Method for preparing light-emitting element and light-emitting element

Abstract

The present invention provides a method for preparing a light-emitting element, relating to the field of semiconductor technology. The method comprises the following steps: sequentially growing a buffer layer, an N-type semiconductor layer, a quantum well layer, and a P-type semiconductor layer on a substrate; etching through the P-type semiconductor layer and the quantum well layer to completely isolate the LED core particles in the quantum well layer to form independent LED pixel core particles; depositing a current spreading layer on the P-type semiconductor layer; depositing a current blocking layer on the current spreading layer; transferring the LED chip to a driver circuit substrate, and completing packaging. The technical solution provided by the present invention can eliminate the processing steps of laser substrate stripping, removal of residual metal gallium, thin-film encapsulation of LED core particles, and subsequent cover plate gluing and vacuum bonding in module packaging in MicroLED mass transfer technology, greatly reducing the difficulty of engineering implementation.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor technology, and in particular to a method for preparing a light-emitting element and the light-emitting element. Background Art

[0002] Micro-LED display is a new display technology composed of micron-sized LED arrays. Compared with existing mainstream display technologies (LCD, OLED, etc.), it has the advantages of self-luminescence, high efficiency, low power consumption, flexibility, high transparency, integration, interactivity, high stability, and all-weather operation. It is considered a display technology with full functions and full application areas. However, it also faces the current situation of low yield, high cost, and poor mass production. Specific challenges are reflected in achieving micron-scale LED chip size consistency and efficiency decline, high-speed and large-scale transfer of Micro-LED chips, bonding of Micro-LED chips to driver chips or backplanes, full-color display, high light extraction efficiency and high contrast, low-power drive technology, detection and repair, and how to achieve splicing technology for large-scale displays.

[0003] Currently, Micro LED display modules mainly use Micro LED chips and driver backplanes to achieve electrical interconnection after bonding, which is mass transfer. The driver backplane includes a glass substrate LTPS / LTPO driver backplane, a silicon-based CMOS driver backplane, or a flexible PET / PI substrate driver backplane. After the Micro LED chip and the driver backplane are powered, they can be lit up to display dynamic images.

[0004] However, the current mass transfer process generally involves preparing the bonding metal between the Micro LED and the driver backplane, preparing pixel spacers, flip-chip bonding, laser lift-off of the Micro LED substrate, cleaning residual gallium metal, thin-film encapsulation, and finally module packaging. High-energy laser irradiation can easily damage the epitaxial layer, and residual gallium ions from laser bonding are difficult to completely remove. Wet removal of residual gallium ions can also damage the epitaxial layer. Summary of the Invention

[0005] The main purpose of the present invention is to provide a method for preparing a light-emitting element and a light-emitting element, aiming to improve the technical problems in the prior art that high-energy laser irradiation is easy to damage the epitaxial layer, the residual gallium ions left by laser decomposition are difficult to remove completely, and the wet method of removing residual gallium ions is easy to damage the epitaxial layer.

[0006] To achieve the above object, the present invention provides a method for preparing a light-emitting element, comprising the following steps:

[0007] A buffer layer, an N-type semiconductor layer, a quantum well layer, and a P-type semiconductor layer are sequentially grown on the substrate;

[0008] Etching through the P-type semiconductor layer and the quantum well layer so that each LED pixel core in a single LED chip is disconnected at the quantum well layer to form an independent LED pixel core;

[0009] depositing a current spreading layer on the P-type semiconductor layer;

[0010] depositing a current blocking layer on the current spreading layer;

[0011] Transfer the LED chip to the driver circuit substrate and complete the packaging.

[0012] Optionally, transferring the LED chip to the driver circuit substrate and completing the packaging includes the following steps:

[0013] Use vacuum evaporation method to plate P-type electrode, N-type electrode and LED bonding metal;

[0014] Performing sidewall protection on the N-type semiconductor layer, the quantum well layer, the P-type semiconductor layer, the current spreading layer, and the P-type electrode;

[0015] Filling the gaps between the LED pixel core particles with a black matrix layer using a photolithography method;

[0016] The driving backplane is plated with driving backplane bonding metal In or InSn or AuSn columns by vacuum evaporation method;

[0017] Use photolithography to make the insulating isolation column between the drive backplane bonding metal

[0018] The LED chip is welded to the driver backplane using flip-chip bonding cold pressure welding technology.

[0019] Optionally, the step of performing sidewall protection on the N-type semiconductor layer, the quantum well layer, the P-type semiconductor layer, the current spreading layer, and the P-type electrode includes:

[0020] PEALD atomic layer deposition of Al2O3 thin film encapsulation layer;

[0021] Inductively coupled plasma is used to etch Al2O3 to expose the LED bonding metal.

[0022] Optionally, the step of depositing a current spreading layer on the P-type semiconductor layer includes:

[0023] Depositing an ITO layer on the surface of the P-type semiconductor layer by a magnetron sputtering process;

[0024] The deposition thickness of the ITO layer is controlled to be 100 Å-1000 Å to form a P-type ohmic contact after annealing.

[0025] Optionally, the step of depositing a current blocking layer on the current spreading layer includes:

[0026] A SiO2 film is deposited on the current spreading layer at 200° C.-400° C. using a plasma enhanced vapor deposition method.

[0027] In addition, to achieve the above-mentioned purpose, the present invention also provides a light-emitting element, including a substrate, an N-type semiconductor layer, a quantum well layer, a P-type semiconductor layer, a current spreading layer, a current blocking layer, a thin film encapsulation layer, an LED bonding metal, a P-type electrode, an N-type electrode, a black matrix layer, a driving backplane bonding metal, a driving backplane pixel electrode, a driving backplane common electrode, an insulating isolation column, and a driving backplane pad;

[0028] Wherein, each LED chip is connected to the driving backplane bonding metal through the LED bonding metal.

[0029] Optionally, each LED chip is connected to the pixel electrode of the driving backplane through the P-type semiconductor layer, and each LED is connected to the common electrode of the driving backplane through the N-type semiconductor layer to form a loop.

[0030] Optionally, each LED chip shares the N-type semiconductor layer and is connected to the LED bonding metal via the N-type electrode.

[0031] Optionally, each LED chip uses the P-type semiconductor layer exclusively and is connected to the LED bonding metal via the P-type electrode.

[0032] In the technical solution provided by the present invention, a Micro LED structure and its preparation method are proposed to address the complex processing technology and difficulty after mass transfer. This can eliminate processing steps such as laser stripping of the substrate, removal of residual metal gallium, thin-film packaging of LED core particles, and cover plate gluing and vacuum bonding in subsequent module packaging, greatly reducing the difficulty of engineering implementation. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying any creative work.

[0034] Figure 1 A schematic structural diagram of an embodiment of a light-emitting element provided by the present invention;

[0035] Figure 2 A schematic flow chart of an embodiment of a method for preparing a light-emitting element provided by the present invention;

[0036] Figure 3 A schematic flow chart of an embodiment of a method for preparing a light-emitting element provided by the present invention;

[0037] Figure 4 A schematic diagram of the structure of the quantum well layer of the light-emitting element provided by the present invention;

[0038] Figure 5 This is a top view of the light-emitting element provided by the present invention.

[0039] Description of Figure Numbers:

[0040] Label name Label name 100 Light-emitting element 111 P-type electrode 101 substrate 112 Current spreading layer 102 quantum well layer 113 Black matrix layer 103 N-type semiconductor layer 114 N-type electrode 104 LED bonding metal 115 P-type semiconductor layer 105 Driving backplane pixel electrodes 116 Thin film encapsulation layer 106 Insulation isolation column 107 Driver backplane bonding metal 108 Driving backplane common electrode 109 Driver backplane pad 110 Current blocking layer

[0041] The purpose, features and advantages of the present invention will be further described with reference to the accompanying drawings and in conjunction with the embodiments. DETAILED DESCRIPTION

[0042] To make the objectives, technical solutions, and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with specific embodiments and with reference to the accompanying drawings. The technical solutions in the present invention are clearly and completely described. Obviously, the embodiments described are part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0043] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. However, it should be understood that these descriptions are exemplary only and are not intended to limit the scope of the present invention. In the following detailed description, for ease of explanation, many specific details are set forth to provide a comprehensive understanding of embodiments of the present invention. However, it is apparent that one or more embodiments may also be implemented without these specific details. In addition, in the following description, descriptions of known structures and technologies are omitted to avoid unnecessary confusion of the concept of the present invention.

[0044] The terms used herein are only for describing specific embodiments and are not intended to limit the present invention. The terms "comprise", "include", etc. used herein indicate the presence of the features, steps, operations and / or components, but do not exclude the presence or addition of one or more other features, steps, operations or components.

[0045] All terms used herein (including technical and scientific terms) have the meanings commonly understood by those skilled in the art unless otherwise defined. It should be noted that the terms used herein should be interpreted as having a meaning consistent with the context of this specification and should not be interpreted in an idealized or overly rigid manner.

[0046] When expressions such as “at least one of A, B, and C, etc.” are used, they should generally be interpreted in accordance with the meaning commonly understood by those skilled in the art (e.g., “a system having at least one of A, B, and C” should include but is not limited to systems having A alone, B alone, C alone, A and B, A and C, B and C, and / or A, B, and C, etc.). When expressions such as “at least one of A, B, or C, etc.” are used, they should generally be interpreted in accordance with the meaning commonly understood by those skilled in the art (e.g., “a system having at least one of A, B, or C” should include but is not limited to systems having A alone, B alone, C alone, A and B, A and C, B and C, and / or A, B, and C, etc.).

[0047] It should be noted that if a directional indication is involved in an embodiment of the present invention, the directional indication is only used to explain the relative position relationship, movement status, etc. between the components in a certain specific posture. If the specific posture changes, the directional indication will also change accordingly.

[0048] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present invention, the descriptions of "first", "second", etc. are only for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of such features. In addition, the meaning of "and / or" appearing throughout the text includes three parallel schemes. Taking "A and / or B" as an example, it includes scheme A, or scheme B, or a scheme in which A and B are satisfied at the same time. In addition, the technical solutions between the various embodiments can be combined with each other, but it must be based on the ability of ordinary technicians in this field to implement it. When the combination of technical solutions is mutually contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0049] In the description of the present invention, it should be noted that the terms "upper", "lower", "top", "bottom", "inside", "outside", etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, they cannot be understood as limiting the present invention.

[0050] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed, detachable, or integral connections; mechanical or electrical connections; direct or indirect connections through an intermediate medium; and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on the specific circumstances.

[0051] In addition, in the description of the present invention, unless otherwise specified, "plurality", "multiple roots" and "multiple groups" mean two or more.

[0052] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0053] The current mass transfer process generally involves preparing the bonding metal between the Micro LED and the driver backplane, preparing pixel spacers, flip-chip bonding, laser lift-off of the Micro LED substrate, cleaning residual gallium metal, thin-film encapsulation, and finally module packaging. However, high-energy laser irradiation can easily damage the epitaxial layer, residual gallium ions from laser bonding are difficult to completely remove, and wet removal of residual gallium ions can easily damage the epitaxial layer, among other defects.

[0054] In view of this, the present invention provides a method for preparing a light-emitting element and a light-emitting element, aiming to solve the above problems. Figure 1-Figure 5 , Figure 2 FIG. 1 is a flow chart of an embodiment of a method for preparing a light-emitting element according to the present invention. In one embodiment, the method for preparing a light-emitting element includes the following steps:

[0055] Step S10 : sequentially growing a buffer layer, an N-type semiconductor layer 103 , a quantum well layer 102 , and a P-type semiconductor layer 115 on the substrate 101 .

[0056] Step S20 : ​​etching through the P-type semiconductor layer 115 and the quantum well layer 102 , so that each LED pixel core in a single LED chip is disconnected at the quantum well layer 102 to form an independent LED pixel core.

[0057] Step S30 : depositing a current spreading layer 112 on the P-type semiconductor layer 115 .

[0058] Step S40 : depositing a current blocking layer 110 on the current spreading layer 112 .

[0059] Step S50: transferring the LED chip to the driving circuit substrate and completing the packaging.

[0060] The substrate material of a semiconductor device is also called the substrate material, and epitaxial layers are grown on this substrate material. A variety of LED substrate materials are available. In this embodiment, a sapphire substrate is used, which has the advantages of good chemical stability, no absorption of visible light, and good light transmittance. The buffer layer and light-emitting structure are grown on the sapphire substrate using metal organic chemical vapor deposition (MOCVD). The light-emitting structure includes an N-type semiconductor layer 103, a quantum well layer 102, and a P-type semiconductor layer 115, which are formed in sequence and constitute the epitaxial layer of the chip.

[0061] The entire epitaxial wafer is etched using inductively coupled plasma down to the N-type semiconductor layer 103 to create independent LED pixel cores. The specific etching depth varies depending on the thickness of the epitaxial wafer, but is generally between 2 and 15 μm. The etching penetrates the P-type semiconductor layer 115 and the quantum well layer 102, isolating each LED pixel core within a single LED chip at the quantum well layer 102, forming independent LED pixel cores capable of emitting light.

[0062] The above-mentioned matrix LED light-emitting element structure usually uses a single LED pixel core to complete the transfer of the LED pixel core to the driver backplane through repeated eutectic bonding, laser stripping of the substrate, cleaning of residual gallium ions, UV dispensing and cover glass packaging protection. Among them, laser stripping of the substrate is particularly prone to damage the epitaxial layer, causing damage to the electrical or optical properties of the light-emitting element. The above-mentioned light-emitting element structure and preparation scheme can eliminate the processes such as laser stripping of the substrate, UV dispensing and cover glass packaging, effectively reducing the process difficulty and cost.

[0063] Furthermore, in this embodiment, step S50 includes the following steps:

[0064] Step S501 : vacuum evaporation is used to deposit the P-type electrode 111 , the N-type electrode 114 and the LED bonding metal 104 .

[0065] Step S502: performing sidewall protection on the N-type semiconductor layer 103, the quantum well layer 102, the P-type semiconductor layer 115, the current spreading layer 112, and the P-type electrode.

[0066] Step S503: Filling the gaps between the LED pixel chips with a black matrix layer 113 using a photolithography method.

[0067] Step S504: using vacuum evaporation to deposit a driving backplane bonding metal 107In column or a bonding metal InSn column or a bonding metal AuSn column.

[0068] Step S505 : using photolithography to form the insulating isolation pillars 106 between the driving backplane bonding metal 107 .

[0069] Step S506: welding the LED chip to the driver backplane using flip-chip bonding cold pressure welding technology.

[0070] It can be understood that bonding involves directly bonding two clean, atomically flat semiconductor materials of the same or different natures under certain conditions, after surface cleaning and activation. The wafers are then bonded together through van der Waals, molecular, and even atomic forces. Vacuum evaporation coating is a vacuum coating method that uses an evaporator to heat the evaporated material, causing it to sublime. The evaporated particles are then directed toward the substrate, where they are deposited as a solid thin film. Alternatively, the coating material is heated and evaporated.

[0071] In this embodiment, vacuum evaporation is used to deposit the P-type electrode 111, N-type electrode 114, and LED bonding metal 104. The P-type electrode 111 and N-type electrode 114 are primarily Au-deposited to a thickness of 1 μm to 10 μm. The LED bonding metal 104 is primarily In-deposited, InSn-deposited, or AuSn-deposited to a thickness of 2 μm to 8 μm.

[0072] The black matrix layer 113 is filled in the gaps between the LED pixel core particles using photolithography, with a film thickness of 3um to 6um, so as to avoid optical crosstalk after the LED quantum well layer 102 is powered on and emits light. The driving backplane is plated with the driving backplane bonding metal 107In or InSn or AuSn column using vacuum evaporation method, with a deposition thickness of 3um to 6um. The insulating isolation column 106 between the driving backplane bonding metal 107 is made using photolithography. It should be noted that the black matrix layer 113 (blackmatrix) is a black photoresist. The material itself is black. Black materials can absorb visible light in various bands. Adjacent LEDs separated by the black matrix layer material will not generate optical crosstalk after the adjacent LED core particles emit light after power is turned on.

[0073] Insulating spacers 106 separate the bonded LED pixel chips. Made of insulating photoresist, the spacers act as insulators. The In, InSn, or AuSn columns serve as metal pads on the top of the driver backplane and the LED pixel chips, respectively. This structure serves as a cold-press soldering material for flip-chip bonding.

[0074] The LED chip and the driver backplane are welded using flip-chip cold pressure welding technology, with a welding temperature of 100°C to 120°C and a bonding pressure of 3kg to 30kg.

[0075] Furthermore, in this embodiment, step S502 includes the following steps:

[0076] Step S5021: Plasma-enhanced atomic layer deposition (PEALD) is used to deposit an Al 2 O 3 thin film encapsulation layer 116 .

[0077] Step S5022: using inductively coupled plasma to etch Al2O3 to expose the LED bonding metal 104.

[0078] In this embodiment, plasma enhanced atomic layer deposition (PEALD) is an advanced method for enhancing ALD performance by using plasmatized gaseous atoms instead of water as an oxide.

[0079] In this embodiment, a plasma-enhanced atomic layer deposition (PEALD) device alternately pulses the gaseous precursor trimethylaluminum into a reactor, enhancing the activity of the reactants under the plasma. Ultimately, the precursor chemically adsorbs and reacts at a certain temperature to form a monoatomic Al2O3 film, which is deposited on the surface of the LED chip. This thin film encapsulates and covers the LED core particles, particularly providing excellent insulation and protection for the sidewall gaps of the LED pixel core particles. Using an inductively coupled plasma device, the plasma-activated reactive gas reacts with the Al2O3, ultimately removing it. In this case, the Al2O3 film covering the LED bonding metal 104 is removed.

[0080] Furthermore, in this embodiment, step S30 includes the following steps:

[0081] Step S301 : depositing an ITO layer on the surface of the P-type semiconductor layer 115 by using a magnetron sputtering process.

[0082] Step S302: Control the deposition thickness of the ITO layer to To form a P-type ohmic contact after annealing.

[0083] In this embodiment, in step S30, an ITO layer is deposited on the surface of the P-type semiconductor layer 115 using a magnetron sputtering process, and the thickness of the deposition is The current spreading layer 112 is deposited on the surface of the P-type semiconductor layer 115 and forms a P-type ohmic contact after annealing. ITO, primarily composed of indium tin oxide, is a transparent conductive semiconductor film that exhibits both low resistivity and high light transmittance, meeting the requirements for both good conductivity and light transmittance. ITO forms a good ohmic contact between the electrode and the epitaxial layer, allowing current to diffuse across the electrode surface and flow more effectively into the electrode, thereby reducing voltage.

[0084] Furthermore, in this embodiment, step S40 includes the following steps:

[0085] Step S401: depositing a SiO2 film on the current spreading layer at 200° C.-400° C. using a plasma enhanced vapor deposition method.

[0086] In this embodiment, the current blocking layer 110 is deposited at a temperature of 200° C. to 500° C. using plasma enhanced vapor deposition. The current blocking layer 110 is deposited using SiO2 with a thickness of 1000 nm.

[0087]

[0088] In addition, in order to achieve the above-mentioned purpose of the invention, see Figure 1 and Figure 5 The present invention also provides a light-emitting element, comprising a substrate 101, an N-type semiconductor layer 103, a quantum well layer 102, a P-type semiconductor layer 115, a current spreading layer 112, a current blocking layer 110, a thin-film encapsulation layer 116, an LED bonding metal 104, a P-type electrode 111, an N-type electrode 114, a black matrix layer 113, a driver backplane bonding metal 107, a driver backplane pixel electrode 105, a driver backplane common electrode 108, an insulating spacer 106, and a driver backplane pad 109. Each LED chip is connected to the driver backplane bonding metal 107 via the LED bonding metal 104. It should be noted that the ohmic contact effect is primarily utilized here. When a metal and a semiconductor form an ohmic contact, the contact point is a pure resistor, and the smaller the resistance, the better. This ensures that, during component operation, the majority of the voltage drop occurs in the active region rather than at the contact surface. Therefore, its IV characteristic exhibits a linear relationship, with a greater slope indicating a lower contact resistance. The magnitude of the contact resistance directly impacts the device's performance. Ohmic contacts are widely used in metal processing, and the main measures to achieve them are to highly dope the semiconductor surface layer or introduce a large number of recombination centers.

[0089] Furthermore, in this embodiment, each LED chip is connected to the driver backplane pixel electrode 105 via the P-type semiconductor layer 115, and each LED chip is connected to the driver backplane common electrode 108 via the N-type semiconductor layer 103, thereby forming a circuit. It should be noted that the driver backplane common electrode 108, i.e., the N electrode, is electrically interconnected with the LED N electrode.

[0090] Furthermore, in this embodiment, each LED chip shares the N-type semiconductor layer 103 and is connected to the LED bonding metal 104 via the N-type electrode 114 to achieve electrical interconnection and ohmic contact.

[0091] Furthermore, in this embodiment, each LED chip has its own P-type semiconductor layer 115 , which is connected to the LED bonding metal 104 via the P-type electrode 111 to electrically interconnect and achieve ohmic contact.

[0092] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention. The specific embodiments described above further illustrate the purpose, technical solutions and beneficial effects of the present invention. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for preparing a light-emitting element, characterized in that: The steps include: A buffer layer, an N-type semiconductor layer, a quantum well layer, and a P-type semiconductor layer are sequentially grown on the substrate; Etching through the P-type semiconductor layer and the quantum well layer so that each LED pixel core in a single LED chip is disconnected at the quantum well layer to form an independent LED pixel core; depositing a current spreading layer on the P-type semiconductor layer; depositing a current blocking layer on the current spreading layer; The LED chip is transferred to the driving circuit substrate and packaged, including: using vacuum evaporation to plate P-type electrodes, N-type electrodes and LED bonding metal; performing sidewall protection on the N-type semiconductor layer, the quantum well layer, the P-type semiconductor layer, the current spreading layer and the P-type electrode; using photolithography to fill the gaps between the LED pixel core particles with a black matrix layer; using vacuum evaporation to plate In, InSn or AuSn columns for driving backplane bonding metal; using photolithography to make insulating isolation columns between the driving backplane bonding metal; and using flip-chip bonding cold pressure welding technology to weld the LED chip to the driving backplane. In each LED chip, the P-type electrode ring is arranged on the periphery of the current blocking layer, and the thickness of the P-type electrode is less than the thickness of the current blocking layer, so that at least part of the current blocking layer protrudes from the surface of the P-type electrode and directly contacts the LED bonding metal; Among them, the driving backplane bonding metal In or InSn or AuSn column in contact with the LED bonding metal on the P-type electrode has a first thickness, and the driving backplane bonding metal In or InSn or AuSn column in contact with the LED bonding metal on the N-type electrode has a second thickness, and the second thickness is greater than the first thickness.

2. The method for preparing a light-emitting element according to claim 1, wherein: The step of performing sidewall protection on the N-type semiconductor layer, the quantum well layer, the P-type semiconductor layer, the current spreading layer, and the P-type electrode includes: Plasma-enhanced atomic layer deposition of Al2O3 thin film encapsulation layer; Inductively coupled plasma is used to etch Al2O3 to expose the LED bonding metal.

3. The method for preparing a light-emitting element according to claim 1, wherein: The step of depositing a current spreading layer on the P-type semiconductor layer comprises: Depositing an ITO layer on the surface of the P-type semiconductor layer by a magnetron sputtering process; Control the deposition thickness of the ITO layer to To form a P-type ohmic contact after annealing.

4. The method for preparing a light-emitting element according to claim 1, wherein: The step of depositing a current blocking layer on the current spreading layer comprises: A SiO2 film is deposited on the current spreading layer at 200° C.-400° C. using a plasma enhanced vapor deposition method.

5. A light-emitting element, prepared by the method for preparing a light-emitting element according to any one of claims 1 to 4, characterized in that: Including substrate, N-type semiconductor layer, quantum well layer, P-type semiconductor layer, current spreading layer, current blocking layer, thin film encapsulation layer, LED bonding metal, P-type electrode, N-type electrode, black matrix layer, driving backplane bonding metal, driving backplane pixel electrode, driving backplane common electrode, insulating isolation column, driving backplane pad; Wherein, each LED chip is connected to the driving backplane bonding metal through the LED bonding metal; In each LED chip, the P-type electrode ring is arranged on the periphery of the current blocking layer, and the thickness of the P-type electrode is less than the thickness of the current blocking layer, so that at least part of the current blocking layer protrudes from the surface of the P-type electrode and directly contacts the LED bonding metal; The driving backplane bonding metal in contact with the LED bonding metal on the P-type electrode has a first thickness, and the driving backplane bonding metal in contact with the LED bonding metal on the N-type electrode has a second thickness, which is greater than the first thickness.

6. The light-emitting element according to claim 5, wherein Each LED chip is connected to the pixel electrode of the driving backplane through the P-type semiconductor layer, and each LED chip is connected to the common electrode of the driving backplane through the N-type semiconductor layer to form a loop.

7. The light-emitting element according to claim 5, wherein Each LED chip shares the N-type semiconductor layer and is connected to the LED bonding metal via the N-type electrode.

8. The light-emitting element according to claim 5, wherein Each LED chip uses the P-type semiconductor layer exclusively and is connected to the LED bonding metal via the P-type electrode.

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