Light emitting diode and light emitting device

Abstract

The invention provides a light emitting diode and a light emitting device. The light emitting diode comprises a semiconductor lamination layer, at least one conductive hole arranged in the semiconductor lamination layer, and an insulating layer and a first bonding layer which are sequentially arranged on the inner side wall of the conductive hole, the semiconductor lamination layer and a substrate are bonded through the first bonding layer and a second bonding layer, a hole is arranged in the first bonding layer corresponding to the lower area of the conductive hole, and the second bonding layer is arranged in the hole corresponding to the lower area of the conductive hole. The repairing layer is arranged in the hole, so that the voidage in the first bonding layer is effectively improved, and the reliability of the light-emitting diode is improved; the thermal conductivity of the repairing layer is greater than that of the first bonding layer, so that the efficiency of conducting heat from the first bonding layer to the surrounding environment is improved, the risk of local hot spots is effectively reduced, and the performance of the light-emitting diode is improved; the hardness of the repairing layer is greater than that of the first bonding layer, so that the mechanical strength of the first bonding layer is improved, and the durability and reliability of the light-emitting diode are improved.

Description

Technical Field

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

[0002] Light Emitting Diode (LED) is a semiconductor optoelectronic device that can directly convert electrical energy into light energy when current passes through it, and works based on the principle of electroluminescence. LED is widely used in general lighting, backlight display, traffic lights, automotive lighting, medical equipment, plant growth lights and other fields.

[0003] One design form of LED is a vertical structure chip, which makes the electrical connection and / or light emission direction perpendicular to the substrate surface. This structure allows more efficient thermal management, current path and light output, and is suitable for high power and high brightness applications.

[0004] Vertical structure chips usually contain P-type layers and N-type layers, which form a mesa structure through specific process steps to realize the vertical conductive path of the device. However, due to the inherent differences in material growth, etching process and subsequent metallization steps, there is often a significant height difference between the N-type mesa (especially the area containing metallized through holes) and the P-type mesa. This height difference becomes a key factor affecting the bonding quality in the subsequent bonding process of silicon (Si)-based substrates or other materials.

[0005] When dealing with this height difference, the bonding process in the prior art often has difficulty ensuring the uniformity and continuity of the metal layer across the entire interface. The height difference between the metal at the N-type hole and the P-table will cause holes to form during the bonding process. These holes not only destroy the integrity of the metal layer, but also become a hidden danger of thermal management in subsequent device operation.

[0006] During the long-term operation of the device, especially when undergoing high-temperature, high-current density aging tests, the air in these holes will accumulate heat due to the thermal resistance effect of the metal layer. As the heat continues to accumulate, the temperature of the metal layer around the holes rises sharply, eventually causing the metal layer to peel off or leak, seriously affecting the performance and reliability of the device.

[0007] In order to improve the performance and reliability of the device, the present application provides a light emitting diode and a light emitting device. Summary of the invention

[0008] In view of the defects and deficiencies of light-emitting diodes in the prior art, the present application provides a light-emitting diode and a light-emitting device. The light-emitting diode is provided with a repair layer in the hole, which effectively improves the void rate in the first bonding layer and improves the reliability of the light-emitting diode; the thermal conductivity of the repair layer is greater than the thermal conductivity of the first bonding layer, which improves the efficiency of heat conduction from the first bonding layer to the surrounding environment, reduces the risk of local hot spots, and improves the performance of the light-emitting diode; the hardness of the repair layer is greater than the hardness of the first bonding layer, which effectively improves the mechanical strength of the first bonding layer and improves the durability and reliability of the light-emitting diode.

[0009] An embodiment of the present application provides a light emitting diode, including:

[0010] A semiconductor stack, wherein the semiconductor stack comprises, from top to bottom, a first semiconductor layer, an active layer, and a second semiconductor layer stacked in sequence;

[0011] A conductive hole, at least one of which is disposed in the semiconductor stack, the conductive hole passes through the second semiconductor layer, the active layer and at least a portion of the first semiconductor layer, and an insulating layer and a first bonding layer are sequentially disposed on the inner sidewall of the conductive hole, and the first bonding layer is electrically connected to the first semiconductor layer through the conductive hole;

[0012] a substrate, wherein the substrate is bonded to the first bonding layer via a second bonding layer;

[0013] Among them, corresponding to the area below the conductive hole, the first bonding layer has a hole, a repair layer is arranged in the hole, the thermal conductivity of the repair layer is greater than the thermal conductivity of the first bonding layer, and the hardness of the repair layer is greater than the hardness of the first bonding layer.

[0014] According to another embodiment of the present application, a light-emitting device is provided, including a circuit board and a plurality of light-emitting elements arranged on the circuit board, wherein the light-emitting elements include the above-mentioned light-emitting diodes, or include light-emitting diodes prepared by the above-mentioned preparation method.

[0015] As described above, the light emitting diode and the light emitting device of the present application have the following beneficial effects:

[0016] The light-emitting diode of the present application repairs the defects of the first bonding layer by setting a repair layer in the holes of the first bonding layer, thereby reducing the void rate in the first bonding layer and improving the reliability of the light-emitting diode; the thermal conductivity of the repair layer is set to be greater than the thermal conductivity of the first bonding layer, thereby improving the efficiency of the first bonding layer conducting heat to the surrounding environment, reducing the risk of local hot spots, and improving the performance of the light-emitting diode; the hardness of the repair layer is greater than the hardness of the first bonding layer, thereby effectively improving the mechanical strength of the first bonding layer and improving the durability and reliability of the light-emitting diode. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 The diagram shows a top view of a light emitting diode in the prior art.

[0018] Figure 2 Display as Figure 1 Schematic diagram of the cross-sectional structure along the AA direction.

[0019] Figure 3 Shown is a schematic cross-sectional structure diagram of a light emitting diode provided in Example 1 of the present application.

[0020] Figures 4 to 10 Shown is a schematic cross-sectional structure diagram of the preparation process in the method for preparing a light emitting diode provided in Example 2 of the present application.

[0021] Fig.11 Shown is a schematic diagram of the structure of the light-emitting device provided in Example 3 of the present application.

[0022] Component number description

[0023] 10, circuit board; 20, light-emitting element; 100, semiconductor stack; 101, conductive hole; 110, first semiconductor layer; 120, active layer; 130, second semiconductor layer; 200, insulating layer; 201, transparent conductive layer; 202, metal reflective layer; 203, metal protective layer; 210, first insulating layer; 211, through hole; 220, second insulating layer; 300, first bonding layer; 301, hole; 302, repair layer; 400, second bonding layer; 500, substrate; 510, first region; 520, second region; 600, metal layer; 700, electrode; 800, passivation layer; 900, substrate. DETAILED DESCRIPTION

[0024] The following describes the embodiments of the present invention through specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention.

[0025] The present application provides a light emitting diode, comprising:

[0026] A semiconductor stack, wherein the semiconductor stack comprises, from top to bottom, a first semiconductor layer, an active layer, and a second semiconductor layer stacked in sequence;

[0027] A conductive hole, at least one of which is disposed in the semiconductor stack, the conductive hole passes through the second semiconductor layer, the active layer and at least a portion of the first semiconductor layer, and an insulating layer and a first bonding layer are sequentially disposed on the inner sidewall of the conductive hole, and the first bonding layer is electrically connected to the first semiconductor layer through the conductive hole;

[0028] a substrate, wherein the substrate is bonded to the first bonding layer via a second bonding layer;

[0029] Among them, corresponding to the area below the conductive hole, the first bonding layer has a hole, a repair layer is arranged in the hole, the thermal conductivity of the repair layer is greater than the thermal conductivity of the first bonding layer, and the hardness of the repair layer is greater than the hardness of the first bonding layer.

[0030] The light-emitting diode provided in this embodiment effectively improves the void rate in the first bonding layer by arranging a repair layer in the hole, avoids the air in the hole from accumulating heat in the first bonding layer, and improves the reliability of the light-emitting diode; the thermal conductivity of the repair layer is greater than the thermal conductivity of the first bonding layer, improves the efficiency of heat conduction from the first bonding layer to the surrounding environment, reduces the risk of local hot spots, and improves the performance of the light-emitting diode; the hardness of the repair layer is greater than the hardness of the first bonding layer, effectively improves the mechanical strength of the first bonding layer, and improves the durability and reliability of the light-emitting diode.

[0031] In some embodiments, the repair layer has insulating properties.

[0032] The repair layer in the light-emitting diode of this embodiment has insulating properties, so that the current heat conduction of the light-emitting diode will not directly pass through the conductive holes, which can effectively realize current diffusion and further reduce heat accumulation.

[0033] In some embodiments, the hole is a hole with a regular or irregular shape that is naturally formed due to height difference after the first bonding layer fills the conductive hole.

[0034] When the first bonding layer is filled with the conductive hole, the height difference between the conductive hole and the second semiconductor layer causes the first bonding layer to have a height difference. When bonding with the second bonding layer, holes will be generated in the first bonding layer in the area below the conductive hole. Since the holes are naturally formed, their shapes may be regular or irregular. After the first bonding layer and the second bonding layer are bonded, the holes will be filled with air. Since the air gathers heat in the first bonding layer, the heat cannot be transferred out, which in turn causes the first bonding layer to peel off or leakage due to the melting of the first bonding layer.

[0035] In some embodiments, a surface of the repair layer close to the second bonding layer is flush with a surface of the first bonding layer close to the second bonding layer.

[0036] The light emitting diode of this embodiment can improve the problem of uneven surface of the first bonding layer and reduce the void ratio in the first bonding layer by setting the surface of the repair layer and the surface of the first bonding layer to be flush.

[0037] In some embodiments, the absolute value of the height difference between the surface of the repair layer close to the second bonding layer and the surface of the first bonding layer close to the second bonding layer is less than 0.1 μm. Since the material of the repair layer is different from that of the first bonding layer, there may be a certain difference in height between the two, but the absolute value of the height difference should be less than 0.1 μm to improve the problem of uneven surface height of the first bonding layer.

[0038] In some embodiments, the aperture of the conductive hole gradually increases from the first semiconductor layer to the second semiconductor layer, and corresponding to the area below the maximum aperture of the conductive hole, the vertical projection area of ​​the first bonding layer on the second bonding layer is larger than the vertical projection area of ​​the repair layer on the second bonding layer.

[0039] In the light-emitting diode of this embodiment, the sizes of the first bonding layer and the repair layer are limited corresponding to the conductive holes to ensure current conduction and improve the performance of the light-emitting diode.

[0040] In some embodiments, corresponding to the area below the maximum aperture of the conductive hole, the sum of the width of the repair layer and twice the width of the first bonding layer is equal to the maximum aperture of the conductive hole.

[0041] In some embodiments, the spacing between the centers of two adjacent conductive holes is less than or equal to 200 μm. By limiting the spacing between the centers of two adjacent conductive holes, it is helpful to evenly distribute the current, improve the luminous efficiency and brightness of the light-emitting diode; and it is helpful to dissipate heat from the light-emitting area to the outside, reduce the operating temperature of the light-emitting diode, improve the reliability of the light-emitting diode, and extend the service life of the light-emitting diode.

[0042] In some embodiments, the spacing between the edges of two adjacent repair layers is less than or equal to 180 μm. By limiting the spacing between the edges of adjacent repair layers, heat can be more effectively transferred to the outside through the repair layer, which helps to improve the heat conduction efficiency of the light-emitting diode and reduce the local temperature; at the same time, due to the high hardness of the repair layer, it can provide additional mechanical support for the light-emitting diode and enhance the overall stability and durability of the light-emitting diode.

[0043] In some embodiments, the thermal conductivity of the repair layer is between 500 W / m·K and 2200 W / m·K, and the Vickers hardness is between 20 GPa and 200 GPa.

[0044] The thermal conductivity of the repair layer in the light-emitting diode of this embodiment is greater than that of the first bonding layer, which can increase the thermal conductivity of the substrate and facilitate the transfer of heat to the surrounding environment; the hardness of the repair layer is greater than that of the first bonding layer, which can improve the mechanical strength of the first bonding layer and improve the reliability of the light-emitting diode.

[0045] In some embodiments, the material of the repair layer is diamond or diamond-like carbon.

[0046] The material of the repair layer of the light emitting diode in this embodiment is diamond or diamond-like carbon. Diamond or diamond-like carbon has a small specific heat, will not cause heat accumulation, and can withstand the thermal shock of sudden cooling and heat accumulation, and is a relatively good heat sink material.

[0047] In some embodiments, a metal layer is further disposed on the inner sidewall of the conductive hole, the metal layer is disposed between the insulating layer and the first bonding layer, and the metal layer passes through the conductive hole to be electrically connected to the first semiconductor layer.

[0048] In some embodiments, the surface of the substrate close to the second bonding layer includes a first region and a second region, and the second region surrounds the first region;

[0049] Corresponding to the first region, the semiconductor stack is disposed above the substrate;

[0050] From top to bottom, the insulating layer, the first bonding layer and the second bonding layer are stacked in sequence between the semiconductor stack and the substrate; the second bonding layer, the first bonding layer and the insulating layer all cover from the first region to the second region.

[0051] In some embodiments, a transparent conductive layer is disposed on a surface of the second semiconductor layer facing away from the active layer, and the transparent conductive layer is disposed between the second semiconductor layer and the insulating layer;

[0052] From top to bottom, the insulating layer includes a first insulating layer and a second insulating layer; corresponding to the area covered by the second semiconductor layer, the first insulating layer is provided with a through hole, a metal reflective layer is provided between the first insulating layer and the second insulating layer, the metal reflective layer covers the first insulating layer and fills the through hole to be electrically connected to the transparent conductive layer; a metal protective layer is provided between the metal reflective layer and the second insulating layer, the metal protective layer covers from the first area to the second area, and the second insulating layer wraps the side wall of the metal protective layer.

[0053] In some embodiments, corresponding to the second region, the first insulating layer has an interruption region, the interruption region is provided with an electrode, and the electrode is electrically connected to the metal protective layer.

[0054] Another embodiment of the present application provides a light-emitting device, including a circuit board and a plurality of light-emitting elements arranged on the circuit board, wherein the light-emitting elements include the above-mentioned light-emitting diodes, or include light-emitting diodes prepared by the above-mentioned preparation method.

[0055] The light-emitting element in the light-emitting device of the present embodiment adopts the light-emitting diode provided by the present application or the light-emitting diode prepared by the preparation method provided by the present application. Since the light-emitting diode provided by the present application is provided with a repair layer in the holes of the first bonding layer to repair the defects of the first bonding layer, the void ratio of the first bonding layer can be reduced, the reliability of the light-emitting diode can be improved, and the reliability of the light-emitting device can be improved; the thermal conductivity of the repair layer is greater than the thermal conductivity of the first bonding layer, the efficiency of the first bonding layer conducting heat to the surrounding environment is improved, the risk of local hot spots is reduced, the performance of the light-emitting diode is improved, and the performance of the light-emitting device is improved; the hardness of the repair layer is greater than the hardness of the first bonding layer, which effectively improves the mechanical strength of the first bonding layer, improves the durability and reliability of the light-emitting diode, and thus improves the durability and reliability of the light-emitting device.

[0056] In the prior art, one design form of light emitting diode is a vertical structure chip, such as Figure 1 and Figure 2 As shown, it generally includes a first semiconductor layer 110 and a second semiconductor layer 130, which form a mesa structure through specific process steps to realize a vertical conductive path of the light-emitting diode. However, due to inherent differences in material growth, etching process and subsequent metallization steps, after the first bonding layer 300 is filled into the conductive hole 101 and formed under the second semiconductor layer 130, there is a height difference between the first bonding layer 300 at the conductive hole 101 and the first bonding layer 300 under the second semiconductor layer 130. In the process of bonding the first bonding layer 300 to the substrate 500 through the second bonding layer 400, due to the height difference of the first bonding layer 300, the first bonding layer 300 corresponding to the conductive hole 101 area will form holes 301 during the bonding process. These holes 301 not only destroy the integrity of the first bonding layer 300, but also become a hidden danger of thermal management in the subsequent operation of the light-emitting diode. It can be understood that Figure 2 The shape of the hole 301 is only an example, and the shape of the hole 301 is likely to be irregular, not as regular as the example in the figure. During the long-term operation of the light-emitting diode, especially when undergoing high temperature and high current density aging tests, the air in these holes 301 will gather heat due to the thermal resistance effect of the metal of the first bonding layer 300. As the heat continues to accumulate, the temperature of the metal around the hole 301 rises sharply, eventually causing the first bonding layer 300 to peel off or leakage due to the melting of the first bonding layer 300, which not only seriously affects the reliability of the light-emitting diode, but may also cause the failure of the light-emitting diode.

[0057] In view of the above defects, the present application provides a light emitting diode and a light emitting device, which are now described in detail through the following embodiments.

[0058] Embodiment 1

[0059] This embodiment provides a light emitting diode, such as Figure 3 As shown, the light emitting diode includes a substrate 500 and a semiconductor stack 100 disposed above the substrate 500. The semiconductor stack 100 includes a first semiconductor layer 110, an active layer 120, and a second semiconductor layer 130 stacked in sequence from top to bottom. At the same time, at least one conductive hole 101 is disposed in the semiconductor stack 100, and the conductive hole 101 penetrates the second semiconductor layer 130, the active layer 120, and at least a portion of the first semiconductor layer 110. The inner sidewall of the conductive hole 101 is sequentially provided with an insulating layer 200 and a first bonding layer 300 from the outside to the inside. The first bonding layer 300 is electrically connected to the first semiconductor layer 110 through the conductive hole 101, and the insulating layer 200 is disposed below the second semiconductor layer 130, and the first bonding layer 300 is disposed below the insulating layer 200. The substrate 500 is bonded to the first bonding layer 300 through the second bonding layer 400. Among them, corresponding to the area below the conductive hole 101, the first bonding layer 300 has a hole 301, and a repair layer 302 is arranged in the hole 301. By filling the repair layer 302 in the hole 301, the void rate in the first bonding layer 300 can be effectively improved, and the reliability of the light-emitting diode can be improved. The thermal conductivity of the repair layer 302 is greater than the thermal conductivity of the first bonding layer 300, which can improve the efficiency of heat conduction from the first bonding layer 300 to the surrounding environment, effectively reduce the risk of local hot spots, and improve the performance of the light-emitting diode. The hardness of the repair layer 302 is greater than the hardness of the first bonding layer 300, which can improve the mechanical strength of the first bonding layer 300 and improve the durability and reliability of the light-emitting diode.

[0060] The hole 301 is a hole 301 of regular or irregular shape that is naturally formed due to the height difference of the first bonding layer 300 after the first bonding layer 300 fills the conductive hole 101. The height difference of the first bonding layer 300 is formed due to the height difference between the second semiconductor layer 130 and the conductive hole 101, and the hole 301 is formed in the first bonding layer 300 in the area below the conductive hole 101.

[0061] The first semiconductor layer 110 is an N-type semiconductor layer that provides electrons through N-type doping. The N-type semiconductor layer can be formed by doping Si, Ge, Sn, Se, Te, etc. in the semiconductor. The second semiconductor layer 130 is a P-type semiconductor layer that provides holes through P-type doping. The P-type semiconductor layer can be formed by doping Mg, Zn, Ca, Sr, Ba, etc. in the semiconductor. The active layer 120 can be a single quantum well structure or a multiple quantum well (MQWs) structure. The multiple quantum well structure is formed by alternately stacking quantum well layers and quantum barrier layers. The quantum barrier layers can be GaN layers, AlGaN layers, or AlGaInP layers. Optionally, the active layer 120 may include multiple quantum well structures such as GaN / AlGaN, InAlGaN / InAlGaN, InGaN / AlGaN, GaInP / AlGaInP, GaInP / AlInP, or InGaAs / AlInGaAs. In order to improve the light emitting efficiency of the active layer 120 , it can be achieved by changing the depth of the quantum well, the number of layers, thickness and / or other characteristics of the paired quantum wells and quantum well barriers in the active layer 120 .

[0062] The substrate 500 provides mechanical support for the light emitting diode, and the substrate 500 may be a conductive substrate, and the material of the conductive substrate may be, for example, silicon, silicon carbide or metal.

[0063] The material of the insulating layer 200 may be SiO 2 、SiN、SiO x N y 、TiO 2 、Si 3 N 4 、Al 2 O 3 、TiN、AlN、ZrO 2 、TiAlN、TiSiN、HfO 2 、TaO 2 MgF 2 One of the aforementioned materials, or a Bragg reflector (DBR) formed by repeatedly stacking two or more of the aforementioned materials.

[0064] The first bonding layer 300 and the second bonding layer 400 adhere one side of the semiconductor stack 100 to the substrate 500. The first bonding layer 300 and the second bonding layer 400 are usually made of metals such as gold, tin, titanium, nickel, platinum, etc. The first bonding layer 300 and the second bonding layer 400 can also be a combination of multiple layers of materials.

[0065] In an optional embodiment, the repair layer 302 is insulating, so that the repair layer 302 can block the current from directly penetrating downward from the conductive hole 101, reduce the current density in the area below and around the conductive hole 101, alleviate the current crowding effect near the conductive hole 101, and allow the current to diffuse more to other areas below the conductive hole 101, thereby reducing the heat generated by the light-emitting diode and improving the reliability, thermal stability and life of the light-emitting diode.

[0066] In an optional embodiment, the surface of the repair layer 302 close to the second bonding layer 400 is flush with the surface of the first bonding layer 300 close to the second bonding layer 400, that is, the bottom of the repair layer 302 is flush with the bottom of the first bonding layer 300, which can improve the flatness of the surface of the first bonding layer 300 bonded to the second bonding layer 400, reduce the void rate in the first bonding layer 300, and improve the reliability of the light-emitting diode.

[0067] In an optional embodiment, the absolute value of the height difference between the surface of the repair layer 302 close to the second bonding layer 400 and the surface of the first bonding layer 300 close to the second bonding layer 400 is less than 0.1 μm. The height difference between the lower surface of the repair layer 302 and the lower surface of the first bonding layer 300 is between -0.1 μm and 0.1 μm. Since the material of the repair layer 302 is different from that of the first bonding layer 300, there may be a certain difference in height between the two, but the height difference should be within the above range, thereby improving the problem of uneven height of the lower surface of the first bonding layer 300. Further, the height difference between the lower surface of the repair layer 302 and the lower surface of the first bonding layer 300 is between -0.05 μm and 0.05 μm, thereby further improving the problem of uneven height of the lower surface of the first bonding layer 300.

[0068] In an optional embodiment, the aperture of the conductive hole 101 gradually increases from the first semiconductor layer 110 to the second semiconductor layer 130, that is, the aperture of the conductive hole 101 gradually increases from top to bottom, the minimum aperture of the conductive hole 101 is R1, and the maximum aperture of the conductive hole 101 is R2. The positions of R1 and R2 marked in the figure are only for illustration, and are used to illustrate the change in the aperture of the conductive hole 101. Corresponding to the area below the maximum aperture R2 of the conductive hole 101, the vertical projection area of ​​the first bonding layer 300 on the second bonding layer 400 is greater than the vertical projection area of ​​the repair layer 302 on the second bonding layer 400, such as Figure 3As shown, corresponding to the area below the conductive hole 101, the width of the first bonding layer 300 below the conductive hole 101 is greater than the width of the repair layer 302. In this way, when the repair layer 302 is insulating, the current can be conducted from the conductive hole 101 to the first bonding layer 300 and to the second bonding layer 400, that is, the conductivity of the first bonding layer 300 is guaranteed. While realizing the conduction of current toward the substrate 500, it can also alleviate the current crowding effect near the conductive hole 101.

[0069] In an optional embodiment, if Figure 3 As described above, corresponding to the area below the maximum aperture R2 of the conductive via 101, the sum of the width T1 of the repair layer 302 and twice the width T2 of the first bonding layer 300 is equal to the maximum aperture R2 of the conductive via 101. More specifically, in the area below the conductive via 101 and where the repair layer 302 is located, R2 = T1 + 2T2.

[0070] In an optional embodiment, the spacing L1 between the hole centers of two adjacent conductive holes 101 is less than or equal to 200 μm. Since the hole wall of the conductive hole 101 may have a certain inclination, but the conductive hole 101 has a central axis, and the hole center is located on the central axis, the spacing L1 between the hole centers of two adjacent conductive holes 101 is limited to improve the uniformity of current distribution, thereby improving the luminous efficiency and brightness of the light-emitting diode; at the same time, it helps to dissipate heat from the light-emitting area to the outside, thereby reducing the operating temperature of the light-emitting diode and improving the reliability and life of the light-emitting diode.

[0071] In an optional embodiment, the spacing L2 between the edges of two adjacent repair layers 302 is less than or equal to 180 μm. Since the thermal conductivity of the repair layer 302 is greater than the thermal conductivity of the first bonding layer 300, by limiting the spacing between the edges of two adjacent repair layers 302, heat can be transferred to the outside faster through the repair layer 302, which helps to reduce the local temperature and improve the thermal conduction efficiency of the light-emitting diode; at the same time, since the repair layer 302 has a high hardness, the adjacent repair layers together provide additional mechanical support for the light-emitting diode, enhancing the overall stability and durability of the light-emitting diode.

[0072] In an optional embodiment, the thermal conductivity of the repair layer 302 is between 500W / m·K and 2200W / m·K, and the Vickers hardness is between 20GPa and 200GPa. Specifically, the thermal conductivity of the repair layer 302 can be, for example, 500W / m·K, 800W / m·K, 1000W / m·K, 1300W / m·K, 1600W / m·K, 1900W / m·K, 2200W / m·K, etc. The thermal conductivity of the repair layer 302 is greater than that of the first bonding layer 300, and the thermal conductivity of the substrate 500 can be increased. The hardness of the repair layer 302 can be, for example, 20GPa, 50GPa, 100GPa, 150GPa, 200GPa, etc. The hardness of the repair layer 302 is greater than that of the first bonding layer 300, and the mechanical strength of the first bonding layer 300 can be improved, thereby improving the reliability of the light-emitting diode.

[0073] In an optional embodiment, the material of the repair layer 302 is diamond or diamond-like carbon. The repair layer 302 uses diamond or diamond-like carbon as a raw material, which can improve the problem of uneven surface of the bonding between the first bonding layer 300 and the second bonding layer 400 and reduce the void rate in the first bonding layer 300; the thermal conductivity of diamond or diamond-like carbon is greater than that of the first bonding layer 300, which can increase the thermal conductivity of the first bonding layer 300, which is beneficial for the first bonding layer 300 to transfer heat to the surrounding environment. Diamond or diamond-like carbon has a small specific heat and will not accumulate thermal energy. It can withstand thermal shock during sudden cooling and heating, and is a good heat sink material; the thermal expansion coefficient of diamond or diamond-like carbon is close to that of silicon. When the substrate 500 is made of silicon material, the repair layer 302 uses diamond or diamond-like carbon, which can further adapt to the stress of the substrate 500; diamond or diamond-like carbon has insulation. When the repair layer 302 uses diamond or diamond-like carbon, the current will not directly pass through the conductive hole 101 during conduction, which can achieve the purpose of current diffusion, further reduce heat accumulation, and improve the performance and reliability of the light-emitting diode.

[0074] In an optional embodiment, if Figure 3 As shown, a metal layer 600 is further disposed on the inner sidewall of the conductive hole 101 between the insulating layer 200 and the first bonding layer 300, and the metal layer 600 passes through the conductive hole 101 and is electrically connected to the first semiconductor layer 110. The metal layer 600 may be an N-type metal layer, and its material may be, for example, Al, Ag, Cr, Pt, or TiW.

[0075] In an optional embodiment, if Figure 1 and Figure 3As shown, the surface of the substrate 500 close to the second bonding layer 400 (that is, the upper surface of the substrate 500) includes a first region 510 and a second region 520, and the second region 520 surrounds the first region 510. It can be understood that the first region 510 and the second region 520 are both three-dimensional regions, which can extend in a direction perpendicular to the upper surface of the substrate 500; corresponding to the first region 510, the semiconductor stack 100 is arranged above the substrate 500; from top to bottom, the insulating layer 200, the first bonding layer 300 and the second bonding layer 400 are stacked in sequence between the semiconductor stack 100 and the substrate 500, and the insulating layer 200, the first bonding layer 300 and the second bonding layer 400 all extend from the first region 510 to the second region 520. Among them, the inner side wall of the conductive hole 101 is sequentially provided with an insulating layer 200, a metal layer 600 and a first bonding layer 300 from the outside to the inside, and the metal layer 600 is also provided at the contact point between the conductive hole 101 and the first semiconductor layer 110, so as to realize the electrical connection between the metal layer 600 and the first semiconductor layer 110; after the insulating layer 200 and the metal layer 600 are provided on the side wall of the conductive hole 101, and the metal layer 600 is provided at the contact point between the conductive hole 101 and the first semiconductor layer 110, the first bonding layer 300 is filled in the remaining space of the conductive hole 101, and the first bonding layer 300 is electrically connected to the first semiconductor layer 110 through the metal layer 600.

[0076] In an optional embodiment, if Figure 3 As shown, corresponding to the semiconductor stack 100 region except the conductive hole 101, a transparent conductive layer 201 is provided between the surface of the second semiconductor layer 130 away from the active layer 120 and the insulating layer 200. The transparent conductive layer 201 can be used as an ohmic contact layer of the second semiconductor layer 130, which is beneficial to the current input and output in the semiconductor stack 100, and is also beneficial to the light-emitting diode having good electrical properties. In addition, the transparent conductive layer 201 also has the function of current expansion, and current expansion is performed on the side surface of the second semiconductor layer 130 away from the active layer 120 (the lower surface of the second semiconductor layer 130), which is beneficial to the light-emitting diode having good electrical properties. The transparent conductive layer 201 may be an oxide material with high transparency, high conductivity and low contact resistance, for example, it may be indium tin oxide (ITO), indium zinc oxide (IZO), aluminum zinc oxide (AZO), zinc oxide (ZnO), cadmium tin oxide (CTO), indium oxide (InO), indium (In)-doped zinc oxide (ZnO), aluminum (Al)-doped zinc oxide (ZnO), gallium (Ga)-doped zinc oxide (ZnO) or any combination thereof. The use of the above materials can enhance the current spreading effect of the transparent conductive layer 201.

[0077] In an optional embodiment, if Figure 3As shown, the insulating layer 200 disposed between the transparent conductive layer 201 and the metal layer 600 includes a first insulating layer 210 and a second insulating layer 220. The first insulating layer 210 is disposed close to the transparent conductive layer 201, and the second insulating layer 220 is disposed between the first insulating layer 210 and the metal layer 600. That is, from top to bottom, the insulating layer 200 includes the first insulating layer 210 and the second insulating layer 220 stacked in sequence. Corresponding to the semiconductor stack 100 region except the conductive hole 101, the first insulating layer 210 is provided with a through hole 211 penetrating the first insulating layer 210, and a metal reflective layer 202 is disposed between the first insulating layer 210 and the second insulating layer 220. The metal reflective layer 202 covers the first insulating layer 210 and fills the through hole 211 to be electrically connected to the transparent conductive layer 201. By providing the through hole 211 in the first insulating layer 210 and filling the metal reflective layer 202 in the through hole 211, the reflectivity of light in the light-emitting diode can be improved, and the light-emitting brightness of the light-emitting diode can be improved. The metal reflective layer 202 can be formed of at least one metal selected from the group consisting of Ag, Al, Ni, Rh, Pd, Ir, Ru, Mg, Zn, Pt, Au, and Hf. The metal reflective layer 202 reflects light radiated from the semiconductor stack 100 toward one side of the metal reflective layer 202 and returns it to the semiconductor stack 100, and radiates it out from the light-emitting side of the semiconductor stack 100, thereby increasing the brightness of the light-emitting diode.

[0078] In an optional embodiment, if Figure 3 As shown, a metal protective layer 203 is disposed between the metal reflective layer 202 and the second insulating layer 220. The metal protective layer 203 covers from the first region 510 to the second region 520. The function of the metal protective layer 203 is to prevent the metal of the metal reflective layer 202 from diffusing to other film layers on the side of the metal protective layer 203 away from the metal reflective layer 202, so as to prevent the reflection effect from being affected. At the same time, the material of the metal protective layer 203 can be a passivated metal material such as Pt, Au, TiW, Cr, etc. The second insulating layer 220 wraps the side wall of the metal protective layer 203 to protect the metal protective layer 203.

[0079] In an optional embodiment, if Figure 3 As shown, corresponding to the second region 520, the first insulating layer 210 has a discontinuity region, and the discontinuity region is provided with an electrode 700, which is electrically connected to the metal protection layer 203. The electrode 700 may be a P electrode, and the material of the P electrode may be, for example, Ti, Pt, Ni, Au, Sn, etc.

[0080] In an optional embodiment, if Figure 3 As shown, the surface of the first semiconductor layer 110 away from the active layer 120 is a rough surface, and the rough surface is beneficial to the light emitting effect of the light emitting diode.

[0081] In an optional embodiment, if Figure 3As shown, a passivation layer 800 is disposed on the sidewalls of the electrode 700 and the semiconductor stack 100 , and the passivation layer 800 performs insulation protection on the light emitting diode.

[0082] Embodiment 2

[0083] This embodiment provides a method for preparing a light emitting diode. Figures 4 to 10 The method for preparing the light emitting diode of this embodiment comprises the following steps:

[0084] S1, such as Figure 4 As shown, a substrate 900 is provided.

[0085] The substrate 900 is a substrate 900 for growing the semiconductor stack 100 , and may be a sapphire substrate, a silicon nitride substrate, a silicon substrate, a gallium nitride substrate, or an aluminum nitride substrate.

[0086] S2, such as Figure 4 As shown, a first semiconductor layer 110 , an active layer 120 , and a second semiconductor layer 130 are sequentially grown on the upper surface of a substrate 900 .

[0087] The first semiconductor layer 110 may be an N-type semiconductor layer, the active layer 120 may be a quantum well layer, and the second semiconductor layer 130 may be a P-type semiconductor layer.

[0088] S3, such as Figure 4 As shown, the second semiconductor layer 130 , the active layer 120 , and at least a portion of the first semiconductor layer 110 are etched along a direction perpendicular to the substrate 900 to form at least one conductive hole 101 .

[0089] In an optional embodiment, step S3 further includes the following steps:

[0090] like Figure 5 As shown, a transparent conductive layer 201 is formed on the second semiconductor layer 130 around the conductive hole 101. The area where the transparent conductive layer 201 and the conductive hole 101 are located is defined as a first area 510, and the area around the transparent conductive layer 201 is defined as a second area 520. Figure 5 The second area 520 marked in FIG. 5 is only a partial area of ​​the second area and is not completely marked.

[0091] S4. Corresponding to the first region 510 and the second region 520, an insulating layer 200 and a first bonding layer 300 are sequentially formed on the second semiconductor layer 130, and an insulating layer 200 and a first bonding layer 300 are sequentially formed on the inner wall of the conductive hole 101 from the outside to the inside, and the first bonding layer 300 is electrically connected to the first semiconductor layer 110 through the conductive hole 101.

[0092] In an optional embodiment, step S4 specifically includes the following steps:

[0093] S410, such as Figure 5 As shown, a first insulating layer 210 is formed on the side walls of the conductive hole 101, above the transparent conductive layer 201, and above the second semiconductor layer 130 of the second region 520; a portion of the first insulating layer 210 in the first region 510 except the conductive hole 101 is etched until the transparent conductive layer 201 is exposed, forming at least one through hole 211.

[0094] S420, such as Figure 6 As shown, corresponding to the first area 510 , a metal reflective layer 202 is formed on the first insulating layer 210 outside the conductive hole 101 , and the metal reflective layer 202 simultaneously fills the through hole 211 and is electrically connected to the transparent conductive layer 201 .

[0095] S430, such as Figure 6 As shown, a metal protection layer 203 is formed above the metal reflective layer 202 , and the metal protection layer 203 extends to a portion of the second region 520 .

[0096] S440, such as Figure 7 As shown, the second insulating layer 220 covers the first insulating layer 210 on the sidewall of the conductive hole 101 and is formed on the metal protection layer 203 and on the first insulating layer 210 in the second region 520 .

[0097] S450, such as Figure 7 As shown, the metal layer 600 is formed above the second insulating layer 220 , and the metal layer 600 covers the second insulating layer 220 on the sidewall of the conductive hole 101 and is formed at the bottom of the conductive hole 101 , thereby achieving electrical connection between the metal layer 600 and the first semiconductor layer 110 .

[0098] S460, such as Figure 7 As shown, the first bonding layer 300 is formed on the metal layer 600 , and the first bonding layer 300 covers the metal layer 600 of the conductive via 101 and fills the conductive via 101 .

[0099] S5, such as Figure 7 As shown, corresponding to the conductive hole 101 area, the first bonding layer 300 has a hole 301; Figure 8 As shown, a repair layer 302 is formed on the upper surface of the first bonding layer 300 from the first region 510 to the second region 520 .

[0100] S6, such as Fig. 9 As shown, the repair layer 302 except for the corresponding conductive hole 101 is etched, the thermal conductivity of the repair layer 302 is greater than the thermal conductivity of the first bonding layer 300 , and the hardness of the repair layer 302 is greater than the hardness of the first bonding layer 300 .

[0101] In an optional embodiment, the upper surface of the repair layer 302 is flush with the upper surface of the first bonding layer 300 .

[0102] In an optional embodiment, the material of the repair layer 302 may be diamond. In this case, the repair layer 302 is formed by coating using electron cyclotron resonance-chemical vapor deposition technology.

[0103] In an optional embodiment, the material of the repair layer 302 may be diamond-like carbon. In this case, the repair layer 302 is formed by sputtering coating.

[0104] S7, such as Fig.10 As shown, a substrate 500 is provided, and the substrate 500 is bonded to the first bonding layer 300 through the second bonding layer 400 .

[0105] In an optional embodiment, after step S7, the following steps are further included:

[0106] S8 , removing the substrate 900 to expose the first semiconductor layer 110 .

[0107] S9, corresponding to the second region, etching the first semiconductor layer 110, the active layer 120, and the second semiconductor layer 130, stopping at the surface of the first insulating layer 210, and the unetched first semiconductor layer 110, the active layer 120, and the second semiconductor layer 130 form a semiconductor stack 100 corresponding to the first region 510.

[0108] S10 , roughening the surface of the first semiconductor layer 110 of the semiconductor stack 100 away from the active layer 120 .

[0109] S11 , etching a portion of the first insulating layer 210 in the second region 520 until the metal protection layer 203 is exposed to form a discontinuity region, forming an electrode 700 in the discontinuity region, and the electrode 700 is electrically connected to the metal protection layer 203 .

[0110] S12 , forming a passivation layer 800 on the sidewalls of the semiconductor stack 100 , the sidewalls of the electrode 700 , and the surface of the first insulating layer 210 in the second region 520 except for the interruption region.

[0111] Embodiment 3

[0112] This embodiment provides a light emitting device, such as Fig.11As shown, it includes a circuit board 10 and a plurality of light-emitting elements 20 arranged on the circuit board 10, and the light-emitting element 20 includes the light-emitting diode of Example 1 or the light-emitting diode prepared by the preparation method provided in Example 2. The light-emitting diode of Example 1 or the light-emitting diode prepared by the preparation method of Example 2 includes a repair layer arranged in the hole 301 of the first bonding layer 300 corresponding to the conductive hole 101 area, which effectively improves the void rate in the first bonding layer 300 and improves the reliability of the light-emitting diode; at the same time, the thermal conductivity of the repair layer 302 is greater than the thermal conductivity of the first bonding layer 300, which improves the efficiency of heat conduction from the first bonding layer 300 to the surrounding environment, effectively reduces the risk of local hot spots, and improves the performance of the light-emitting diode; the hardness of the repair layer 302 is greater than the hardness of the first bonding layer 300, which improves the mechanical strength of the first bonding layer 300 and improves the durability and reliability of the light-emitting diode.

[0113] The above-mentioned light-emitting device can be used for vehicle lighting, handheld devices, stage lights, etc., and can improve the reliability, stability and durability of the above-mentioned devices.

[0114] The above embodiments are merely illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Anyone familiar with the art may 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 a person of ordinary skill in the art without departing from the spirit and technical ideas disclosed by the present invention shall still be covered by the claims of the present invention.

Claims

1. A light emitting diode, characterized in that: include: A semiconductor stack, wherein the semiconductor stack comprises, from top to bottom, a first semiconductor layer, an active layer, and a second semiconductor layer stacked in sequence; A conductive hole, at least one of which is disposed in the semiconductor stack, the conductive hole passes through the second semiconductor layer, the active layer and at least a portion of the first semiconductor layer, and an insulating layer and a first bonding layer are sequentially disposed on the inner sidewall of the conductive hole, and the first bonding layer is electrically connected to the first semiconductor layer through the conductive hole; a substrate, wherein the substrate is bonded to the first bonding layer via a second bonding layer; Among them, corresponding to the area below the conductive hole, the first bonding layer has a hole, a repair layer is arranged in the hole, the thermal conductivity of the repair layer is greater than the thermal conductivity of the first bonding layer, and the hardness of the repair layer is greater than the hardness of the first bonding layer.

2. The light emitting diode according to claim 1, characterized in that: The repairing layer has insulating properties.

3. The light emitting diode according to claim 1, characterized in that: The hole is a hole with a regular or irregular shape that is naturally formed due to the height difference after the first bonding layer fills the conductive hole.

4. The light emitting diode according to claim 1 or 2, characterized in that: A surface of the repair layer close to the second bonding layer is flush with a surface of the first bonding layer close to the second bonding layer.

5. The light emitting diode according to claim 1 or 2, characterized in that: An absolute value of a height difference between a surface of the repair layer close to the second bonding layer and a surface of the first bonding layer close to the second bonding layer is less than 0.1 μm.

6. The light emitting diode according to claim 1, characterized in that: The aperture of the conductive hole gradually increases from the first semiconductor layer to the second semiconductor layer. Corresponding to the area below the maximum aperture of the conductive hole, the vertical projection area of ​​the first bonding layer on the second bonding layer is larger than the vertical projection area of ​​the repair layer on the second bonding layer.

7. The light emitting diode according to claim 6, characterized in that: Corresponding to the area below the maximum aperture of the conductive hole, the sum of the width of the repair layer and twice the width of the first bonding layer is equal to the maximum aperture of the conductive hole.

8. The light emitting diode according to claim 1, characterized in that: The distance between the centers of two adjacent conductive holes is less than or equal to 200 μm.

9. The light emitting diode according to claim 1, characterized in that: The distance between the edges of two adjacent repair layers is less than or equal to 180 μm.

10. The light emitting diode according to claim 1, characterized in that: The thermal conductivity of the repair layer is between 500W / m·K~2200W / m·K, Vickers hardness is between 20Gpa~200Gpa.

11. The light emitting diode according to claim 1 or 2, characterized in that: The material of the repair layer is diamond or diamond-like carbon.

12. The light emitting diode according to claim 1, characterized in that: A metal layer is also disposed on the inner side wall of the conductive hole. The metal layer is disposed between the insulating layer and the first bonding layer, and the metal layer passes through the conductive hole to be electrically connected to the first semiconductor layer.

13. The light emitting diode according to claim 12, characterized in that: The surface of the substrate close to the second bonding layer includes a first area and a second area, and the second area surrounds the first area; Corresponding to the first region, the semiconductor stack is disposed above the substrate; From top to bottom, the insulating layer, the first bonding layer and the second bonding layer are stacked in sequence between the semiconductor stack and the substrate; the second bonding layer, the first bonding layer and the insulating layer all cover from the first region to the second region.

14. The light emitting diode according to claim 13, characterized in that: A transparent conductive layer is disposed on a surface of the second semiconductor layer facing away from the active layer, and the transparent conductive layer is disposed between the second semiconductor layer and the insulating layer; From top to bottom, the insulating layer includes a first insulating layer and a second insulating layer; corresponding to the area covered by the second semiconductor layer, the first insulating layer is provided with a through hole, a metal reflective layer is provided between the first insulating layer and the second insulating layer, the metal reflective layer covers the first insulating layer and fills the through hole to be electrically connected to the transparent conductive layer; a metal protective layer is provided between the metal reflective layer and the second insulating layer, the metal protective layer covers from the first area to the second area, and the second insulating layer wraps the side wall of the metal protective layer.

15. The light emitting diode according to claim 14, characterized in that: Corresponding to the second region, the first insulating layer has a discontinuity region, the discontinuity region is provided with an electrode, and the electrode is electrically connected to the metal protection layer.

16. A light emitting device, characterized in that: It comprises a circuit board and a plurality of light-emitting elements arranged on the circuit board, wherein the light-emitting elements comprise the light-emitting diodes according to any one of claims 1 to 15.

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