TWI911541B - Light-emitting device - Google Patents

Abstract

A light-emitting device includes a first semiconductor layer including a first inclined surface; a semiconductor mesa located on the first semiconductor layer, including an active layer and a second semiconductor layer, and including a second inclined surface connected to the first semiconductor layer; a contact electrode located on the second semiconductor layer; a reflective structure located on the contact electrode and including a plurality of reflective structure openings; and a metal reflective layer covering the reflective structure opening, wherein the contact electrode includes a plurality of contact openings forming an one-to-one arrangement with the plurality of reflective structure openings, a plurality of contact recesses forming an one-to-one arrangement with the plurality of reflective structure openings, or a plurality of contact protrusions forming an one-to-one arrangement with the plurality of reflective structure openings.

Description

Light-emitting element

This invention relates to a light-emitting element, and more particularly to a flip-chip light-emitting element comprising a metal reflective layer and a reflective structure.

Light-emitting diodes (LEDs) are solid-state semiconductor light-emitting devices. Their advantages include low power consumption, low heat generation, long lifespan, shock resistance, small size, fast response speed, and excellent photoelectric characteristics, such as stable emission wavelength. Therefore, LEDs are widely used in household appliances, equipment indicator lights, and optoelectronic products.

A light-emitting element includes a first semiconductor layer including a first bevel; a semiconductor platform located on the first semiconductor layer, including an active layer and a second semiconductor layer, and including a second bevel connected to the first semiconductor layer; a contact electrode located on the second semiconductor layer; a reflective structure located on the contact electrode, including a plurality of reflective structure openings; and a metal reflective layer covering the reflective structure openings, wherein the contact electrode includes a plurality of contact openings and a plurality of reflective structure openings arranged in a one-to-one configuration, a plurality of contact recesses and a plurality of reflective structure openings arranged in a one-to-one configuration, or a plurality of contact protrusions and a plurality of reflective structure openings arranged in a one-to-one configuration.

The following disclosure provides many different embodiments to implement the different features of this application. The following disclosure describes specific examples of the components and their arrangement for simplification. Of course, these specific examples are not intended to be limiting. For example, if this disclosure describes a first feature component formed on or above a second feature component, it indicates that it may include embodiments where the first and second feature components are in direct contact, or embodiments where an additional feature component is formed between the first and second feature components, so that the first and second feature components may not be in direct contact.

It should be understood that additional operation steps may be performed before, during, or after the method, and in other embodiments of the method, some operation steps may be replaced or omitted.

In addition, spatial terms may be used, such as "below," "lower," "above," "above," "higher," and similar terms. These spatial terms are used to facilitate the description of the relationship between one or more elements or features in the diagram and another element or feature(s). These spatial terms include different orientations of the device in use or operation, as well as the orientations described in the diagram. When the device is turned to different orientations (rotated 45 degrees or other orientations), the spatial adjectives used will also be interpreted according to the orientation after the turn. Furthermore, when referring to a first material layer located on or above a second material layer, this includes situations where the first and second material layers are in direct contact, or situations where one or more other material layers may be present in between, in which case the first and second material layers may not be in direct contact. In some embodiments disclosed herein, terms such as "connection" and "interconnection," unless specifically defined, may refer to two structures being in direct contact, or they may refer to two structures not being in direct contact, with other structures disposed between them. Moreover, these terms regarding joining and connecting may also include situations where both structures are movable or both structures are fixed.

In the specification, the terms "approximately," "about," "roughly," "substantially," "same," and "similar" generally indicate a eigenvalue within ±15%, ±10%, ±5%, ±3%, ±2%, ±1%, or ±0.5% of a given value. The quantities given here are approximate, meaning that even without specific mention of "approximately," "roughly," "substantially," or "substantially," these terms can still be implied.

It should be understood that although the terms "first," "second," "third," etc., are used herein to describe different elements, components, regions, layers, and/or segments, these elements, components, regions, layers, and/or segments should not be limited by these terms. These terms may only be used to distinguish one element, component, region, layer, or segment from another. Therefore, without departing from the art disclosed herein, the first element, component, region, layer, or segment discussed below may be referred to as a second element, component, region, layer, or segment.

Unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by those skilled in the art to which this disclosure pertains. It is understood that these terms, such as those defined in commonly used dictionaries, should be interpreted in a manner consistent with the relevant technology and the context of this disclosure, and should not be interpreted in an idealized or overly formal manner, unless specifically defined in the embodiments of this disclosure.

Figure 1 is a top view of a light-emitting element 1 disclosed in an embodiment of the present invention. Figure 2 is a cross-sectional view along the tangent L-L’ of Figure 1. Figure 3 is a partial enlarged view of the area A indicated by the dashed line in Figure 1. Figure 4 is a cross-sectional view along the tangent X-X’ of Figure 3.

Referring to Figures 1, 2, 3, and 4, a light-emitting element 1 according to an embodiment includes a substrate 10 having an upper surface 10s, a first semiconductor layer 21 located on the upper surface 10s of the substrate 10 and including a first inclined surface S1 in contact with the upper surface 10s of the substrate 10, and a semiconductor platform M located on the first semiconductor layer 21. The semiconductor platform M includes an active layer 22 and a second semiconductor layer 23, and a second inclined surface S2 in contact with the first semiconductor layer 21.

The light-emitting element 1 further includes a contact electrode 30 located on the second semiconductor layer 23. A reflective structure 40 is located on the contact electrode 30 and includes a plurality of reflective structure openings 400 located on the second semiconductor layer 23. A connection layer 51 covers the reflective structure 40 and fills the plurality of reflective structure openings 400 to contact the contact electrode 30 and/or the second semiconductor layer 23. A metallic reflective layer 52 is located on the connection layer 51 and fills the plurality of reflective structure openings 400.

The light-emitting element 1 further includes a first insulating structure 60 located on the semiconductor platform M, covering the interconnect layer 51, the metal reflective layer 52 and the reflective structure 40, and includes a first opening 601 of the first insulating structure located on the first semiconductor layer 21 and a second opening 602 of the first insulating structure located on the metal reflective layer 52.

The light-emitting element 1 further includes a first extended electrode 71 covering the semiconductor platform M and electrically connected to the first semiconductor layer 21 through a first opening 601 of the first insulating structure. A second extended electrode 72 covers the semiconductor platform M and the second opening 602 of the first insulating structure, and is electrically connected to the second semiconductor layer 23 through a metal reflective layer 52 covering the reflective structure opening 400. A second insulating structure 80 covers the first extended electrode 71 and the second extended electrode 72, and includes a first opening 801 of the second insulating structure located on the first extended electrode 71 and a second opening 802 of the second insulating structure located on the second extended electrode 72. A first electrode pad 91 covers the first opening 801 of the second insulation structure and forms an electrical connection with the first semiconductor layer 21 through a first extended electrode 71. A second electrode pad 92 covers the second opening 802 of the second insulation structure and forms an electrical connection with the second semiconductor layer 23 through a second extended electrode 72.

The substrate 10 may be a growth substrate epitaxially grown to form a semiconductor structure 20. In one embodiment, the semiconductor structure 20 includes a first semiconductor layer 21, an active layer 22, and a second semiconductor layer 23. The substrate 10 includes gallium arsenide (GaAs) wafers for epitaxial growth of aluminum gallium indium phosphide (AlGaInP), or sapphire ( _Al₂O₃ ) wafers, gallium nitride (GaN) wafers, silicon carbide ( _SiC ) wafers, or aluminum gallium nitride (AlN) wafers for growth of gallium nitride (GaN), indium gallium nitride (InGaN), or aluminum gallium nitride (AlGaN).

In one embodiment of the present invention, the light-emitting element 1 may not have a substrate 10. For example, the substrate 10 may be a growth substrate for growing a semiconductor structure 20, and then the substrate 10 may be separated from the semiconductor structure 20 by means of laser lift-off or chemical peeling.

In one embodiment of the present invention, a semiconductor structure 20 with optoelectronic properties, such as a light-emitting layer, is formed on a substrate 10 by metal organic chemical vapor deposition (MOCVD), molecular beam epitaxy (MBE), hydrogen vapor deposition (HVPE), physical vapor deposition (PVD), or ion electroplating. The physical vapor deposition method includes sputtering or evaporation.

The wavelength of light emitted by the light-emitting element 1 is adjusted by changing the physical and chemical composition of one or more layers in the semiconductor structure 20. The semiconductor structure 20 includes a first semiconductor layer 21, an active layer 22, and a second semiconductor layer 23. The material of the semiconductor structure 20 includes group III-V semiconductor materials, such as Al _{_x}In_{_y}Ga_{_(1-xy)}N or Al _{_x} In_yGa_{_(1-xy)}P, where 0≦x, y≦1; (x+y)≦1. When the material of the semiconductor structure 20 is an AlInGaP series material, red light with a wavelength between 610 nm and 650 nm can be emitted. When the semiconductor structure 20 is made of InGaN series materials, it emits blue light with wavelengths between 400 nm and 490 nm, or green light with wavelengths between 530 nm and 570 nm. When the semiconductor structure 20 is made of AlGaN series or AlInGaN series materials, it emits ultraviolet light with wavelengths between 250 nm and 400 nm.

The first semiconductor layer 21 and the second semiconductor layer 23 can be cladding layers or confinement layers, and they have different conduction types, electrical properties, and polarities, or they can be doped with elements to provide electrons or holes. For example, the first semiconductor layer 21 is an n-type semiconductor, and the second semiconductor layer 23 is a p-type semiconductor. An active layer 22 is formed between the first semiconductor layer 21 and the second semiconductor layer 23. Electrons and holes recombine in the active layer 22 under the drive of a current, converting electrical energy into light energy to emit light. The active layer 22 can be a single heterostructure (SH), a double heterostructure (DH), a double-side double heterostructure (DDH), or a multi-quantum well (MQW). The material of the active layer 22 can be a neutral, p-type, or n-type semiconductor. The first semiconductor layer 21, the active layer 22, or the second semiconductor layer 23 can be a single layer or a structure containing multiple sublayers.

In one embodiment of the present invention, the semiconductor structure 20 may further include a buffer layer (not shown) located between the first semiconductor layer 21 and the substrate 10 to release the stress generated between the substrate 10 and the semiconductor structure 20 due to material lattice mismatch, thereby reducing misalignment and lattice defects and improving epitaxial quality. The buffer layer may be a single layer or a structure containing multiple sublayers. In one embodiment, PVD aluminum nitride (AlN) may be selected as the buffer layer and formed between the semiconductor structure 20 and the substrate 10 to improve the epitaxial quality of the semiconductor structure 20. In one embodiment, the target material used to form PVD aluminum nitride (AlN) is composed of aluminum nitride. In another embodiment, an aluminum target can be used to reactively form aluminum nitride with the aluminum target in a nitrogen source environment.

As shown in Figures 2 and 4, the semiconductor structure 20 includes a first recessed region E1, a second recessed region E2, and a semiconductor platform M surrounding the first recessed region E1. In one embodiment, the first recessed region E1 and the second recessed region E2 can be formed by etching away a portion of the second semiconductor layer 23, the active layer 22, and the first semiconductor layer 21. In other words, the first recessed region E1 and the second recessed region E2 expose the first upper surface 21t of the first semiconductor layer 21. In a top view of one of the light-emitting elements 1, as shown in Figure 1, the first recessed region E1 is located on at least one side of the semiconductor platform M, and the second recessed region E2 is located inside the semiconductor platform M and surrounded by the semiconductor platform M. In Figure 2, the designation "B1" indicates the first boundary B1 between the first recessed region E1 and the semiconductor platform M. In Figure 4, the designation "B2" indicates the second boundary B2 between the second recessed region E2 and the semiconductor platform M. The upper surface 20t of the semiconductor platform M (the second upper surface 23t of the second semiconductor layer 23) may be higher than the upper surface 20b of the first recessed region E1 (the first upper surface 21t of the first semiconductor layer 21) and the upper surface 20b' of the second recessed region E2 (the first upper surface 21t of the first semiconductor layer 21). In one embodiment, the semiconductor platform M may narrow towards its top. Therefore, the side surfaces of the semiconductor platform M may be sloped, such as the second slope S2 shown in Figures 2 and 4.

In one embodiment, as shown in Figure 2, a portion of the upper surface 20b of the first recessed region E1 may be a first contact region CT1. As shown in Figure 4, a portion of the upper surface 20b' of the second recessed region E2 may be a first contact region CT1'. In one embodiment, at least a portion of the upper surface 20t of the semiconductor platform M is defined as a second contact region CT2. The first insulating structure 60 includes a plurality of first insulating structure first openings 601 to expose the first contact region CT1 and the first contact region CT1'. The reflective structure 40 includes a plurality of reflective structure openings 400 located on the second contact region CT2 and exposing the contact electrode 30 and/or the second semiconductor layer 23. In one embodiment, a ratio (A1/A2) between the first total area A1 of one of the plurality of first contact second regions CT1' and the second total area A2 of one of the plurality of first contact first regions CT1 is between 1 and 2 to improve the current distribution of the light-emitting element 1. If the ratio (A1/A2) is less than 1, the brightness of the light-emitting element 1 will decrease; if the ratio (A1/A2) is greater than 2, the voltage (Vf) of the light-emitting element 1 will increase.

As shown in Figure 1, the substrate 10 includes a first side 11, a second side 12, a third side 13, and a fourth side 14. The semiconductor platform M can be spaced apart from the first side 11 to the fourth side 14, and the first recessed region E1 can be distributed between the semiconductor platform M and any one or more of the first side 11 to the fourth side 14. For example, the first recessed region E1 can be disposed between the semiconductor platform M and the first side 11 and between the semiconductor platform M and the second side 12, or between the semiconductor platform M and the third side 13 and between the semiconductor platform M and the fourth side 14. The first side 11 and the second side 12 can be opposite each other, and the third side 13 and the fourth side 14 can be opposite each other. In one embodiment, a plurality of second recessed regions E2, having an elongated, rectangular, circular, or elliptical shape and spaced apart from each other, can be disposed inside the semiconductor platform M.

As shown in Figures 2 and 4, the contact electrode 30 can be directly disposed on the second semiconductor layer 23. The area where the contact electrode 30 contacts the second semiconductor layer 23 constitutes the second contact area CT2 and is electrically connected to the second semiconductor layer 23. The contact electrode 30 is used to disperse the current injected from the outside and then inject it onto the second semiconductor layer 23 through the upper surface 20t of the semiconductor platform M (the second upper surface 23t of the second semiconductor layer 23).

In one embodiment, the reflective structure 40 includes a plurality of reflective structure openings 400 disposed on the semiconductor platform M. As shown in Figures 1 and 3, in a top view of one of the light-emitting elements 1, the reflective structure openings 400 include circular, semi-circular, elliptical, triangular, rectangular, polygonal, arc-shaped, or annular shapes. The plurality of reflective structure openings 400 may be arranged on the semiconductor platform M in a hexagonal grid pattern with the closest possible arrangement, but is not limited thereto. In another embodiment, the plurality of reflective structure openings 400 may be arranged in various patterns. For example, a rectangular grid pattern. As shown in Figures 2 and 4, the reflective structure 40 is located above the contact electrode 30 and covers the second inclined surface S2 of the semiconductor platform M, and covers a portion of the first semiconductor layer 21 and a portion of the second semiconductor layer 23. For example, the reflective structure 40 may cover a portion of the first upper surface 21t of the first semiconductor layer 21 and a portion of the second upper surface 23t of the second semiconductor layer 23.

In one embodiment of the invention, the reflective structure 40 includes an insulating mirror 41 and/or an insulating layer 42. The reflective structure opening 400 includes a first reflective structure opening 410 extending through the insulating mirror 41. As shown in Figures 2 and 4, the insulating mirror 41 of the reflective structure 40 covers the second inclined surface S2 of the semiconductor platform M to reflect light from the active layer 22 and increase the light extraction efficiency of the light-emitting element 1.

In one embodiment of the invention, the insulating layer 42 of the reflective structure 40 is located between the contact electrode 30 and the insulating mirror 41. The reflective structure opening 400 includes a second reflective structure opening 420 passing through the insulating layer 42. As shown in Figure 3, in the top view of the light-emitting element 1, the first reflective structure opening 410 and the second reflective structure opening 420 form a concentric circle pattern. In one embodiment, as shown in Figure 3, the first reflective structure opening 410 includes a first opening width W1 that is greater than a second opening width W2 included in the second reflective structure opening 420. In a side view of the light-emitting element 1, the first aperture width W1 is between 9 micrometers (μm) and 15 micrometers, and the second aperture width W2 is between 3 micrometers and 9 micrometers.

As shown in Figures 1 and 3, the connecting layer 51 covers the reflective structure 40 and fills the first reflective structure opening 410 to contact the contact electrode 30. The connecting layer 51 includes titanium oxide (TiO _x ), titanium nitride (TiN _x ), aluminum oxide (Al ₂ O ₃ ), indium tin oxide (ITO), zinc-doped indium tin oxide (ZITO), zinc indium oxide (ZIO), gallium indium oxide (GIO), zinc tin oxide (ZTO), fluorine-doped tin oxide (FTO), aluminum-doped zinc oxide (AZO), gallium-doped zinc oxide (GZO), or zinc magnesium oxide (Zn _(1-x) Mg _x O, 0≤x ≤1). The contact electrode 30 comprises indium tin oxide (ITO), zinc-doped indium tin oxide (ZITO), zinc-doped indium oxide (ZIO), gallium-doped indium oxide (GIO), zinc-doped tin oxide (ZTO), fluorine-doped tin oxide (FTO), aluminum-doped zinc oxide (AZO), gallium-doped zinc oxide (GZO), or zinc-magnesium oxide (Zn _{(1-x) MgxO} , 0≤x≤1). In one embodiment of the invention, the interconnect layer 51 has a thickness less than that of the contact electrode 30. For example, the interconnect layer 51 has a thickness between 10 Å and 60 Å, and the contact electrode 30 has a thickness between 100 Å and 400 Å. In one embodiment of the invention, the contact electrode 30 and the interconnect layer 51 contain the same material; for example, the contact electrode 30 and the interconnect layer 51 contain indium tin oxide (ITO). In one embodiment of the invention, the contact electrode 30 and the interconnect layer 51 contain different materials; for example, the contact electrode 30 contains indium tin oxide (ITO), and the interconnect layer 51 contains aluminum oxide.

The metal reflective layer 52 fills the reflective structure opening 400 of the reflective structure 40 through the connecting layer 51, wherein the connecting layer 51 can improve the adhesion between the reflective structure 40 and the metal reflective layer 52. In a side view of the light-emitting element 1, in one embodiment, the metal reflective layer 52 can be disposed on the connecting layer 51 and conformally to the connecting layer 51. For example, the metal reflective layer 52 and the connecting layer 51 can completely overlap or partially overlap each other.

In one embodiment, the metal reflective layer 52 comprises silver (Ag), chromium (Cr), nickel (Ni), titanium (Ti), aluminum (Al), rhodium (Rh), ruthenium (Ru), or a combination of the foregoing materials.

In one embodiment, the light-emitting element 1 further includes a barrier layer (not shown) disposed on the metal reflective layer 52. The barrier layer has a multilayer structure, for example, a multilayer structure of alternating Ti and Ni layers.

The reflective structure 40, the connecting layer 51, and the metal reflective layer 52 can be configured as an omni-directional reflector (ODR). The omni-directional reflector can increase the reflectivity of light emitted from the active layer 22, thereby improving the light extraction efficiency of the light-emitting element 1.

In one embodiment, the insulating layer 42 of the reflective structure 40 is an insulating film and has a single-layer structure comprising oxides or nitrides, such as at least one oxide or nitride selected from the group consisting of silicon (Si), titanium (Ti), zirconium (Zr), niobium (Nb), tantalum (Ta), and aluminum (Al). In another embodiment, the insulating layer 42 may also be a multilayer structure, such as a stack composed of any two or more of the above-mentioned oxides or nitrides, for example _, a multilayer structure composed of _SiO2 , _TiO2 , and _Al2O3 .

In one embodiment, referring to Figures 2 and 4, the insulating mirror 41 may be formed of a material with a refractive index lower than that of the second semiconductor layer 23. The material of the insulating mirror 41 includes _SiO₂ , _SiN , _SiOₓNy , _TiO₂ , _Si₃N₄ , _Al₂O₃ , _TiN , AlN, _ZrO₂ , TiAlN, _TiSiN , HfO, _TaO₂ , _Nb₂O₅ , or _{MgF₂ .} In one embodiment, the insulating mirror 41 is a multilayer film structure in which insulating sublayers with different refractive indices are alternately stacked, such as a distributed Bragg mirror (DBR). A distributed Bragg reflector structure is formed by alternatingly stacking a plurality of first sublayers having a first refractive index and a plurality of second sublayers having a second refractive index, wherein the first refractive index is less than _the second refractive index. For example, it can be formed by stacking _SiO2 / _TiO2 or _SiO2 / _Nb2O5 .

In one embodiment of the invention, when the insulating mirror 41 comprises a distributed Bragg reflector structure having stacked _SiO2 / _TiO2 or _{SiO2 / Nb2O5} , the insulating layer 42 has a thickness greater than the thickness of any of the sublayers comprised of the insulating mirror 41. In one embodiment of the invention, the thickness of the insulating layer 42 is between 3000 angstroms and 7000 angstroms.

The bottom or top layer of the insulating reflector 41 may be an oxide or nitride selected from the group consisting of silicon (Si), titanium (Ti), zirconium (Zr), niobium (Nb), tantalum (Ta), and aluminum (Al). In one embodiment, the bottom and top layers of the insulating reflector 41 comprise a material and/or a thickness and/or a forming process different from that of the intermediate layer located between them.

In one embodiment, the insulating layer 42 may comprise the same material as a plurality of the first sublayers of the insulating mirror 41. For example, when the insulating mirror 41 is formed of a distributed Bragg reflector comprising _SiO2 / _TiO2 or _SiO2 / _Nb2O5 , _the insulating layer 42 may be formed of _SiO2 . Although the insulating layer 42 is formed of at least a portion of the same material as the insulating mirror 41, it is not required to have the high film quality of an insulating film such as a DBR; therefore, the insulating mirror 41 and the insulating layer 42 may be formed by different processes. The interface of the insulating layer 42 relative to the insulating mirror 41 can be visually distinguished (e.g., by SEM or TEM images). In one embodiment, the total thickness of one of the plurality of first sublayers of the insulating mirror 41 is less than the total thickness of one of the insulating layers 42.

Figure 3 is a top view of the reflective structure opening 400 and the second recessed area E2 within region A, which is indicated by dashed lines in Figure 1. Figure 4 is a cross-sectional view along the tangent X-X’ in Figure 3.

As shown in Figure 3, a plurality of reflective structure openings 400 are arranged in a ring along the second boundary B2 between the second recessed region E2 and the semiconductor platform M. The plurality of reflective structure openings 400 are uniformly spaced from each other by a first shortest distance D1 so that the current injected into the light-emitting element 1 can be uniformly distributed. In one embodiment, the reflective structure openings 400 and the second boundary B2 are spaced by a second shortest distance D2, wherein the first shortest distance D1 may be greater than the second shortest distance D2. In one embodiment, the first shortest distance D1 and/or the second shortest distance D2 may be less than a minimum width w encompassed by the second recessed region E2. The first shortest distance D1 and/or the second shortest distance D2 can be greater than the first opening width W1 of the first reflective structure opening 410 and the second opening width W2 of the second reflective structure opening 420.

Figures 5A to 5D are cross-sectional views of a method for manufacturing a reflective structure opening 400 of a light-emitting element 1, as disclosed in an embodiment of the present invention.

As shown in Figure 5A, a contact electrode 30 is first formed on the second semiconductor layer 23. The contact electrode 30 can form a low-resistance contact with the second semiconductor layer 23, such as an ohmic contact. Next, an insulating layer 42 is formed on the contact electrode 30, and an insulating mirror 41 is formed on the insulating layer 42. Referring to Figures 2 and 4, when the insulating mirror 41 covers the second inclined surface S2 of the semiconductor platform M, the angle of the endpoint of the second inclined surface S2 will affect the coating quality of the insulating mirror 41. For example, when the insulating mirror 41 covers the semiconductor platform M, a fracture surface (not shown) is easily formed at the junction of the second inclined surface S2 of the semiconductor platform M and the first upper surface 21t of the first semiconductor layer 21, or at the junction of the second inclined surface S2 of the semiconductor platform M and the second upper surface 23t of the second semiconductor layer 23. External moisture can easily penetrate the semiconductor structure 20 along the fracture surface, reducing the reliability of the light-emitting element 1. To improve the above-mentioned fracture surface problem, in this embodiment, an insulating layer 42 is formed before forming the insulating mirror 41. The insulating layer 42 has a denser film than the insulating mirror 41 and/or a more uniform film thickness. When the insulating mirror 41 is composed of multiple sublayers, the insulating layer 42 is thicker than the sublayers of the insulating mirror 41. The insulating layer 42 can be formed using the same or different methods as the insulating mirror 41. In one embodiment, the insulating layer 42 with better coating properties can be formed using chemical vapor deposition (CVD) or plasma-enhanced chemical vapor deposition (PECVD). In one embodiment, the high gradient coverage of atomic layer deposition (ALD) can be used to form a uniformly thick insulating mirror 41 or insulating layer 42. When the insulating mirror 41 includes a distributed Bragg reflector (DBR) structure, the thickness of each sublayer of the DBR structure affects the reflectivity of the insulating mirror 41. In this embodiment, the insulating mirror 41 can be formed by electron beam evaporation to stably control the thickness of each sublayer of the DBR structure.

As shown in Figure 5B, a mask layer 900 is formed on the insulating reflector 41 through steps such as spin coating, exposure, and development.

As shown in Figure 5C, the insulating mirror 41 not covered by the mask layer 900 is removed by a first etching process, wherein the method for removing the first insulating mirror 41 includes dry etching or wet etching. In one embodiment, the insulating mirror 41 can be dry-etched on the mask layer 900 having an opening of a first diameter to form a first reflective structure opening 410. The insulating layer 42 can serve as a protective layer or stop layer for dry etching, preventing the plasma ion source from damaging the contact electrode 30 and the second semiconductor layer 23 of the light-emitting element 1 during the dry etching process. To prevent residue from the insulating reflector 41, an over-etching of 5% to 30% of the insulating layer 42 can be performed during the first etching step to form the first reflective structure opening 410 and expose an upper surface 42s of the insulating layer, ensuring that there is no residual insulating reflector 41. In another embodiment, during the process of forming the first reflective structure opening 410, the entire depth of the insulating layer 42 can be etched through the first etching step until the upper surface 30s of one of the second contact electrodes 30 are exposed, so that one sidewall of the second reflective structure opening 420 and one sidewall of the first reflective structure opening 410 are located on the same inclined plane.

As shown in Figure 5D, the insulating layer 42 is removed by a second etching process until the contact electrode 30 is exposed. In one embodiment, the insulating layer 42 can be removed from a mask layer (not shown) having an opening of a second diameter to form a second reflective structure opening 420. The method for removing the insulating layer 42 in the second etching process can be the same as or different from the method for removing the insulating reflector 41 in the first etching process. In this embodiment, the first etching process is performed by dry etching, and the second etching process is performed by wet etching, which is a different method than the first etching process described above. In one embodiment, the second diameter of the opening in the mask layer during the second etching process can be less than or equal to the first diameter of the opening in the mask layer during the first etching process. The mask layer 900 is preferably made of a material that is easily removed, such as polyimide or photoresist. When the material of the mask layer 900 is polyimide or photoresist, it can be removed by plasma etching. In one embodiment, the second etching can be performed by adjusting the etching gas or liquid to reduce damage to the contact electrode 30, while causing minimal physical damage. In another embodiment, the damage to the contact electrode 30 caused by the second etching can be reduced by reducing the etching time.

Figure 6 is a cross-sectional view of the reflective structure opening 400 disclosed in an embodiment of the present invention. When an externally injected current is injected into the contact electrode 30 through the reflective structure opening 400 in the metal reflective layer 52, the contact area between the metal reflective layer 52 and the contact electrode 30 is limited by the size of the reflective structure opening 400, so there cannot be a large contact area between the metal reflective layer 52 and the contact electrode 30. In addition, the longitudinal diffusion ability of the current in the contact electrode 30 is strong, while the lateral diffusion ability of the current in the contact electrode 30 is weak, making it easier for the current to accumulate in or near the reflective structure opening 400. In this embodiment, to improve the lateral current diffusion in or around the reflective structure opening 400, the contact electrode 30 may include a plurality of contact openings 300 and a plurality of reflective structure openings 400 in a one-to-one configuration. In a top view of the light-emitting element 1 (not shown), the contact openings 300 may have the same or different shapes as the reflective structure openings 400, and/or be formed in, for example, circular or polygonal shapes. As shown in Figure 6, the insulating reflector 41 includes a first top portion 41t, and the first reflective structure opening 410 passes through the insulating reflector 41 and includes a first side e1. The insulating layer 42 includes an upper surface 42s, and the second reflective structure opening 420 passes through the insulating layer 42 and includes a second side e2. The contact opening 300 passes through the contact electrode 30 and includes a third side e3. The first opening width W1 of the first reflective structure opening 410 is greater than the second opening width W2 of the second reflective structure opening 420, such that the first side e1 and the second side e2 are respectively connected to different positions on the upper surface 42s of the insulating layer and at the end of the upper surface 42s of the insulating layer. In Figure 6, the designation "C1" indicates the first edge C1 between the first top portion 41t and the first side e1; the designation "C2" indicates the second edge C2 between the upper surface 42s of the insulation layer and the second side e2; and the designation "C3" indicates the third edge C3 between the second side e2 and the third side e3. The first reflective structure opening 410 is surrounded by the first edge C1 and is defined by the first edge C1, the first side e1, the upper surface 42s of the insulation layer, and its horizontal extension line 42s'. The second reflective structure opening 420 is surrounded by the second edge C2 and is defined by the second edge C2 and the second side e2. The contact opening 300 is surrounded by the third side e3 and is defined by the third side e3 and the second upper surface 23t of the second semiconductor layer 23.

A bonding layer 51 and a metal reflective layer 52 are formed on the reflective structure 40 and filled into the first reflective structure opening 410 and the second reflective structure opening 420, respectively. A first region of the second upper surface 23t of the second semiconductor layer 23 includes a high-resistance region 23H, and a second region of the second upper surface 23t of the second semiconductor layer 23 includes a low-resistance region 23L. The low-resistance region 23L can form a low-resistance contact with the contact electrode 30, such as an ohmic contact. In one embodiment, the second region of the second semiconductor layer 23 can be formed by selecting a low-resistance material, which may include a III-V group semiconductor material with highly doped n-type or p-type impurities, to form the low-resistance region 23L. The high-resistance region 23H is connected to the interconnect layer 51 to form a high-resistance contact, such as an insulating contact or a Schottky contact. In one embodiment, the first region of the second semiconductor layer 23 can be formed by selecting a high-resistance material, which may include a low-doped III-V group semiconductor material, so that a high-resistance contact is formed between the second semiconductor layer 23 in the first region and the interconnect layer 51, wherein the high-resistance region 23H may be surrounded by the low-resistance region 23L. When an external current is injected, as the current is conducted from the metal reflective layer 52 to the second semiconductor layer 23, due to the high-resistivity region 23H between the interconnect layer 51 and the first region of the second semiconductor layer 23, very little or no current is conducted downwards through the high-resistivity region 23H to the second semiconductor layer 23. The current is conducted through the third side e3 of the contact opening 300 between the interconnect layer 51 and the contact electrode 30, improving the lateral current conduction and reducing current congestion near the reflective structure opening 400 and/or the contact opening 300. The low-resistivity region 23L contains n-type or p-type impurities, with n-type impurities including silicon (Si), carbon (C), or germanium (Ge). p-type impurities include magnesium (Mg). n-type or p-type impurities with a concentration greater than 5... 10 ¹⁹ cm ^-3 , or greater than or equal to 1 10 ²⁰ cm ^-3 . Low resistance region 23L contains Al _x In _y Ga _(1-xy) N(0 x 1,0 y 1) or Al _x Ga _(1-x) N (0 x 1) In one embodiment, the Al composition of the low-resistivity region 23L can be 0.03. x 0.3. The high-resistivity region 23H contains p-type impurities such as magnesium (Mg), but is not particularly limited to magnesium (Mg). In one embodiment, the p-type impurity concentration in the high-resistivity region 23H is greater than or equal to 1. 10 ^{19 cm⁻³} , but less than the concentration of n-type or p-type impurities in the low-resistivity region 23L. The high- _{resistivity region 23H contains Al₂S₃In₃tGa₂ ( 1-st)} N(0). s 1,0 t 1) or Al _s Ga _(1-s) N (0 s 0.2 or 0 s 1). In one embodiment, the Al composition of the high-resistivity region 23H can be 0.01. s 0.05. In one embodiment, when the light-emitting element 1 can emit ultraviolet light with wavelengths between 250 nm and 400 nm, the Al composition of the high-resistivity region 23H can be 0.3. s 0.8 or 0.4 s 0.6.

Referring to the method of the reflective structure opening 400 shown in Figures 5A to 5D, after forming a contact electrode 30 that can make ohmic contact with the second semiconductor layer 23, an insulating layer 42 and an insulating mirror 41 are sequentially formed on the contact electrode 30. As shown in Figure 6, the insulating mirror 41 is etched with a mask layer (not shown) having an opening of a first diameter to form the first reflective structure opening 410, and then the insulating layer 42 is etched with a mask layer (not shown) having an opening of a second diameter to form the second reflective structure opening 420, wherein the second diameter may be smaller than the first diameter. In this embodiment, by forming the first reflective structure opening 410 and the second reflective structure opening 420 in different processes, the first side e1 of the insulating reflector 41 and the second side e2 of the insulating layer 42 are not located on the same inclined plane. In this embodiment, the second reflective structure opening 420 and the contact opening 300 can be formed in the same process, so that the third side e3 of the contact opening 300 and the second side e2 have the same slope and are located on the same inclined plane. During the formation of the contact opening 300, the second semiconductor layer 23 (low-resistance region 23L) containing low-resistance material in the first region is etched away to expose the high-resistance region 23H, such that there is a step difference h between the low-resistance region 23L and the high-resistance region 23H on the second upper surface 23t of the second semiconductor layer 23. In one embodiment, the step difference h includes a thickness of less than or equal to 20 nm, but at least greater than 0.1 nm.

Figure 7 is a cross-sectional view of the reflective structure opening 400 disclosed in another embodiment of the present invention. In the embodiment disclosed in Figure 7, the material composition of the high-resistivity region 23H and the low-resistivity region 23L is similar to that disclosed in Figure 6, and will not be described again here. Referring to the method of the reflective structure opening 400 disclosed in Figures 5A to 5D, after forming a contact electrode 30 that can make ohmic contact with the second semiconductor layer 23, an insulating layer 42 and an insulating mirror 41 are sequentially formed on the contact electrode 30. As shown in Figure 7, an insulating mirror 41 is etched with a mask layer (not shown) having an opening of a first diameter to form a first reflective structure opening 410. An insulating layer 42 is etched with a mask layer (not shown) having an opening of a second diameter to form a second reflective structure opening 420. A contact electrode 30 is etched with a mask layer (not shown) having an opening of a third diameter to form a contact opening 300. The second diameter may be smaller than the first diameter and the third diameter may be smaller than the second diameter. In this embodiment, as shown in Figure 7, the insulating reflector 41 includes a first top portion 41t, and a first reflective structure opening 410 extends through the insulating reflector 41 and includes a first side e1. The insulating layer 42 includes an upper surface 42s, and a second reflective structure opening 420 extends through the insulating layer 42 and includes a second side e2. The contact opening 300 extends through the contact electrode 30 and includes a third side e3. In this embodiment, by forming the first reflective structure opening 410, the second reflective structure opening 420, and the contact opening 300 in different manufacturing processes, the first side e1 of the insulating reflector 41 and the second side e2 of the insulating layer 42 are not located on the same inclined plane, and the third side e3 of the contact opening 300 and the second side e2 of the insulating layer 42 are not located on the same inclined plane. The width W1 of the first opening included in the first reflective structure opening 410 is greater than the width W2 of the second opening included in the second reflective structure opening 420, so that the first side e1 and the second side e2 are respectively connected to different positions on the upper surface 42s of the insulating layer and at the end of the upper surface 42s of the insulating layer. The width W2 of the second opening included in the second reflective structure opening 420 is greater than the width W3 of the third opening included in the contact opening 300, such that the second side e2 and the third side e3 are respectively connected to different positions on the upper surface 30s of one of the contact electrodes 30 and at the end of the upper surface 30s. In Figure 7, the mark "C1" indicates the first edge C1 between the first top 41t and the first side e1, the mark "C2" indicates the second edge C2 between the upper surface 42s of the insulating layer and the second side e2, and the mark "C3" indicates the third edge C3 between the upper surface 30s of the contact electrode 30 and the third side e3. The first reflective structure opening 410 is surrounded by the first edge C1 and is defined by the first edge C1, the first side e1, the upper surface 42s of the insulating layer, and its horizontal extension line 42s'. The second reflective structure opening 420 is surrounded by the second edge C2 and is defined by the second edge C2, the second side e2, the upper surface 30s of the contact electrode 30, and its horizontal extension line 30s'. The contact opening 300 is surrounded by the third edge C3 and is defined by the third edge C3, the third side e3, and the second upper surface 23t of the second semiconductor layer 23. During the formation of the contact opening 300, the second semiconductor layer 23 (low-resistance region 23L) containing low-resistance material in the first region is etched away to expose the high-resistance region 23H, such that there is a step difference h between the low-resistance region 23L and the high-resistance region 23H on the second upper surface 23t of the second semiconductor layer 23. In one embodiment, the step difference h includes a thickness of less than or equal to 20 nm, but at least greater than 0.1 nm. When an external current is injected, as the current is conducted to the second semiconductor layer 23 through the metal reflective layer 52, because there is a high-resistance region 23H between the connecting layer 51 and the first region of the second semiconductor layer 23, no or very little current is conducted downward through the high-resistance region 23H to the second semiconductor layer 23. The current is conducted through the third side e3 of the contact opening 300 of the contact layer 51 and the contact electrode 30, which improves the conduction and distribution of the lateral current and reduces current congestion in the vicinity of the reflective structure opening 400 and/or the contact opening 300.

Figure 8 is a cross-sectional view of the reflective structure opening 400 disclosed in an embodiment of the present invention. In the embodiment disclosed in Figure 8, the material composition of the high-resistivity region 23H and the low-resistivity region 23L is similar to that disclosed in Figure 6, and will not be repeated here. In this embodiment, the second semiconductor layer 23 can be etched to a depth of the second semiconductor layer 23 using a mask layer (not shown) with an opening of a fourth diameter, exposing a first region of the second upper surface 23t to form a second semiconductor layer recess 231 with a high-resistivity region 23H. The second upper surface 23t of the second region of the second semiconductor layer 23 is the low-resistivity region 23L, which forms an ohmic contact with the contact electrode 30. After the second semiconductor layer 23 containing low-resistivity material in the first region is etched away to expose the second semiconductor layer recess 231 having a high-resistivity region 23H, when the contact electrode 30 is filled into the second semiconductor layer recess 231, the contact electrode 30 includes a contact recess 302 with a third side surface e3' corresponding to the second semiconductor layer recess 231. The contact electrode 30 forms an ohmic contact with the low-resistivity region 23L of the second semiconductor layer 23, and the contact electrode 30 located in the second semiconductor layer recess 231 is connected to the high-resistivity region 23H to form a high-resistivity contact. Referring to the method of the reflective structure opening 400 shown in Figures 5A to 5D, after forming the contact electrode 30 on the second semiconductor layer 23, an insulating layer 42 and an insulating mirror 41 are sequentially formed on the contact electrode 30. As shown in Figure 8, the insulating mirror 41 is etched with a mask layer (not shown) having an opening of a first diameter to form the first reflective structure opening 410, and then the insulating layer 42 is etched with a mask layer (not shown) having an opening of a second diameter to form the second reflective structure opening 420. Subsequently, a connection layer 51 and a metal reflective layer 52 are formed on the contact electrode 30. The connection layer 51 and the contact recess 302 of the contact electrode 30 have a low resistance contact. When an external current is injected through the metal reflective layer 52 and the connection layer 51, the current cannot be conducted downward to the second semiconductor layer 23 because there is a high resistance contact between the contact recess 302 of the contact electrode 30 and the high resistance region 23H. Therefore, the current is laterally dispersed through the contact electrode 30 and then injected into the second semiconductor layer 23, reducing current congestion near the opening 400 of the reflective structure.

Compared to the low-resistivity region 23L of the second semiconductor layer 23, the second semiconductor layer recess 231 located in the high-resistivity region 23H includes a step difference H. In one embodiment, the step difference H includes a depth less than or equal to 20 nm, but at least greater than 0.1 nm. When the contact electrode 30 is filled into the second semiconductor layer recess 231, the contact recess 302 includes a step difference h that is substantially the same as the step difference H of the second semiconductor layer recess 231, or the step difference h of the contact recess 302 and the step difference H of the second semiconductor layer recess 231 include a difference less than 10% of the step difference H of the second semiconductor layer recess 231 or the step difference h of the contact recess 302. In this embodiment, as shown in Figure 8, the insulating reflector 41 includes a first top portion 41t, and a first reflective structure opening 410 extends through the insulating reflector 41 and includes a first side e1. The insulating layer 42 includes an upper surface 42s, and a second reflective structure opening 420 extends through the insulating layer 42 and includes a second side e2. The contact recess 302 of the contact electrode 30 includes a third side e3'. The width W1 of the first opening of the first reflective structure opening 410 is greater than the width W2 of the second opening of the second reflective structure opening 420, such that the first side e1 and the second side e2 are respectively connected to different positions on the upper surface 42s of the insulation layer and at the end of the upper surface 42s of the insulation layer. The width W2 of the second opening of the second reflective structure opening 420 is greater than the width W3' of a third recess included in the contact recess 302, such that the second side e2 and the third side e3' are respectively connected to different positions on the upper surface 30s of the contact electrode 30 and at the end of the upper surface 30s of the contact electrode 30. In Figure 8, the designation "C1" indicates the first edge C1 between the first top portion 41t and the first side e1, and the designation "C2" indicates the second edge C2 between the upper surface 42s of the insulating layer and the second side e2. The first reflective structure opening 410 is surrounded by the first edge C1 and is defined by the first edge C1, the first side e1, the upper surface 42s of the insulating layer, and its horizontal extension line 42s'. The second reflective structure opening 420 is surrounded by the second edge C2 and is defined by the second edge C2, the second side e2, the upper surface 30s of the contact electrode 30, the third side e3', and the second upper surface 23t of the second semiconductor layer 23.

Viewed from a top view (not shown) of the light-emitting element 1, the second semiconductor layer recess 231 and the plurality of reflective structure openings 400 are configured in a one-to-one manner. When the contact electrode 30 is formed on the second upper surface 23t of the second semiconductor layer 23, the contact electrode 30 includes a planar portion 301 located on the low resistance region 23L and a contact recess 302 located on the high resistance region 23H. Viewed from a top view (not shown) of the light-emitting element 1, the plurality of contact recesses 302 of the contact electrode 30 and the plurality of reflective structure openings 400 are configured in a one-to-one manner, and the planar portion 301 surrounds the plurality of contact recesses 302. In one embodiment, the thickness difference between the thickness of the planar portion 301 of the contact electrode 30 and the thickness of the contact recess 302 of the contact electrode 30 is less than 10% of the thickness of the planar portion 301 or the contact recess 302.

Figure 9 is a cross-sectional view of the reflective structure opening 400 disclosed in an embodiment of the present invention. In the embodiment disclosed in Figure 9, the second upper surface 23t of the second semiconductor layer 23 includes a low-resistance region 23L that can form an ohmic contact with the contact electrode 30. The material composition of the low-resistance region 23L is similar to that of the embodiment disclosed in Figure 6, and will not be described again here. In this embodiment, a plurality of current blocking portions 33 are formed on the second upper surface 23t of the second semiconductor layer 23, and the contact electrode 30 covers the second upper surface 23t of the second semiconductor layer 23 and the plurality of current blocking portions 33. Referring to the method of the reflective structure opening 400 shown in Figures 5A to 5D, after forming a contact electrode 30 that can make ohmic contact with the second semiconductor layer 23, an insulating layer 42 and an insulating mirror 41 are sequentially formed on the contact electrode 30. As shown in Figure 9, the insulating mirror 41 is etched with a mask layer (not shown) having an opening of a first diameter to form the first reflective structure opening 410, and then the insulating layer 42 is etched with a mask layer (not shown) having an opening of a second diameter to form the second reflective structure opening 420.

In a top view of the light-emitting element 1 (not shown), a plurality of current-blocking portions 33 and a plurality of reflective structure openings 400 are configured one-to-one. When a contact electrode 30 is formed on the second upper surface 23t of the second semiconductor layer 23, the contact electrode 30 includes a planar portion 301 located on the low-resistance region 23L and a contact protrusion 303 located on the current-blocking portion 33. In one embodiment, the contact electrode 30 includes a plurality of contact protrusions 303 respectively located on the plurality of current-blocking portions 33, and configured one-to-one with the plurality of reflective structure openings 400. As shown in Figure 9, the insulating mirror 41 includes a first top portion 41t, and a first reflective structure opening 410 passes through the insulating mirror 41 and includes a first side e1. The insulating layer 42 includes an upper surface 42s, and a second reflective structure opening 420 passes through the insulating layer 42 and includes a second side e2. The first reflective structure opening 410 has a first opening width W1 that is greater than the second opening width W2 of the second reflective structure opening 420, such that the first side e1 and the second side e2 are respectively connected to different positions on the upper surface 42s and at the end of the upper surface 42s. In Figure 9, the designation "C1" indicates the first edge C1 between the first top portion 41t and the first side edge e1, and the designation "C2" indicates the second edge C2 between the upper surface 42s of the insulation layer and the second side edge e2. The first reflective structure opening 410 is surrounded by the first edge C1 and is defined by the first edge C1, the first side edge e1, the upper surface 42s of the insulation layer, and its horizontal extension line 42s'. The second reflective structure opening 420 is surrounded by the second edge C2 and is defined by the second edge C2, the second side edge e2, the upper surface 30s of the contact electrode 30, and the surface of the contact protrusion 303. When an external current is injected through the metal reflective layer 52 and the connecting layer 51, a high-resistance contact exists between the contact protrusion 303 and the second semiconductor layer 23 due to the current blocking portion 33. This prevents the current from being conducted downwards to the second semiconductor layer 23. Therefore, the current is laterally dispersed through the contact electrode 30 and then injected into the second semiconductor layer 23, reducing current congestion near the reflective structure opening 400.

A plurality of current blocking portions 33 are located between a plurality of contact protrusions 303 of the contact electrode 30 and the second semiconductor layer 23. The current blocking portions 33 may be disposed below the reflective structure opening 400 and have the same or different shape as the reflective structure opening 400. Compared with the reflective structure opening 400, the current blocking portions 33 may have a smaller size, so the contact electrode 30 may be formed on one side 33e of the current blocking portion 33. For example, the current blocking portion 33 includes a fourth width W4 that is smaller than the second opening width W2 included in the second reflective structure opening 420. The current blocking portion 33 may include an insulating material, such as one of _SiO2 , SiN, _Al2O3 , _HfO , _TiO2 , and ZrO. Since the current blocking portion 33 is disposed below the reflective structure opening 400, the current applied to the metal reflective layer 52 can be laterally distributed to the contact electrode 30 through the reflective structure opening 400, without accumulating at the reflective structure opening 400. In one embodiment, the current blocking portion 33 may be a multilayer film structure with alternating layers of insulators with different refractive indices, such as a distributed Bragg reflector (DBR). A distributed Bragg reflector (DBR) structure is formed by alternatingly stacking a plurality of first sublayers having a first refractive index and a plurality of second sublayers having a second refractive index, wherein the first refractive index is less than the second refractive index. For example, _it can be formed by stacking _SiO2 / _TiO2 or _SiO2 / _Nb2O5 .

In one embodiment, the current blocking portion 33 includes a thickness T of less than or equal to 1000 nm, but at least greater than 100 nm. When the contact electrode 30 covers the current blocking portion 33, the contact protrusion 303 includes a step difference h protruding from the upper surface 30s of the contact electrode 30. The step difference h of the contact protrusion 303 is approximately the same as the thickness T of the current blocking portion 33, or the difference between the step difference h of the contact protrusion 303 and the thickness T of the current blocking portion 33 includes a value less than 10% of the thickness T of the current blocking portion 33. In one embodiment, the thickness difference between the thickness of the planar portion 301 of the contact electrode 30 and the thickness of the contact protrusion 303 of the contact electrode 30 is less than 10% of the thickness of the planar portion 301.

As shown in Figures 2 and 4, the first insulating structure 60 includes a first opening 601 located in a first recessed region E1 and a second recessed region E2. The first insulating structure 60 may expose one sidewall 40s of the reflective structure 40. In another embodiment (not shown), the first insulating structure 60 may cover the sidewall 40s of the reflective structure 40. In another embodiment, a minimum distance Smax greater than 10 micrometers exists between a first sidewall 601s included in the first opening 601 of the first insulating structure and the second inclined surface S2 of the semiconductor platform M. This ensures that the first insulating structure 60 includes a thickness to cover the reflective structure 40, preventing damage to the reflective structure 40 and a reduction in the reflectivity of the reflective structure 40 when the first insulating structure 60 is etched away to form the first opening 601. The first extended electrode 71 is connected to the first semiconductor layer 21 exposed in the first recessed region E1 and the second recessed region E2 through the first opening 601 of the first insulating structure.

As shown in Figure 2, the first insulating structure 60 continuously covers all exposed surfaces of the metal reflective layer 52 and the connecting layer 51 to protect the metal reflective layer 52, such as the upper and side surfaces of the metal reflective layer 52 and the connecting layer 51. The metal reflective layer 52 and the connecting layer 51 can be encapsulated between the first insulating structure 60 and the reflective structure 40. In one embodiment of the invention, by forming the first insulating structure 60, the reflectivity of the metal reflective layer 52 can be prevented from deteriorating due to subsequent processes, and the migration of metal elements contained in the metal reflective layer 52 can be suppressed.

As shown in Figure 2, the first insulation structure 60 includes a first insulation structure first opening 601 and a first insulation structure second opening 602. The first insulation structure first opening 601 extends through the reflective structure 40 to expose the first semiconductor layer 21 of the first contact first region CT1 and the first contact second region CT1'. The first insulation structure first opening 601 may be disposed on the first recessed region E1 and the second recessed region E2, and the first insulation structure second opening 602 is located above the metal reflective layer 52 of the second contact region CT2. In one embodiment of the invention, to increase the light extraction efficiency of the light-emitting element 1, the first insulation structure 60 includes a first distributed Bragg reflector (DBR) structure, which is formed by alternating stacks of a plurality of non-metallic oxide layers and a plurality of metallic oxide layers. _The materials of _the non-metallic oxide layers include _SiO₂ , SiN, _SiOₓNy , _{and Si₃N₄} . The materials of the metallic oxide layers include _TiO₂ , _Si₃N₄ , _Al₂O₃ , TiN, AlN, _{ZrO₂ ,} TiAlN, TiSiN, _HfO , _TaO₂ , _Nb₂O₅ , or _MgF₂ . For example, it can be achieved by stacking _SiO₂ / _TiO₂ or _SiO₂ / _{Nb₂O₅ layers} . To improve the adhesion between the first insulating structure 60, the first extended electrode 71, and the metal reflective layer 52, the metal reflective layer 52 can be connected to the non-metallic oxide layer of the first insulating structure 60 by means of a metal other than silver (Ag), such as platinum (Pt), for example, SiO ₂ , and the first insulating structure 60 is connected to the first extended electrode 71 by means of a metal oxide layer, such as TiO ₂ or Nb ₂ O ₅ .

In one embodiment, as shown in Figure 1, the second opening 602 of the first insulating structure is staggered with the plurality of reflective structure openings 400, that is, the second opening 602 of the first insulating structure does not overlap with the plurality of reflective structure openings 400. In order to maintain the pattern of the plurality of reflective structure openings 400 being arranged at equal intervals, the second opening 602 of the first insulating structure includes an irregular ring, and the plurality of reflective structure openings 400 are surrounded by the ring, wherein the second opening 602 of the first insulating structure does not overlap with the plurality of reflective structure openings 400. In another embodiment, as shown in Figure 10A, the second opening 602 of the first insulating structure comprises a rectangle, and a plurality of reflective structural openings 400 are enclosed by the rectangle, wherein the second opening 602 of the first insulating structure overlaps with the plurality of reflective structural openings 400. In another embodiment, as shown in Figure 10B, the second opening 602 of the first insulating structure comprises a rectangle, and a plurality of reflective structural openings 400 are located in the area outside the rectangle, wherein the second opening 602 of the first insulating structure does not overlap with the plurality of reflective structural openings 400. In another embodiment, the rectangle shown in Figures 10A and 10C can be varied into a circle, a triangle, or a regular or irregular polygon.

In one embodiment, as shown in Figure 1, the second opening 602 of the first insulation structure includes a mesh opening having a closed curve outer contour. A plurality of reflective structure openings 400 include a first portion 4001 located within the closed curve outer contour and a second portion 4002 located outside the closed curve outer contour, wherein the first portion 4001 and the second portion 4002 are arranged in a hexagonal lattice pattern on the semiconductor platform M. In another embodiment, as shown in Figure 10C, the second opening 602 of the first insulation structure includes a closed curve outer contour, and a plurality of reflective structure openings 400 are located outside the closed curve outer contour and arranged in a hexagonal lattice pattern on the semiconductor platform M.

As shown in Figures 2 and 4, the first extended electrode 71 can be disposed on the first insulating structure 60 and extend through the first opening 601 of the first insulating structure to contact and electrically connect to the first semiconductor layer 21, which is in contact with the first contact area CT1 and the first contact area CT1'. In one embodiment, in order to improve the contact resistance characteristics between the first extended electrode 71 and the first semiconductor layer 21, a conductive contact layer (not shown) can be disposed between the first extended electrode 71 and the first semiconductor layer 21. The conductive contact layer may contain conductive metal oxides such as indium tin oxide (ITO), zinc-doped indium tin oxide (ZITO), zinc indium oxide (ZIO), gallium indium oxide (GIO), zinc tin oxide (ZTO), fluorine-doped tin oxide (FTO), aluminum-doped zinc oxide (AZO), gallium-doped zinc oxide (GZO), or zinc magnesium oxide (Zn _{(1-x) MgxO} , 0≤x≤1). In one embodiment, a metal contact layer (not shown) may be provided on the upper surface 20b of the first recessed region E1 and/or the upper surface 20b' of the second recessed region E2. A portion of the upper surface of the metal contact layer may be a first contact with the first region CT1 and/or a first contact with the second region CT1'.

The second extended electrode 72 can be disposed on the first insulating structure 60 and extend to the metal reflective layer 52 through the second opening 602 of the first insulating structure and be electrically connected to the second semiconductor layer 23.

In one embodiment, the first extended electrode 71 and the second extended electrode 72 may be disposed on the first insulating structure 60, formed of different materials, and spaced apart from each other. For example, the first extended electrode 71 and the second extended electrode 72 may be formed of a material including at least one of the following: aluminum (Al), gold (Au), tungsten (W), platinum (Pt), iridium (Ir), silver (Ag), copper (Cu), nickel (Ni), titanium (Ti), chromium (Cr), and alloys of the above materials.

The second insulation structure 80 includes a first opening 801 of the second insulation structure located on the first extended electrode 71 and a second opening 802 of the second insulation structure located on the second extended electrode 72. The first opening 801 of the second insulation structure can expose the first extended electrode 71, and the second opening 802 of the second insulation structure can expose the second extended electrode 72.

A first electrode pad 91 can be disposed on a first extended electrode 71 through a first opening 801 of a second insulation structure, and a second electrode pad 92 can be disposed on a second extended electrode 72 through a second opening 802 of a second insulation structure. A first solder pad (not shown) can be disposed on the first electrode pad 91, and a second solder pad (not shown) can be disposed on the second electrode pad 92. The first and second solder pads can be formed of a conductive material (e.g., Sn or AuSn). As shown in Figure 1, in a top view, the first electrode pad 91 can be adjacent to the first side 11, and the second electrode pad 92 can be adjacent to the second side 12.

The first electrode pad 91 and the second electrode pad 92 comprise metallic materials, such as chromium (Cr), titanium (Ti), tungsten (W), gold (Au), aluminum (Al), indium (In), tin (Sn), nickel (Ni), platinum (Pt), silver (Ag), or alloys thereof. The first electrode pad 91 and the second electrode pad 92 may consist of a single layer or multiple layers. For example, the first electrode pad 91 or the second electrode pad 92 may include a Ti/Au layer, a Ti/Pt/Au layer, a Cr/Au layer, a Cr/Pt/Au layer, a Ni/Au layer, a Ni/Pt/Au layer, a Cr/Al/Cr/Ni/Au layer, or an Ag/NiTi/TiW/Pt layer. The first electrode pad 91 and the second electrode pad 92 can serve as current paths for external power supply to the first semiconductor layer 21 and the second semiconductor layer 23. In one embodiment, the first electrode pad 91 and the second electrode pad 92 each include a layer with a thickness between 0.5 micrometers and 5 micrometers.

In one embodiment, the insulating layer 42, the first insulating structure 60, and the second insulating structure 80 are disposed on the semiconductor structure 20, serving as a protective film for the light-emitting element 1 and an interlayer insulating film for preventing static electricity. In one embodiment, as an insulating film, the insulating layer 42, the first insulating structure 60, and the second insulating structure 80 can be a single-layer structure comprising a metal oxide or a metal nitride, for example, preferably using at least one oxide or nitride selected from the group consisting of silicon (Si), titanium (Ti), zirconium (Zr), niobium (Nb), tantalum (Ta), and aluminum (Al). In another embodiment, the insulating layer 42, the first insulating structure 60, and the second insulating structure 80 comprise two or more materials with different refractive indices stacked alternately to form a distributed Bragg reflector (DBR) structure that selectively reflects light of specific wavelengths. For example, a highly reflective reflective structure can be formed by stacking two or _three insulating layers such as _SiO2 , _TiO2 , _Nb2O5 , or _Al2O3 . For example _, when a distributed Bragg reflector (DBR ₎ structure is formed by stacking sublayers such as _SiO2 / _TiO2 or _SiO2 / _Nb2O5 , each sublayer of the distributed Bragg reflector structure is designed to be one or an integer multiple of the optical thickness of one-quarter of the wavelength of light emitted by the active layer 22. The optical thickness of each sublayer of the distributed Bragg reflector (DBR) structure can have a deviation of ±30% on a basis of one or an integer multiple of λ/4. Since the change in the optical thickness of each sublayer of the DBR structure affects the reflectivity, the physical thickness of each sublayer in the insulating layer 42, the first insulating structure 60, and the second insulating structure 80, obtained based on the optical thickness of the DBR structure, can be formed using electron beam evaporation to stably control the thickness of each sublayer in the insulating layer 42, the first insulating structure 60, and the second insulating structure 80.

Figure 11 is a schematic diagram of a light-emitting device 2 according to an embodiment of the present invention. The light-emitting element 1 of the aforementioned embodiment is mounted as a flip chip on the first pad 501 and the second pad 502 of the packaging substrate 50. The first pad 501 and the second pad 502 are electrically insulated from each other by an insulating portion 53 containing insulating material. In flip chip mounting, the growth substrate facing upwards opposite the electrode pad formation surface is designated as the primary light extraction surface; for example, the light-emitting surface 10t of the substrate 10 of the light-emitting element 1 is the primary light extraction surface of the light-emitting element 1. To increase the light extraction efficiency of the light-emitting device 2, a reflective structure 54 can be provided around the light-emitting element 1.

Figure 12 is a schematic diagram of a light-emitting device 3 according to an embodiment of the present invention. The light-emitting device 3 is a bulb lamp, including a lampshade 612, a reflector 604, a light-emitting module 600, a lamp holder 611, a heat dissipation fin 614, a connecting part 616, and an electrical connection element 618. The light-emitting module 600 includes a support part 606, and a plurality of light-emitting units 608 are located on the support part 606, wherein the plurality of light-emitting units 608 may be the light-emitting element 1 or the light-emitting device 2 in the aforementioned embodiments.

Figure 13 is a schematic diagram of a backlight module 4 according to an embodiment of the present invention. The backlight module 4 includes a first frame 201, a liquid crystal display panel 202, a brightness enhancement film 310, an optical module 430, a light-emitting module assembly 500, and a second frame 700. The light-emitting module assembly 500 includes a plurality of light-emitting elements 1 or light-emitting devices 2 as described in the aforementioned embodiments, arranged in the light-emitting module assembly 500 in an edge-type or direct-type light emission manner. In one embodiment, the backlight module 4 further includes a wavelength conversion structure 610 disposed on the light-emitting module assembly 500.

Figure 14 is a schematic diagram of a display 5 according to an embodiment of the present invention. The display 5 includes an LED light-emitting panel 3000 and a current source (not shown). A bracket 2000 is used to support the LED light-emitting panel 3000. The LED light-emitting panel 3000 includes any one of the light-emitting elements 1 or light-emitting devices 2 in the aforementioned embodiments or a backlight module 4. In one embodiment, the LED light-emitting panel 3000 includes a plurality of pixel units. Each pixel unit includes a plurality of light-emitting elements 1 or light-emitting devices 2 in the aforementioned embodiments to emit different colors. For example, each pixel unit includes three light-emitting elements 1 or light-emitting devices 2 that emit red light, green light, and blue light respectively.

Figure 15 is a schematic diagram of a light-emitting device 6 according to an embodiment of the present invention. In one embodiment, the light-emitting device 6 is an LED bulb for automobiles, which can be inserted and fixed into a mounting through hole on the rear cover of the automobile headlight assembly. The light-emitting device 6 includes a first LED chip 4100 for low beam illumination or a second LED chip 4200 for high beam illumination, a long columnar lamp post 4300, a driver power circuit board 4400, a heat dissipation fin (not shown), a heat dissipation fan (not shown), a fan cover (not shown) for protecting the fan, a power cord (not shown) for electrical connection with the vehicle battery, and a plug (not shown) disposed at the end of the power cord. The first LED chip 4100 or the second LED chip 4200 in the light-emitting device 6 may include one or more of the aforementioned light-emitting element 1 or light-emitting device 2.

Figure 16 is a schematic diagram of a light-emitting device 7 according to an embodiment of the present invention. In one embodiment, the light-emitting device 7 can be an automotive lighting lamp 5000, which can be used as a daytime running light, headlight, taillight, or turn signal. The main lighting lamp 5100 can be the main light in the automotive lighting lamp 5000. For example, when the automotive lighting lamp 5000 is used as a headlight, the main lighting lamp 5100 can have the function of illuminating the front of the vehicle as a headlight. The combination lighting lamp 5200 can have at least two functions. For example, when the automotive lighting lamp is used as a headlight, the combination lighting lamp 5200 can perform the functions of a daytime running light (DRL) and a turn signal. The main lighting 5100 or the combination lighting 5200 may include one or more of the aforementioned light-emitting elements 1 or light-emitting devices 2.

The components of the above embodiments are provided to enable those skilled in the art to better understand the viewpoints of the embodiments disclosed herein. Those skilled in the art should understand that they can design or modify other processes and structures based on the embodiments disclosed herein to achieve the same purpose and/or advantages as the embodiments described herein. Those skilled in the art should also understand that such equivalent structures do not depart from the spirit and scope of this disclosure, and they can make various changes, substitutions, and replacements without departing from the spirit and scope of this disclosure. Therefore, the scope of protection of this disclosure shall be determined by the appended patent claims. Furthermore, although this disclosure has disclosed several preferred embodiments as described above, it is not intended to limit this disclosure.

References to features, advantages, or similar language throughout this specification do not imply that all features and advantages achievable using this disclosure should or can be achieved in any single embodiment of this disclosure. Instead, language relating to features and advantages is understood to mean that a particular feature, advantage, or characteristic described in connection with an embodiment is included in at least one embodiment of this disclosure. Therefore, discussions of features and advantages, as well as similar language, throughout this specification may, but do not necessarily, represent the same embodiments.

Furthermore, in one or more embodiments, the features, advantages, and characteristics described herein can be combined in any suitable manner. Based on the description herein, those skilled in the art will recognize that this disclosure can be implemented without any particular feature or advantage of a particular embodiment. In other cases, additional features and advantages may be identified in some embodiments that may not be present in all embodiments of this disclosure.

1: Light-emitting element

2: Light-emitting device

3: Light-emitting device

4: Backlight Module

5: Display

6: Light-emitting device

7: Light-emitting device

10:Substrate

10s: Top surface

10t: Emitting surface

11: First side

12: Second side

13: Third side

14: Fourth side

20: Semiconductor Structure

20b: Upper surface of the first recessed region E1

20b’: Upper surface of the second recessed region E2

20t: Upper surface of semiconductor platform M

21: First Semiconductor Layer

21t: First upper surface

22: Active layer

23: Second Semiconductor Layer

23H: High resistance region

23L: Low resistance region

23t: Second upper surface

231: Second semiconductor layer recess

201: First Framework

202: LCD display panel

2000: Bracket

30: Contact electrode

30s: Top surface

300: Contact opening

300b: Third bottom

300t: Third Top

302: Contact Recess

303: Contact protrusion

301: Planar Section

33: Current blocking section

33e: Side view

310: Brightening film

3000: Light-emitting panel

40: Reflective Structure

40s: Sidewall

400: Reflective structure opening

4001: Part One

4002: Part Two

41: Insulating reflector

410: First reflective structure opening

41t: First top

410b: First bottom

420: Second reflection structure opening

420t: Second Top

420b: Second bottom

42: Insulation Layer

42s: Insulation layer upper surface

4100: First LED chip

4200: Second LED chip

430: Optical Module

4300: Long, columnar lamppost

4400: Driver Power Circuit Board

50: Packaging substrate

51: Connector Layer

52: Metal reflective layer

53: Section on Separation

54: Reflective Structure

500: Light-emitting module assembly

501: First pad

502: Second pad

5000: Automotive lights

5100: Main Lighting

5200: Combination Lighting

60: First Insulation Structure

600: Light-emitting module

601: First opening of the first insulation structure

601s: First sidewall

602: First insulation structure, second opening

604: Mirror

606: Load-bearing section

608: Light-emitting unit

610: Wavelength conversion structure

611: Lamp stand

612: Lampshade

614: Heat dissipation plate

616: Connecting part

618: Electrical connection components

71: First extended electrode

711: First Metal Reflective Layer

711e: Metal end

72: Second extended electrode

700: Second Frame

80: Second insulation structure

801: First opening of the second insulation structure

802: Second opening of the second insulation structure

91: First electrode pad

92: Second electrode pad

B1: First Boundary

B2: Second Boundary

CT1: First contact, first area

CT1’: First contact with the second area

CT2: Second contact area

D1: First shortest distance

D2: Second shortest distance

E1: First Depression Region

E2: Second Depression Region

e1: First side

e2: Second side

e3: Third side

e3’: Third side

H: grade difference

h: grade difference

M: Semiconductor Platform

Smax: Minimum distance

S1: First inclined plane

S2: Second inclined plane

T: Thickness

W: Minimum Width

W1: First opening width

W2: Second opening width

W3: Third opening width

W4: Fourth width

The embodiments of this disclosure will be described in detail below with reference to the accompanying drawings. It should be noted that the various feature components are not drawn to scale and are only used for illustrative purposes. In fact, the dimensions of the components may be enlarged or reduced to clearly show the technical features of the embodiments of this disclosure.

Figure 1 is a top view of one of the light-emitting elements 1 disclosed in an embodiment of the present invention.

Figure 2 is a cross-sectional view along the tangent line L-L’ of Figure 1.

Figure 3 is a magnified view of area A, which is represented by the dashed line in Figure 1.

Figure 4 is a cross-sectional view along the tangent X-X’ of Figure 3, as shown in an embodiment of the present invention.

Figures 5A to 5D are cross-sectional views of a method for manufacturing a reflective structure opening of a light-emitting element 1 as disclosed in an embodiment of the present invention.

Figure 6 is a cross-sectional view of the opening of the reflective structure disclosed in an embodiment of the present invention.

Figure 7 is a cross-sectional view of the opening of the reflective structure disclosed in an embodiment of the present invention.

Figure 8 is a cross-sectional view of the reflective structure opening disclosed in an embodiment of the present invention.

Figure 9 is a cross-sectional view of the opening of the reflective structure disclosed in an embodiment of the present invention.

Figures 10A to 10C are partial top views of the light-emitting element 1 disclosed in an embodiment of the present invention.

Figure 11 is a schematic diagram of a light-emitting device 2 according to an embodiment of the present invention.

Figure 12 is a schematic diagram of a light-emitting device 3 according to an embodiment of the present invention.

Figure 13 is a schematic diagram of a backlight module 4 according to an embodiment of the present invention.

Figure 14 is a schematic diagram of a display 5 according to an embodiment of the present invention.

Figure 15 is a schematic diagram of a light-emitting device 6 according to an embodiment of the present invention.

Figure 16 is a schematic diagram of a light-emitting device 7 according to an embodiment of the present invention.

without

1: Light-emitting element

10:Substrate

10s: Top surface

10t: Polished surface

11: First side

12: Second side

20: Semiconductor Structure

20b: Upper surface of the first recessed region E1

20t: Upper surface of semiconductor platform M

21: First Semiconductor Layer

21t: First upper surface

22: Active layer

23: Second Semiconductor Layer

23t: Second upper surface

30: Contacting the electrode

40: Reflective Structure

400: Reflective structure opening

41: Insulating reflector

42: Insulation Layer

51: Connector Layer

52: Metal Reflective Layer

60: First Insulation Structure

601: First opening of the first insulation structure

602: First insulation structure, second opening

71: First Extended Electrode

72: Second Extended Electrode

80: Second Insulation Structure

801: First opening of the second insulation structure

802: Second opening in the second insulation structure

91: First electrode pad

92: Second electrode pad

B1: First Boundary

CT1: First Contact, First Area

CT2: Second Contact Area

E1: First depression region

M: Semiconductor Platform

S1: First inclined plane

S2: Second inclined plane

Claims (10)

A light-emitting element includes: a first semiconductor layer including a first slope; a semiconductor platform located on the first semiconductor layer, including an active layer and a second semiconductor layer, and including a second slope connected to the first semiconductor layer; a contact electrode located on the second semiconductor layer; and a reflective structure located on the contact electrode, including a plurality of reflective structure openings; wherein the contact electrode includes a plurality of contact openings and the plurality of reflective structure openings arranged in a one-to-one configuration, or a plurality of contact recesses and the plurality of reflective structure openings arranged in a one-to-one configuration, or a plurality of contact protrusions and the plurality of reflective structure openings arranged in a one-to-one configuration. The light-emitting element as described in claim 1, wherein the contact electrode comprises indium tin oxide (ITO), zinc-doped indium tin oxide (ZITO), zinc indium oxide (ZIO), gallium indium oxide (GIO), zinc tin oxide (ZTO), fluorine-doped tin oxide (FTO), aluminum-doped zinc oxide (AZO), gallium-doped zinc oxide (GZO), or zinc magnesium oxide (Zn _{(1-x) MgxO} , 0≤x≤1). _The light-emitting element as described in claim 2 further includes a bonding layer covering the plurality of reflective structure openings for contact with the contact electrode, wherein the bonding layer comprises aluminum oxide ( _Al₂O₃ ), indium tin oxide (ITO), zinc-doped indium tin oxide (ZITO), zinc indium oxide (ZIO), gallium indium oxide (GIO), zinc tin oxide (ZTO), fluorine-doped tin oxide (FTO), aluminum-doped zinc oxide (AZO), gallium-doped zinc oxide (GZO), or zinc magnesium oxide (Zn _{(1-x) MgxO} , 0≤x≤1). The light-emitting element as described in claim 3, wherein the contact electrode and the bonding layer comprise the same material. The light-emitting element as described in claim 3, wherein the contact electrode and the bonding layer comprise different materials. The light-emitting element as claimed in claim 1, wherein the reflective structure includes an insulating mirror covering the second slope of the semiconductor platform, and the plurality of reflective structure openings include a plurality of first reflective structure openings passing through the insulating mirror. The light-emitting element as claimed in claim 1, wherein the reflective structure includes an insulating layer covering the second slope of the semiconductor platform, and the plurality of reflective structure openings include a plurality of second reflective structure openings passing through the insulating layer. The light-emitting element as described in claim 1 further includes a first insulating structure covering the second slope of the semiconductor platform, including a first opening of the first insulating structure exposing a first surface of the first semiconductor layer, the first opening of the first insulating structure including a first sidewall, and the first sidewall and the second slope of the semiconductor platform including a minimum spacing greater than 10 micrometers. The light-emitting element as described in claim 1 further includes a plurality of current-blocking portions located between the plurality of contact protrusions of the contact electrode and the second semiconductor layer. The light-emitting element as claimed in claim 1, wherein the second semiconductor layer includes a plurality of second semiconductor layer recesses configured one-to-one with the plurality of contact recesses of the contact electrode.