Light emitting diode and light emitting device

Abstract

The application provides a light emitting diode and a light emitting device. A semiconductor epitaxial stack of the light emitting diode is divided into a first mesa and a second mesa by an isolation groove. A second semiconductor layer exposed at the isolation groove is formed into an electrode mesa. A second pad electrode of the light emitting diode is formed at the electrode mesa and extends from the electrode mesa to cover at least the upper surface of the second mesa. Further, the second pad electrode extends from the electrode mesa to the upper surface of the second mesa, the outer sidewall opposite to the isolation groove, and the edge region of the upper surface of the first mesa close to the isolation groove. Since the second mesa and the first mesa are at the same height, the second pad electrode is at least partially at the same height as the first pad electrode above the first mesa. During subsequent soldering, the second pad electrode is more easily contacted by solder, and the solder is more easily filled to the isolation groove and contacted with the second pad electrode. Thus, the occurrence of false soldering is avoided, and the reliability of the light emitting diode is improved.

Description

Technical Field

[0001] This invention relates to the field of semiconductor devices and apparatus, and particularly to a light-emitting diode and a light-emitting device. Background Technology

[0002] Light-emitting diodes (LEDs) have advantages such as high luminous intensity, high efficiency, small size, and long lifespan, and are considered one of the most promising light sources today. In recent years, LEDs have been widely used in daily life, such as lighting, signal display, backlighting, automotive lights, and large-screen displays. At the same time, these applications have also placed higher demands on the brightness and luminous efficiency of LEDs.

[0003] For flip chips, especially flip mini-chips, forming the P-electrode typically requires etching semiconductor layers to create a mesa structure. This results in a height difference between the P and N-electrodes. During soldering, insufficient contact between the solder paste or flux and the P and N pads can lead to cold solder joints or missing solder joints. The lower-positioned P-electrode is particularly prone to cold solder joints because the solder fails to fully fill the space of the P-pad area. Poor contact due to cold solder joints can cause open circuits or voltage spikes, severely impacting chip reliability. Summary of the Invention

[0004] In view of the shortcomings and defects in the reliability of existing light-emitting diodes due to the height difference between the N and P pads, the present invention provides a light-emitting diode and a light-emitting device to solve one or more of the above-mentioned problems.

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

[0006] A semiconductor epitaxial stack, wherein the semiconductor epitaxial stack comprises a second semiconductor layer, an active layer and a first semiconductor layer stacked sequentially;

[0007] An isolation trench extends through the first semiconductor layer and the active layer in the stacking direction of the semiconductor epitaxial stack. The isolation trench divides the semiconductor epitaxial stack into a first mesa and a second mesa that are independent of each other. The second semiconductor layer exposed by the isolation trench is formed as an electrode mesa, and the first mesa is the light-emitting mesa of the light-emitting diode.

[0008] The first pad electrode is formed on the first mesa and electrically connected to the first semiconductor layer;

[0009] A second pad electrode is formed on the electrode mesa and electrically connected to the second semiconductor layer, the second pad electrode extending from the electrode mesa to at least cover the upper surface of the second mesa.

[0010] Another embodiment of this application provides a light-emitting device, which includes a circuit board and a light-emitting element disposed on the circuit board, wherein the light-emitting element includes the light-emitting diode provided in this application.

[0011] As described above, the light-emitting diode and light-emitting device of this application have the following beneficial effects:

[0012] The semiconductor epitaxial stack of the light-emitting diode (LED) of this application is divided into a first mesa and a second mesa by an isolation trench. The second semiconductor layer exposed at the isolation trench is formed as an electrode mesa. A second pad electrode of the LED is formed at the electrode mesa and extends from the electrode mesa to at least cover the upper surface of the second mesa. Furthermore, the second pad electrode extends from the electrode mesa to the upper surface of the second mesa and to the outer wall opposite the isolation trench, and the edge region of the first mesa near the upper surface of the isolation trench. Since the second mesa and the first mesa are at the same height, the second pad electrode is at least partially at the same height as the first pad electrode above the first mesa, making it easier for the second pad electrode to contact the solder during subsequent soldering. Due to the external pressure during soldering, the solder easily fills the isolation trench (electrode mesa) and contacts the second pad electrode there, thus avoiding cold solder joints and improving the reliability of the LED. Attached Figure Description

[0013] Figure 1 The diagram shows a schematic representation of the structure of a light-emitting diode (LED) in the prior art.

[0014] Figure 2 The diagram shown is a schematic diagram of the structure of a light-emitting diode provided in Embodiment 1 of the present invention.

[0015] Figure 3 The diagram shown is a schematic representation of the structure of a light-emitting diode provided in an alternative embodiment of Embodiment 1.

[0016] Figure 4 Displayed as Figure 3 The diagram shown is a top view of the structure of a light-emitting diode.

[0017] Figure 5 The diagram shown is a schematic diagram of the structure of a light-emitting diode provided in another alternative embodiment of Embodiment 1.

[0018] Figure 6 Displayed as Figure 5 The diagram shows a top view of the structure of a light-emitting diode.

[0019] Figure 7 The diagram shown is a top view of the light-emitting diode provided in another alternative embodiment of Example 1.

[0020] Figure 8The diagram shown is a schematic diagram of the light-emitting device provided in Embodiment 3 of the present invention.

[0021] Component designation explanation

[0022] 01. Light-emitting mesa; 02. Pad mesa; 11. P-type semiconductor layer; 12. Light-emitting layer; 13. N-type semiconductor layer; 14. N-pad; 15. P-pad.

[0023] 110, Semiconductor epitaxial stack; 1101, First mesa; 1102, Second mesa; 1103, Electrode mesa; 111, First semiconductor layer; 112, Active layer; 113, Second semiconductor layer; 120, Substrate; 121, Bonding layer; 130, Isolation trench; 1411, First pad electrode; 1412, First connecting electrode; 1421, Second pad electrode; 1422, Second connecting electrode; 1423, Extension electrode; 150, Insulating protective layer.

[0024] 200, Light-emitting device; 201, Circuit board; 202, Light-emitting unit. Detailed Implementation

[0025] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention.

[0026] like Figure 1 As shown, in the prior art, a flip chip includes an epitaxial structure comprising a P-type semiconductor layer 11, a light-emitting layer 12, and an N-type semiconductor layer 13. To form the flip structure, the N-type semiconductor layer 13 and the light-emitting layer 12 are etched from the N-type semiconductor layer 13 side to form a pad mesa 02 exposing the P-type semiconductor layer 11. The unetched epitaxial structure forms a light-emitting mesa 01. As described above, the pad mesa 02 is formed by etching a portion of the epitaxial structure, thus creating a height difference between the pad mesa 02 and the light-emitting mesa 01. A P-pad 15 is formed above the pad mesa 02, and an N-pad 14 is formed above the light-emitting mesa 01, resulting in a similar height difference between the P-pad 15 and the N-pad 14. During subsequent soldering, due to this height difference, solder paste or flux cannot fully contact the P and N pads. Especially for the lower-positioned P-electrode, cold solder joints are prone to occur because the solder fails to fully fill the space of the P-pad 15 area. Poor contact due to poor soldering can lead to open circuits or voltage rises in the chip, which can seriously affect the chip's reliability.

[0027] To address the reliability issues of existing light-emitting diodes (LEDs) caused by differences in pad height, one embodiment of this application provides an LED that includes at least:

[0028] A semiconductor epitaxial stack, wherein the semiconductor epitaxial stack comprises a second semiconductor layer, an active layer and a first semiconductor layer stacked sequentially;

[0029] An isolation trench extends through the first semiconductor layer and the active layer in the stacking direction of the semiconductor epitaxial stack. The isolation trench divides the semiconductor epitaxial stack into a first mesa and a second mesa that are independent of each other. The second semiconductor layer exposed by the isolation trench is formed as an electrode mesa, and the first mesa is the light-emitting mesa of the light-emitting diode.

[0030] The first pad electrode is formed on the first mesa and electrically connected to the first semiconductor layer;

[0031] A second pad electrode is formed on the electrode mesa and electrically connected to the second semiconductor layer, the second pad electrode extending from the electrode mesa to at least cover the upper surface of the second mesa.

[0032] As described above, the semiconductor epitaxial stack is divided into a second mesa and a first mesa by forming an isolation trench. Therefore, the second mesa and the first mesa are at the same height, which ensures that the second pad electrode is at least partially at the same height as the first pad electrode above the first mesa. During subsequent soldering, the second pad electrode makes it easier for the solder to contact the solder. Due to the external pressure during soldering, the solder easily fills the isolation trench (electrode mesa) and contacts the second pad electrode there, thus preventing cold solder joints and improving the reliability of the light-emitting diode.

[0033] Optionally, the second pad electrode extends from the electrode mesa to the upper surface covering the second mesa and the edge region of the upper surface of the first mesa near the isolation trench. The second pad electrode is insulated from the first semiconductor layer and is spaced apart from the first pad electrode.

[0034] Optionally, the second pad electrode extends from the electrode mesa to cover the upper surface of the second mesa, the sidewall of the second mesa opposite to the isolation trench, and the edge region of the first mesa near the upper surface of the isolation trench. The second pad electrode is insulated from the first semiconductor layer and is spaced apart from the first pad electrode.

[0035] The aforementioned arrangement of the second pad electrode ensures that its four corners are at the same height, increasing the pad area at the same height as the first pad electrode. This makes it easier for the second pad electrode to contact the solder during subsequent soldering. Due to the external pressure during soldering, the solder easily fills the isolation groove (electrode mesa) and contacts the second pad electrode there, thus preventing cold solder joints and improving the reliability of the LED.

[0036] Optionally, the light-emitting diode further includes an insulating protective layer that covers the surfaces and sidewalls of the first mesa, the second mesa, and the electrode mesa, with the first pad electrode and the second pad electrode formed above the insulating protective layer.

[0037] The insulating protective layer serves two purposes: firstly, it protects against external moisture and impurities that could damage the light-emitting diode, especially the semiconductor epitaxial stack; secondly, it provides insulation, ensuring that the first and second pad electrodes are mutually insulated, thus guaranteeing the electrical reliability of the light-emitting diode.

[0038] Optionally, the light-emitting diode has a long side and a short side, and the isolation trench penetrates the semiconductor epitaxial stack along the direction of the short side.

[0039] The isolation trench extends through the semiconductor epitaxial stack along the short side. On the one hand, it can reduce the loss of the light-emitting surface and ensure the luminous efficiency of the light-emitting diode. On the other hand, it is beneficial to the filling of solder during welding, prevent defects such as bubbles and voids, and improve welding reliability.

[0040] Optionally, the electrode mesa has a central region and extended regions located at both ends of the central region in the direction of extension of the short side, the width of the isolation groove in the central region being greater than the width in the extended regions, the width being the distance along the direction of extension of the long side.

[0041] Optionally, a second connecting electrode is formed in the middle region of the electrode mesa, and the second connecting electrode is connected to the second pad electrode.

[0042] The above-mentioned arrangement of the electrode platform corresponding to the isolation groove ensures that the second connecting electrode has sufficient forming space on the one hand, and minimizes the loss of the light-emitting surface on the other hand, so as to ensure the luminous efficiency of the light-emitting diode.

[0043] Optionally, the extended region of the electrode mesa is formed with an extended electrode, which is connected to the second connecting electrode.

[0044] The formation of extended electrodes can increase current diffusion and improve luminous efficiency.

[0045] Optionally, the isolation groove is an axisymmetric shape along the direction of the short side.

[0046] The structural design of the isolation groove helps to simplify its formation process and reduce process complexity.

[0047] Optionally, a first connection electrode is formed above the first platform, and the first connection electrode is connected to the first pad electrode.

[0048] Optionally, the sidewall of the second mesa has an included angle α with respect to the plane containing the second semiconductor layer, where 60°≤α≤75°.

[0049] The sidewall of the second platform is set as an inclined sidewall with the above-mentioned tilt angle, which is conducive to the formation of the second pad electrode, prevents defects such as breakage and peeling, and ensures its structural integrity and performance reliability.

[0050] Optionally, the projection is made on the plane where the second semiconductor layer is located, and the projected area of ​​the second mesa is smaller than the projected area of ​​the first mesa.

[0051] The first platform, as the light-emitting platform, has a large projected area to ensure the luminous efficiency of the light-emitting diode. The projected area of ​​the second platform is sufficient to form the second pad electrode, ensuring the reliability of the light-emitting diode.

[0052] Optionally, the light-emitting diode further includes a substrate, and the semiconductor epitaxial stack is formed on the substrate.

[0053] The substrate can be either a growth substrate or a bonding substrate, which can support the semiconductor epitaxial stack and improve its stability during the transfer and transport process.

[0054] Another embodiment of the present invention provides a light-emitting device, which includes a circuit board and a light-emitting element disposed on the circuit board, the light-emitting element including the light-emitting diode provided in this application. This light-emitting device includes the light-emitting diode of this application, and therefore can achieve good light extraction efficiency and brightness.

[0055] Example 1

[0056] This embodiment provides a light-emitting diode, such as Figure 2 As shown, the light-emitting diode includes at least a semiconductor epitaxial stack 110. The semiconductor epitaxial stack 110 comprises a first semiconductor layer 111, an active layer 112, and a second semiconductor layer 113 stacked sequentially from top to bottom. Optionally, as also as... Figure 2 As shown, the light-emitting diode in this embodiment also includes a substrate 120, and a semiconductor epitaxial stack 110 is formed on the front side of the substrate 120.

[0057] The substrate 120 described above can be a conductive substrate or a non-conductive substrate, and it can also be a transparent substrate or a non-transparent substrate. Figure 2 In the illustrated embodiment, substrate 120 is a transparent, non-conductive substrate. Substrate 120 can be made of a conductive or semiconductor material. For example, substrate 120 can be at least one of silicon carbide (SiC), silicon (Si), magnesium oxide (MgO), aluminum gallium oxide (LiGaO2), and gallium nitride (GaN). In this embodiment, substrate 120 is a transparent substrate formed of a material that is optically transparent relative to the emission wavelength from active layer 112, allowing light emitted from the semiconductor epitaxial stack 110 to pass through, and possessing sufficient strength to mechanically support the semiconductor epitaxial stack 110. Furthermore, substrate 120 can be a chemically stable material with excellent moisture resistance, such as a material that does not contain easily corroded materials like Al. Substrate 120 can be a substrate with a coefficient of thermal expansion close to that of the semiconductor epitaxial stack 110 and excellent moisture resistance, such as GaP, SiC, sapphire, or transparent glass with good thermal conductivity.

[0058] The semiconductor epitaxial stack 110 can be formed on the substrate 120 by bonding. For example, after the semiconductor epitaxial stack 110 is formed on the growth substrate, the semiconductor epitaxial stack 110 is bonded to the substrate 120 by a bonding layer 121. The bonding layer 121 can be a light-transmitting material or a transparent material. The bonding layer can be a single-layer or composite layer structure, and can be made of conductive or insulating materials, or can be transparent or opaque materials.

[0059] The semiconductor epitaxial stack 110 can be any semiconductor epitaxial stack 110 capable of providing light with a specific central emission wavelength under voltage, such as blue light, green light, red light, infrared light, violet light, or ultraviolet light. This embodiment uses the semiconductor epitaxial stack 110 providing red or infrared light as an example. The first semiconductor layer 111 and the second semiconductor layer 113 have different conductivity types, electrical properties, polarities, or are doped with elements to provide electrons or holes. In this embodiment, the first semiconductor layer 111 can be an N-type semiconductor layer that can provide electrons to the active layer 112 under power. In some embodiments, the first semiconductor layer 111 can be N-type doped AlGaInP, AlGaAs, or other materials belonging to the same system as these two.

[0060] The active layer 112 can be a quantum well (QW) structure. In some embodiments, the active layer 112 can be a multiple quantum well (MQW) structure consisting of alternating well layers and barrier layers. The active layer 112 can be a single quantum well structure or a multiple quantum well structure. The barrier layer can be a GaN layer, an AlGaN layer, or an AlGaInP layer. In some embodiments, the active layer 112 can include a GaN / AlGaN, InAlGaN / InAlGaN, InGaN / AlGaN, InGaAS / AlGaAs, GaInP / AlGaInP, or GaInP / AlInP multiple quantum well structure. To improve the luminescence efficiency of the active layer 112, this can be achieved by changing the depth of the quantum wells, the number of paired well layers and barrier layers, the thickness, and / or other characteristics in the active layer 112.

[0061] The second semiconductor layer 113 can be a P-type semiconductor layer, which can provide holes to the active layer 112 under power supply. In some embodiments, the second semiconductor layer 113 includes a P-type doped nitride layer, a phosphide layer, or an arsenide layer. The P-type doped nitride layer, phosphide layer, or arsenide layer may include one or more P-type impurities of group II elements. The P-type impurities may be one or a combination of Mg, Zn, and Be. The second semiconductor layer 113 can be a single-layer structure or a multi-layer structure with different compositions. It is understood that the arrangement of the semiconductor epitaxial stack 110 is not limited to this, and other functional structure layers that optimize the performance of the light-emitting element can be selected according to actual needs.

[0062] Continue to refer to Figure 2 An isolation trench 130 is formed in the semiconductor epitaxial stack 110. This isolation trench 130 penetrates the first semiconductor layer 111 and the active layer 112 in the stacking direction of the semiconductor epitaxial stack 110, exposing the second semiconductor layer 113. (See also...) Figure 4 The light-emitting diode is configured to have a long side ( Figure 4 (in the X direction) and a short side ( Figure 4Along the Y-direction, the isolation trench 130 extends horizontally across the semiconductor epitaxial stack 110 above the second semiconductor layer 113, dividing the semiconductor epitaxial stack 110 into two independent mesa 1101 and mesa 1102. The second mesa 1102 serves as the light-emitting mesa of the light-emitting diode. The isolation trench 130 can be formed by an etching process, for example, sequentially etching the first semiconductor layer 111 and the active layer 112 from one side of the first semiconductor layer 111 until the second semiconductor layer 113 is exposed. The portion of the second semiconductor layer 113 exposed in the area corresponding to the isolation trench 130 is defined as the electrode mesa 1103, which is used to form the electrode structure electrically connecting the second semiconductor layer 113.

[0063] like Figure 2 As shown, a first pad electrode 1411 electrically connected to the first semiconductor layer 111 is formed above the first mesa 1101 of the light-emitting diode, and a second pad electrode 1421 electrically connected to the second semiconductor layer 113 is formed above the electrode mesa 1103. The second pad electrode 1421 covers the electrode mesa 1103 and extends along the electrode mesa 1103 towards the second mesa 1102 until it covers the upper surface of the second mesa 1102 along the sidewall of the second mesa 1102 located in the isolation trench 130. Since the second mesa 1102 and the first mesa 1101 are at the same height, at least the portion of the second pad electrode 1421 formed on the upper surface of the second mesa 1102 is at the same height as the first pad electrode 1411. Therefore, during subsequent soldering, the second pad electrode 1421 can more easily contact the solder. Meanwhile, due to the external pressure during soldering, the solder easily fills the isolation groove (electrode mesa) and partially contacts the second pad electrode 1421 there, thus avoiding cold solder joints and improving the reliability of the light-emitting diode. Especially in small-sized light-emitting diodes (such as Mini LEDs and MicroLEDs with a chip size of less than or equal to 300 μm), the equal height setting of the first pad electrode 1411 and the second pad electrode 1421 has a significant effect on improving the overall luminous performance of the light-emitting diode.

[0064] Similarly, refer to Figure 2The light-emitting diode of this embodiment further includes a first connecting electrode 1412 and a second connecting electrode 1422, and an insulating protective layer 150. The first connecting electrode 1412 is formed above the first mesa 1101 and is electrically connected to the first semiconductor layer 111, for example, by forming an ohmic contact. The second connecting electrode 1422 is formed above the electrode mesa 1103 and is electrically connected to the second semiconductor layer 113, similarly by forming an ohmic contact. The insulating protective layer 150 at least covers the surface and sidewalls of the semiconductor epitaxial stack 110. Specifically, the insulating protective layer 150 covers the surface and sidewalls of the first mesa 1101, the second mesa 1102, and the electrode mesa 1103, covers the first connecting electrode 1412 and the second connecting electrode 1422, and exposes the first connecting electrode 1412 and the second connecting electrode 1422 by forming openings above them. Optionally, the insulating protective layer 150 is a transparent insulating layer, such as any one or a combination of Al2O3, TiO2, SiO2, SiN, etc. The first pad electrode 1411 and the second pad electrode 1421 are formed above the insulating protective layer 150 and are electrically connected to the first connecting electrode 1412 and the second connecting electrode 1422 respectively through the openings.

[0065] The first connecting electrode 1412 and the second connecting electrode 1422 can be made of metallic materials, such as chromium (Cr), titanium (Ti), tungsten (W), gold (Au), aluminum (Al), indium (In), tin (Sn), nickel (Ni), rhodium (Rh), platinum (Pt), germanium (Ge), beryllium (Be), gold-germanium (AuGe), gold-germanium-nickel (AuGeNi), beryllium gold (BeAu), gold-zinc (AuZn), etc., or a combination of more than one of these materials. The first connecting electrode 1412 and the second connecting electrode 1422 can be a single-layer structure or a multilayer structure, for example, Ti / Au, Ti / Pt / Au, Cr / Au, Cr / Pt / Au, Ni / Au, Ni / Pt / Au, Cr / Al / Cr / Ni / Au, Au / AuGeNi / Au, or Au / BeAu / Au, etc.

[0066] Similarly, refer to Figure 2As described above, since both the insulating protective layer 150 and the second pad electrode 1421 cover the sidewall of the second mesa 1102, the sidewall of the second mesa 1102 is formed as an inclined sidewall to improve the adhesion reliability of the insulating protective layer 150 and the second pad electrode 1421 on the sidewall. Specifically, this sidewall forms an angle α with the plane where the second semiconductor layer 113 is located, and 60°≤α≤75°, further, 65°≤α≤70°. This angle setting can improve the uniformity and reliability of the adhesion of the insulating protective layer 150 on the sidewall, thereby improving the uniformity and reliability of the coverage of the second pad electrode 1421 and preventing phenomena such as breakage and peeling. Similarly, the sidewall of the first mesa 1101 can also be formed as an inclined sidewall with a similar angle.

[0067] like Figure 3 As shown, in another optional embodiment of this example, the second pad electrode 1421 extends from the surface of the electrode mesa 1103 to the first mesa 1101 and the second mesa 1102 on both sides, until it covers the upper surface of the second mesa 1102 and the edge region of the first mesa 1101 near the upper surface of the isolation groove 130. This ensures that all four corners of the second pad electrode 1421 are at the same height, allowing for more thorough contact between the second pad electrode 1421 and the solder, thus improving the soldering yield.

[0068] Reference Figure 4 It shows Figure 3 The diagram shows a top view of the structure. The LED has a long side in the X direction and a short side in the Y direction. The isolation trench 130 extends along the short side (Y direction) and crosses the semiconductor epitaxial stack 110 above the second semiconductor layer 113. Because the isolation trench 130 crosses the semiconductor epitaxial stack 110 above the second semiconductor layer 113 in the Y direction, the filling efficiency and uniformity of the solder at the isolation trench 130 are increased. This avoids defects such as bubbles and voids during solder filling, improving the soldering yield and the reliability of the LED.

[0069] Similarly, refer to Figure 4 To simplify the formation and process complexity of the isolation trench 130, it is configured as an axisymmetric shape along the X direction. The electrode mesa 1103 corresponding to the isolation trench 130 has a central region and extended regions at both ends of the central region along the Y direction. In the X direction, the width D0 of the central region is greater than the width D1 of the extended regions. The second connecting electrode 1422 is formed in the central region, thereby providing more space for its formation and ensuring electrical connection with the second semiconductor layer 113.

[0070] Refer again Figure 4The projected area of ​​the first stage 1101, which serves as the light-emitting stage, is larger than the projected area of ​​the second stage 1102. For example, the projected area of ​​the first stage 1101 is 2 to 5 times that of the second stage 1102. The larger projected area of ​​the first stage 1101 ensures that the light-emitting diode has sufficient light-emitting area, while the projected area of ​​the second stage 1102 meets the formation requirements of the second pad electrode 1421, ensuring the reliability of the formation process of the second pad electrode 1421 and subsequent soldering processes.

[0071] like Figure 5 and Figure 6 As shown, in another optional embodiment of this example, the second pad electrode 1421 extends from the upper surface of the second mesa 1102 to cover the sidewall of the second mesa 1102 opposite to the isolation groove 130. This design can significantly increase the surface area of ​​the second pad electrode 1421, and correspondingly increase its contact area with the solder, further improving the reliability of the soldering.

[0072] Reference Figure 7 In another optional embodiment of this invention, an extension electrode 1423 is formed in the extended region of the electrode mesa 1103 corresponding to the isolation trench 130. The extension electrode 1423 forms a continuous structure with the second connecting electrode 1422, specifically extending from the second connecting electrode 1422 towards both ends in the Y direction. The extension electrode 1423 increases the contact area with the second semiconductor layer 113, thereby improving its conductivity, increasing current diffusion, and improving the luminous efficiency of the light-emitting diode.

[0073] Example 2

[0074] This embodiment provides a light-emitting device, such as... Figure 8 As shown, the light-emitting device 200 includes a circuit board 201 and at least one light-emitting unit 202 fixed to the circuit board 201. The light-emitting unit 202 includes any one or more light-emitting diodes provided in Embodiment 1 of this application. Because the light-emitting device includes the light-emitting diodes provided in Embodiment 1, it has good light extraction efficiency and better reliability.

[0075] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in the present invention should still be covered by the claims of the present invention.

Claims

1. A light emitting diode, characterized by, At least including: A semiconductor epitaxial stack, wherein the semiconductor epitaxial stack comprises a second semiconductor layer, an active layer and a first semiconductor layer stacked sequentially; An isolation trench extends through the first semiconductor layer and the active layer in the stacking direction of the semiconductor epitaxial stack. The isolation trench divides the semiconductor epitaxial stack into a first mesa and a second mesa that are independent of each other. The second mesa and the first mesa are at the same height. The second semiconductor layer exposed by the isolation trench is formed as an electrode mesa. The first mesa is the light-emitting mesa of the light-emitting diode. The first pad electrode is formed on the first mesa and electrically connected to the first semiconductor layer; A second pad electrode is formed on the electrode mesa and electrically connected to the second semiconductor layer. The second pad electrode extends from the electrode mesa to at least cover the upper surface of the second mesa, such that the second pad electrode is at least partially at the same height as the first pad electrode above the first mesa.

2. The light emitting diode of claim 1, wherein, The second pad electrode extends from the electrode mesa to the upper surface covering the second mesa and the edge region of the upper surface of the first mesa near the isolation trench. The second pad electrode is insulated from the first semiconductor layer and is spaced apart from the first pad electrode.

3. The light emitting diode of claim 1, wherein, The second pad electrode extends from the electrode mesa to cover the upper surface of the second mesa and the sidewall of the second mesa opposite to the isolation trench, as well as the edge region of the first mesa near the upper surface of the isolation trench. The second pad electrode is insulated from the first semiconductor layer and is spaced apart from the first pad electrode.

4. The light emitting diode of claim 1, wherein, It also includes an insulating protective layer that covers the surfaces and sidewalls of the first platform, the second platform, and the electrode platform, with the first pad electrode and the second pad electrode formed above the insulating protective layer.

5. The light emitting diode of claim 1, wherein, The light-emitting diode has a long side and a short side, and the isolation trench extends through the semiconductor epitaxial stack along the direction of the short side.

6. The light emitting diode of claim 5, wherein, The electrode platform has a central region and extended regions located at both ends of the central region in the direction of extension of the short side. The width of the isolation groove in the central region is greater than the width in the extended regions, and the width is the distance along the direction of extension of the long side.

7. The light emitting diode of claim 6, wherein, A second connecting electrode is formed in the middle region of the electrode platform, and the second connecting electrode is connected to the second pad electrode.

8. The light emitting diode of claim 7, wherein, An extension electrode is formed in the extended region of the electrode platform, and the extension electrode is connected to the second connecting electrode.

9. The light emitting diode of claim 5, wherein, The isolation groove is an axisymmetric shape along the direction of the short side.

10. The light emitting diode of claim 1, wherein, A first connection electrode is formed above the first platform, and the first connection electrode is connected to the first pad electrode.

11. The light emitting diode of claim 1, wherein, The sidewall of the second mesa has an included angle α with respect to the plane containing the second semiconductor layer, where 60°≤α≤75°.

12. The light emitting diode of claim 1, wherein, Projected onto the plane containing the second semiconductor layer, the projected area of ​​the second mesa is smaller than that of the first mesa.

13. The light emitting diode of claim 1, wherein, It also includes a substrate, on which the semiconductor epitaxial stack is formed.

14. A light-emitting device, characterized in that, A light emitting element including a circuit substrate and a light emitting diode provided on the circuit substrate, the light emitting diode including the light emitting diode according to any one of claims 1 to 13.

Images