18. Since the corner or the recess region exists at the junction between the first semiconductor layer 121 or the transparent conductive layer 18 and the electrode side surface, the adhesion such as peeling may be poor in the protective layer 50 located there, and the adhesion between the protective layer 50 and the first electrode 20 (or the second electrode 30) may be ensured by extending the first metal adhesion layer 203 (303) to the upper surface S5.

Fig. 6 shows a cross-sectional view of the first electrode 20 or the second electrode 30 in another embodiment. The difference from the previous embodiment is that the bottom width of the upper electrode 20b (30 b) is larger than the width of the first opening 501 (or the second opening 502), and the upper surface area of the upper electrode 20b (30 b) is larger than the area of the first opening 501 (or the second opening 502). The second metal adhesion layer 204 (304) covers a portion of the upper surface S6 of the protection layer 50 in addition to the first metal adhesion layer 203 (303) that is connected to the lower side of the first opening 501 (or the second opening 502). By extending the passivation layer 50 under the upper electrode 20b (30 b), moisture at the corners can be prevented from penetrating, and by extending the second metal adhesion layer 204 (304) over the passivation layer 50, adhesion between the passivation layer 50 and the upper electrode 20b (30 b) can be further improved.

Fig. 7 shows a cross-sectional view of a light emitting element 2 according to another embodiment of the present invention. The difference from the light emitting element 1 is that the second electrode 30 includes a PAD portion PAD and an extension portion FR extending from the PAD portion PAD. In a top view (not shown), the width of the extension FR is smaller than the width of the PAD for diffusing the current. As shown in fig. 7, the PAD portion PAD includes a portion of the lower electrode 30a, the upper electrode 30b, and the extension FR, which has the same structure and material as the lower electrode 30a, includes a first main structure 301 and a first metal adhesion layer 303. The protective layer 50 covers the lower electrode 30b and the extension FR of the second electrode 30, and the second opening 502 is located at the PAD portion PAD of the second electrode 30 and exposes the upper electrode 30b.

Fig. 8 shows a light emitting device package 100 according to an embodiment of the invention. As shown in fig. 7, the light emitting element package 100 includes a main body 16 having a cavity 160, a first wire terminal 60a and a second wire terminal 60b disposed in the main body 16, the

light emitting element

1 or 2 according to any of the embodiments of the present invention, the wire 14, the metal solder ball 70, and the encapsulation material 23. The cavity 160 may include an open structure recessed from the top surface of the body 16, and in one embodiment, the sidewalls of the cavity 160 may include a reflective structure. The first wire terminal 60a is disposed in a first region of the bottom region of the cavity 160, the second wire terminal 60b is disposed in a second region of the bottom region of the cavity 160, and the first wire terminal 60a and the second wire terminal 60b are spaced apart from each other within the cavity 160. The

light emitting element

1 or 2 is provided on at least one of the first and

second wire terminals

60a and 60b. For example, the

light emitting element

1 or 2 may be disposed on the first wire terminal 60a, and the first electrode 20 and the second electrode 306 of the

light emitting element

1 or 2 are electrically connected to the first and

second wire terminals

60a and 60b, respectively, using the wire 14 and the metal solder ball 70. The encapsulation material 23 is disposed in the cavity 160 of the body 16 and covers the light emitting elements. The encapsulating material 23 comprises, for example, silicon or epoxy, and may have a single layer or multiple layers. In an embodiment, the encapsulation material 23 may further include a wavelength conversion material, such as a phosphor, and/or a scattering material, for changing the wavelength of the light generated by the light emitting element 1.

It should be noted that, the

light emitting elements

1 and 2 or the light emitting element package 100 in the above embodiments may be combined or changed by those skilled in the art without departing from the technical principle and spirit of the present invention. For example, as shown in fig. 3, the side surface of the first body structure 301 of the light emitting device may include a first portion S3 covered by the first metal bonding layer 303, and a second portion S4 not covered by the first metal bonding layer 303, and the first body structure 301 may include a stack of different metal layers as shown in fig. 4. For example, the first electrode 20 of the light emitting element may include a PAD portion PAD and an extension portion FR as shown in fig. 7, and the protective layer 50 covers the extension portion FR of the first electrode 20, and the first opening 501 is located at the PAD portion PAD of the first electrode 20 and exposes the upper electrode 20b.

The above-described embodiments are merely illustrative of the principles of the present invention and its effectiveness, and are not intended to limit the invention. Modifications and variations may be made to the above-described embodiments by those skilled in the art without departing from the spirit and principles of the present invention. All equivalent changes and modifications of shape, construction, characteristics and spirit according to the present invention shall be included in the scope of the appended claims.

Claims

1. A light emitting element comprising:

a semiconductor stack;

an electrode on and electrically connected to the semiconductor stack, comprising a lower electrode and an upper electrode on the lower electrode; and

a protective layer covering the semiconductor stack and the lower electrode, including an opening on the lower electrode and exposing the upper electrode;

the lower electrode comprises a first main body structure and a first metal bonding layer, wherein the first metal bonding layer is positioned on the upper surface and the side surface of the first main body structure and is connected with the upper electrode.

2. The light emitting device of claim 1, wherein the upper electrode comprises a second metal adhesion layer, the first metal adhesion layer being in contact with the second metal adhesion layer.

3. The light emitting device of claim 2, wherein the first metal adhesion layer and the second metal adhesion layer comprise the same material.

4. The light-emitting device according to claim 1, wherein the first metal adhesion layer comprises chromium (Cr), tungsten (W), titanium (Ti), nickel (Ni), molybdenum (Mo), tantalum (Ta), rhodium (Rh), tin (Sn) or a laminate or alloy thereof, and the first metal adhesion layer has a thickness between

5. The light-emitting element according to claim 1, wherein:

the side surface of the first body structure includes a first portion covered by the first metal adhesion layer and a second portion uncovered by the first metal adhesion layer; and

the first metal adhesion layer has a height in the thickness direction of greater than or equal to 40% of the thickness of the lower electrode.

6. The light-emitting device according to claim 1, wherein the thickness of the lower electrode is 0.5-2.0 μm and/or the ratio of the thickness of the upper electrode to the thickness of the lower electrode is 0.8-3.

7. The light emitting device of claim 1, wherein the first body structure comprises a functional structure and a first metal base layer is located between the first metal adhesion layer and the functional structure; wherein the upper electrode comprises a second body structure comprising a second metal base layer; and

the functional structure comprises a reflective layer and/or a barrier layer.

8. The light-emitting device according to claim 7, wherein the first metal base layer and the second metal base layer comprise the same material.

9. The light-emitting device according to claim 1, wherein a ratio of an upper surface area of the upper electrode to an upper surface area of the lower electrode is 50% to 96%, and/or the upper surface area of the upper electrode is smaller than or equal to an area of the opening.

10. A light emitting element package, comprising:

a main body;

a cavity located in the body;

the wire terminal is positioned at the bottom of the cavity;

a light emitting element located at the bottom;

the wire and the metal solder ball are positioned in the cavity; and

an encapsulation material disposed in the cavity and covering the light emitting element;

wherein, this light emitting component includes:

a semiconductor stack;

wherein the lower electrode comprises a first main body structure and a first metal bonding layer, and the first metal bonding layer is positioned on the upper surface and the side surface of the first main body structure and is connected with the upper electrode;

the metal solder ball is located on the upper electrode, and the wire is connected with the metal solder ball and the wire terminal.