Light emitting diode and light emitting device

Abstract

The invention relates to the technical field of semiconductor manufacturing, in particular to a light-emitting diode which comprises an epitaxial laminated layer, a dielectric layer, a metal reflecting layer, a substrate and an oxidation protection layer, the epitaxial laminated layer sequentially comprises a first semiconductor layer, a light-emitting layer and a second semiconductor layer in the direction from the upper surface to the lower surface, the dielectric layer is arranged on the lower surface of the epitaxial laminated layer, and the metal reflecting layer is arranged on the metal reflecting layer. The dielectric layer is provided with a plurality of through holes, the metal reflecting layer is arranged on one side, far away from the epitaxial laminated layer, of the dielectric layer and is electrically connected with the epitaxial laminated layer through the through holes, the substrate is arranged on one side, far away from the epitaxial laminated layer, of the metal reflecting layer, and the oxidation protection layer wraps the side wall of the metal reflecting layer. By means of the arrangement, the metal migration phenomenon of the metal reflecting layer can be effectively avoided, the electric leakage phenomenon of the light-emitting diode is avoided, and the quality of the light-emitting diode is improved.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor manufacturing technology, and in particular to a light emitting diode and a light emitting device. Background Art

[0002] Light Emitting Diode (LED) is a semiconductor light-emitting element, usually made of semiconductors such as GaN, GaAs, GaP, GaAsP, etc., and its core is a PN junction with light-emitting characteristics. LED has the advantages of high luminous intensity, high efficiency, small size, and long service life, and is considered to be one of the most promising light sources at present. LED has been widely used in lighting, monitoring and command, high-definition broadcasting, high-end cinemas, office displays, conference interaction, virtual reality and other fields.

[0003] At present, in order to improve the light extraction efficiency of LED chips, a metal reflective layer or an ODR reflective structure formed by a combination of a metal reflective layer and a dielectric layer is usually designed on one side of the metal bonding layer to reflect the light on one side of the metal bonding layer to the light extraction side of the epitaxial stack, thereby improving the light extraction efficiency. Considering that Ag has a high reflectivity and good thermal and electrical conductivity, Ag mirrors are usually selected when designing metal reflective layers. However, since Ag itself is prone to migration, it causes chip leakage. In order to solve this problem, the prior art will perform graphic processing on the Ag mirror, thereby coating the surface of the Ag mirror with a barrier layer. This design usually increases the chip manufacturing process and process difficulty, resulting in higher costs.

[0004] It should be noted that the information disclosed in this background technology section is only intended to increase the understanding of the overall background of the present invention, and should not be regarded as acknowledging or suggesting in any form that the information constitutes prior art already known to a person skilled in the art. Summary of the invention

[0005] The present invention provides a light-emitting diode, which comprises an epitaxial stack, a dielectric layer, a metal reflective layer, a substrate and an oxidation protection layer. The epitaxial stack has an upper surface and a lower surface opposite to each other, and the epitaxial stack comprises a first semiconductor layer, a light-emitting layer and a second semiconductor layer in sequence from the upper surface to the lower surface. The dielectric layer is arranged on the lower surface of the epitaxial stack, and the dielectric layer has a plurality of through holes. The metal reflective layer is arranged on a side of the dielectric layer away from the epitaxial stack, and the metal reflective layer is electrically connected to the epitaxial stack through the through holes. The substrate is arranged on a side of the metal reflective layer away from the epitaxial stack. The oxidation protection layer covers the side wall of the metal reflective layer.

[0006] The present invention further provides a light emitting device, which includes a light emitting diode, and the light emitting diode is any one of the light emitting diodes described above.

[0007] A light-emitting diode and a light-emitting device provided by the present invention can effectively avoid metal migration in the metal reflective layer and leakage of the light-emitting diode by setting an oxidation protection layer on the side wall of the metal reflective layer without the need for graphic processing of the metal reflective layer and additional barrier layer, thereby improving the quality of the light-emitting diode, simplifying the process difficulty and reducing the production cost.

[0008] Other features and beneficial effects of the present invention will be described in the following description, and some of the technical features and beneficial effects can be obviously derived from the description or understood by implementing the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, a brief introduction is given below to the drawings required for use in the embodiments or the description of the prior art. Obviously, some of the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0010] Figure 1 is a schematic structural diagram of a light emitting diode provided by an embodiment of the present invention; Figure 2 yes Figure 1 A partial enlarged schematic diagram of Figure 3 is a schematic diagram of the side structure of a substrate provided by an embodiment of the present invention; Figure 4 is a FIB schematic diagram of a light emitting diode provided by an embodiment of the present invention; Figure 5 is a schematic structural diagram of a light emitting diode provided by another embodiment of the present invention; Figure 6 It is a schematic diagram of the side structure of a substrate provided by another embodiment of the present invention.

[0011] Reference numerals: 10-epitaxial stack; 101-upper surface; 102-lower surface; 103-first semiconductor layer; 104-light-emitting layer; 105-second semiconductor layer; 12-passivation layer; 14-first electrode; 16-dielectric layer; 18-metal reflective layer; 20-bonding layer; 22-substrate; 24-second electrode; 26-current diffusion layer; 31-first epitaxial sidewall; 32-second epitaxial sidewall; 40-oxidation protection layer; 42-channel; 44-hole; 50-sidewall; A-inflection point; B-angle; d1-distance from inflection point to the upper surface of light-emitting layer; H1-thickness of first semiconductor layer; W1-vertical projection length; W2-width of channel; W3-projection width of light-emitting diode; S1-thickness of oxidation protection layer. DETAILED DESCRIPTION

[0012] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all the embodiments; the technical features designed in different implementation modes of the present invention described below can be combined with each other as long as they do not conflict with each other; based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0013] In the description of the present invention, it should be understood that the terms "center", "lateral", "up", "down", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or component referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. In addition, the terms "first" and "second" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "multiple" means two or more. In addition, the term "including" and any variation thereof all mean "at least including".

[0014] See also Figures 1 to 4 , Figure 1 is a schematic diagram of the structure of a light emitting diode provided by an embodiment of the present invention, Figure 2 yes Figure 1 A partial enlarged schematic diagram of Figure 3 is a schematic diagram of the side structure of a substrate 22 provided in one embodiment of the present invention; Figure 4 FIG. 1 is a FIB schematic diagram of a light emitting diode provided by an embodiment of the present invention. It should be noted that: Figure 3 It can be understood that Figure 1 The schematic diagram of the structure of the substrate 22 when the light emitting diode is viewed from the left to the right. The FIB schematic diagram refers to an image presented by microscopic analysis of the light emitting diode using the focused ion beam (FIB) technology.

[0015] To achieve at least one of the above advantages or other advantages, the first embodiment of the present invention provides a light emitting diode. As shown in the figure, the light emitting diode includes an epitaxial stack 10, a dielectric layer 16, a metal reflective layer 18, a substrate 22 and an oxidation protection layer 40.

[0016] The epitaxial stack 10 has an upper surface 101 and a lower surface 102 opposite to each other. The epitaxial stack 10 includes a first semiconductor layer 103 , a light emitting layer 104 and a second semiconductor layer 105 in sequence from the upper surface 101 to the lower surface 102 .

[0017] The epitaxial stack 10 can be formed on a growth substrate by physical vapor deposition (PVD), chemical vapor deposition (CVD), epitaxial growth technology or atomic layer deposition (ALD). The first semiconductor layer 103 and the second semiconductor layer 105 are semiconductors with different conductivity, electrical properties and polarities, which provide electrons or holes according to the doped elements; for example, when the first semiconductor layer 103 is n-type, the second semiconductor layer 105 is p-type, and the light-emitting layer 104 is formed between the first semiconductor layer 103 and the second semiconductor layer 105. The electrons and holes are recombined in the light-emitting layer 104 under the driving of a current, and the electrical energy is converted into light energy to emit light. The wavelength of the light emitted by the light-emitting diode is adjusted by changing the physical and chemical composition of one or more layers of the epitaxial light-emitting layer 104; and vice versa. In this embodiment, a light emitting diode in which the first semiconductor layer 103 is an n-type and the second semiconductor layer 105 is a p-type is taken as an example.

[0018] The light-emitting layer 104 is a region for providing light radiation for the recombination of electrons and holes. Different materials can be selected according to different light-emitting wavelengths. The light-emitting layer 104 can be a single heterostructure (SH), a double heterostructure (DH), a double-sided double heterostructure (DDH), or a multi-quantum well structure (MQW). The light-emitting layer 104 includes a well layer and a barrier layer, wherein the barrier layer has a larger band gap than the well layer. By adjusting the composition ratio of the semiconductor material in the light-emitting layer 104, it is expected to radiate light of different wavelengths. In this embodiment, the semiconductor epitaxial stack 100 is a semiconductor material layer capable of radiating ultraviolet, blue, green, yellow, red, infrared light, etc., and can specifically be a material of 200nm to 950nm, such as a common nitride, specifically a gallium nitride-based semiconductor epitaxial stack 100, which is commonly doped with elements such as aluminum and indium, and mainly provides radiation in the 200-550nm band; or a common aluminum gallium indium phosphorus-based or aluminum gallium arsenic-based semiconductor epitaxial stack 100, which mainly provides radiation in the 550-950nm band. In order to improve the luminous efficiency, it can be achieved by changing the depth of the quantum well, the number of layers, thickness and / or other features of the paired quantum wells and quantum barriers in the light-emitting layer 104. In this embodiment, the semiconductor epitaxial stack 10 is preferably composed of AlGaInP-based or GaAs-based materials.

[0019] The dielectric layer 16 is disposed on the lower surface 102 of the epitaxial stack 10, and the dielectric layer 16 has a plurality of conductive through holes. The plurality of through holes can expose the epitaxial stack 10. The dielectric layer 16 is light-transmissive. The material of the dielectric layer 16 can include transparent compounds such as silicon nitride, silicon oxide, titanium oxide, and their stacked combinations, for example, it can be a Bragg reflector (DBR) formed by repeatedly stacking two materials with different refractive indices.

[0020] The metal reflective layer 18 is disposed on the side of the dielectric layer 16 away from the epitaxial stack 10, and the metal reflective layer 18 is electrically connected to the epitaxial stack 10 through a through hole. The metal reflective layer 18 can be made of a metal material. The metal reflective layer 18 can have a reflectivity of more than 90%, and can be formed of a metal or alloy containing at least one of Ag, Ni, Al, Rh, Pd, Ir, Ru, Mg, Ti, Cr, Zn, Pt, Au and Hf. The metal reflective layer 18 can reflect the light radiated from the epitaxial stack 10 toward the substrate 22 side back to the epitaxial stack 10, and radiate out from the light emitting surface side.

[0021] The substrate 22 is disposed on the side of the metal reflective layer 18 away from the epitaxial stack 10. The substrate 22 is a conductive substrate 22, and the conductive substrate 22 may be silicon, silicon carbide, aluminum nitride or a metal substrate 22, and the metal substrate 22 is preferably a copper, tungsten, copper tungsten or molybdenum substrate 22. In order to support the epitaxial stack 10 with sufficient mechanical strength, the thickness of the substrate 22 may be greater than 50 μm.

[0022] The oxidation protection layer 40 covers the sidewalls of the metal reflective layer 18. The material of the oxidation protection layer 40 is different from the passivation layer 12. The material of the oxidation protection layer 40 may include silicon oxide. The oxidation protection layer 40 is doped with at least one element in the group consisting of gallium, indium, tin, nickel, titanium, platinum and gold. That is, the oxidation protection layer 40 is doped with at least one or more compounds or single substances consisting of gallium, indium, tin, nickel, titanium, platinum, gold and other elements. In some embodiments, the oxidation protection layer 40 may be formed by laser chip splitting. For example, during the laser chip splitting process, the laser hits the chip cutting path position, and the components of part of the chip are broken and melted and sputtered to the surrounding sidewalls due to the high intensity of the laser. In the process, oxidation products are generated, and the oxidation products are attached to the sidewalls to form an oxidation protection layer 40 with a certain thickness. The oxidation protection layer 40 covers the sidewalls of the metal reflective layer 18. By setting the oxidation protection layer 40, there is no need to perform graphic processing on the metal reflective layer 18 and set an additional barrier layer, which can effectively avoid metal migration in the metal reflective layer 18 and leakage of the light-emitting diode, thereby improving the quality of the light-emitting diode, simplifying the process difficulty and reducing production costs.

[0023] In some embodiments, to further avoid metal migration, the upper surface of the oxidation protection layer 40 is not lower than the lower surface of the second semiconductor layer 105. The lower surface of the oxidation protection layer 40 is not higher than the upper surface of the substrate 22. The upper surface and lower surface of the oxidation protection layer 40 may refer to the surfaces where the highest point and the lowest point are located.

[0024] In some embodiments, the upper surface of the oxidation protection layer 40 is higher than the lower surface of the second semiconductor layer 105 , and the oxidation protection layer 40 extends upward from the lower surface of the second semiconductor layer 105 to be higher than the upper surface of the second semiconductor layer 105 .

[0025] In some embodiments, the upper surface height and the lower surface height of the oxidation protection layer 40 can be adjusted by controlling the intensity of the laser, and the power of the laser can be 2-10W. The higher the laser power, that is, the greater the laser intensity, the more oxides are produced and the higher the upper surface. Similarly, a high-intensity laser produces a deeper oxide layer, and the oxidation protection layer 40 can have a lower lower surface. Conversely, the oxidation protection layer 40 formed by a weaker laser will not be very deep. The laser power can be adjusted according to the needs to obtain an oxidation protection layer of appropriate specifications.

[0026] In some embodiments, the oxidation protection layer 40 has a maximum thickness, and the thickness S1 of the oxidation protection layer 40 gradually decreases from its maximum thickness toward the substrate 22 until it reaches the minimum thickness and no longer changes. Such a structure is formed due to laser scratching. The strongest fragmentation and sputtering are formed where the laser is the strongest, so the most oxide is produced nearby, and there is almost no oxide in the weakest part of the laser. This kind of oxidation protection layer 40 with a gradual thickness does not require additional processes and can be produced in one step during laser scratching, which greatly simplifies the process difficulty and has the advantage of protecting the metal reflective layer 18. Similarly, the thickness S1 of the oxidation protection layer 40 gradually decreases from its maximum thickness toward the upper surface 101 of the epitaxial stack 10 until it reaches the minimum thickness and no longer changes. The maximum thickness of the oxidation protection layer 40 may be located in the sidewall region of the second semiconductor layer 105.

[0027] In some embodiments, Figure 1 As shown, the projection width W3 of the light-emitting diode on the horizontal plane is the smallest at the second semiconductor layer 105, and the projection width W3 gradually increases from its smallest width toward the substrate 22. It should be noted that, as shown in the figure, the projection width W3 does not include the oxidation protection layer 40, that is, the width of the light-emitting diode changes after the oxidation protection layer 40 is removed. Due to the laser scratching process, such a change in the projection width W3 is due to the fact that when the laser energy is stronger, the more parts of the original side of the light-emitting diode are knocked off at the second semiconductor layer 105, and the less is left, the smaller its projection width W3 becomes; and when the projection width W3 reaches the maximum, the subsequent laser intensity is almost gone, so the projection width W3 is almost unchanged after reaching the maximum.

[0028] In some embodiments, the light-emitting diode has a side wall 50. The thickness of the side wall 50 is the smallest at the second semiconductor 105, and the thickness of the side wall 50 gradually increases from its minimum thickness toward the substrate 22. It should be noted that the side wall 50 does not include the oxidation protection layer 40. For example, the side wall 50 may refer to the side wall from the second semiconductor layer 105, downward through the side wall of the dielectric layer 16, the side wall of the metal reflective layer 18, and the side wall of the bonding layer 20, until it extends to the side wall of the substrate 22. In some embodiments, when the thickness of the side wall 50 gradually increases in the direction of the substrate 22, when the thickness reaches the thickest state, it will no longer change. Due to the laser scratching process, the stronger the laser energy, the more parts of the original side wall 50 of the light-emitting diode are knocked off, and the less is left, and when the thickness of the side wall 50 reaches the thickest state, the subsequent laser intensity is almost gone, so the thickness of the side wall 50 is almost unchanged.

[0029] In some embodiments, in combination Figure 3 and Figure 4As shown, there are multiple channels 42 on the sidewalls of the substrate 22, and the oxidation protection layer 40 fills the channels 42. The channels 42 have a maximum width, and the width W2 of the channels 42 gradually decreases along the direction from the maximum width to the lower surface of the substrate 22. Corresponding to the figure, the width W2 of the channels 42 narrows from top to bottom. Adjacent channels 42 are connected to each other at the maximum width of the channels 42, that is, the upper parts of the channels 42 are connected to each other and are an integral part. The maximum width of the channels 42 is usually the width at the upper surface of the channels 42. A hole 44 is formed at the bottom of each channel 42, and the width of the channel 42 is the smallest at the hole 44, and the width of the channel 42 is the smallest at the lowest end. Referring to the shape shown in the figure, the shape from the minimum width W2 of the channel 42 to the maximum width W2 of the channel 42 is quasi-inverted triangle. It should be noted that in the attached Figure 3 In order to facilitate understanding of the corresponding relationship between the channel 42 and the hole 44, the change of the width W2 of the channel 42, etc., only the channels 42 and holes 44 are relatively symmetrical and one-to-one corresponding. However, the present invention is not limited to this. In actual situations, there are many situations for the channels 42 and holes 44, such as the heights of adjacent holes 44 are inconsistent, or the maximum widths of the channels 42 are inconsistent, or the maximum width areas of the channels 42 are inconsistent, etc., but the channels 42 and holes 44 in the same channel 42 must meet the above-mentioned width change relationship.

[0030] In some embodiments, Figure 4 As shown, the surface morphology of the oxidation protection layer 40 has a fish-scale texture. The fish-scale texture can be composed of a plurality of sheet-like units arranged, and there is a certain thickness difference and height difference between each sheet-like unit, that is, the thickness and height between each sheet-like unit can be uneven and irregularly arranged. The reason for its formation is: in the process of laser scratching the chip, there are multiple 2-10w lasers. The first laser forms the first channel, the second laser forms the second channel, and part of the oxide is sputtered to the adjacent first / third channel, and so on. Each channel will have part of the oxide sputtered from other parts, and finally a stacked, irregular fish-scale texture is formed. The fish-scale oxidation protection layer 40 can well protect the metal reflective layer 18.

[0031] In some embodiments, the light emitting diode may further include a passivation layer 12 , a first electrode 14 , a bonding layer 20 and a second electrode 24 .

[0032] The passivation layer 12 is partially disposed outside the epitaxial stack 10, mainly for protection and isolation. The material of the passivation layer 12 may include silicon oxide, etc. The sidewall morphology of the passivation layer 12 may be the same as the morphology after the first epitaxial sidewall 31 is connected to the second epitaxial sidewall 32.

[0033] The first electrode 14 is disposed on the upper surface 101 of the epitaxial stack 10. The first electrode 14 may be a single-layer structure, a double-layer structure or a multi-layer structure. The first electrode 14 may be made of metal materials, such as Cr, Pt, Au, Ni, Ti, Al and the like.

[0034] The bonding layer 20 is disposed between the metal reflective layer 18 and the substrate 22. The bonding layer 20 is used for the substrate 22 and the epitaxial stack 10 to improve the connection strength of the overall structure. The bonding layer 20 can be made of metal elements such as gold, tin, titanium, tungsten, nickel, platinum, indium, etc. The bonding layer 20 can be a single-layer structure or a multi-layer structure, and can be a combination of multiple materials.

[0035] The second electrode 24 is disposed on a side of the substrate 22 away from the epitaxial stack 10. The second electrode 24 can be made of metal.

[0036] In some embodiments, a current diffusion layer 26 may be further disposed below the second semiconductor layer 105. The current diffusion layer 26 diffuses current, and the material of the current diffusion layer 26 may include gallium phosphide, etc. The dielectric layer 16 covers the current diffusion layer 26, and the through hole of the dielectric layer 16 exposes part of the current diffusion layer 26. The metal reflective layer 18 is electrically connected to the current diffusion layer 26 through the through hole.

[0037] The epitaxial stack 10 has a first epitaxial sidewall 31 and a second epitaxial sidewall 32 on the same side. The first epitaxial sidewall 31 and the second epitaxial sidewall 32 on the left side are used as examples for explanation. The first epitaxial sidewall 31 is a partial sidewall on the first semiconductor layer 103. The second epitaxial sidewall 32 extends from a partial sidewall of the second semiconductor layer 105 toward the upper surface 101 of the epitaxial stack 10, through the sidewall of the light-emitting layer 104 until it extends to the sidewall of the first semiconductor layer 103. In other words, the second epitaxial sidewall 32 is generally composed of a partial sidewall of the second semiconductor layer 105, a sidewall of the light-emitting layer 104, and a partial sidewall of the first semiconductor layer 103. Further, the first epitaxial sidewall 31 is connected to the second epitaxial sidewall 32, and an inflection point A is formed at the connection between the first epitaxial sidewall 31 and the second epitaxial sidewall 32, and an angle B is formed at the inflection point A, and the angle B>90°. Compared with the traditional right-angle L-shaped side wall, the present invention forms two inclined side walls by setting an inflection point A, and the inflection point A is located on the side wall of the first semiconductor layer 103 above the light-emitting layer 104, so that after the chip is cut, it is easier to clean the organic matter in the degumming process, and it is also beneficial to the continuity of other subsequent protective layers covering these side walls; and, since the inflection point A is set at the first semiconductor layer 103, the light-emitting layer 104 and the second semiconductor are not exposed, so that even if some organic matter remains, the problem of leakage burns can be avoided, and the light-emitting layer 104 can be ensured to have a flat surface, and it is not easy to leave organic matter, thereby reducing the risk of leakage. Optionally, the first epitaxial side wall 31 is a portion extending from the upper surface 101 of the epitaxial stack 10 to the lower surface 102 of the epitaxial stack 10 to the inflection point A, and the inflection point A is located on the side wall of the first semiconductor layer 103. Optionally, considering the influence of the light-emitting effect, the range of the angle B can be 91~120°.

[0038] In some embodiments, the distance from the inflection point A to the upper surface of the light-emitting layer 104 is defined as d1, the thickness of the first semiconductor layer 103 is H1, and 0.05H1≤d1≤0.4H1. If d1 is less than 0.05H1, it means that the inflection point A is too close to the light-emitting layer 104, and organic matter may still be attached near the light-emitting layer 104, which may easily cause leakage problems; if d1 is greater than 0.4H1, it means that the inflection point A is located at a high position, resulting in a too narrow cutting path, which is not conducive to the implementation of subsequent processes.

[0039] In some embodiments, the upper surface 101 of the epitaxial stack 10 is used as a reference plane, and the angle between the extension line of the first epitaxial sidewall 31 and the upper surface 101 of the epitaxial stack 10 is 80° to 100°. In the illustrated embodiment, the angle is 90°, that is, the first epitaxial sidewall 31 is perpendicular to the upper surface 101 of the epitaxial stack 10.

[0040] In some embodiments, the vertical projection length W1 of the second epitaxial side wall 32 located on one side of the epitaxial stack 10 on the lower surface 102 of the epitaxial stack 10 ranges from 10 to 30 μm, that is, the overall width W1 of the second epitaxial side wall 32 in the horizontal direction is 10 to 30 μm. On the contrary, if it is greater than 30 μm, the remaining light-emitting layer is too small 104, which is not conducive to the light-emitting efficiency; if it is less than 10 μm, the cutting path is too narrow, which is not conducive to the subsequent cutting process.

[0041] In some embodiments, the second epitaxial sidewall 32 at least extends over the entire second semiconductor layer 105 . For example, the second epitaxial sidewall 32 may further extend downward to the underlying dielectric layer 16 .

[0042] See also Figure 5 , Figure 5 is a schematic diagram of the structure of a light emitting diode provided by another embodiment of the present invention. Figure 1 With respect to the light emitting diode shown in the figure, the main difference of this embodiment is that the oxidation protection layer 40 extends upward to cover a portion of the passivation layer 12 , that is, the oxidation protection layer 40 covers a portion of the passivation layer 12 .

[0043] See also Figure 6 , Figure 6 FIG. 1 is a schematic diagram of the side structure of a substrate provided by another embodiment of the present invention. Figure 3 As shown, the main difference of this embodiment is that the shape from the minimum width W2 of the channel 42 to the maximum width W2 of the channel 42 is quasi-inverted arc shape.

[0044] An embodiment of the present invention further provides a light emitting device, which includes a light emitting diode. The light emitting diode can be the light emitting diode described in any of the above embodiments.

[0045] In summary, a light-emitting diode and a light-emitting device provided by an embodiment of the present invention can effectively avoid metal migration in the metal reflective layer 18 and leakage of the light-emitting diode by setting an oxidation protection layer 40 on the side wall of the metal reflective layer 18 without the need to perform patterning on the metal reflective layer 18 and set an additional barrier layer, thereby improving the quality of the light-emitting diode, simplifying the process difficulty, and reducing the production cost.

[0046] In addition, those skilled in the art should understand that, although there are many problems in the prior art, each embodiment or technical solution of the present invention can be improved in only one or several aspects, without having to solve all the technical problems listed in the prior art or background technology at the same time. Those skilled in the art should understand that the content not mentioned in a claim should not be used as a limitation on the claim.

[0047] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A light emitting diode, characterized in that: The light emitting diode comprises: An epitaxial stack having an upper surface and a lower surface opposite to each other, wherein the epitaxial stack comprises a first semiconductor layer, a light emitting layer and a second semiconductor layer in sequence from the upper surface to the lower surface; A dielectric layer, the dielectric layer is arranged on the lower surface of the epitaxial stack, and the dielectric layer has a plurality of through holes; A metal reflective layer, the metal reflective layer is arranged on a side of the dielectric layer away from the epitaxial stack, and the metal reflective layer is electrically connected to the epitaxial stack through the through hole; A substrate, the substrate being arranged on a side of the metal reflective layer away from the epitaxial stack; The oxidation protection layer covers the side wall of the metal reflective layer.

2. The light emitting diode according to claim 1, characterized in that: An upper surface of the oxidation protection layer is not lower than a lower surface of the second semiconductor layer.

3. The light emitting diode according to claim 1, characterized in that: The lower surface of the oxidation protection layer is not higher than the upper surface of the substrate.

4. The light emitting diode according to claim 1, characterized in that: The upper surface of the oxidation protection layer is higher than the lower surface of the second semiconductor layer, and the oxidation protection layer extends upward from the lower surface of the second semiconductor layer to be higher than the upper surface of the second semiconductor layer.

5. The light emitting diode according to claim 1, characterized in that: The material of the oxidation protection layer includes silicon oxide, and the oxidation protection layer is doped with at least one element from the group consisting of gallium, indium, tin, nickel, titanium, platinum and gold.

6. The light emitting diode according to claim 1, characterized in that: The surface morphology of the oxidation protection layer has a fish-scale texture, and the fish-scale texture is composed of a plurality of sheet-like units arranged, and there are thickness differences and height differences between the sheet-like units.

7. The light emitting diode according to claim 1, characterized in that: The oxidation protection layer has a maximum thickness, and the thickness of the oxidation protection layer gradually decreases from the maximum thickness toward the substrate.

8. The light emitting diode according to claim 1, characterized in that: The oxidation protection layer has a maximum thickness, and the thickness of the oxidation protection layer gradually decreases from the maximum thickness toward the upper surface of the epitaxial stack.

9. The light emitting diode according to claim 1, characterized in that: The projection width of the light emitting diode on the horizontal plane is the smallest at the second semiconductor layer, and the projection width gradually increases from the smallest width toward the substrate.

10. The light emitting diode according to claim 1, characterized in that: There are a plurality of trenches on the sidewall of the substrate, the trenches are filled with the oxidation protection layer, the trenches have a maximum width, and the width of the trenches gradually decreases from the maximum width to the lower surface of the substrate.

11. The light emitting diode according to claim 10, characterized in that: Adjacent channels are connected to each other at the maximum width of the channels.

12. The light emitting diode according to claim 10, characterized in that: A hole is formed at the bottom of each channel, and the width of the channel is smallest at the hole.

13. The light emitting diode according to claim 10, characterized in that: The shape from the smallest width of the channel to the largest width of the channel is quasi-inverted triangle or inverted arc shape.

14. The light emitting diode according to claim 1, characterized in that: The light-emitting diode also includes a passivation layer, a first electrode, a bonding layer and a second electrode. Part of the passivation layer is arranged on the outside of the epitaxial stack, the first electrode is arranged on the upper surface of the epitaxial stack, the bonding layer is arranged between the metal reflective layer and the substrate, and the second electrode is arranged on a side of the substrate away from the epitaxial stack.

15. The light emitting diode according to claim 1, characterized in that: The epitaxial stack has a first epitaxial sidewall and a second epitaxial sidewall on the same side, the first epitaxial sidewall is a partial sidewall on the first semiconductor layer, the second epitaxial sidewall extends from a partial sidewall of the second semiconductor layer toward the upper surface of the epitaxial stack, through the sidewall of the light-emitting layer until it extends to the sidewall of the first semiconductor layer, the first epitaxial sidewall is connected to the second epitaxial sidewall, an inflection point is formed at the connection between the first epitaxial sidewall and the second epitaxial sidewall, and an angle is formed at the inflection point, and the angle is greater than 90°.

16. The light emitting diode according to claim 15, characterized in that: The first epitaxial sidewall is a portion extending from the upper surface of the epitaxial stack toward the lower surface of the epitaxial stack to the inflection point, and the inflection point is located on the sidewall of the first semiconductor layer.

17. The light emitting diode according to claim 15, characterized in that: The angle ranges from 91° to 120°.

18. The light emitting diode according to claim 15, characterized in that: The distance from the inflection point to the upper surface of the light emitting layer is defined as d1, the thickness of the first semiconductor layer is defined as H1, and 0.05H1≤d1≤0.4H1.

19. The light emitting diode according to claim 15, characterized in that: Taking the upper surface of the epitaxial stack as a reference plane, the angle between the extension line of the first epitaxial side wall and the upper surface of the epitaxial stack is 80° to 100°.

20. A light emitting device, characterized in that: The light emitting device comprises a light emitting diode, and the light emitting diode is a light emitting diode as claimed in any one of claims 1 to 19.

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