Light emitting diode and light emitting device

Abstract

The application relates to a light emitting diode and a light emitting device. The light emitting diode comprises: a semiconductor stack, from bottom to top, comprising a first semiconductor layer, a light emitting layer and a second semiconductor layer which are sequentially stacked; a transparent conductive layer formed on the second semiconductor layer; a protective layer formed on the transparent conductive layer; a second electrode formed on the protective layer, comprising a pad part and an extension part; the protective layer forms a first opening and a second opening on the pad part and the extension part of the second electrode respectively, and the second electrode forms an electrical connection with the second semiconductor layer through the first opening and the second opening; characterized in that: the second opening of the protective layer comprises a plurality of first opening parts and a second opening part, the second opening part is formed at the end far away from the pad part of the second electrode, and the size of the second opening part is greater than that of the first opening part. The application differentiates the size of the second opening of the protective layer on the extension part of the second electrode, thereby improving the reliability of the chip.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of semiconductor manufacturing, in particular to a light emitting diode and a light emitting device. BACKGROUND

[0002] A light emitting diode (LED) is usually made of a semiconductor such as GaN, GaAs, GaP, GaAsP, etc., and its core is a PN junction with light emitting characteristics. Under a forward voltage, electrons are injected from an N region to a P region, and holes are injected from the P region to the N region. A part of the minority carriers entering the opposite region recombine with the majority carriers to emit light. The LED has the advantages of high light intensity, high efficiency, small size, long service life, etc., and is considered to be one of the most potential light sources.

[0003] The early gallium nitride LED chip manufacturing process includes four processes of mesa etching (MESA), making a transparent conductive layer (such as ITO), making an electrode, and making a protective layer. In recent years, in order to improve the light emitting efficiency of the light emitting diode, a new four-process technology of mesa etching (MESA), making a transparent conductive layer, making an electrode, and making a protective layer is known in the industry. In the current LED industry, in order to achieve effective current expansion, multiple expansion electrode designs are generally used. Since the end of the expansion electrode is often a high current density area, in this new four-process technology, the end of the expansion electrode often becomes prone to ESD explosion and burns due to excessive concentration of electric charges, thereby causing chip failure and dead lights. Therefore, how to further optimize the design of the protective layer to improve the reliability of the light emitting diode chip is a technical problem that needs to be solved by those skilled in the art. SUMMARY

[0004] In view of the defects and deficiencies of the prior art light emitting diode, the present application provides a light emitting diode and a light emitting device to improve the reliability of the chip.

[0005] One embodiment of the present application provides a light emitting diode, which at least includes:

[0006] a semiconductor stack, including a first semiconductor layer, a light emitting layer, and a second semiconductor layer stacked in sequence from bottom to top;

[0007] a transparent conductive layer formed on the second semiconductor layer;

[0008] a protective layer formed on the transparent conductive layer;

[0009] a second electrode formed on the protective layer, including a pad portion and an expansion portion;

[0010] The protective layer forms a first opening and a second opening at the pad part and the extension part of the second electrode respectively, exposing part of the upper surface of the second semiconductor layer at the pad part of the second electrode and part of the upper surface of the transparent conductive layer at the extension part of the second electrode, and the second electrode forms an electrical connection with the second semiconductor layer through the first opening and the second opening.

[0011] The second opening of the protective layer comprises a plurality of first opening parts and at least one second opening part, the second opening part is formed at the end away from the pad part of the second electrode, and the size of the second opening part is larger than that of the first opening part.

[0012] According to another embodiment of the present application, a light emitting device is also provided, which uses the light emitting diode according to any one of the above embodiments.

[0013] The light emitting diode provided by the present application can avoid the ESD explosion point at the end of the extension electrode due to the excessive concentration of electric charges, improve the anti-static impact capability of the chip, and thus ensure the reliability of the light emitting diode.

[0014] Other features and advantages of the present application will be illustrated in the following description, and some of them will become apparent from the description, or will be understood by those skilled in the art through implementation of the present application.

[0015] In view of the defects and deficiencies of the prior art light emitting diode, the present application provides a light emitting diode and a light emitting device to improve the reliability of the chip.

[0016] In one embodiment of the present application, a light emitting diode is provided, which at least comprises:

[0017] A semiconductor stack comprising, from bottom to top, a first semiconductor layer, a light emitting layer and a second semiconductor layer stacked in sequence;

[0018] A transparent conductive layer formed on the second semiconductor layer;

[0019] A protective layer formed on the transparent conductive layer;

[0020] A second electrode formed on the protective layer, comprising a pad part and an extension part;

[0021] The protective layer forms a first opening and a second opening at the pad part and the extension part of the second electrode respectively, exposes part of the upper surface of the second semiconductor layer at the pad part of the second electrode and part of the upper surface of the transparent conductive layer at the extension part of the second electrode, and the second electrode forms an electrical connection with the second semiconductor layer through the first opening and the second opening.

[0022] The second opening of the protective layer comprises a plurality of first opening parts and at least one second opening part, the second opening part is formed at the end far from the pad part of the second electrode, and the size of the second opening part is larger than that of the first opening part.

[0023] According to another embodiment of the present application, a light emitting device is provided, which comprises the light emitting diode according to any one of the above embodiments.

[0024] The light emitting diode provided by the present application can avoid the ESD explosion point at the end of the extension electrode due to the excessive concentration of electric charges, improve the anti-static impact capability of the chip, and thus ensure the reliability of the light emitting diode.

[0025] Other features and advantages of the present application will be illustrated in the following description, and some of them will become apparent from the description, or will be understood by those skilled in the art through implementation of the present application. BRIEF DESCRIPTION OF DRAWINGS

[0026] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings in the following description are some embodiments of the present application, and those skilled in the art can also obtain other drawings according to these drawings without any creative effort.

[0027] Figure 1 A top view of the light emitting diode according to Embodiment One of the present application is shown in the figure.

[0028] Figure 2 A cross-sectional structure view along the A-A' line of the light emitting diode according to Embodiment One of the present application is shown in the figure. Figure 1

[0029] A partial enlarged view of the box area in the figure. Figure 3 Figure 2

[0030] Figure 4 ​​FIG. 1 is a schematic diagram of a cross-sectional structure along the line B-B' of the light emitting diode according to the present application; Figure 1

[0031] Figure 5 FIG. 4 is a mask pattern for fabricating the light emitting diode according to the present application;

[0032] Figure 6 FIG. 5 is a schematic diagram of a current flow path of the light emitting diode according to the present application;

[0033] Figure 7 FIG. 6 is a schematic diagram of a top view of the light emitting diode according to the second embodiment of the present application;

[0034] Figure 8 FIG. 8 is a schematic diagram of a cross-sectional structure along the line A-A' of the light emitting diode according to the third embodiment of the present application; Figure 7

[0035] FIG. 9 is a schematic diagram of a top view of the light emitting diode according to the third embodiment of the present application; Figure 9

[0036] FIG. 11 is a schematic diagram of a cross-sectional structure along the line A-A' of the light emitting diode according to the fourth embodiment of the present application; Figure 10 Figure 9 FIG. 12 is a schematic diagram of a top view of the light emitting diode according to the fourth embodiment of the present application;

[0037] Figure 11 FIG. 14 is a schematic diagram of a cross-sectional structure along the line A-A' of the light emitting diode according to the fourth embodiment of the present application;

[0038] Figure 12 Figure 11 FIG. 15 is a schematic diagram of a top view of the light emitting diode according to the fourth embodiment of the present application;

[0039] Figure 13 FIG. 17 is a schematic diagram of a cross-sectional structure along the line A-A' of the light emitting diode according to the fourth embodiment of the present application;

[0040] Figure 14 FIG. 18 is a schematic diagram of a top view of the light emitting diode according to the fourth embodiment of the present application; Figure 13

[0041] FIG. 20 is a schematic diagram of a cross-sectional structure along the line A-A' of the light emitting diode according to the fourth embodiment of the present application; Figure 15

[0042] FIG. 22 is a schematic diagram of a top view of the light emitting diode according to the fourth embodiment of the present application; Figure 16 Figure 15 FIG. 24 is a schematic diagram of a cross-sectional structure along the line A-A' of the light emitting diode according to the fourth embodiment of the present application;

[0043] Figure 17 FIG. 26 is a schematic diagram of a top view of the light emitting diode according to the fourth embodiment of the present application;

[0044] Figure 18 Figure 17 FIG. 28 is a schematic diagram of a cross-sectional structure along the line A-A' of the light emitting diode according to the fourth embodiment of the present application.

[0045] Reference numerals:

[0046] ​​​​​10 - substrate; 12 - semiconductor stack; 123 - first semiconductor layer; 124 - light emitting layer; 125 - second semiconductor layer; 14 - insulating layer; 16 - transparent conductive layer; 18 - protective layer; 21 - first electrode; 211 - first electrode pad portion; 212 - first electrode extension portion; 22 - second electrode; 221 - second electrode pad portion; 222 - second electrode extension portion; 2221 - first end of second electrode extension portion; 2222 - second end of second electrode extension portion; 2220 - terminal end of second electrode extension portion; 31 - first opening; 310 - antenna; 32 - second opening; 321 - first opening portion; 322 - second opening portion; 33 - third opening; 34 - fourth opening; 35 - fifth opening; 36 - sixth opening; 40 - via hole. DETAILED DESCRIPTION

[0047] In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. The technical features designed in different embodiments of the present application can be combined with each other as long as they do not conflict with each other.

[0048] The present application provides a light emitting diode, which at least comprises:

[0049] a semiconductor stack comprising, from bottom to top, a first semiconductor layer, a light emitting layer and a second semiconductor layer which are stacked in sequence;

[0050] a transparent conductive layer formed on the second semiconductor layer;

[0051] a protective layer formed on the transparent conductive layer;

[0052] a second electrode formed on the protective layer, comprising a pad portion and an extension portion;

[0053] the protective layer forms a first opening and a second opening on the pad portion and the extension portion of the second electrode respectively, exposing part of the upper surface of the second semiconductor layer at the pad portion of the second electrode and part of the upper surface of the transparent conductive layer at the extension portion of the second electrode, and the second electrode forms an electrical connection with the second semiconductor layer through the first opening and the second opening;

[0054] characterized in that the second opening of the protective layer comprises a plurality of first opening portions and at least one second opening portion, the second opening portion is formed at the terminal end away from the pad portion of the second electrode, and the size of the second opening portion is greater than the size of the first opening portion.

[0055] The application can avoid ESD explosion point at the end of the extended electrode due to excessive charge concentration, thereby improving the anti-static impact capability of the chip, and further ensuring the reliability of the light emitting diode; on the other hand, the current can be diffused as uniformly as possible to the periphery through the large-size second opening part at the end of the extended electrode, avoiding direct injection of the current at the end of the extended electrode, promoting the lateral expansion of the current, improving the overall current uniformity of the light emitting diode, and further improving the light emitting efficiency of the light emitting diode chip.

[0056] In an embodiment, the second electrode extension part has a first end connected with the second electrode pad part and a second end away from the second electrode pad part, and the second opening part is formed below the second end of the second electrode extension part. Since the second end of the second electrode extension part is often a high current density area, by setting the largest-size second opening part in the high current density area, ESD explosion point can be prevented due to excessive charge concentration in this area, thereby improving the reliability of the light emitting diode chip.

[0057] In an embodiment, the sizes of the plurality of first opening parts are the same.

[0058] In an embodiment, the sizes of the plurality of first opening parts gradually increase along the extension direction away from the second electrode pad part. In the application, the sizes of the first opening parts can be the same or different. Since the current density often gradually increases along the extension direction of the second electrode extension part, in some preferred embodiments, by designing the sizes of the first opening parts to gradually increase along the extension direction of the second electrode extension part, ESD explosion point can be prevented due to excessive charge concentration in areas with high current density, such as near the end of the extended electrode; at the same time, the current congestion effect on the second electrode can be alleviated, the overall current uniformity of the light emitting diode is improved, and the reliability and light emitting efficiency of the light emitting diode chip are further improved.

[0059] In an embodiment, the size of the second opening part is at least 2 times larger than the size of the first opening part. By limiting the ratio of the size of the second opening part to the size of the first opening part, the current can be more effectively diffused uniformly to the periphery through the large-size second opening part, avoiding ESD explosion point caused by charge concentration, and improving the overall current uniformity of the light emitting diode, thereby improving the reliability and light emitting efficiency of the light emitting diode chip.

[0060] In an embodiment, the size of the second opening part is 2-20 times the size of the first opening part. By further limiting the size of the second opening part to the size of the first opening part, the current is further promoted to diffuse more effectively and uniformly through the large size of the second opening part at the end of the extended electrode, thereby further improving the overall performance of the LED.

[0061] In an embodiment, the second openings have a spacing therebetween, and the size of the spacing is the same.

[0062] In an embodiment, the second openings have a spacing therebetween, and the size of the spacing decreases sequentially along the extension direction away from the second electrode pad part. In the present application, the spacing between the second openings can be the same or different, and since the current density tends to increase along the extension direction of the second electrode extension part, in some preferred embodiments, by designing the spacing between the second openings to decrease sequentially along the extension direction of the second electrode extension part, the ESD explosion point caused by excessive concentration of charges in the area with high current density can also be prevented; at the same time, the current congestion effect on the second electrode can also be alleviated, the overall current uniformity of the light-emitting diode is improved, and the reliability and luminous efficiency of the light-emitting diode chip are further improved.

[0063] In an embodiment, the second opening part and the second electrode extension part have an overlapping part, and the length of the overlapping part is 2%-40% of the length of the second electrode extension part.

[0064] In an embodiment, the second opening part and the second electrode extension part have an overlapping part, and the area of the overlapping part is 2%-40% of the area of the second electrode extension part.

[0065] By the length or area ratio of the overlapping part of the second opening part and the second electrode extension part, the current is further promoted to diffuse more effectively and uniformly through the large size of the second opening part, thereby improving the overall current uniformity on the second electrode and further improving the luminous efficiency of the light-emitting diode chip.

[0066] In an embodiment, the light-emitting diode further comprises an insulating layer formed on the second semiconductor layer and arranged corresponding to the second opening part, and the transparent conductive layer covers the insulating layer. By arranging the insulating layer corresponding to the second opening part, i.e., the insulating layer is also arranged only under the end of the extended electrode away from the second electrode pad part, on the one hand, the design of the insulating layer can avoid direct injection of current, further ensuring the reliability of the light-emitting diode, and on the other hand, the design can further promote the current to diffuse more effectively and uniformly at the end of the extended electrode, thereby improving the luminous efficiency of the light-emitting diode chip; in addition, by arranging only a small amount of necessary insulating layer, the chip voltage rise caused by the excessive area of the current blocking layer can be effectively avoided.

[0067] In an embodiment, the width of the insulating layer is greater than or equal to the width of the second opening. Thus, the current is diffused to the periphery from the end of the extension electrode, and the overall current uniformity of the light emitting diode is further improved.

[0068] In an embodiment, the ratio of the area of the insulating layer to the area of the second opening is in the range of 10% to 200%. Through the cooperation of the insulating layer at the end of the extension electrode and the large-size second opening, the reliability and light emitting efficiency of the light emitting diode chip are further improved, and the voltage rise caused by the excessive area of the current blocking layer can be avoided.

[0069] In an embodiment, the transparent conductive layer forms a third opening in the pad portion of the second electrode, exposing part of the upper surface of the second semiconductor layer in the pad portion of the second electrode, and the size of the third opening is smaller than the size of the pad portion of the second electrode.

[0070] In an embodiment, the size of the first opening is smaller than the size of the third opening, the pad portion of the second electrode is in contact with the second semiconductor layer, and the extension portion of the second electrode is in contact with the transparent conductive layer.

[0071] Through the above arrangement, the pad portion of the second electrode can form an electrical connection with the second semiconductor layer through the first opening of the protective layer and the third opening of the transparent conductive layer, and the extension portion of the second electrode can be in contact with the transparent conductive layer through the second opening of the protective layer, and then form an electrical connection with the second semiconductor layer. At the same time, by setting the size of the first opening to be smaller than the size of the third opening, the brightness of the light emitting diode is further improved.

[0072] In an embodiment, the first opening is a ring structure, and the inner diameter and the outer diameter of the ring structure are both smaller than the diameter of the third opening, further improving the brightness of the light emitting diode.

[0073] In an embodiment, the protective layer further comprises at least one antenna extending from the first opening to the periphery of the pad portion of the second electrode, exposing part of the upper surface of the transparent conductive layer, and at the position of the antenna, the pad portion of the second electrode is in contact with the second semiconductor layer and the transparent conductive layer at the same time. Through the antenna, the pad portion of the second electrode can be in contact with the transparent conductive layer, and the contact area between the pad portion of the second electrode and the transparent conductive layer can be increased, which is conducive to the diffusion of current, thereby further relieving the current congestion effect on the second electrode, reducing the risk of metal precipitation and electrode burnout.

[0074] In an embodiment, the light emitting diode further comprises a first electrode, the first electrode comprises a pad portion and an extension portion, the pad portion of the first electrode is located above the first semiconductor layer, the extension portion of the first electrode is located above the second semiconductor layer and forms an ohmic contact with the first semiconductor layer through a series of through holes penetrating the second semiconductor layer and the light emitting layer, and a protective layer is arranged between the extension portion of the first electrode and the second semiconductor layer.

[0075] The present invention also provides a light-emitting device that employs a light-emitting diode as described in any of the above embodiments, so as to effectively improve the performance of the light-emitting device.

[0076] The technical solution of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention and through various specific implementation methods. Example 1

[0077] Please see Figures 1 to 4 , Figure 1 This is a top view schematic diagram of the light-emitting diode provided in Embodiment 1 of the present invention. Figure 2 For along Figure 1 A schematic diagram of the cross-sectional structure of line A-A'. Figure 3 For is Figure 2 A magnified view of the area within the box. Figure 4 For along Figure 1 A schematic diagram of the cross-sectional structure of the B-B' line. To achieve at least one or more of the aforementioned advantages, an embodiment of the present invention provides a light-emitting diode (LED), which may include at least a substrate 10, a semiconductor stack 12, a first electrode 21, a second electrode 22, a transparent conductive layer 16, and a protective layer 18. The first electrode 21 includes a pad portion 211 and an extension portion 212, and the second electrode 22 includes a pad portion 221 and an extension portion 222. The second electrode extension portion 222 includes a first end 2221 connected to the second electrode pad portion 221 and a second end 2222 away from the second electrode pad portion 221.

[0078] Specifically, the substrate 10 can be a transparent substrate, a non-transparent substrate, or a semi-transparent substrate. The substrate 10 may be selected from materials including but not limited to sapphire, aluminum nitride, gallium nitride, silicon, silicon carbide, and glass. Its surface structure may be a planar structure or a patterned structure. In some embodiments, the substrate 10 may be a combined patterned substrate. In other embodiments, the substrate 10 may be thinned or removed to form a thin-film chip.

[0079] A semiconductor stack 12 is disposed on the upper surface of the substrate 10. The semiconductor stack 12 includes a first semiconductor layer 123, a light-emitting layer 124, and a second semiconductor layer 125 stacked sequentially. The first semiconductor layer 123 is formed on the substrate 10 and, as a layer grown on the substrate 10, can be a gallium nitride semiconductor layer doped with n-type impurities, such as Si. In some embodiments, a buffer layer may also be disposed between the first semiconductor layer 123 and the substrate 10. In other embodiments, the first semiconductor layer 123 may also be connected to the substrate 10 via an adhesive layer.

[0080] The light emitting layer 124 is formed on the first semiconductor layer 123, and can be a quantum well structure (QW). In some embodiments, the light emitting layer 124 can also be a multiple quantum well structure (MQW) including a plurality of quantum well layers (Well) and a plurality of quantum barrier layers (Barrier) alternately arranged in a repeated manner. In addition, the composition and thickness of the well layers in the light emitting layer 124 determine the wavelength of the generated light. In particular, by adjusting the composition of the well layers, light emitting layers generating ultraviolet light, blue light, green light, yellow light, etc. of different colors can be provided.

[0081] The second semiconductor layer 125 is formed on the light emitting layer 124, and can be a gallium nitride-based semiconductor layer doped with a p-type impurity such as Mg. Although the first semiconductor layer 123 and the second semiconductor layer 125 can each be a single layer structure, the present case is not limited thereto, and can also be a multiple layer, and can further include a superlattice layer. In addition, in other embodiments, in the case where the first semiconductor layer 123 is doped with a p-type impurity, the second semiconductor layer 125 can be doped with an n-type impurity, i.e., the first semiconductor layer 123 is a P-type semiconductor layer, and the second semiconductor layer 125 is an N-type semiconductor layer.

[0082] In an embodiment, the mesa and a series of through holes 40 are formed on the second semiconductor layer 125 to form the first electrode 21, the through holes 40 penetrating the second semiconductor layer 125 and the light emitting layer 124 to expose part of the surface of the first semiconductor layer 123, the number of the through holes 40 being 1-15. The transparent conductive layer 16 is formed on the second semiconductor layer 125, a third opening 33 is formed at the corresponding position of the pad portion 221 of the second electrode to expose part of the upper surface of the second semiconductor layer 125 at the pad portion of the second electrode, a sixth opening 36 is formed at the corresponding position of the extension portion 212 of the first electrode, the size of the sixth opening 36 being larger than the size of the through hole 40, and the transparent conductive layer 16 and the protective layer 18 are arranged between the first electrode extension portion 212 and the second semiconductor layer 125 outside the through hole 40; the protective layer 18 is formed on the transparent conductive layer 16 to cover the upper surface of the mesa and the sidewall between the mesa and the upper surface of the second semiconductor layer 125, i.e. to cover the surface of the entire device, and a first opening 31 and a second opening 32 are formed at the corresponding positions of the pad portion 221 and the extension portion 222 of the second electrode to expose part of the upper surface of the second semiconductor layer 125 at the pad portion of the second electrode and part of the upper surface of the transparent conductive layer 16 at the extension portion of the second electrode, so that the second electrode pad portion 221 is in contact with the second semiconductor layer 125 through the first opening 31, the second electrode extension portion 222 is in contact with the transparent conductive layer 16 through the second opening 32, and the protective layer 18 forms a fourth opening 34 and a fifth opening 35 at the corresponding positions of the pad portion 211 and the extension portion 212 of the first electrode, the fifth opening 35 being formed in the through hole 40, the size of the fifth opening 35 being smaller than the size of the through hole 40, and the protective layer 18 covering the sidewall of the through hole 40 in the through hole 40; the first electrode 21 and the second electrode 22 are formed on the protective layer 18, wherein the first electrode pad portion 211 is formed on the mesa and is in contact with the first semiconductor layer 123 through the fourth opening 34, as shown in FIG. 4A, the fourth opening 34 can be a ring-shaped opening, the first electrode extension portion 212 is formed on the protective layer 18 above the second semiconductor layer 125 and is in contact with the first semiconductor layer 123 through the fifth opening 35 and the through hole 40, the second electrode pad portion 221 is in contact with the second semiconductor layer 125 through the first opening 31, and the second electrode extension portion 222 is in contact with the transparent conductive layer 16 through the second opening 32, as shown in FIG. 4B, the first opening 31 can be a ring-shaped opening. Figure 1 、 Figure 4 Figures 1 to 3 ,

[0083] ​The first electrode 21 and the second electrode 22 can be metal electrodes, i.e. the first electrode 21 and the second electrode 22 are made of a metal material, for example at least one of nickel, gold, chromium, titanium, platinum, palladium, rhodium, iridium, aluminum, tin, indium, tantalum, copper, cobalt, iron, ruthenium, zirconium, tungsten and molybdenum, or at least one of an alloy or a stack of the above-mentioned materials. As an example, in the present embodiment, the first electrode 21 can be an N electrode and the second electrode 22 can be a P electrode.

[0084] The transparent conductive layer 16 can comprise at least one of 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). As an example, in the present embodiment, the transparent conductive layer 16 is preferably an ITO (indium tin oxide semiconductor transparent conductive film) layer formed by an evaporation or sputtering process.

[0085] The material of the protective layer 18 can comprise a non-conductive material. The non-conductive material is preferably an inorganic material or a dielectric material. The inorganic material can comprise silica gel. The dielectric material comprises electrically insulating materials such as aluminum oxide, silicon nitride, silicon oxide, titanium oxide, or magnesium fluoride. For example, the protective layer 18 can be silicon dioxide, silicon nitride, titanium oxide, tantalum oxide, niobium oxide, barium titanate, or a combination thereof, which can be a Bragg reflector (DBR) formed by a stack of two different refractive index materials. As an example, in the present embodiment, the material of the protective layer 18 is selected to be SiO2. The protective layer 18 has different functions according to the designed position. In the light emitting diode structure described in the present embodiment, the protective layer 18 protects the surface of the light emitting diode on one hand, and acts as a current blocking layer on the other hand, for inhibiting current over-injection under the electrode, increasing current diffusion of the transparent conductive layer 16, and taking into account both requirements, the thickness d of the protective layer 18 is preferably λ / 4n x (2k-1), where λ is the light emitting wavelength of the light emitting layer 124, n is the refractive index of the protective layer 18, and k is a natural number greater than or equal to 1, and the preferred value of k is 2-3, and the corresponding thickness is preferably 150-500 nm. When the thickness of the protective layer 18 is too small, it is not conducive to play the role of the current blocking layer and the protection function, and when the thickness is too large, the material itself will additionally increase the light loss due to absorption.

[0086] Please refer to Figure 3 , Figure 3 for Figure 2A partial enlarged view of the block area of FIG. 1, showing a partial enlarged view of the second electrode 22, the transparent conductive layer 16 forms a third opening 33 at the position corresponding to the second electrode pad portion 221, the protective layer 18 forms a first opening 31 at the position corresponding to the second electrode pad portion 221, the protective layer 18 covers the inner sidewall of the third opening 33, the diameter of the first opening 31 is preferably smaller than the diameter of the third opening 33, thereby further improving the brightness of the light emitting diode. Specifically, the first opening 31 is annular, the inner diameter of the first opening 31 is defined as d1', the outer diameter of the first opening 31 is defined as d1, the diameter of the second electrode pad portion 221 is defined as d2, and the diameter of the third opening 33 is defined as d3, and the relationship between the four is preferably d2>d3>d1>d1'. Thus, the upper surface of the second electrode pad portion 221 is stepped. It should be noted that in other embodiments, the diameter of the first opening 31 can also be greater than the diameter of the third opening 33. In this design, the adhesion between the electrode and the epitaxial layer can be effectively increased, and the risk of electrode and adhesive interface falling off during wire bonding can be reduced. Similarly, in the present embodiment, the outer diameter and the inner diameter of the first opening 31 are preferably both smaller than the diameter of the third opening 33, thereby further improving the brightness of the light emitting diode. However, in other embodiments, the outer diameter of the first opening 31 can be greater than the diameter of the third opening 33, and the inner diameter of the first opening 31 can be smaller than the diameter of the third opening 33. Similarly, the adhesion between the electrode and the epitaxial layer can be effectively increased, and the wire bonding ability of the electrode can be improved.

[0087] More preferably, the first opening 31 under the second electrode pad portion 221 can have at least one tentacle 310 extending away from the pad portion 221. The number of tentacles 310 is 1-20. At the position of the tentacle 310, the second electrode pad portion 221 is in contact with both the second semiconductor layer 125 and the transparent conductive layer 16. Through the tentacle 310, the second electrode pad portion 221 can be in contact with the transparent conductive layer 16, which can increase the contact area between the second electrode pad portion 221 and the transparent conductive layer 16, which is beneficial to the diffusion of current, thereby further relieving the current congestion effect on the second electrode, reducing the risk of metal precipitation and electrode burning.

[0088] In the present embodiment, the protective layer 18 of the light emitting diode protects the light emitting diode from being damaged on one hand, and can be directly used as a current blocking layer on the other hand, for inhibiting current over-injection below the electrode and increasing current diffusion of the transparent conductive layer 16; the second electrode 22 is directly in contact with the semiconductor layer in the pad area, effectively increasing the adhesion between the electrode and the epitaxial layer, and can reduce the risk of the electrode and the adhesion interface falling off during wire bonding; the second electrode pad part 221 adopts a design of multiple steps, which can effectively buffer the wire bonding impact force and reduce the impact and damage of the wire bonding process on the pad part; the second electrode extension part 222 is located on the protective layer 18 and is in contact with the transparent conductive layer 16 by being punched on the protective layer 18, so that the electrode extension part forms a step shape with upper and lower undulations, increases the angle of light emission at the electrode extension part, and improves the light extraction efficiency; at the same time, since the electrode extension part has high and low step undulations, the contact area of the electrode and other objects can be reduced, the damage of the electrode extension part in the later processes such as reverse film, transportation and transfer can be effectively reduced, and the contamination of the electrode extension part can be reduced.

[0089] In the present application, the protective layer 18 forms a series of second openings 32 under the second electrode extension part 222, the second openings 32 are arranged in sequence along the extension direction of the second electrode pad part 221, that is, along the direction from the first end 2221 of the second electrode extension part to the second end 2222 of the second electrode extension part, the second openings 32 have intervals between them, the second openings 32 and the intervals are arranged alternately along the extension direction of the second electrode pad part 221, the number of the second openings 32 and the intervals is 1-25. In the present embodiment, the intervals between the second openings 32 are of the same size, and the second openings 32 include a plurality of first opening parts 321 of the same size and at least one second opening part 322, the second opening part 322 is formed at the end 2220 of the second electrode extension part away from the second electrode pad part 221, that is, the second opening part 322 is formed under the second end 2222 of the second electrode extension part, wherein the size of the second opening part 322 is larger than that of the first opening part 321. The present application differentiates the size of the second openings 32 of the protective layer 18 on the second electrode extension part 222, specifically, increases the size of the second opening part 322 at the end 2220 of the second electrode extension part away from the second electrode pad part 221, on the one hand, since the end of the extension electrode is often a high current density area, by arranging the largest second opening part 322 under the second end 2222 of the second electrode extension part, the ESD explosion point caused by excessive concentration of electric charge at the end of the extension electrode can be avoided, thereby improving the anti-static impact capability of the chip, and further ensuring the reliability of the light emitting diode; on the other hand, the current at the end of the extension electrode can be diffused as evenly as possible to all directions through the large-size second opening part 322, avoiding direct injection of current at the end of the extension electrode, promoting the lateral expansion of the current, and at the same time improving the overall current uniformity of the light emitting diode, thereby improving the reliability and light emitting efficiency of the light emitting diode chip. For details, please refer to Figure 6 , Figure 6 The current flow path schematic diagram of the light emitting diode provided by the present application is shown in the figure Figure 6 (a) is the known four-process technology of mesa etching (MESA), transparent conductive layer (such as ITO), protective layer and electrode mentioned in the background technology, it can be seen that at the second end 2222 of the second electrode extension part / the end 2220 of the second electrode extension part, the current is easy to concentrate too much, thereby generating an ESD explosion point; Figure 6(b) The current flow path schematic of the light emitting diode provided by the present application, by increasing the size of the second opening part 322 at the end of the second electrode extension part 2220 away from the second electrode pad part 221, the current can be made to spread as evenly as possible to all directions through the large size second opening part 322 at the end of the extension electrode, and further improve the reliability and light emitting efficiency of the light emitting diode chip. In addition, the protective layer 18 is formed on the transparent conductive layer 16 first, and then the second electrode 22 is formed, which can reduce the probability of oxidation of the active metal in the electrode structure during the manufacturing process of the protective layer 18. It should be noted that in the present application, the second opening part 322 can also be more than one, for example, the second opening part 322 is two or more, and the size of any one second opening part 322 is larger than the size of any first opening part 321, which can be selected and used according to the specific actual needs, and the present application is not limited to this. For example, when the size of the second opening part 322 is less than 10 times the size of the first opening part 321, it is preferred that the second opening part 322 is one; when the size of the second opening part 322 is more than 10 times the size of the first opening part 321, it is preferred that the second opening part 322 is two or more.

[0090] In the present application, the size of the second opening part 322 is at least 2 times the size of the first opening part 321; preferably, the size of the second opening part 332 is 2-20 times the size of the first opening part 321; more preferably, the size of the second opening part 332 is 2-15 times the size of the first opening part 321; further, the size of the second opening part 332 is 4-12 times the size of the first opening part 321, and optionally, the size of the second opening part 322 is at least 5 times, 8 times, 10 times, 12 times, 14 times, etc. the size of the first opening part 321. By limiting the size of the second opening part 322 to the size of the first opening part 321, the current can be made to spread more effectively and evenly to all directions through the large size second opening part 322, avoiding the ESD explosion point caused by the charge concentration phenomenon, and further improving the overall current uniformity of the light emitting diode, and further improving the reliability and light emitting efficiency of the light emitting diode chip.

[0091] Please continue to read Figure 1The second opening 322 and the second electrode extension 222 have an overlapping portion. The length of the overlapping portion accounts for 2% to 40% of the length of the second electrode extension 222, or the area of ​​the overlapping portion accounts for 2% to 40% of the area of ​​the second electrode extension 222. Preferably, this percentage is 5% to 25%, more preferably, it is 10% to 20%. Optionally, the length percentage or area percentage of the overlapping portion can be, for example, 12%, 14%, 16%, 18%, etc. By adjusting the length or area percentage of the overlapping portion between the second opening 322 and the second electrode extension 222, the current is further promoted to diffuse more effectively and uniformly to the surroundings through the large-sized second opening 322, thereby improving the overall current uniformity on the second electrode 22 and further improving the luminous efficiency of the light-emitting diode chip. It should be noted that the second electrode extension 222 does not consist of a simple straight section. For example, in this embodiment, the second electrode extension 222 includes a first curved section 222-1, a straight section 222-2, and a second curved section 222-3. One end of the first curved section 222-1 is connected to the second electrode pad section 221, and the other end is connected to the straight section 222-2. One end of the straight section 222-2 is connected to the first curved section 222-1, and the other end is connected to the second curved section 222-3. One end of the second curved section 222-3 is connected to the straight section 222-2, and the other end gradually curves away from the first electrode 21. More specifically, the first curved section 222-1 includes an extension 222-1-0, one end of which is connected to the electrode pad section, and the other end is connected to the straight section 222-2. The second curved section 222-3 includes a circular end portion 222-3-0. The length and area of ​​the second electrode extension 222 mentioned above include the length and area of ​​the entire section from the extension 222-1-0 to the near-circular end 222-3-0.

[0092] The method for manufacturing the light-emitting diode of the present invention mainly includes four processes: mesa etching (MESA), fabrication of a transparent conductive layer 16, fabrication of a protective layer 18, and fabrication of electrodes. Figure 5 The five processes involve corresponding photomask patterns, which are briefly explained below.

[0093] First, a semiconductor stack 12 is provided, which generally includes a substrate 10, a first semiconductor layer 123, a light-emitting layer 124, and a second semiconductor layer 125.

[0094] Next, refer to Figure 5 The pattern shown in (a) defines a first electrode region and a second electrode region on the surface of the semiconductor stack 12, removes the void region, and forms the mesa of the first electrode 21 and a series of through holes 40.

[0095] Next, refer to Figure 5The pattern shown in (b) involves fabricating a transparent conductive layer 16 on the second semiconductor layer 125 of the semiconductor stack 12, etching away the mesa region, forming an opening 33 in the pad region of the second electrode region, and forming an opening 36 at the position corresponding to the via 40.

[0096] Next, refer to Figure 5 As shown in (c), a protective layer 18 is formed on the transparent conductive layer 16. This protective layer 18 simultaneously covers the sidewalls of the via 40, the sidewalls between the transparent conductive layer 16 and the mesa, and the surface of the mesa. An opening 31 is formed in the pad area of ​​the second electrode region, an opening 32 is formed in the extension area of ​​the second electrode region, an opening 34 is formed on the mesa, and an opening 35 is formed in the extension area of ​​the first electrode. The opening 35 is formed within the via 40, and the size of the opening 35 is smaller than the size of the via 40. Preferably, the opening 31 is an annular structure, and the inner diameter d1' and the outer diameter d1 of the annulus are both smaller than the diameter d3 of the opening 33. Preferably, the opening 32 includes multiple first openings 321 of the same size and a second opening 322. The second opening 322 is disposed below the second end 2222 of the second electrode extension, and the size of the second opening 322 is larger than the size of the first openings 321.

[0097] Next, refer to Figure 5 The pattern shown in (d) depicts a first electrode 21 and a second electrode 22 fabricated on a protective layer 18. The second electrode pad 221 contacts the second semiconductor layer 125 through a first opening 31, and the second electrode pad 221 contacts both the second semiconductor layer 125 and the protective layer 18. The second electrode extension 222 contacts the transparent conductive layer 16 through a second opening 32. The first electrode pad 211 is located above the first semiconductor layer 123, and the first electrode pad 211 contacts the first semiconductor layer 123 through a fourth opening 34. The first electrode pad 221 contacts both the first semiconductor layer 123 and the protective layer 18. The first electrode extension 212 is located above the second semiconductor layer 125, and the first electrode extension 212 contacts the first semiconductor layer 123 through a fifth opening 35 and a through-hole 40.

[0098] It should be noted that the shape and size of openings 31 and 34 are not limited to those described above. They can also be formed into non-annular structures. For example, in some embodiments, there is no protective layer 18 below the center of the electrode pad, and it is in direct contact with the semiconductor stack 12. In other embodiments, openings 31 and 34 can be designed as a series of tentacle structures distributed around the pad area, exposing the transparent conductive layer 16. The pad area does not form an opening structure. In this case, the electrode pad is completely formed on the protective layer 18 and can be connected to the tentacle structure through metal leads. Example 2

[0099] Please seeFigure 7 、 Figure 8 , Figure 7 is a top view schematic diagram of a light emitting diode provided by the second embodiment of the present application, Figure 8 is a cross-sectional structure schematic diagram along the A-A' line of Figure 7 Compared with the light emitting diode of the first embodiment of the present application, the difference of the light emitting diode of the second embodiment mainly lies in that in the present embodiment, the sizes of the second openings 32 of the several protective layers 18 gradually increase along the extension direction gradually away from the second electrode pad part 221. Specifically, the size of the second opening 32 is the smallest near the second electrode pad part 221, and the size of the opening 32 becomes larger and larger away from the second electrode pad part 221, and the size of the second opening 32 at the second end 2222 of the second electrode extension part is the largest. Since the current density gradually increases along the extension direction gradually away from the second electrode pad part 221, in some preferred embodiments, by the design that the sizes of the second openings 32 gradually increase along the extension direction of the electrode extension part, the ESD explosion point due to too much concentration of charges can be prevented in the area with high current density, for example, near the end of the extension electrode; at the same time, the current congestion effect on the second electrode can be alleviated, the overall current uniformity of the light emitting diode is improved, and the reliability and light emitting efficiency of the light emitting diode chip are further improved. Embodiment 3

[0100] Please refer to Figure 9 、 Figure 10 , Figure 9 is a top view schematic diagram of a light emitting diode provided by the third embodiment of the present application, Figure 10 is a cross-sectional structure schematic diagram along the A-A' line of Figure 9 Compared with the light emitting diode of the first embodiment of the present application, the difference of the light emitting diode of the third embodiment mainly lies in that the protective layer 18 has several second openings 32, and the sizes of the intervals between the second openings 32 gradually decrease along the extension direction gradually away from the second electrode pad part 221. Specifically, the size of the interval between the second openings 32 is the largest near the second electrode pad part 221, and the size of the interval becomes smaller and smaller away from the second electrode pad part 221, and the size of the interval between the second openings 32 at the second end 2222 of the second electrode extension part is the smallest. By the design that the sizes of the intervals between the second openings 32 gradually decrease along the extension direction of the second electrode extension part 222, the ESD explosion point due to too much concentration of charges can also be prevented in the area with high current density; at the same time, the overall current uniformity of the light emitting diode can be improved, and the reliability and light emitting efficiency of the light emitting diode chip are further improved.

[0101] Further, in some variant embodiments, the first openings 321 have a first interval therebetween, the first openings 321 and the second openings 322 have a second interval therebetween, the first intervals have the same size, and the second intervals can have a size larger than that of the first intervals. This further facilitates the current to be more effectively diffused uniformly in all directions at the end of the extension electrode through the second openings 322 of large size. In some variant embodiments, the size of the first intervals gradually decreases in sequence along the extension direction away from the second electrode pad portion 221, and the size of the second intervals can be larger than that of some or all of the first intervals. Embodiment 4

[0102] Please refer to Figures 11 to 18 , Figure 11 a top view schematic diagram of a light emitting diode provided for Embodiment 4 of the present application, Figure 13 , Figure 15 , Figure 17 top view schematic diagrams of several other light emitting diodes provided for Embodiment 4 of the present application, Figure 12 , Figure 14 , Figure 16 , Figure 18 are respectively along Figure 11 , Figure 13 , Figure 15 , Figure 17A-A' line profile structure diagram. Compared with the first embodiment of the application, the difference between the fourth embodiment of the light emitting diode mainly lies in that the light emitting diode further comprises an insulating layer 14 formed on the second semiconductor layer 125, sandwiched between the second semiconductor layer 125 and the transparent conductive layer 16, the transparent conductive layer 16 covers the insulating layer 14, and the insulating layer 14 is only formed under the second end 2222 of the second electrode extension part corresponding to the second opening part 322, wherein the second end 2222 of the second electrode extension part is located away from one end of the second electrode pad part 221. In a more preferred embodiment, the insulating layer 14 is only provided under the end 2220 of the second electrode extension part. Specifically, the second end 2222 of the second electrode extension part has the transparent conductive layer 16, the insulating layer 14, and the second semiconductor layer 125 in sequence from top to bottom, and the other regions of the second electrode extension part 222 have the protective layer 18, the transparent conductive layer 16, and the second semiconductor layer 125 in sequence from top to bottom. The upper surface of the second electrode extension part 222 formed in this way is stepped. The light emitting diode described in this embodiment is designed with the insulating layer 14 corresponding to the second opening part 322, that is, the insulating layer 14 is only formed as a current blocking layer under the second end 2222 of the second electrode extension part away from the second electrode pad part 221. On the one hand, the design of the insulating layer 14 can avoid direct injection of current, further ensuring the reliability of the light emitting diode, on the other hand, the design can further promote the current to diffuse uniformly around the end of the extension electrode, thereby improving the light emitting efficiency of the light emitting diode chip; in addition, by setting only a small amount of necessary insulating layer, the chip voltage rise caused by the excessive area of the current blocking layer can be avoided. Further, the four-layer structure of the insulating layer 14, the transparent conductive layer 16, the protective layer 18, and the second electrode extension part 222 can form a full-angle reflector, thereby improving the reflection ability of the electrode extension area and reducing the light absorption efficiency. The insulating layer 14 is an insulating material, which can be an oxide, and can be a relatively transparent material, such as one or a combination of materials such as silicon oxide, titanium oxide, silicon nitride, aluminum oxide, magnesium fluoride, spin-on glass (SOG), polymer, etc., and the application is not limited to the examples listed here. The materials of the insulating layer 14 and the protective layer 18 are preferably low-refractive insulating materials, preferably with a refractive index of 1.5 or less, which can be the same or different. As an example, in this embodiment, the material of the insulating layer 14 is selected as SiO2. Preferably, the thickness of the insulating layer 14 is between 50-500 nm.

[0103] In the present application, the width of the insulating layer 14 is preferably greater than or equal to the width of the second opening part 322, so as to strengthen the diffusion of the current at the end of the extension electrode to the periphery, further improving the overall current uniformity of the light emitting diode. It should be noted that in other embodiments, the area of the insulating layer 14 can also be smaller than the area of the second opening part 322, and can be selected and used according to the actual needs, and the present application is not limited thereto. The ratio of the area of the insulating layer 14 to the area of the second opening part 322 is in the range of 10% to 200%. Preferably, the ratio is 40% to 150%, and more preferably, the ratio is 50% to 120%, for example, it can be 50%, 70%, 90%, 110%, etc. Please continue to refer to Figure 11 , Figure 12 In the present embodiment, the width of the insulating layer 14 is greater than the width of the second opening part 322, and the area of the insulating layer 14 is greater than the area of the second opening part 322. In some variant embodiments, please refer to Figure 13 , Figure 14 In this embodiment, the width of the insulating layer 14 is greater than the width of the second opening part 322, and the area of the insulating layer 14 is smaller than the area of the second opening part 322. In some variant embodiments, please refer to Figure 15 , Figure 16 In this embodiment, the width of the insulating layer 14 is equal to the width of the second opening part 322, and the area of the insulating layer 14 is equal to the area of the second opening part 322. Through the cooperation design of the insulating layer 14 at the end of the extension electrode and the large-size second opening part 322, the reliability and light emitting efficiency of the light emitting diode chip are further improved, and at the same time, the voltage rise caused by the excessive area of the current blocking layer can also be avoided.

[0104] In some embodiments, please refer to Figure 17 , Figure 18The insulating layer 14 is distributed in blocks, and is composed of a series of discrete block structures with gaps between the block structures, so that the current at the end of the extension electrode not only diffuses to the periphery, but also diffuses through the gaps between the blocks, so that the current at the end of the extension electrode diffuses more uniformly, further improving the overall current uniformity of the light-emitting diode. The areas of the block structures can be equal, and in some preferred embodiments, the areas of the block structures can also be unequal (not shown in the figure). Specifically, when the insulating layer 14 is composed of a series of block structures with unequal areas, the area of the block structure is the largest at the position close to the second end 2222 of the second electrode extension part, and the area becomes smaller and smaller as it moves away from the second end 2222 of the second electrode extension part, and the area of the block structure farthest from the second end 2222 of the second electrode extension part is the smallest. In this way, it can be prevented that ESD explosion points occur due to excessive concentration of charges at a position close to the end of the extension electrode where the current density is high; at the same time, the current congestion effect on the second electrode can be alleviated, the overall current uniformity of the light-emitting diode is improved, and the reliability and luminous efficiency of the light-emitting diode chip are further improved.

[0105] The application also provides a light-emitting device using the light-emitting diode according to any one of the above embodiments, which can effectively improve the performance of the light-emitting device.

[0106] In summary, the light-emitting diode provided by the application improves the reliability of the chip by designing the size of the second opening of the second electrode extension part farthest from the second electrode pad part to be larger.

[0107] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the application, and not to limit them; although the application has been described in detail with reference to the above embodiments, those skilled in the art should understand that: it can still modify the technical solutions recorded in the above embodiments, or make equivalent replacement to part or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the application.

Claims

1. A light-emitting diode, characterized in that, The light-emitting diode includes: The semiconductor stack comprises, from bottom to top, a first semiconductor layer, a light-emitting layer, and a second semiconductor layer stacked sequentially. A transparent conductive layer is formed on the second semiconductor layer; A protective layer is formed on top of the transparent conductive layer; The second electrode is formed on the protective layer and includes a pad portion and an extension portion; The protective layer forms a first opening and a second opening in the pad portion and the extended portion of the second electrode, respectively, exposing a portion of the upper surface of the second semiconductor layer located in the pad portion of the second electrode and a portion of the upper surface of the transparent conductive layer located in the extended portion of the second electrode. The second electrode forms an electrical connection with the second semiconductor layer through the first opening and the second opening. The feature is that the second opening of the protective layer includes a plurality of first openings and at least one second opening, the second opening being formed at the end away from the second electrode pad, and the size of the second opening being larger than the size of the first opening.

2. The light-emitting diode according to claim 1, characterized in that: The second electrode extension has a first end connected to the second electrode pad and a second end away from the second electrode pad, and the second opening is formed below the second end of the second electrode extension.

3. The light-emitting diode according to claim 1, characterized in that: The dimensions of several of the first openings are all the same.

4. The light-emitting diode according to claim 1, characterized in that: The dimensions of several of the first openings increase sequentially along the extension direction that gradually moves away from the second electrode pad.

5. The light-emitting diode according to claim 1, characterized in that: The size of the second opening is at least twice the size of the first opening.

6. The light-emitting diode according to claim 1, characterized in that: The size of the second opening is a multiple of the size of the first opening, ranging from 2 to 20 times.

7. The light-emitting diode according to claim 1, characterized in that: The second openings are spaced apart, and the spacers are of the same size.

8. The light-emitting diode according to claim 1, characterized in that: The second openings are spaced apart, and the size of the spaced apart decreases sequentially along the direction of extension that gradually moves away from the second electrode pad portion.

9. The light-emitting diode according to claim 1, characterized in that: The second opening and the second electrode extension have an overlapping portion, the length of which is 2% to 40% of the length of the second electrode extension.

10. The light-emitting diode according to claim 1, characterized in that: The second opening and the second electrode extension have an overlapping portion, the area of ​​which is 2% to 40% of the area of ​​the second electrode extension.

11. The light-emitting diode according to claim 1, characterized in that: The light-emitting diode further includes an insulating layer formed on the second semiconductor layer and disposed corresponding to the second opening, and the transparent conductive layer covers the insulating layer.

12. The light-emitting diode according to claim 11, characterized in that: The width of the insulating layer is greater than or equal to the width of the second opening.

13. The light-emitting diode according to claim 11, characterized in that: The ratio of the area of ​​the insulating layer to the area of ​​the second opening is in the range of 10% to 200%.

14. The light-emitting diode according to claim 1, characterized in that: The transparent conductive layer forms a third opening in the pad portion of the second electrode, exposing a portion of the upper surface of the second semiconductor layer located in the pad portion of the second electrode. The size of the third opening is smaller than the size of the pad portion of the second electrode.

15. The light-emitting diode according to claim 14, characterized in that: The size of the first opening is smaller than the size of the third opening, the pad portion of the second electrode is in contact with the second semiconductor layer, and the extension portion of the second electrode is in contact with the transparent conductive layer.

16. The light-emitting diode according to claim 14, characterized in that: The first opening is a ring-shaped structure, and the inner and outer diameters of the ring-shaped structure are both smaller than the diameter of the third opening.

17. The light-emitting diode according to claim 14, characterized in that: The protective layer also includes at least one tentacles extending from the first opening to the periphery of the second electrode pad portion, exposing a portion of the upper surface of the transparent conductive layer, at the location of the tentacles, where the pad portion of the second electrode is in contact with both the second semiconductor layer and the transparent conductive layer.

18. The light-emitting diode according to claim 1, characterized in that: The light-emitting diode further includes a first electrode, which includes a pad portion and an extension portion. The pad portion of the first electrode is located on the first semiconductor layer, and the extension portion of the first electrode is located on the second semiconductor layer. The extension portion of the first electrode forms an ohmic contact with the first semiconductor layer through a series of through holes penetrating the second semiconductor layer and the light-emitting layer. The protective layer is provided between the extension portion of the first electrode and the second semiconductor layer.

19. A light-emitting device, characterized in that: The light-emitting diode used is any one of claims 1-18.

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