LED chip, high-voltage LED chip and light-emitting device

Abstract

According to the LED chip, the high-voltage LED chip and the light-emitting device provided by the invention, the first insulating layer, the transparent conductive layer, the second insulating layer and the second electrode are provided with the composite region on the light-emitting tabletop, so that the ODR structure is formed through the mutual structural relationship of the transparent conductive layer, the first insulating layer, the second electrode and the second insulating layer; the light can form total reflection in the composite area, so that the light, corresponding to the composite area, of the second electrode is reflected and then taken out from the upper surface of the LED chip, and the light extraction efficiency is effectively improved. Meanwhile, the second insulating layer is arranged on the surface of the epitaxial laminated layer and part of the surface of the first electrode / the second electrode, so that the first insulating layer and the second insulating layer with different extension directions can be formed at the edge of the second electrode to construct a connecting structure with an included angle; tensile stress diffusion generated by the LED chip in a special environment (such as high temperature and high pressure) can be effectively relieved, so that the risk that a functional dielectric layer (such as a transparent conductive layer and an insulating layer) is welded to be broken or cracked is improved, and the reliability of the LED chip is further affected. And through dual protection of the first insulating layer and the second insulating layer, the moisture-proof capability of the LED chip is improved.

Description

Technical Field

[0001] The present invention relates to the field of LED chips, and in particular to an LED chip, a high-voltage LED chip and a light-emitting device. Background Art

[0002] Light Emitting Diode (LED) has the advantages of high efficiency, long life, small size, low power consumption, etc., and is widely used in indoor and outdoor white light illumination, screen display, backlight source and other fields. The function of LED chip is to convert electrical energy into light energy. Specifically, it includes an epitaxial wafer and an N-type electrode and a P-type electrode respectively arranged on the epitaxial wafer. The epitaxial wafer includes a P-type semiconductor layer, an N-type semiconductor layer and an active layer located between the N-type semiconductor layer and the P-type semiconductor layer. When current passes through the LED chip, the holes in the P-type semiconductor and the electrons in the N-type semiconductor will move to the active layer and recombine in the active layer, so that the LED chip emits light.

[0003] As the LED application market (especially display applications) continues to expand, in order to ensure the application performance of LED products, LED packaging manufacturers have put forward higher requirements for the light extraction efficiency and reliability of LED chips. At present, the internal quantum efficiency of most LED chips is close to 99%, but their light extraction efficiency is generally low. The main factors include: 1. Due to the serious total reflection phenomenon inside the LED chip, only a small part of the light generated by the light-emitting layer can be extracted; 2. Due to the current crowding effect, the luminous efficiency of the LED chip is low.

[0004] The main factors affecting the reliability of LED chips include: 1. There are many functional dielectric layers in contact with the bottom of the P pad area, such as the current blocking layer (also referred to as the CB layer in the field) and the transparent conductive layer (also referred to as the ITO layer in the field). This structure easily exposes the functional dielectric layers in contact to the risk of solder collapse or cracking, thereby affecting the reliability of the LED chip. 2. In actual operation, the LED chip may be micro-shorted in a reverse pressure environment due to water vapor penetration, which will eventually cause the LED chip to burn out and die, affecting the reliability of the LED chip in actual applications and limiting the actual application of the LED chip. Therefore, how to improve the light extraction efficiency and reliability of the LED chip without affecting the optoelectronic performance has become a technical problem that needs to be solved urgently.

[0005] In view of this, the inventor specially designed an LED chip, a high-voltage LED chip and a light-emitting device, and this case was thus generated. Summary of the invention

[0006] The object of the present invention is to provide an LED chip, a high-voltage LED chip and a light-emitting device to solve the technical problems of low light-emitting efficiency and poor reliability of LED chips in the prior art.

[0007] In order to achieve the above object, the technical solution adopted by the present invention is as follows:

[0008] An LED chip comprises a substrate and a plurality of LED light-emitting units arranged on the surface of the substrate and isolated from each other by grooves, wherein the LED light-emitting units comprise:

[0009] An epitaxial stack is arranged on the surface of the substrate; the epitaxial stack comprises a first-type semiconductor layer, an active region and a second-type semiconductor layer stacked in sequence along a first direction; and a local area of ​​the epitaxial stack is etched to the first-type semiconductor layer to form a groove and a light-emitting table; wherein the first direction is perpendicular to the substrate and points from the substrate to the epitaxial stack;

[0010] A transparent conductive layer, which is stacked on the light-emitting mesa and has a second hole exposing a portion of the second-type semiconductor layer;

[0011] A first insulating layer formed on a surface of the transparent conductive layer facing away from the epitaxial stack;

[0012] A first electrode, which is stacked on a portion of the surface of the groove and is disposed away from the light-emitting mesa;

[0013] A second electrode, which is arranged in the second hole and extends to a portion of the surface of the first insulating layer;

[0014] The second insulating layer is disposed on the surface of the epitaxial stack and exposes at least a portion of the surface of the first electrode and the second electrode.

[0015] Preferably, the first insulating layer exposes a portion of the transparent conductive layer to form a step, and the second electrode extends to the surface of the first insulating layer through the step.

[0016] Preferably, the projection of the second electrode on the transparent conductive layer and the projection of the second electrode on the first insulating layer have an area S a and the projection area of ​​the second electrode on the transparent conductive layer is S1, then 0<S a ≤S1 / 2.

[0017] Preferably, the step is arranged around the edge of the second hole.

[0018] Preferably, a current blocking layer is provided on the bottom surface of the second hole.

[0019] Preferably, the current blocking layer and the transparent conductive layer form a separation groove, and the second electrode is embedded in the separation groove to form contact with the second-type semiconductor layer.

[0020] Preferably, the projection area of ​​the current blocking layer on the transparent conductive layer is S2, the bottom area of ​​the second hole is S3, and 0<S2≤S3 / 2.

[0021] Preferably, the first insulating layer and the current blocking layer are formed simultaneously by photolithography of a transparent dielectric layer.

[0022] Preferably, the transparent medium layer includes one or more of silicon oxide, silicon nitride, aluminum oxide, and magnesium fluoride.

[0023] Preferably, a third insulating layer is further provided on the surface of the groove, and the third insulating layer has a first hole exposing a portion of the first-type semiconductor layer; and the first electrode is stacked on the surface of the third insulating layer by being embedded in the first hole.

[0024] Preferably, the first insulating layer and the third insulating layer are formed simultaneously by photolithography of a transparent dielectric layer.

[0025] Preferably, the LED chip further comprises a refractive index matching layer, which is arranged on the surface of the second insulating layer on the side away from the epitaxial stack and forms a gradient refractive index structure with the second insulating layer, so as to further improve the light extraction efficiency; preferably, the refractive index of the refractive index matching layer is not less than the refractive index of the second insulating layer. Furthermore, if the first insulating layer or the second insulating layer comprises a layered structure composed of one or more of SiO2 and MgF2, the refractive index matching layer may comprise a layered structure composed of one or more of TiO2, Si3N4 and Al2O3. Preferably, the second insulating layer is a SiO2 layer, and the refractive index matching layer is an Al2O3 layer. Through the excellent passivation performance of Al2O3, the dangling bonds and defect states on the surface of SiO2 can be effectively covered, and the non-radiative recombination of carriers on the surface can be reduced. The reduction of non-radiative recombination directly improves the internal quantum efficiency (IQE), that is, more electrical energy is converted into light energy rather than heat.

[0026] Preferably, a reflective layer is provided on the surface of the substrate facing away from the epitaxial stack. Further, the reflective layer comprises a distributed Bragg reflective layer composed of alternately stacked high refractive index material layers and low refractive index material layers, and the reflective layer may also be a metal reflective layer.

[0027] Preferably, the first electrode includes a first electrode pad arranged at the first end of the LED chip, and the second hole is formed at the second end of the LED chip; the second electrode includes a second electrode pad and at least one electrode extension strip connected to the second electrode pad, wherein the second electrode pad extends to the surface of the first insulating layer by being arranged in the second hole, and the electrode extension strip extends from the second electrode pad toward the second end of the LED chip.

[0028] Furthermore, the first electrode may also include an electrode extension strip connected to the first electrode pad and extending toward the first end.

[0029] Preferably, at least a partial area of ​​the electrode extension strip of the second electrode is in contact with the transparent conductive layer.

[0030] Preferably, the electrode extension strip has interdigitated fingers, and the interdigitated fingers are in contact with the transparent conductive layer by being embedded in the first insulating layer through perforations. Alternatively, the transparent conductive layer has perforations, and the electrode extension strip has interdigitated fingers, and the interdigitated fingers are formed in and maintained in the perforations of the transparent conductive layer.

[0031] Preferably, the second insulating layer covers the light emitting mesas and the grooves in a manner of being maintained on an exposed surface of the first-type semiconductor layer.

[0032] Preferably, the transparent conductive layer covers at least 80% of the area of ​​the light-emitting mesa except the second hole.

[0033] Preferably, the second electrode has a metal reflective layer.

[0034] Preferably, the bottom layer of the second electrode is the metal reflective layer.

[0035] Preferably, the metal reflective layer includes one or more of Ag, Ni, Al, Rh, Pd, Ir, Ru, Mg, Zn, Pt and Au.

[0036] The present invention also provides a high-voltage LED chip, which electrically interconnects the adjacent LED light-emitting units described in any of the above items through a bridging electrode; wherein an insulating layer is also provided in the groove, and the bridging electrode connects two adjacent LED units by being stacked on the insulating layer.

[0037] The present invention further provides a light emitting device, which includes a light emitting diode. The light emitting diode adopts the LED chip as described in any one of the above items.

[0038] The present invention also provides another light-emitting device, characterized in that the light-emitting device comprises a light-emitting diode, and the light-emitting diode adopts the high-voltage LED chip described above.

[0039] Through the above technical solution, it can be known that the LED chip provided by the present invention is configured as follows: the epitaxial stack includes a first-type semiconductor layer, an active area and a second-type semiconductor layer stacked in sequence along a first direction; and a local area of ​​the epitaxial stack is etched to the first-type semiconductor layer to form a groove and a light-emitting table; the transparent conductive layer is stacked on the light-emitting table and has a second hole that exposes a portion of the second-type semiconductor layer; the first insulating layer is formed on a side surface of the transparent conductive layer away from the epitaxial stack; the first electrode is stacked on a portion of the surface of the groove and is arranged away from the light-emitting table; the second electrode extends to a portion of the surface of the first insulating layer by being arranged in the second hole; the second insulating layer is arranged on the surface of the epitaxial stack and at least a portion of the surface of the first electrode and the second electrode is exposed. Based on the above arrangement, the first insulating layer and the transparent conductive layer, the second insulating layer, and the second electrode have a composite region, so that an ODR structure is formed through the mutual structural relationship of the transparent conductive layer, the first insulating layer, the second electrode, and the second insulating layer, and light can be totally reflected in the composite region, so that the light corresponding to the composite region of the second electrode is reflected and then taken out from the upper surface of the LED chip, thereby effectively improving the light extraction efficiency; at the same time, since the second insulating layer is arranged on the surface of the epitaxial stack and part of the surface of the first electrode / the second electrode, the first insulating layer and the second insulating layer with different extension directions can be formed at the edge of the second electrode to construct a connection structure with an angle, which can effectively alleviate the diffusion of tensile stress generated by the LED chip in special environments (such as high temperature and high pressure, etc.), thereby increasing the risk of functional dielectric layers (such as transparent conductive layers, insulating layers, etc.) being welded or cracked, thereby affecting the reliability of the LED chip; and the waterproof vapor resistance of the LED chip is improved through the double protection of the first insulating layer and the second insulating layer.

[0040] Secondly, by setting the first insulating layer to expose part of the transparent conductive layer to form a step, and the second electrode extends to the surface of the first insulating layer through the step, the electrode contact area can be increased through the step, thereby dispersing stress and reducing the risk of local failure.

[0041] Then, by setting: the projection of the second electrode on the transparent conductive layer and the projection of the second electrode on the first insulating layer have an area S a and the projection area of ​​the second electrode on the transparent conductive layer is S1, then 0<S a≤S1 / 2. Thus, while ensuring the contact area between the second electrode and the transparent conductive layer to reduce the contact resistance, the size of the composite region is ensured to improve the ODR reflection effect.

[0042] Next, by setting: a current blocking layer is provided on the bottom surface of the second hole, the current blocking layer and the transparent conductive layer form a spacing groove, and the second electrode is embedded in the spacing groove to form contact with the second type semiconductor layer, so that while improving the current concentration phenomenon and promoting the lateral expansion of the current, the mutual structural relationship of the second electrode, the first insulating layer (dielectric layer), the spacing groove, the current blocking layer (dielectric layer) and the transparent conductive layer (conductive layer) forms an ODR structure again, which is beneficial to the total reflection layer area under the electrode and further improves the reflection efficiency; further, the projection area of ​​the current blocking layer on the transparent conductive layer is S2, and the bottom surface area of ​​the second hole is S3, then 0<S2≤S3 / 2. Therefore, while ensuring the current blocking and total reflection effects, the contact area between the second electrode and the second type semiconductor layer is ensured to improve the reliability of the electrode bonding wire.

[0043] In addition, by setting: the first electrode includes a first electrode pad disposed at the first end of the LED chip, the second hole is formed at the second end of the LED chip; the second electrode includes a second electrode pad and at least one electrode extension strip connected to the second electrode pad, wherein the second electrode pad extends to the surface of the first insulating layer by being disposed in the second hole, and the electrode extension strip extends from the second electrode pad toward the second end of the LED chip. The current can be better guided and extended through the electrode extension strip to avoid current crowding.

[0044] The present invention also provides a high-voltage LED chip, which electrically interconnects the adjacent LED light-emitting units described in any of the above items through a bridging electrode; wherein an insulating layer is also provided in the groove, and the bridging electrode connects two adjacent LED units by being stacked on the insulating layer; it has the beneficial effects of the above-mentioned LED chip.

[0045] The present invention further provides a light emitting device, comprising a light emitting diode, wherein the light emitting diode adopts the LED chip as described in any one of the above items; the light emitting device has the beneficial effects of the above LED chips.

[0046] The present invention also provides another light emitting device, which includes a light emitting diode. The light emitting diode adopts the high-voltage LED chip as mentioned above; the light emitting diode has the beneficial effects of the above LED chip. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0048] Figure 1 This is a schematic cross-sectional structure diagram of an LED chip provided in Example 1 of the present invention;

[0049] Figures 2 to 10 A schematic structural diagram corresponding to the steps of the method for manufacturing an LED chip provided in Embodiment 2 of the present invention;

[0050] Fig.11 This is a schematic cross-sectional structure diagram of an LED chip provided in Embodiment 3 of the present invention;

[0051] Fig.12 This is a schematic cross-sectional structure diagram of an LED chip provided in Embodiment 4 of the present invention;

[0052] Fig.13 This is a schematic cross-sectional structure diagram of an LED chip provided in Example 5 of the present invention;

[0053] Fig.14 This is a schematic cross-sectional structure diagram of an LED chip provided in Example 6 of the present invention;

[0054] Fig.15 This is a schematic cross-sectional structure diagram of an LED chip provided in Example 7 of the present invention;

[0055] Fig.16 This is a schematic cross-sectional structure diagram of an LED chip provided in Example 8 of the present invention;

[0056] Explanation of symbols in the figure:

[0057] 1. Substrate;

[0058] 2. A first type semiconductor layer;

[0059] 3. Active area;

[0060] 4. Type II semiconductor layer;

[0061] 5. Transparent conductive layer, 5.1. Second hole;

[0062] 6. The first insulating layer;

[0063] 7. A second electrode;

[0064] 8. a first electrode;

[0065] 9. Second insulating layer;

[0066] 10. Groove;

[0067] 11. Luminous table top;

[0068] 12. a third insulating layer, 12.1. a first hole;

[0069] 13. Current blocking layer;

[0070] 14. Electrode extension strip;

[0071] 15. Refractive index matching layer;

[0072] 16. Reflective layer;

[0073] 17. Groove. DETAILED DESCRIPTION

[0074] To make the content of the present invention clearer, the content of the present invention is further described below in conjunction with the accompanying drawings. The present invention is not limited to this specific embodiment. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0075] An LED chip comprises a substrate and a plurality of LED light-emitting units arranged on the surface of the substrate and isolated from each other by grooves, wherein the LED light-emitting units comprise:

[0076] An epitaxial stack is arranged on the surface of the substrate; the epitaxial stack comprises a first-type semiconductor layer, an active region and a second-type semiconductor layer stacked in sequence along a first direction; and a local area of ​​the epitaxial stack is etched to the first-type semiconductor layer to form a groove and a light-emitting table; wherein the first direction is perpendicular to the substrate and points from the substrate to the epitaxial stack;

[0077] A transparent conductive layer, which is stacked on the light-emitting mesa and has a second hole exposing a portion of the second-type semiconductor layer;

[0078] A first insulating layer formed on a surface of the transparent conductive layer facing away from the epitaxial stack;

[0079] A first electrode, which is stacked on a portion of the surface of the groove and is disposed away from the light-emitting mesa;

[0080] A second electrode, which is arranged in the second hole and extends to a portion of the surface of the first insulating layer;

[0081] The second insulating layer is disposed on the surface of the epitaxial stack and exposes at least a portion of the surface of the first electrode and the second electrode. Further, the second insulating layer covers the light-emitting mesa and the groove and exposes a portion of the surface of the first electrode and the second electrode.

[0082] It should be noted that the type of substrate is not limited in the LED chip of this embodiment. For example, the substrate may be, but is not limited to, a sapphire substrate, a silicon substrate, etc. In addition, the types of the first-type semiconductor layer, the active region, and the second-type semiconductor layer of the epitaxial stack may also not be limited in the LED chip of this embodiment. In the embodiment of the present invention, the first-type semiconductor layer may be an N-type semiconductor layer, and correspondingly, the second-type semiconductor layer may be a P-type semiconductor layer; for example, the first-type semiconductor layer may be, but is not limited to, an N-type gallium nitride layer, and correspondingly, the second-type semiconductor layer may be, but is not limited to, a P-type gallium nitride layer.

[0083] It should be noted that in the embodiments of the present application, in order to highlight the technical features of the present application, only one epitaxial stacking unit is illustrated in the embodiment diagram. In actual product applications, it may include thousands of epitaxial stacking units, depending on the application of the LED chip product. The present application does not limit this.

[0084] Based on the above, in one embodiment of the present application, the first insulating layer exposes a portion of the transparent conductive layer to form a step, and the second electrode extends to the surface of the first insulating layer through the step.

[0085] Based on the above, in one embodiment of the present application, the projection of the second electrode on the transparent conductive layer and the projection of the second electrode on the first insulating layer have an area S a and the projection area of ​​the second electrode on the transparent conductive layer is S1, then 0<S a ≤S1 / 2.

[0086] Based on the above, in one embodiment of the present application, the step is arranged around the edge of the second hole.

[0087] Based on the above, in one embodiment of the present application, a current blocking layer is provided on the bottom surface of the second hole.

[0088] Based on the above, in one embodiment of the present application, the current blocking layer and the transparent conductive layer form a spacing groove, and the second electrode is embedded in the spacing groove to form contact with the second-type semiconductor layer.

[0089] Based on the above, in one embodiment of the present application, the projection area of ​​the current blocking layer on the transparent conductive layer is S2, and the bottom area of ​​the second hole is S3, then 0<S2≤S3 / 2.

[0090] Based on the above, in one embodiment of the present application, the first insulating layer and the current blocking layer are formed simultaneously by photolithography of a transparent dielectric layer.

[0091] Based on the above, in one embodiment of the present application, the transparent medium layer includes one or more of silicon oxide, silicon nitride, aluminum oxide, and magnesium fluoride.

[0092] Based on the above, in one embodiment of the present application, a third insulating layer is further provided on the surface of the groove, and the third insulating layer has a first hole exposing a portion of the first-type semiconductor layer; the first electrode is stacked on the surface of the third insulating layer by being embedded in the first hole.

[0093] Based on the above, in one embodiment of the present application, the first insulating layer and the third insulating layer are formed simultaneously by photolithography of a transparent dielectric layer.

[0094] Based on the above, in one embodiment of the present application, the LED chip also includes a refractive index matching layer, which is arranged on a surface of the second insulating layer facing away from the epitaxial stack and forms a gradient refractive index structure with the second insulating layer to further improve the light extraction efficiency; preferably, the refractive index of the refractive index matching layer is not less than the refractive index of the second insulating layer.

[0095] Furthermore, the first insulating layer or the second insulating layer includes a layered structure composed of one or more of SiO2 and MgF2, and the refractive index matching layer may include a layered structure composed of one or more of TiO2, Si3N4, and Al2O3. Preferably, the second insulating layer is a SiO2 layer, and the refractive index matching layer is an Al2O3 layer. Through the excellent passivation performance of Al2O3, the dangling bonds and defect states on the surface of SiO2 can be effectively covered, reducing the non-radiative recombination of carriers on the surface. The reduction of non-radiative recombination directly improves the internal quantum efficiency (IQE), that is, more electrical energy is converted into light energy rather than heat.

[0096] On the basis of the above, in one embodiment of the present application, a reflective layer is further provided on the surface of the substrate facing away from the epitaxial stack. Further, the reflective layer comprises a distributed Bragg reflective layer composed of alternating high refractive index material layers and low refractive index material layers, and the reflective layer may also be a metal reflective layer.

[0097] Based on the above, in one embodiment of the present application, the first electrode includes a first electrode pad arranged at the first end of the LED chip, and the second hole is formed at the second end of the LED chip; the second electrode includes a second electrode pad and at least one electrode extension strip connected to the second electrode pad, wherein the second electrode pad extends to the surface of the first insulating layer by being arranged in the second hole, and the electrode extension strip extends from the second electrode pad toward the second end of the LED chip.

[0098] Furthermore, the first electrode may also include an electrode extension strip connected to the first electrode pad and extending toward the first end.

[0099] Based on the above, in one embodiment of the present application, at least a portion of the electrode extension strip is in contact with the transparent conductive layer.

[0100] Based on the above, in one embodiment of the present application, the electrode extension strip has interdigitated fingers, and the interdigitated fingers are embedded in the first insulating layer through perforations to form contact with the transparent conductive layer. Alternatively, the transparent conductive layer has perforations, and the electrode extension strip has interdigitated fingers, and the interdigitated fingers are formed in and maintained in the perforations of the transparent conductive layer.

[0101] Based on the above, in one embodiment of the present application, the second insulating layer covers the light emitting mesa and the groove in a manner of being maintained on the exposed surface of the first-type semiconductor layer.

[0102] Based on the above, in one embodiment of the present application, the transparent conductive layer covers at least 80% of the area of ​​the light-emitting mesa except the second hole.

[0103] Based on the above, in one embodiment of the present application, the second electrode has a metal reflective layer.

[0104] Based on the above, in one embodiment of the present application, the bottom layer of the second electrode is the metal reflective layer.

[0105] Based on the above, in one embodiment of the present application, the metal reflective layer includes one or more of Ag, Ni, Al, Rh, Pd, Ir, Ru, Mg, Zn, Pt and Au.

[0106] Based on the above, in one embodiment of the present application, the transparent conductive layer includes a metal film or a metal oxide layer.

[0107] Based on the above, in one embodiment of the present application, the metal film includes one or more of gold, silver, platinum, copper, aluminum, chromium and palladium.

[0108] Based on the above, in one embodiment of the present application, the metal oxide layer includes one or more of indium oxide, indium tin oxide, zirconium oxide, cadmium oxide, and titanium nitride.

[0109] Through the above technical solution, it can be known that the LED chip provided by the present invention is configured as follows: the epitaxial stack includes a first-type semiconductor layer, an active area and a second-type semiconductor layer stacked in sequence along a first direction; and a local area of ​​the epitaxial stack is etched to the first-type semiconductor layer to form a groove and a light-emitting table; the transparent conductive layer is stacked on the light-emitting table and has a second hole that exposes a portion of the second-type semiconductor layer; the first insulating layer is formed on a side surface of the transparent conductive layer away from the epitaxial stack; the first electrode is stacked on a portion of the surface of the groove and is arranged away from the light-emitting table; the second electrode extends to a portion of the surface of the first insulating layer by being arranged in the second hole; the second insulating layer is arranged on the surface of the epitaxial stack and at least a portion of the surface of the first electrode and the second electrode is exposed. Based on the above configuration, the first insulating layer and the transparent conductive layer, the second insulating layer, and the second electrode have a composite region, so that an ODR structure is formed through the mutual structural relationship of the transparent conductive layer, the first insulating layer, the second electrode, and the second insulating layer, and the light can be totally reflected in the composite region, so that the light corresponding to the composite region of the second electrode is reflected and then taken out from the upper surface of the LED chip, thereby effectively improving the light extraction efficiency. At the same time, based on the above configuration, the second insulating layer is arranged on the surface of the epitaxial stack and part of the surface of the first electrode / second electrode, and the first insulating layer and the second insulating layer with different extension directions can be formed at the edge of the second electrode to construct a connection structure with an angle, which can effectively alleviate the diffusion of tensile stress generated by the LED chip in special environments (such as high temperature and high pressure, etc.), thereby increasing the risk of solder collapse or solder cracking of the functional dielectric layer (such as the transparent conductive layer, the insulating layer, etc.), thereby affecting the reliability of the LED chip; and the waterproof vapor resistance of the LED chip is improved through the double protection of the first insulating layer and the second insulating layer.

[0110] Secondly, by setting the first insulating layer to expose part of the transparent conductive layer to form a step, and the second electrode extends to the surface of the first insulating layer through the step, the electrode contact area can be increased through the step, thereby dispersing stress and reducing the risk of local failure.

[0111] Then, by setting: the projection of the second electrode on the transparent conductive layer and the projection of the second electrode on the first insulating layer have an area S a and the projection area of ​​the second electrode on the transparent conductive layer is S1, then 0<S a≤S1 / 2. Thus, while ensuring the contact area between the second electrode and the transparent conductive layer to reduce the contact resistance, the size of the composite region is ensured to improve the ODR reflection effect.

[0112] Next, by setting: a current blocking layer is provided on the bottom surface of the second hole, the current blocking layer and the transparent conductive layer form a spacing groove, and the second electrode is embedded in the spacing groove to form contact with the second type semiconductor layer, so that while improving the current concentration phenomenon and promoting the lateral expansion of the current, the mutual structural relationship of the second electrode, the first insulating layer (dielectric layer), the spacing groove, the current blocking layer (dielectric layer) and the transparent conductive layer (conductive layer) forms an ODR structure again, which is beneficial to the total reflection layer area under the electrode and further improves the reflection efficiency; further, the projection area of ​​the current blocking layer on the transparent conductive layer is S2, and the bottom surface area of ​​the second hole is S3, then 0<S2≤S3 / 2. Therefore, while ensuring the current blocking and total reflection effects, the contact area between the second electrode and the second type semiconductor layer is ensured to improve the reliability of the electrode bonding wire.

[0113] In addition, by setting: the first electrode includes a first electrode pad disposed at the first end of the LED chip, the second hole is formed at the second end of the LED chip; the second electrode includes a second electrode pad and at least one electrode extension strip connected to the second electrode pad, wherein the second electrode pad extends to the surface of the first insulating layer by being disposed in the second hole, and the electrode extension strip extends from the second electrode pad toward the second end of the LED chip. The current can be better guided and extended through the electrode extension strip to avoid current crowding.

[0114] Example 1

[0115] An LED chip comprises a substrate 1 and a plurality of LED light-emitting units arranged on the surface of the substrate 1 and isolated from each other by grooves, such as Figure 1 As shown, the LED light emitting unit comprises:

[0116] An epitaxial stack is provided on the surface of the substrate 1; the epitaxial stack includes a first-type semiconductor layer 2, an active region 3, and a second-type semiconductor layer 4 stacked in sequence along a first direction; and a local area of ​​the epitaxial stack is etched to the first-type semiconductor layer 2 to form a groove 10 and a light-emitting table 11 (the diagram can refer to the corresponding manufacturing method shown in Example 2). Figure 5 ); wherein the first direction is perpendicular to the substrate 1 and points from the substrate 1 to the epitaxial stack;

[0117] a transparent conductive layer 5, which is stacked on the light-emitting mesa 11 and has a second hole 5.1 exposing a portion of the second-type semiconductor layer 4;

[0118] A first insulating layer 6 formed on a surface of the transparent conductive layer 5 facing away from the epitaxial stack;

[0119] A first electrode 8, which is stacked on a portion of the surface of the groove 10 and is disposed away from the light-emitting table 11;

[0120] A second electrode 7, which is arranged in the second hole 5.1 and extends to a part of the surface of the first insulating layer 6;

[0121] The second insulating layer 9 is disposed on the surface of the epitaxial stack and exposes at least part of the surface of the first electrode 8 and the second electrode 7. Furthermore, the second insulating layer 9 covers the light-emitting mesas and grooves and exposes part of the surface of the first electrode 8 and the second electrode 7.

[0122] It should be noted that the type of substrate 1 is not limited in the LED chip of this embodiment. For example, the substrate 1 may be, but is not limited to, a sapphire substrate 1, a silicon substrate 1, etc. In addition, the types of the first-type semiconductor layer 2, the active region 3, and the second-type semiconductor layer 4 of the epitaxial stack may also not be limited in the LED chip of this embodiment. In the embodiment of the present invention, the first-type semiconductor layer 2 may be an N-type semiconductor layer, and correspondingly, the second-type semiconductor layer 4 may be a P-type semiconductor layer; for example, the first-type semiconductor layer 2 may be, but is not limited to, an N-type gallium nitride layer, and correspondingly, the second-type semiconductor layer 4 may be, but is not limited to, a P-type gallium nitride layer.

[0123] It should be noted that in the embodiments of the present application, in order to highlight the technical features of the present application, only one epitaxial stacking unit is illustrated in the figure. In actual product applications, it may include thousands of epitaxial stacking units, depending on the application of the LED chip product. The present application does not limit this.

[0124] Based on the above, in one embodiment of the present application, the first insulating layer 6 exposes a portion of the transparent conductive layer 5 to form a step, and the second electrode 7 extends to the surface of the first insulating layer 6 through the step.

[0125] Based on the above, in one embodiment of the present application, the projection of the second electrode 7 on the transparent conductive layer 5 and the projection of the second electrode 7 on the first insulating layer 6 have an area S a and the projection area of ​​the second electrode 7 on the transparent conductive layer 5 is S1, then 0<S a ≤S1 / 2.

[0126] Based on the above, in one embodiment of the present application, the step is arranged around the edge of the second hole 5.1.

[0127] On the basis of the above, in one embodiment of the present application, the transparent conductive layer 5 covers at least 80% of the area of ​​the light-emitting table 11 except the second hole 5.1. Further, the edge of the transparent conductive layer 5 is located on the inner side of the edge of the second-type semiconductor layer 4, and the two have a spacing d, which is not greater than 2.5μm. Preferably, in some embodiments, the spacing d is not greater than 1.5μm, for example, 1μm. By reducing the distance from the edge of the transparent conductive layer 5 to the edge of the second-type semiconductor layer 4, the area of ​​the transparent conductive layer 5 is increased, and then the area of ​​the light-emitting area is increased, so as to further improve the brightness of the light-emitting diode.

[0128] Based on the above, in one embodiment of the present application, the second insulating layer 9 covers the light-emitting mesas and the grooves in a manner of being maintained on the exposed surface of the first-type semiconductor layer 2, and exposes part of the surface of the first electrode 8 and the second electrode 7.

[0129] Based on the above, in one embodiment of the present application, the second electrode 7 has a metal reflective layer.

[0130] Based on the above, in one embodiment of the present application, the bottom layer of the second electrode 7 is the metal reflective layer.

[0131] Based on the above, in one embodiment of the present application, the metal reflective layer includes one or more of Ag, Ni, Al, Rh, Pd, Ir, Ru, Mg, Zn, Pt and Au.

[0132] Based on the above, in one embodiment of the present application, the transparent conductive layer 5 includes a metal film or a metal oxide layer.

[0133] Based on the above, in one embodiment of the present application, the metal film includes one or more of gold, silver, platinum, copper, aluminum, chromium and palladium.

[0134] Based on the above, in one embodiment of the present application, the metal oxide layer includes one or more of indium oxide, indium tin oxide, zirconium oxide, cadmium oxide, and titanium nitride.

[0135] Based on the above, in one embodiment of the present application, the second insulating layer 9 includes but is not limited to one or more of silicon oxide and magnesium fluoride.

[0136] Through the above technical solution, it can be known that the LED chip provided by the present invention is arranged by: the epitaxial stack includes a first-type semiconductor layer 2, an active area 3 and a second-type semiconductor layer 4 stacked in sequence along a first direction; and a local area of ​​the epitaxial stack is etched to the first-type semiconductor layer 2 to form a groove 10 and a light-emitting table 11; the transparent conductive layer 5 is stacked on the light-emitting table 11 and has a second hole 5.1 exposing a portion of the second-type semiconductor layer 4; the first insulating layer 6 is formed on the side surface of the transparent conductive layer 5 away from the epitaxial stack; the first electrode 8 is stacked on a portion of the surface of the groove 10 and is arranged away from the light-emitting table 11; the second electrode 7 extends to a portion of the surface of the first insulating layer 6 by being arranged in the second hole 5.1; the second insulating layer 9 is arranged on the surface of the epitaxial stack and at least a portion of the surface of the first electrode 8 and the second electrode 7 is exposed. Based on the above configuration, the first insulating layer 6 and the transparent conductive layer 5, the second insulating layer 9, and the second electrode 7 have a composite region, so that an ODR structure is formed through the mutual structural relationship of the transparent conductive layer 5, the first insulating layer 6, the second electrode 7, and the second insulating layer 9, and the light can be totally reflected in the composite region, so that the light corresponding to the composite region of the second electrode 7 is reflected and then taken out from the upper surface of the LED chip, thereby effectively improving the light extraction efficiency. At the same time, based on the above configuration, the second insulating layer 9 is arranged on the surface of the epitaxial stack and part of the surface of the first electrode 8 / the second electrode 7, and the first insulating layer 6 and the second insulating layer 9 with different extension directions can be formed at the edge of the second electrode 7 to construct a connection structure with an angle, which can effectively alleviate the diffusion of tensile stress generated by the LED chip in special environments (such as high temperature and high pressure, etc.), thereby increasing the risk of solder collapse or solder cracking of the functional dielectric layer (such as the transparent conductive layer 5, the insulating layer, etc.), thereby affecting the reliability of the LED chip; and the waterproof vapor resistance of the LED chip is improved through the double protection of the first insulating layer 6 and the second insulating layer 9.

[0137] Secondly, by setting the first insulating layer 6 to expose part of the transparent conductive layer 5 to form a step, and the second electrode 7 extends to the surface of the first insulating layer 6 through the step, the electrode contact area can be increased through the step, thereby dispersing stress and reducing the risk of local failure.

[0138] Then, by setting: the projection of the second electrode 7 on the transparent conductive layer 5 and the projection of the second electrode 7 on the first insulating layer 6 have an area S a and the projection area of ​​the second electrode 7 on the transparent conductive layer 5 is S1, then 0<S a≤S1 / 2. Thus, while ensuring the contact area between the second electrode 7 and the transparent conductive layer 5 to reduce the contact resistance, the size of the recombination region is ensured to improve the ODR reflection effect.

[0139] Example 2

[0140] The embodiment of the present invention provides a method for preparing an LED chip, which is used to prepare the LED chip described in embodiment 1. The preparation method comprises the following steps:

[0141] S01, such as Figure 2 As shown, a substrate 1 is provided;

[0142] It should be noted that the type of the substrate 1 is not limited in the LED chip of this embodiment. For example, the substrate 1 can be, but is not limited to, a sapphire substrate or a silicon substrate.

[0143] S02, such as Figure 3 As shown, an epitaxial stack is grown, the epitaxial stack comprising a first-type semiconductor layer 2, an active region 3, and a second-type semiconductor layer 4 sequentially stacked along a first direction; wherein the first direction is perpendicular to the substrate 1 and points from the substrate 1 to the epitaxial stack;

[0144] It should be noted that, in an embodiment of the present invention, the first-type semiconductor layer 2 may be an N-type semiconductor layer, and correspondingly, the second-type semiconductor layer 4 may be a P-type semiconductor layer; for example, the first-type semiconductor layer 2 may be but is not limited to an N-type gallium nitride layer, and correspondingly, the second-type semiconductor layer 4 may be but is not limited to a P-type gallium nitride layer.

[0145] S03, such as Figure 4 As shown, the epitaxial stack is deeply etched until the surface of the substrate 1 is exposed, thereby forming a plurality of epitaxial stack units that are independent of each other through trenches;

[0146] In one embodiment of the present application, the epitaxial stack is deeply etched to expose the surface of the substrate 1 to form a plurality of epitaxial stack units spaced apart from each other by grooves; including: using an inductively coupled plasma (ICP) process, the etching gas includes: Cl2, Ar and O2. However, the present application does not limit this, and it depends on the specific situation.

[0147] It should be noted that in the embodiments of the present application, in order to highlight the technical features of the present application, only one epitaxial stacking unit is illustrated in the figure. In actual product applications, it may include thousands of epitaxial stacking units, depending on the application of the LED chip product. The present application does not limit this.

[0148] S04, such as Figure 5As shown, each of the epitaxial stacking units is etched to expose part of the first-type semiconductor layer 2, thereby forming a groove 10 and a light-emitting mesa 11;

[0149] In one embodiment of the present application, etching the epitaxial stack to form the groove 10 and the light-emitting mesa 11 includes: using an inductively coupled plasma (ICP) process, and the etching gas includes: Cl2, Ar and O2, but the present application does not limit this, and it depends on the specific situation.

[0150] In one embodiment of the present application, the groove is disposed at the first end portion of the LED chip.

[0151] In one embodiment of the present application, the exposed surface of the first-type semiconductor layer is disposed around the periphery of the light-emitting mesa 11 .

[0152] S05, such as Figure 6 As shown, a transparent conductive layer 5 is formed on the light-emitting mesa 11, wherein the transparent conductive layer 5 has a second hole 5.1 exposing a portion of the second-type semiconductor layer 4;

[0153] On the basis of the above, in one embodiment of the present application, the transparent conductive layer 5 covers at least 80% of the area of ​​the light-emitting table 11 except the second hole 5.1. Further, the edge of the transparent conductive layer 5 is located on the inner side of the edge of the second-type semiconductor layer 4, and the two have a spacing d, which is not greater than 2.5μm. Preferably, in some embodiments, the spacing d is not greater than 1.5μm, for example, 1μm. By reducing the distance from the edge of the transparent conductive layer 5 to the edge of the second-type semiconductor layer 4, the area of ​​the transparent conductive layer 5 is increased, and then the area of ​​the light-emitting area is increased, so as to further improve the brightness of the light-emitting diode.

[0154] In one embodiment of the present application, the transparent conductive layer 5 includes a metal film or a metal oxide layer.

[0155] Based on the above, in one embodiment of the present application, the metal film includes one or more of gold, silver, platinum, copper, aluminum, chromium and palladium.

[0156] Based on the above, in one embodiment of the present application, the metal oxide layer includes one or more of indium oxide, indium tin oxide, zirconium oxide, cadmium oxide, and titanium nitride.

[0157] S06, depositing a transparent dielectric layer, the transparent dielectric layer covers the exposed surface of each epitaxial stacking unit; then, coating the surface of the transparent dielectric layer with photoresist, and performing masking and etching processes to obtain a transparent dielectric layer located on the surface of the transparent conductive layer 5, so as to form a transparent conductive layer 5 as shown in FIG. Figure 7 The first insulating layer 6 shown;

[0158] Based on the above, in one embodiment of the present application, the transparent medium layer includes one or more materials such as silicon oxide, titanium oxide, silicon nitride, aluminum oxide, magnesium fluoride, spin-on glass (SOG), polymer, etc.

[0159] Based on the above, in one embodiment of the present application, the first insulating layer 6 exposes a portion of the transparent conductive layer 5 to form a step.

[0160] Based on the above, in one embodiment of the present application, the step is arranged around the edge of the second hole 5.1.

[0161] S07, such as Figure 8 As shown, a first electrode 8 and a second electrode 7 are manufactured;

[0162] The first electrode 8 is stacked on a portion of the surface of the groove 10 and is disposed away from the light-emitting table 11;

[0163] The second electrode 7 is arranged in the second hole 5.1 and extends to a portion of the surface of the first insulating layer 6; further, the second electrode 7 extends to the surface of the first insulating layer 6 through the step.

[0164] Based on the above, in one embodiment of the present application, the projection of the second electrode 7 on the transparent conductive layer 5 and the projection of the second electrode 7 on the first insulating layer 6 have an area S a and the projection area of ​​the second electrode 7 on the transparent conductive layer 5 is S1, then 0<S a ≤S1 / 2.

[0165] In this embodiment, the first electrode 8 and the second electrode 7 can be metal electrodes, that is, they are made of metal materials, for example: at least one of nickel, gold, chromium, titanium, platinum, palladium, rhodium, iridium, aluminum, tin, indium, tantalum, copper, cobalt, iron, ruthenium, zirconium, tungsten and molybdenum, or at least one of alloys or laminates selected from the above materials.

[0166] In one embodiment of the present application, the second electrode 7 has a metal reflective layer.

[0167] On the basis of the above, in one embodiment of the present application, the bottom layer of the second electrode 7 is the metal reflective layer. Further, the metal reflective layer includes one or more of Ag, Ni, Al, Rh, Pd, Ir, Ru, Mg, Zn, Pt and Au.

[0168] S08, such as Fig. 9As shown, a second insulating layer 9 is formed, which is disposed on the surface of the epitaxial stack and exposes at least a portion of the surface of the first electrode 8 and the second electrode 7. Further, the second insulating layer 9 covers the light-emitting mesa 11 and the groove 10 in a manner of being maintained on the exposed surface of the first-type semiconductor layer 2, and exposes a portion of the surface of the first electrode 8 and the second electrode 7.

[0169] Based on the above, in one embodiment of the present application, the second insulating layer 9 includes but is not limited to one or more of silicon oxide and magnesium fluoride.

[0170] S09, cutting along the channel, and finally obtaining a plurality of Fig.10 The LED light-emitting unit shown.

[0171] Example 3

[0172] See also Fig.11 This is a schematic diagram of the cross-sectional structure of the LED chip provided in Example 3 of the present invention. Compared with the LED chip in Example 1 of the present invention, the difference of the LED chip in Example 3 is mainly that: a third insulating layer 12 is further provided on the surface of the groove 10, and the third insulating layer 12 has a first hole 12.1 exposing a portion of the first-type semiconductor layer 2; the first electrode 8 is laminated on the surface of the third insulating layer 12 by embedding the first hole 12.1. Thereby, the stability of the first electrode 8 is further improved.

[0173] It should be noted that, based on the above, in one embodiment of the present application, the first insulating layer 6 and the third insulating layer can be formed simultaneously by photolithography of the transparent dielectric layer in step S06 of embodiment 2.

[0174] Example 4

[0175] See also Fig.12 The schematic diagram of the cross-sectional structure of the LED chip provided in Example 4 of the present invention. Compared with the LED chip in Example 1 of the present invention, the difference of the LED chip in Example 4 is mainly that: a current blocking layer 13 is provided on the bottom surface of the second hole 5.1; further, the current blocking layer 13 and the transparent conductive layer 5 form a spacing groove, and the second electrode 7 is embedded in the spacing groove to form contact with the second type semiconductor layer 4. Thus, while improving the current concentration phenomenon and promoting the lateral expansion of the current, the mutual structural relationship of the second electrode 7, the first insulating layer 6 (dielectric layer), the spacing groove, the current blocking layer 13 (dielectric layer) and the transparent conductive layer 5 (conductive layer) forms an ODR structure again, which is conducive to increasing the total reflection layer area under the second electrode 7 and further improving the reflection efficiency.

[0176] On the basis of the above, in one embodiment of the present application, the projection area of ​​the current blocking layer 13 on the transparent conductive layer 5 is S2, and the bottom area of ​​the second hole 5.1 is S3, then 0<S2≤S3 / 2. Thus, while ensuring the current blocking and total reflection effects, the contact area between the second electrode 7 and the second-type semiconductor layer 4 is ensured to improve the reliability of the electrode welding wire. It should be noted that the specific area of ​​the current blocking layer 13 only needs to meet the above requirements, and this application will not go into details here. Similarly, the shape of the current blocking layer 13 can be a trapezoid, a square or a rectangle, and this application will not go into details here.

[0177] It should be noted that, based on the above, in one embodiment of the present application, the first insulating layer 6 and the current blocking layer 13 can be formed simultaneously by photolithography of the transparent dielectric layer in step S06 of embodiment 2.

[0178] Example 5

[0179] See also Fig.13 A schematic diagram of the cross-sectional structure of the LED chip provided in Example 5 of the present invention. Compared with the LED chip in Example 1 of the present invention, the difference of the LED chip in Example 5 is mainly that: the first electrode 8 includes a first electrode pad arranged at the first end of the LED chip, and the second hole 5.1 is formed at the second end of the LED chip; the second electrode 7 includes a second electrode pad and at least one electrode extension strip 14 connected to the second electrode pad, wherein the second electrode pad extends to the surface of the first insulating layer 6 by being arranged in the second hole 5.1, and the electrode extension strip 14 extends from the second electrode pad toward the second end of the LED chip; thereby, the current can be better guided and expanded through the electrode extension strip 14 to avoid current crowding. It should be noted that the material, shape and structure of the electrode extension strip 14 only need to meet the requirements of electrode extension guidance, and this application will not elaborate on it in detail.

[0180] Furthermore, the first electrode 8 may also include an electrode extension strip connected to the first electrode pad and extending toward the first end portion, which will not be described in detail in the present application.

[0181] On the basis of the above, in one embodiment of the present application, at least a portion of the electrode extension strip 14 is in contact with the transparent conductive layer 5 .

[0182] Based on the above, in one embodiment of the present application, the electrode extension strip 14 has interdigitated fingers, and the interdigitated fingers are embedded in the first insulating layer 6 through perforations to form contact with the transparent conductive layer 5. Alternatively, the transparent conductive layer 5 has perforations, and the electrode extension strip 14 has interdigitated fingers, and the interdigitated fingers are formed in and maintained in the perforations of the transparent conductive layer 5.

[0183] It should be emphasized that in other embodiments, embodiment 5 and embodiment 4 may be used in combination, and this application will not go into details here.

[0184] Example 6

[0185] See also Fig.14 The schematic diagram of the cross-sectional structure of the LED chip provided in Example 6 of the present invention. Compared with the LED chip in Example 1 of the present invention, the difference of the LED chip in Example 6 of this embodiment is mainly that: the LED chip also includes a refractive index matching layer 15, and the refractive index matching layer 15 is arranged on the surface of the second insulating layer 9 away from the epitaxial stack and forms a gradient refractive index structure with the second insulating layer 9, so as to further improve the light extraction efficiency; preferably, the refractive index of the refractive index matching layer 15 is not less than the refractive index of the second insulating layer 9. Further, the first insulating layer 6 or the second insulating layer 9 includes a layered structure composed of one or more of SiO2 and MgF2, and the refractive index matching layer 15 may include a layered structure composed of one or more of TiO2, Si3N4, and Al2O3. Preferably, the second insulating layer 9 is a SiO2 layer, and the refractive index matching layer 15 is an Al2O3 layer. Through the excellent passivation performance of Al2O3, the dangling bonds and defect states on the surface of SiO2 can be effectively covered, and the non-radiative recombination of carriers on the surface can be reduced. The reduction in non-radiative recombination directly increases the internal quantum efficiency (IQE), which means that more electrical energy is converted into light energy rather than heat.

[0186] Example 7

[0187] See also Fig.15 The cross-sectional structure diagram of the LED chip provided in Example 7 of the present invention. Compared with the LED chip in Example 1 of the present invention, the difference of the LED chip in Example 7 is mainly that: a reflective layer 16 is also provided on the surface of the substrate 1 on the side away from the epitaxial stack. Furthermore, the reflective layer 16 includes a distributed Bragg reflective layer composed of alternating stacks of high refractive index material layers and low refractive index material layers, and the reflective layer can also be a metal reflective layer. As long as the material meets the requirements of the distributed Bragg reflective layer / metal reflection, the present application will not elaborate on it here.

[0188] Example 8

[0189] See also Fig.16 The cross-sectional structure diagram of the LED chip provided in Example 8 of the present invention. Compared with the LED chip in Example 1 of the present invention, the difference of the LED chip in Example 7 is mainly that: the exposed surface of the first-type semiconductor layer is only arranged in the groove, and it is not arranged around the periphery of the light-emitting table 11, so the second insulating layer 9 does not completely cover the epitaxial stack.

[0190] Based on the above embodiments, in actual application, any two or more of the above embodiments may be used in combination, depending on the requirements of the technical solution of the specific product, and this application does not limit this.

[0191] It should also be noted that the LED chips provided in the above embodiments are also applicable to high-voltage LED chips, and the high-voltage LED chips electrically interconnect the adjacent LED light-emitting units described in any of the above embodiments through bridge electrodes; wherein an insulating layer is also provided in the groove, and the bridge electrode connects two adjacent LED units by being stacked on the insulating layer. The specific structure, performance and advantages thereof can be referred to the above contents, and will not be described in detail here.

[0192] In addition, the present invention also provides a light-emitting device, which includes a light-emitting diode. The light-emitting diode uses an LED chip or a high-voltage LED chip as provided in the above embodiments. Its specific performance and advantages can be referred to the above content and will not be elaborated here.

[0193] The device provided in the embodiment of the present invention has the same implementation principle and technical effects as the aforementioned method embodiment. For the sake of brief description, for matters not mentioned in the device embodiment, reference can be made to the corresponding contents in the aforementioned method embodiment. Those skilled in the art can clearly understand that for the convenience and simplicity of description, the specific working processes of the aforementioned systems, devices and units can all refer to the corresponding processes in the aforementioned method embodiment, and will not be repeated here.

[0194] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0195] It should also be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "comprises", "comprising" or any other variants thereof are intended to cover non-exclusive inclusion, so that an article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such article or device. In the absence of further restrictions, the elements defined by the sentence "comprising a ..." do not exclude the existence of other identical elements in the article or device including the above elements.

[0196] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present application. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to the embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. An LED chip, comprising a substrate and a plurality of LED light-emitting units arranged on the surface of the substrate and isolated from each other by grooves, characterized in that: The LED light emitting unit comprises: An epitaxial stack is arranged on the surface of the substrate; the epitaxial stack comprises a first-type semiconductor layer, an active region and a second-type semiconductor layer stacked in sequence along a first direction; and a local area of ​​the epitaxial stack is etched to the first-type semiconductor layer to form a groove and a light-emitting table; wherein the first direction is perpendicular to the substrate and points from the substrate to the epitaxial stack; A transparent conductive layer, which is stacked on the light-emitting mesa and has a second hole exposing a portion of the second-type semiconductor layer; A first insulating layer formed on a surface of the transparent conductive layer facing away from the epitaxial stack; A first electrode, which is stacked on a portion of the surface of the groove and is disposed away from the light-emitting mesa; A second electrode, which is arranged in the second hole and extends to a portion of the surface of the first insulating layer; The second insulating layer is disposed on the surface of the epitaxial stack and exposes at least a portion of the surface of the first electrode and the second electrode.

2. The LED chip according to claim 1, characterized in that: The first insulating layer exposes a portion of the transparent conductive layer to form a step, and the second electrode extends to a surface of the first insulating layer through the step.

3. The LED chip according to claim 1, characterized in that: The projection of the second electrode on the transparent conductive layer and the projection of the second electrode on the first insulating layer have an area S a and the projection area of ​​the second electrode on the transparent conductive layer is S1, then 0<S a ≤S1 / 2.

4. The LED chip according to claim 2, characterized in that: The step is arranged around the edge of the second hole.

5. The LED chip according to claim 1, characterized in that: A current blocking layer is provided on the bottom surface of the second hole.

6. The LED chip according to claim 5, characterized in that: The current blocking layer and the transparent conductive layer form a separation groove, and the second electrode is embedded in the separation groove to form contact with the second-type semiconductor layer.

7. The LED chip according to claim 6, characterized in that: The projection area of ​​the current blocking layer on the transparent conductive layer is S2, and the bottom area of ​​the second hole is S3, then 0<S2≤S3 / 2.

8. The LED chip according to claim 7, characterized in that: The first insulating layer and the current blocking layer are formed simultaneously by photolithography of a transparent dielectric layer.

9. The LED chip according to claim 3, characterized in that: The transparent medium layer includes one or more of silicon oxide, silicon nitride, aluminum oxide, and magnesium fluoride.

10. The LED chip according to claim 1, characterized in that: A third insulating layer is further provided on the surface of the groove, and the third insulating layer has a first hole exposing a portion of the first-type semiconductor layer; and the first electrode is stacked on the surface of the third insulating layer by being embedded in the first hole.

11. The LED chip according to claim 10, characterized in that: The first insulating layer and the third insulating layer are formed simultaneously by photolithography of a transparent dielectric layer.

12. The LED chip according to claim 1, characterized in that: The LED chip further includes a refractive index matching layer, which is disposed on a surface of the second insulating layer facing away from the epitaxial stack and forms a gradient refractive index structure with the second insulating layer, and the refractive index of the refractive index matching layer is not less than the refractive index of the second insulating layer.

13. The LED chip according to claim 1, characterized in that: A reflective layer is also provided on the surface of the substrate on the side facing away from the epitaxial stack.

14. The LED chip according to claim 1, characterized in that: The first electrode includes a first electrode pad arranged at the first end of the LED chip, and the second hole is formed at the second end of the LED chip; the second electrode includes a second electrode pad and at least one electrode extension strip connected to the second electrode pad, wherein the second electrode pad extends to the surface of the first insulating layer by being arranged in the second hole, and the electrode extension strip extends from the second electrode pad toward the second end of the LED chip.

15. The LED chip according to claim 14, characterized in that: At least a portion of the electrode extension strip is in contact with the transparent conductive layer.

16. The LED chip according to claim 18, characterized in that: The electrode extension strip has interdigitated fingers, and the interdigitated fingers are embedded in the first insulating layer through perforations to form contact with the transparent conductive layer.

17. The LED chip according to claim 1, characterized in that: The second insulating layer covers the light emitting mesa and the groove in a manner of being maintained on an exposed surface of the first-type semiconductor layer.

18. A high voltage LED chip, characterized in that: The high-voltage LED chip electrically interconnects the adjacent LED light-emitting units described in any one of claims 1 to 17 through a bridging electrode; wherein an insulating layer is also provided in the groove, and the bridging electrode connects two adjacent LED units by being stacked on the insulating layer.

19. A light emitting device, characterized in that: The light emitting device comprises a light emitting diode, and the light emitting diode adopts the LED chip as claimed in any one of claims 1 to 17.

20. A light emitting device, characterized in that: The light emitting device comprises a light emitting diode, and the light emitting diode adopts the high-voltage LED chip as claimed in claim 18.

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