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, comprising a first semiconductor layer, a light emitting layer and a second semiconductor layer which are sequentially stacked from bottom to top; an insulating layer formed on the second semiconductor layer; a transparent conductive layer formed on the second semiconductor layer and covering the insulating layer; a protective layer formed on the transparent conductive layer and having an opening exposing part of the upper surface of the transparent conductive layer; a second electrode formed on the protective layer, comprising a pad part and an extension part, and electrically connected with the transparent conductive layer through the opening of the protective layer; 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 insulating layer is only formed under the second end of the second electrode extension part. By arranging the insulating layer only at the end away from the second electrode pad part, the voltage rise is avoided while the reliability and light emitting efficiency of the chip are improved.

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. The core of the LED 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 and the majority carriers recombine to emit light. The LED has the advantages of high light intensity, high efficiency, small size, long service life, etc. and is considered as one of the most potential light sources.

[0003] The known gallium nitride LED chip manufacturing process currently includes four processes of mesa etching (MESA), making a transparent conductive layer (such as ITO), making a protective layer, and making an electrode, or five processes of mesa etching (MESA), making an insulating layer, making a transparent conductive layer (such as ITO), making a protective layer, and making an electrode. In the LED industry, in order to achieve effective current expansion, multiple expansion electrodes are generally designed. In the existing four processes, the charges are easy to concentrate near the end of the expansion electrode, which leads to the ESD explosion point and burnout in this area, and thus causes chip failure and dead light. In the existing five processes, an insulating layer is added as a current blocking layer, and the insulating layer is set corresponding to the expansion electrode and is designed to be expanded outward. However, the area of the current blocking layer is too large, which often leads to an increase in voltage. Therefore, how to further optimize the design of the current blocking layer to improve the overall performance of the light emitting diode chip is a technical problem 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 and light emitting efficiency of the chip while avoiding an increase in chip voltage.

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

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

[0007] an insulating layer formed on the second semiconductor layer;

[0008] a transparent conductive layer formed on the second semiconductor layer and covering the insulating layer;

[0009] A protective layer is formed on the transparent conductive layer and has an opening to expose part of the upper surface of the transparent conductive layer;

[0010] A second electrode is formed on the protective layer and includes a pad portion and an extension portion, and forms an electrical connection with the transparent conductive layer through the opening of the protective layer;

[0011] In particular, the extension portion of the second electrode has a first end connected to the pad portion of the second electrode and a second end away from the pad portion of the second electrode, and the insulating layer is only formed under the second end of the extension portion of the second electrode.

[0012] According to another embodiment of the present application, a light emitting device is 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 caused by the excessive concentration of charges at the end of the extension electrode, improve the anti-static impact capability of the chip, and ensure the reliability of the light emitting diode.

[0014] Other features and advantages of the present application will be described in the following description and become apparent from the description, or can be learned by practice of the present application. BRIEF DESCRIPTION OF DRAWINGS

[0015] 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.

[0016] Figure 1 A top view of the light emitting diode provided by the first embodiment of the present application;

[0017] Figure 2 A cross-sectional structure schematic view along the A-A' line of the light emitting diode provided by the first embodiment of the present application; Figure 1

[0018] Figure 3 A partial enlarged schematic view of the block region of the light emitting diode provided by the first embodiment of the present application; Figure 2

[0019] Figure 4 A partial enlarged schematic view of the block region of the light emitting diode provided by the first embodiment of the present application; Figure 1 ​​a cross-sectional structure schematic view along B-B' line of

[0020] Figure 5 a mask pattern for manufacturing the light emitting diode provided by the present application;

[0021] Figure 6 a current flow path schematic view of the light emitting diode provided by the present application;

[0022] Figure 7 a top view schematic view of another light emitting diode provided by the first embodiment of the present application;

[0023] Figure 8 a cross-sectional structure schematic view along A-A' line of Figure 7

[0024] Figure 9 a top view schematic view of still another light emitting diode provided by the first embodiment of the present application;

[0025] Figure 10 a cross-sectional structure schematic view along A-A' line of Figure 9

[0026] Figure 11 a top view schematic view of yet another light emitting diode provided by the first embodiment of the present application;

[0027] Figure 12 a cross-sectional structure schematic view along A-A' line of Figure 11

[0028] Figure 13 a top view schematic view of the light emitting diode provided by the second embodiment of the present application;

[0029] Figure 14 a cross-sectional structure schematic view along A-A' line of Figure 13

[0030] Figure 15 a top view schematic view of the light emitting diode provided by the third embodiment of the present application;

[0031] Figure 16 a cross-sectional structure schematic view along A-A' line of Figure 15

[0032] Figure 17 a top view schematic view of the light emitting diode provided by the fourth embodiment of the present application;

[0033] Figure 18 a cross-sectional structure schematic view along A-A' line of Figure 17

[0034] Figure 19 a top view schematic view of the light emitting diode provided by the fifth embodiment of the present application;​​​​​​

[0035] Figure 20 Another top view schematic diagram of a light emitting diode is provided for the fifth embodiment of the present application.

[0036] Reference signs:

[0037] 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 - pad portion of first electrode; 212 - extension portion of first electrode; 22 - second electrode; 221 - pad portion of second electrode; 222 - extension portion of second electrode; 2221 - first end of extension portion of second electrode; 2222 - second end of extension portion of second electrode; 2220 - terminal end of extension portion of second electrode; 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

[0038] In order to make the objectives, 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.

[0039] The present application provides a light emitting diode, comprising:

[0040] a semiconductor stack comprising, from bottom to top, a first semiconductor layer, a light emitting layer and a second semiconductor layer which are sequentially stacked;

[0041] an insulating layer formed on the second semiconductor layer;

[0042] a transparent conductive layer formed on the second semiconductor layer and covering the insulating layer;

[0043] a protective layer formed on the transparent conductive layer and having an upper surface with an opening exposing a portion of the transparent conductive layer;

[0044] a second electrode formed on the protective layer, comprising a pad portion and an extension portion, and electrically connected to the transparent conductive layer through the opening of the protective layer;

[0045] characterized in that the extension portion of the second electrode has a first end connected to the pad portion of the second electrode and a second end away from the pad portion of the second electrode, and the insulating layer is only formed under the second end of the extension portion of the second electrode.

[0046] The application can avoid the ESD explosion point caused by the excessive concentration of electric charges at the end of the extended electrode, thereby improving the anti-static impact capability of the chip and ensuring the reliability of the light emitting diode; secondly, the current can be prevented from being directly injected at the end of the extended electrode, so that the current at the end of the extended electrode can be diffused as evenly as possible in all directions, thereby promoting the lateral expansion of the current and improving the overall current uniformity of the light emitting diode, and further improving the light emitting efficiency of the light emitting diode chip; in addition, the unnecessary current blocking layer under the extended electrode can be cancelled, thereby effectively reducing the area of the current blocking layer and avoiding the voltage rise of the chip.

[0047] In an embodiment, the insulating layer has an overlapping portion with the extended portion of the second electrode, and the length of the overlapping portion accounts for 1% to 50% of the length of the extended portion of the second electrode.

[0048] In an embodiment, the insulating layer has an overlapping portion with the extended portion of the second electrode, and the area of the overlapping portion accounts for 1% to 50% of the area of the extended portion of the second electrode.

[0049] By controlling the size of the current blocking layer under the extended electrode through the length or area ratio of the overlapping portion of the insulating layer and the extended portion of the second electrode, the voltage rise caused by the excessive area of the current blocking layer can be avoided.

[0050] In an embodiment, the insulating layer has a width difference with the extended portion of the second electrode directly above it, and the width difference gradually increases in the direction from the first end of the extended portion of the second electrode to the second end of the extended portion of the second electrode. Through the gradual change of the width difference, the phenomenon of excessive concentration of electric charges at the second end of the extended portion of the second electrode away from the pad portion of the second electrode under static impact can be further improved, and the current congestion near the second end due to the position offset of the insulating layer can also be avoided, thereby further improving the anti-static impact performance of the chip and the overall reliability of the electrode structure.

[0051] In an embodiment, the insulating layer is composed of a series of block structures. By setting the insulating layer as a series of block structures, the current can be diffused more evenly at the end of the extended electrode, thereby further improving the overall current uniformity of the light emitting diode.

[0052] In an embodiment, the protective layer forms a first opening and a second opening respectively at the pad portion and the extended portion of the second electrode, thereby 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 extended portion of the second electrode.

[0053] In an embodiment, the transparent conductive layer forms a third opening in the pad portion of the second electrode, exposing a part of the upper surface of the second semiconductor layer in the pad portion of the second electrode, and the third opening has a size smaller than that of the pad portion of the second electrode.

[0054] In an embodiment, the first opening has a size smaller than that of the third opening, the pad portion of the second electrode is in contact with the second semiconductor layer, and the extended portion of the second electrode is in contact with the transparent conductive layer.

[0055] With 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 extended portion of the second electrode can form an electrical connection with the second semiconductor layer through the second opening of the protective layer and the transparent conductive layer. Meanwhile, by arranging the first opening to have a size smaller than that of the third opening, the brightness of the light-emitting diode is further improved.

[0056] In an embodiment, the first opening has 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.

[0057] 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 a 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 both the second semiconductor layer and the transparent conductive layer. With 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, further alleviating the current congestion effect on the second electrode, and reducing the risk of metal precipitation and electrode burnout.

[0058] In an embodiment, the protective layer has a plurality of second openings, and the second openings are arranged in sequence along the extension direction gradually away from the pad portion of the second electrode.

[0059] In an embodiment, the plurality of second openings have the same size.

[0060] In an embodiment, the sizes of the second openings gradually increase along the extension direction of the pad portion of the second electrode. In the present application, the sizes of the second openings can be the same or different. Since the current density gradually increases along the extension direction of the extension portion of the second electrode, in some preferred embodiments, the design that the sizes of the second openings gradually increase along the extension direction of the extension portion of the second electrode can prevent ESD breakdown points from occurring due to excessive concentration of charges in areas with high current density, such as near the end of the extension electrode. At the same time, it can also alleviate the current congestion effect on the second electrode, improve the overall current uniformity of the light-emitting diode, and further improve the reliability and luminous efficiency of the light-emitting diode chip.

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

[0062] In an embodiment, the second openings have a spacing therebetween, and the sizes of the spacing gradually decrease along the extension direction of the pad portion of the second electrode. In the present application, the sizes of the spacing between the second openings can be the same or different. By designing the sizes of the spacing between the second openings to gradually decrease along the extension direction of the extension portion of the second electrode, ESD breakdown points can also be prevented from occurring due to excessive concentration of charges in areas with high current density. At the same time, it can also alleviate the current congestion effect on the second electrode, improve the overall current uniformity of the light-emitting diode, and further improve the reliability and luminous efficiency of the light-emitting diode chip.

[0063] In an embodiment, the second opening includes a plurality of first opening portions with the same size and at least one second opening portion. The second opening portion is arranged below the second end of the extension portion of the second electrode and corresponds to the insulating layer. The size of the second opening portion is greater than that of the first opening portion. Since the end of the extension electrode is often a high current density area, by arranging the second opening portion with the largest size below the second end of the extension portion of the second electrode, the current can be diffused as uniformly as possible to the surroundings through the large-size second opening portion at the end of the extension electrode, avoiding ESD breakdown points due to excessive concentration of charges at the end of the extension electrode. At the same time, it can also improve the overall current uniformity of the light-emitting diode, and further improve the reliability and luminous efficiency of the light-emitting diode chip.

[0064] In an embodiment, the width of the insulating layer is greater than or equal to the width of the second opening portion. Thus, the current can be diffused to the surroundings at the end of the extension electrode, further improving the overall current uniformity of the light-emitting diode.

[0065] In one embodiment, the ratio of the area of ​​the insulating layer to the area of ​​the second opening ranges from 10% to 200%. By combining the insulating layer located at the end of the extended electrode with the large-sized second opening, the reliability and luminous efficiency of the light-emitting diode chip are further improved, while also avoiding voltage rise caused by an excessively large current blocking layer area.

[0066] In one embodiment, 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 a first semiconductor layer, and the extension portion of the first electrode is located on a 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. A protective layer is provided between the extension portion of the first electrode and the second semiconductor layer.

[0067] 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.

[0068] 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

[0069] Please see Figures 1-4 , 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, an insulating layer 14, 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 extension portion 222 of the second electrode includes a first end 2221 connected to the pad portion 221 of the second electrode and a second end 2222 away from the pad portion 221 of the second electrode.

[0070] 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.

[0071] The semiconductor stack 12 is disposed on the upper surface of the substrate 10, and includes a first semiconductor layer 123, a light emitting layer 124, and a second semiconductor layer 125, which are sequentially stacked. The first semiconductor layer 123 is formed on the substrate 10, and can be a gallium nitride-based semiconductor layer doped with n-type impurities, such as Si, as a layer grown on the substrate 10. In some embodiments, a buffer layer can be further disposed between the first semiconductor layer 123 and the substrate 10. In other embodiments, the first semiconductor layer 123 can be joined to the substrate 10 through an adhesive layer.

[0072] The light emitting layer 124 is formed on the first semiconductor layer 123, and can be a quantum well (QW) structure. In some embodiments, the light emitting layer 124 can also be a multiple quantum well (MQW) structure including a plurality of quantum well layers (Wells) and a plurality of quantum barrier layers (Barriers) 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, a light emitting layer generating ultraviolet light, blue light, green light, yellow light, or the like can be provided.

[0073] The second semiconductor layer 125 is formed on the light emitting layer 124, and can be a gallium nitride-based semiconductor layer doped with p-type impurities, such as Mg. Although the first semiconductor layer 123 and the second semiconductor layer 125 can each be a single layer structure, the present disclosure 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 p-type impurities, the second semiconductor layer 125 can be doped with n-type impurities, 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.

[0074] 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, and the number of the through holes 40 is 1-15. The insulating layer 14 is formed on the second semiconductor layer 125 and distributed below the position of the extension part 222 of the second electrode; the transparent conductive layer 16 is formed on the second semiconductor layer 125 and covers the insulating layer 14, and forms the third opening 33 at the corresponding position of the pad part 221 of the second electrode to expose part of the upper surface of the second semiconductor layer 125 at the pad area of the second electrode, forms the sixth opening 36 at the corresponding position of the extension part 212 of the first electrode, and the size of the sixth opening 36 is larger than that of the through hole 40, and the transparent conductive layer 16 and the protective layer 18 are arranged between the extension part 212 of the first electrode and the second semiconductor layer 125 outside the through hole 40; the protective layer 18 is formed on the transparent conductive layer 16 and covers the upper surface of the mesa and the sidewall between the upper surface of the mesa and the upper surface of the second semiconductor layer 125, i.e. covers the surface of the entire device, and forms the first opening 31 and the second opening 32 at the corresponding positions of the pad part 221 of the second electrode and the extension part 222 of the second electrode to expose part of the upper surface of the second semiconductor layer 125 at the pad area of the second electrode and part of the upper surface of the transparent conductive layer 16 at the extension area of the second electrode, so that the pad part 221 of the second electrode is in contact with the second semiconductor layer 125 through the first opening 31, and the extension part 222 of the second electrode is in contact with the transparent conductive layer 16 through the second opening 32, the protective layer 18 forms the fourth opening 34 and the fifth opening 35 at the corresponding positions of the pad part 211 of the first electrode and the extension part 212 of the first electrode, the fifth opening 35 is formed in the through hole 40, and the size of the fifth opening 35 is smaller than that of the through hole 40, and the protective layer 18 covers 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 pad part 211 of the first electrode is formed on the mesa and is in contact with the first semiconductor layer 123 through the fourth opening 34, as shown in Figure 1 、 Figure 4 , the fourth opening 34 can be a ring-shaped opening, the extension part 212 of the first electrode 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 pad part 221 of the second electrode is in contact with the second semiconductor layer 125 through the first opening 31, and the extension part 222 of the second electrode is in contact with the transparent conductive layer 16 through the second opening 32, as shown in Figures 1-3 , the first opening 31 can be a ring-shaped opening.

[0075] 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 selected from the above 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.

[0076] The transparent conductive layer 16 can include 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.

[0077] The material of the protective layer 18 can include a non-conductive material. The non-conductive material is preferably an inorganic material or a dielectric material. The inorganic material can include silica gel. The dielectric material includes 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 repeating a stack of two materials with different refractive indices, for example. 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 the requirements of both, the thickness d 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 of 1 or more, 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.

[0078] Please refer to Figure 3 , Figure 3 for Figure 2The partial enlarged view of the block area of FIG. 1, the partial enlarged view of the second electrode 22, the third opening 33 of the transparent conductive layer 16 is formed at the position corresponding to the pad part 221 of the second electrode, the first opening 31 of the protective layer 18 is formed at the position corresponding to the pad part 221 of the second electrode, 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 structure, the inner circle diameter of the first opening 31 is defined as d1', the outer circle diameter of the first opening 31 is defined as d1, the diameter of the pad part 221 of the second electrode is defined as d2, the diameter of the third opening 33 is defined as d3, and the relationship among the four is preferably d2>d3>d1>d1'. Thus, the upper surface of the pad part 221 of the second electrode is stepped. It should be noted that in some 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 circle diameter and the inner circle 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 some other embodiments, the outer circle diameter of the first opening 31 can be greater than the diameter of the third opening 33, and the inner circle 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.

[0079] More preferably, the first opening 31 of the protective layer 18 located below the pad part 221 of the second electrode can have at least one tentacle 310 extending away from the pad part 221 of the second electrode. The number of tentacles 310 is 1-20. At the position of the tentacle 310, the pad part 221 of the second electrode is in contact with both the second semiconductor layer 125 and the transparent conductive layer 16. Through the tentacle 310, the pad part 221 of the second electrode can be in contact with the transparent conductive layer 16, which can increase the contact area between the pad part 221 of the second electrode and the transparent conductive layer 16, and is conducive to the diffusion of current, thereby further relieving the current congestion effect on the second electrode and reducing the risk of metal precipitation and electrode burning.

[0080] 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 under 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 pad part 221 of the second electrode adopts a design of multiple steps, which can effectively buffer the impact force of wire bonding and reduce the impact and damage of the wire bonding process on the pad part; the extension part 222 of the second electrode 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 film pouring, transportation and transfer can be effectively reduced, and the contamination of the electrode extension part can be reduced.

[0081] In the present application, the insulating layer 14 is distributed below the position of the extension part 222 of the second electrode, and the insulating layer 14 is only formed below the second end 2222 of the extension part of the second electrode, wherein the second end 2222 of the extension part of the second electrode is located away from the pad part 221 of the second electrode, and the insulating layer 14 is sandwiched between the semiconductor stack 12 and the transparent conductive layer 16. In a more preferred embodiment, the insulating layer 14 is only provided below the end 2220 of the extension part of the second electrode. The protective layer 18 forms a series of second openings 32 below the extension part 222 of the second electrode, and has second openings 32 corresponding to the insulating layer 14, that is, the protective layer 18 has at least one second opening 32 formed below the second end 2222 of the extension part of the second electrode. Specifically, the second end 2222 of the extension part of the second electrode has the transparent conductive layer 16, the insulating layer 14 and the second semiconductor layer 125 in sequence below, and the other regions of the extension part 222 of the second electrode have the partial protective layer 18, the transparent conductive layer 16 and the second semiconductor layer 125 in sequence below. The upper surface of the extension part 222 of the second electrode formed in this way is in a step shape. The light emitting diode described in the present embodiment can form the insulating layer 14 as a current blocking layer only below the second end 2222 of the extension part of the second electrode away from the pad part 221 of the second electrode, which can first avoid the occurrence of ESD explosion points at the end of the extension electrode due to excessive concentration of electric charges, thereby improving the anti-static impact capability of the chip and ensuring the reliability of the light emitting diode; secondly, it can avoid direct injection of current at the end of the extension electrode, so that the current at the end of the extension electrode diffuses as uniformly as possible in all directions, promotes the lateral expansion of the current, improves the overall current uniformity of the light emitting diode, and further improves the light emitting efficiency of the light emitting diode chip; 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 following figure: Figure 6 (a) in the above figure is the four-process technology of mesa etching (MESA), transparent conductive layer (e.g. ITO), protective layer and electrode mentioned in the background technology, and it can be seen that at the second end 2222 of the extension of the second electrode / the end 2220 of the extension of the second electrode, ESD explosion points are easily generated due to the excessive concentration of electric charges; Figure 6 (b) in the above figure is the current flow path schematic diagram of the light emitting diode provided by the present application, and by forming the insulating layer 14 below the second end 2222 of the extension of the second electrode / the end 2220 of the extension of the second electrode away from the pad part 221 of the second electrode, the current can be diffused to the periphery at the end of the extension electrode, so as to avoid the ESD explosion point phenomenon. In addition, by canceling the unnecessary current blocking layer arranged below the extension electrode, compared with the design that the insulating layer in the existing five-process technology mentioned in the background technology is arranged and expanded outside the extension electrode, the present application can effectively reduce the area of the current blocking layer and avoid the voltage rise of the chip. In addition, the protective layer 18 is formed on the transparent conductive layer 16 first, and then the second electrode 22 is formed, so as to reduce the probability that the active metal in the electrode structure is oxidized in the manufacturing process of the protective layer 18. Further, the four-layer structure of the insulating layer 14, the transparent conductive layer 16, the protective layer 18 and the extension part 222 of the second electrode can form a full-angle reflector, so as to improve the reflection ability of the electrode extension area and reduce 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 (Polymer) and the like, and the present 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 the present embodiment, the material of the insulating layer 14 is selected to be SiO2. Preferably, the thickness of the insulating layer 14 is between 50-500 nm.

[0082] Please continue to refer to Figure 1The length of the overlapping portion accounts for 1% to 50% of the length of the extension portion 222 of the second electrode, or the area of the overlapping portion accounts for 1% to 50% of the area of the extension portion 222 of the second electrode. Preferably, the ratio is 5% to 30%, more preferably, the ratio is 10% to 25%, and optionally, the length ratio or the area ratio of the overlapping portion can be 12%, 15%, 18%, 20%, etc. By further limiting the length ratio or the area ratio of the overlapping portion of the insulating layer 14 and the extension portion 222 of the second electrode, the size of the current blocking layer under the extension electrode can be controlled, thereby avoiding the voltage rise caused by the excessive area of the current blocking layer. It should be particularly noted that the extension portion 222 of the second electrode is not simply a straight line, for example, in the present embodiment, the extension portion 222 of the second electrode includes a first curved portion 222-1, a straight line portion 222-2, and a second curved portion 222-3, one end of the first curved portion 222-1 is connected to the pad portion 221 of the second electrode and the other end is connected to the straight line portion 222-2, one end of the straight line portion 222-2 is connected to the first curved portion 222-1 and the other end is connected to the second curved portion 222-3, one end of the second curved portion 222-3 is connected to the straight line portion 222-2 and the other end gradually bends away from the first electrode 21. More specifically, the first curved portion 222-1 includes an extension portion 222-1-0, one end of which is connected to the electrode pad portion and the other end is connected to the straight line portion 222-2, and the second curved portion 222-3 includes a circular-shaped end portion 222-3-0. The length and area of the above-mentioned extension portion 222 of the second electrode include the length and area from the extension portion 222-1-0 to the circular-shaped end portion 222-3-0.

[0083] Please continue to see Figure 1 、 Figure 2In the present application, the protective layer 18 has a plurality of second openings 32, which are arranged in sequence along the extension direction of the pad portion 221 of the second electrode, i.e. the direction from the first end 2221 of the extension portion of the second electrode to the second end 2222 of the extension portion of the second electrode, and have a spacing therebetween, the second openings 32 and the spacing being arranged alternately along the extension direction of the pad portion 221 of the second electrode, the number of the second openings 32 and the spacing being 1-25. In some embodiments, the sizes of the plurality of second openings 32 are the same, and the sizes of the spacing between the second openings 32 are also the same. In some variant embodiments, the sizes of the plurality of second openings 32 increase in sequence along the extension direction of the pad portion 221 of the second electrode, which will be described in detail in Embodiment 3. In some variant embodiments, the sizes of the spacing decrease in sequence along the extension direction of the pad portion 221 of the second electrode, which will be described in detail in Embodiment 4. Of course, the second openings 32 with the same size can also match the spacing with varying sizes, and the spacing with the same size can also match the second openings 32 with varying sizes, which can be selected and used according to specific actual needs, and the present application is not limited thereto. In the present embodiment, the second openings 32 include a plurality of first opening portions 321 with the same size and at least one second opening portion 322, the second opening portion 322 is arranged below the second end 2222 of the extension portion of the second electrode and corresponds to the insulating layer 14, and the size of the second opening portion 322 is greater than that of the first opening portion 321. This is because the end of the extension electrode is often a high current density area. By arranging the second opening portion 322 with the largest size below the second end 2222 of the extension portion of the second electrode, the current at the end of the extension electrode can be diffused as uniformly as possible to the surrounding through the second opening portion 322 with the large size, avoiding the occurrence of ESD explosion points due to excessive concentration of electric charges at the end of the extension electrode, 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. In the present application, the size of the second opening portion 322 is at least 2 times greater than that of the first opening portion 321; preferably, the size of the second opening portion 332 is 2-20 times greater than that of the first opening portion 321; more preferably, the size of the second opening portion 332 is 2-15 times greater than that of the first opening portion 321; further, the size of the second opening portion 332 is 4-12 times greater than that of the first opening portion 321; optionally, the size of the second opening portion 322 is at least 5 times, 8 times, 10 times, 12 times, 14 times, etc. greater than that of the first opening portion 321.By limiting the ratio of the size of the second opening 322 to the size of the first opening 321, the current can be more effectively and evenly diffused through the larger second opening 322, avoiding ESD bursts caused by charge concentration. This also improves the overall current uniformity of the LED, thereby enhancing the reliability and luminous efficiency of the LED chip. It should be noted that in this invention, there can be more than one second opening 322; for example, there can be two or more second openings 322, and the size of any one of the second openings 322 can be larger than the size of any one of the first openings 321. The appropriate selection can be made according to specific practical needs, and this application is not limited to this. For example, when the ratio of the size of the second opening 322 to the size of the first opening 321 is less than 10 times, it is preferable to have one second opening 322; when the ratio of the size of the second opening 322 to the size of the first opening 321 is more than 10 times, it is preferable to have two or more second openings 322.

[0084] In this invention, the width of the insulating layer 14 is preferably greater than or equal to the width of the second opening 322, thereby enhancing the diffusion of current at the end of the extended electrode and 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 may also be smaller than the area of ​​the second opening 322, and can be selected according to specific actual needs; this application is not limited to this. The ratio of the area of ​​the insulating layer 14 to the area of ​​the second opening 322 ranges from 10% to 200%. Preferably, this ratio is 40% to 150%, more preferably 50% to 120%, for example, 50%, 70%, 90%, 110%, etc. Please continue reading. Figure 1 In this embodiment, the width of the insulating layer 14 is greater than the width of the second opening 322, and the area of ​​the insulating layer 14 is greater than the area of ​​the second opening 322. For some modified embodiments, please refer to... Figure 7 , Figure 8 , Figure 7 This is a top view schematic diagram of another light-emitting diode provided in Embodiment 1 of the present invention. Figure 8 For along Figure 7 A cross-sectional view of line A-A' is shown in this embodiment. In this embodiment, the width of the insulating layer 14 is greater than the width of the second opening 322, and the area of ​​the insulating layer 14 is smaller than the area of ​​the second opening 322. For some modified embodiments, please refer to... Figure 9 , Figure 10 , Figure 9 This is a top view schematic diagram of another light-emitting diode provided in Embodiment 1 of the present invention. Figure 10 For along Figure 9A cross-sectional view of line A-A' is shown in this embodiment. In this embodiment, the width of the insulating layer 14 is equal to the width of the second opening 322, and the area of ​​the insulating layer 14 is equal to the area of ​​the second opening 322. For some modified embodiments, please refer to... Figure 11 , Figure 12 , Figure 11 This is a top view schematic diagram of another light-emitting diode provided in Embodiment 1 of the present invention. Figure 12 For along Figure 11 A cross-sectional view of the A-A' line is shown in this embodiment. In this embodiment, the width of the insulating layer 14 is equal to the width of the second opening 322, and the area of ​​the insulating layer 14 is smaller than the area of ​​the second opening 322. By combining the insulating layer 14 located at the end of the extended electrode with the large-sized second opening 322, the reliability and luminous efficiency of the light-emitting diode chip are further improved, while also avoiding voltage rise caused by an excessively large current blocking layer area.

[0085] Furthermore, the second opening 322 and the extension portion 222 of the second electrode have an overlapping portion. The length of the overlapping portion accounts for 5% to 25% of the length of the extension portion 222 of the second electrode, or the area of ​​the overlapping portion accounts for 5% to 25% of the area of ​​the extension portion 222 of the second electrode. Preferably, this percentage 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 extension portion 222 of the second electrode, 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 and further improving the luminous efficiency of the light-emitting diode chip.

[0086] The method for manufacturing the light-emitting diode of the present invention mainly includes five processes: mesa etching (MESA), fabrication of insulating layer 14, fabrication of transparent conductive layer 16, fabrication of protective layer 18, and fabrication of electrodes. Figure 5 The five processes involve corresponding photomask patterns, which are briefly explained below.

[0087] 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.

[0088] 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.

[0089] Next, refer to Figure 5The pattern shown in (b) shows that an insulating layer 14 is formed on the second semiconductor layer 125 of the semiconductor stack 12, which is formed only below the second end 2222 of the extension of the second electrode, wherein the second end 2222 of the extension of the second electrode is located at one end of the pad portion 221 away from the second electrode.

[0090] Next, refer to Figure 5 The pattern shown in (c) involves fabricating a transparent conductive layer 16 on the second semiconductor layer 125 of the semiconductor stack 12, etching away the mesa region, forming a third opening 33 in the pad area of ​​the second electrode region, and forming a sixth opening 36 at the position corresponding to the via 40.

[0091] Next, refer to Figure 5 As shown in (d), 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. A first opening 31 is formed in the pad area of ​​the second electrode region, a second opening 32 is formed in the extension area of ​​the second electrode region, a fourth opening 34 is formed on the mesa, and a fifth opening 35 is formed in the extension portion 212 of the first electrode. The fifth opening 35 is formed within the via 40, and its size is smaller than that of the via 40. Preferably, the first opening 31 is an annular structure, and the inner diameter d1' and outer diameter d1 of the annulus are both smaller than the diameter d3 of the third opening 33. Preferably, the second opening 32 includes multiple first opening portions 321 of the same size and at least one second opening portion 322. The second opening portion 322 is disposed below the second end 2222 of the extension portion of the second electrode, corresponding to the insulating layer 14, and its size is larger than that of the first opening portion 321.

[0092] Next, refer to Figure 5 The pattern shown in (e) depicts a first electrode 21 and a second electrode 22 fabricated on a protective layer 18. The pad portion 221 of the second electrode contacts the second semiconductor layer 125 through a first opening 31, and also contacts the second semiconductor layer 125 and the protective layer 18. The extension portion 222 of the second electrode contacts the transparent conductive layer 16 through a second opening 32. The pad portion 211 of the first electrode is located above the first semiconductor layer 123, and also contacts the first semiconductor layer 123 through a fourth opening 34. The pad portion 221 of the first electrode contacts the first semiconductor layer 123 and the protective layer 18. The extension portion 212 of the first electrode is located above the second semiconductor layer 125, and also contacts the first semiconductor layer 123 through a fifth opening 35 and a through-hole 40.

[0093] It should be noted that the shape and size of the first opening 31 and the fourth opening 34 are not limited to the above description, and they can also be directly formed into a non-cyclic structure, for example, in some embodiments, the center part of the pad part of the electrode is not protected by the protective layer 18, and is directly in contact with the semiconductor stack 12. In other embodiments, the first opening 31 and the fourth opening 34 can also be designed as a series of tentacle structures distributed around the pad area, exposing the transparent conductive layer 16, and the pad area is not formed with an opening structure, and the pad part of the electrode is completely formed on the protective layer 18, and can be connected to the tentacle structure through a metal lead. Embodiment 2

[0094] Please refer to Figure 13 、 Figure 14 , Figure 13 the top view schematic diagram of the light emitting diode provided in the second embodiment of the present application, Figure 14 is a cross-sectional structure schematic diagram along the A-A' line of Figure 13 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 insulating layer 14 is distributed in a block shape and is composed of a series of discrete block structures with gaps between the block structures. By setting the insulating layer 14 as a series of block structures, the current at the end of the extended electrode can not only diffuse to the surrounding, but also diffuse through the gaps between the blocks, so that the current at the end of the extended electrode is more uniform, and the overall current uniformity of the light emitting diode is further improved. 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 largest at the position close to the second end 2222 of the extended part of the second electrode, and becomes smaller and smaller as it is farther away from the second end 2222 of the extended part of the second electrode, and the area of the block structure farthest from the second end 2222 of the extended part of the second electrode is the smallest. In this way, it can be prevented that ESD explosion points appear due to excessive concentration of electric charges at the position close to the end of the extended electrode with high current density; 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

[0095] Please refer to Figure 15 、 Figure 16 , Figure 15 the top view schematic diagram of the light emitting diode provided in the third embodiment of the present application, Figure 16 is a cross-sectional structure schematic diagram along the A-A' line of Figure 15A cross-sectional view of line A-A'. Compared to the light-emitting diode of the first embodiment of the present invention, the main difference of this third embodiment is that, in this embodiment, the size of several second openings 32 of the protective layer 18 increases sequentially along the extension direction of the pad portion 221 gradually moving away from the second electrode. Specifically, the size of the second opening 32 is smallest near the pad portion 221 of the second electrode, and increases with distance from the pad portion 221 of the second electrode. The second opening 32 furthest from the pad portion 221 of the second electrode, that is, located at the second end 2222 of the extension portion of the second electrode, has the largest size. Since the current density tends to increase gradually along the extension direction of the pad portion 221 that is gradually moving away from the second electrode, in some preferred embodiments, by designing the size of the second opening 32 to increase sequentially along the extension direction of the electrode extension portion, it is possible to prevent ESD bursts due to excessive charge concentration in areas with high current density, such as near the end of the extension electrode; at the same time, it can also alleviate the current congestion effect on the second electrode, improve the overall current uniformity of the light-emitting diode, and thus improve the reliability and luminous efficiency of the light-emitting diode chip. Example 4

[0096] Please see Figure 17 , Figure 18 , Figure 17 This is a top view schematic diagram of the light-emitting diode provided in Embodiment 4 of the present invention. Figure 18 For along Figure 17 A cross-sectional view of line A-A'. Compared to the light-emitting diode of the first embodiment of the present invention, the main difference of the light-emitting diode of this fourth embodiment is that the protective layer 18 has a plurality of second openings 32, with intervals between them. The size of the intervals decreases sequentially along the extension direction of the pad portion 221, which is gradually farther away from the second electrode. Specifically, the interval size of the second openings 32 is largest near the pad portion 221 of the second electrode, and decreases further away from the pad portion 221 of the second electrode. The interval size of the second openings 32 is smallest at the second end 2222 of the extension portion of the second electrode, which is furthest from the pad portion 221 of the second electrode. By designing the intervals between the second openings 32 to decrease sequentially along the extension direction of the extension portion 222 of the second electrode, ESD bursts due to excessive charge concentration in areas of high current density can also be prevented; at the same time, the overall current uniformity of the light-emitting diode can be improved, thereby improving the reliability and luminous efficiency of the light-emitting diode chip. Example 5

[0097] Please see Figure 19 , Figure 20 , Figure 19A top view of a light emitting diode according to a fifth embodiment of the present application, Figure 20 A top view of another light emitting diode according to the fifth embodiment of the present application. Compared with the light emitting diode according to the first embodiment of the present application, the light emitting diode according to the fifth embodiment is mainly different in that the insulating layer 14 and the extension part 222 of the second electrode directly above the insulating layer 14 have a width difference AW, which gradually increases from the first end 2221 of the extension part of the second electrode to the second end 2222 of the extension part of the second electrode. In some embodiments, please refer to Figure 18 , the extension part 222 of the second electrode gradually tapers from the first end 2221 to the second end 2222, or in other words, the extension part 222 of the second electrode gradually tapers away from the pad part 221 of the second electrode and has widths W1 and W3 above the insulating layer 14, where the width W3 is closer to the second end 2222 of the extension part of the second electrode than the width W1, and W1>W3; the width of the insulating layer 14 is constant or gradually increases from the first end 2221 to the second end 2222 (not shown in the figure) and has widths W2 below the width W1 and W4 below the width W3, where the width W4 is closer to the second end 2222 of the extension part of the second electrode than the width W2, and W2≤W4, the first width difference between the width W2 and the width W1 is AW1, and the second width difference between the width W4 and the width W3 is AW2, AW1<AW2. In some modified embodiments, please refer to Figure 19 , the width of the insulating layer 14 gradually increases from the first end 2221 to the second end 2222, or in other words, the width of the insulating layer 14 gradually decreases away from the pad part 221 of the second electrode and has widths W2 and W4 below the extension part 222 of the second electrode, where the width W4 is closer to the second end 2222 of the extension part of the second electrode than the width W2, and W2

[0098] The application also provides a light emitting device using the light emitting diode as claimed in any one of the above embodiments, which can effectively improve the performance of the light emitting device.

[0099] In summary, the light emitting diode provided by the application can improve the reliability and light emitting efficiency of the chip while avoiding voltage rise by arranging the insulating layer only at one end of the pad portion away from the second electrode.

[0100] 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 they can still modify the technical solutions recorded in the above embodiments, or make equivalent replacement for 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 by, The light emitting diode comprises: a semiconductor stack comprising, from bottom to top, a first semiconductor layer, a light emitting layer and a second semiconductor layer stacked in sequence; an insulating layer formed on the second semiconductor layer; a transparent conductive layer formed on the second semiconductor layer and covering the insulating layer; a protective layer formed on the transparent conductive layer and having an opening exposing part of the upper surface of the transparent conductive layer; a second electrode formed on the protective layer, comprising a pad portion and an extension portion, and electrically connected with the transparent conductive layer through the opening of the protective layer; characterized in that the extension portion of the second electrode has a first end connected with the pad portion of the second electrode and a second end away from the pad portion of the second electrode, the insulating layer is only formed under the second end of the extension portion of the second electrode, the insulating layer and the extension portion of the second electrode above it have a width difference, and the width difference gradually increases along the direction from the first end of the extension portion of the second electrode to the second end of the extension portion of the second electrode.

2. The light emitting diode of claim 1, wherein: The insulating layer and the extension portion of the second electrode have an overlapping portion, and the length of the overlapping portion accounts for 1% to 50% of the length of the extension portion of the second electrode.

3. The light emitting diode of claim 1, wherein: The insulating layer and the extension portion of the second electrode have an overlapping portion, and the area of the overlapping portion accounts for 1% to 50% of the area of the extension portion of the second electrode.

4. The light emitting diode of claim 1, wherein: The insulating layer is composed of a series of block structures.

5. The light emitting diode of claim 1, wherein: The protective layer forms a first opening and a second opening in the pad portion and the extension portion of the second electrode respectively, exposing part of the upper surface of the second semiconductor layer located in the pad portion of the second electrode and part of the upper surface of the transparent conductive layer located in the extension portion of the second electrode.

6. The light emitting diode of claim 5, wherein: 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 located in the pad portion of the second electrode, and the size of the third opening is smaller than that of the pad portion of the second electrode.

7. The light emitting diode of claim 6, wherein: The size of the first opening is smaller than that 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.

8. The light emitting diode of claim 6, wherein: 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.

9. The light emitting diode of claim 5, wherein: 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 both the second semiconductor layer and the transparent conductive layer.

10. The light emitting diode of claim 5, wherein: The protective layer has a plurality of the second openings, which are arranged in sequence along the extension direction gradually away from the pad portion of the second electrode.

11. The light emitting diode of claim 10, wherein: The sizes of the plurality of the second openings are the same.

12. The light emitting diode of claim 10, wherein: The second openings have a spacing therebetween, and the sizes of the spacing are the same.

13. The light emitting diode of claim 10, wherein: The second opening comprises a plurality of first opening portions of the same size and at least one second opening portion, the second opening portion is arranged below the second end of the extension portion of the second electrode, is arranged corresponding to the insulating layer, and the size of the second opening portion is greater than the size of the first opening portion.

14. The light emitting diode of claim 13, wherein: The width of the insulating layer is greater than or equal to the width of the second opening portion.

15. The light emitting diode of claim 13, wherein: The ratio of the area of the insulating layer to the area of the second opening portion ranges from 10% to 200%.

16. The light emitting diode of claim 1, wherein: 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 on the first semiconductor layer, the extension portion of the first electrode is located on 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 the extension portion of the first electrode is provided with the protective layer between the second semiconductor layer.

17. A light-emitting device, characterized in that: The light emitting diode as claimed in any one of claims 1-16 is adopted.

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