Thin film vertical structure red light Micro-LED preparation and display technology

Abstract

The invention discloses a thin film vertical structure red light Micro-LED preparation and display technology, and belongs to the technical field of Micro-LED display, and the IPC classification number of the thin film vertical structure red light Micro-LED preparation and display technology is H01L33. According to the thin film vertical structure red light Micro-LED and the display module based on the thin film vertical structure red light Micro-LED, the thin film vertical structure red light Micro-LED is provided with a two-step passivation structure of the MESA passivation layer and the isolation passivation layer, and the thin film vertical structure red light Micro-LED and the display module have the advantage of being high in light emitting efficiency in application. The invention further provides a preparation and transfer method of the thin film vertical structure red light Micro-LED. High-efficiency and low-damage stripping and transfer of the Micro-LED are realized by adopting the composite nitride de-bonding layer; the process provided by the invention is good in adaptability and has a wide application prospect.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of Micro-LED display, and the IPC classification number is H01L33, and particularly relates to a thin film vertical structure red light Micro-LED preparation and display technology. BACKGROUND

[0002] Micro light emitting diode (Micro-LED) is considered to be the most powerful competitor of the next generation display technology because of its high brightness, high contrast, low power consumption and long service life. The phosphide red light emitting diode epitaxial structure is grown on a GaAs opaque substrate, and the red light emitted by the LED quantum well is absorbed by GaAs, which will significantly reduce the light emitting efficiency of the chip. Therefore, preparing a thin film vertical structure phosphide red light Micro-LED chip is an important means to improve the light emitting efficiency of the chip.

[0003] The electrodes of the flip chip are on the same side of the chip, and the size of the electrode restricts the size of the chip. The p / n pads of the vertical structure chip are on both sides of the chip, and compared with the flip chip, a higher resolution display can be realized. For example, document (J. Shin, H. Kim, S. Sundaram et al. Vertical full-colour micro-LEDs via 2Dmaterials-based layer transfer. Nature 614, 81-87 (2023).) reported a full-color vertical stacked Micro-LED, which realized high array density (5100 pixels / inch) and small size (4 μm) through 2D material-based layer transfer technology (2DLT). The technology allows remote or van der Waals epitaxy, mechanical release and stacking of LEDs, and then manufacturing from top to bottom, growing near-submicron thickness RGB LEDs on a 2D material coating substrate. This study provides full-color Micro-LED display for AR and VR, and provides an extensible platform for more extensive 3D integrated devices. However, the vertical structure chip still faces the problem of reduced light emitting efficiency caused by the top electrode blocking the light emission of the chip. Document (W. S. Cho, J. Y. Park, C. J. Yoo, J.-L. Lee, Design of highly transparent ohmic contact to N face n-GaN for enhancing light extraction in GaN-based micro LED display, Opt. ExpressThe Micro-LED described in 31, 41611-41621 (2023) introduces In / ITO n-type contacts to achieve excellent contact characteristics and high transparency. ITO with an intermediate In layer was used as the n-type contact electrode, and the contact characteristics were observed at different annealing temperatures after annealing in a nitrogen atmosphere. After annealing at 200 °C, the In / ITO n-type contact exhibited ohmic characteristics and a transparency of up to 74% in the blue wavelength region. However, in vertically structured chips, the p / n pads are located on the top and bottom sides of the chip, making it difficult to electrically connect the electrode on the light-emitting side of the chip to the driver circuit board, causing integration difficulties. Summary of the Invention

[0004] In view of the above-mentioned deficiencies of the prior art, in a first aspect of the present invention, a thin-film vertical structure red Micro-LED with high luminous efficiency and good process adaptability is provided, comprising: MESA light-emitting region, p-GaP layer, n-type electrode, MESA passivation layer, isolation passivation layer, transparent conductive layer; The MESA emitting region consists of an n-AlGaInP layer and a multi-quantum-well layer, which is located on the p-GaP layer mesa and is smaller than the p-GaP layer mesa; the light-emitting surface of the p-GaP layer is covered with a transparent conductive layer. The MESA passivation layer encapsulates the top and sidewalls of the MESA luminescent region and the p-GaP layer mesa; An isolation passivation layer encapsulates the surface of the MESA passivation layer and the sidewalls of the p-GaP layer; The MESA passivation layer and isolation passivation layer have pathways for connecting the n-AlGaInP layer to the n-type electrode, with the n-type electrode located on the top surface of the n-AlGaInP layer.

[0005] Preferably, the MESA passivation layer encapsulates the MESA light-emitting region and the p-GaP mesa; the thickness of the MESA passivation layer is one-quarter of the wavelength of the thin-film vertical structure red Micro-LED emission divided by the refractive index.

[0006] Preferably, the MESA passivation layer is made of a low-refractive-index insulating material, including SiO2 or MgF.

[0007] Preferably, the isolation passivation layer covers the MESA passivation layer and wraps the sidewalls of the p-GaP layer; the thickness of the isolation passivation layer is one-quarter of the emission wavelength of the thin-film vertical structure red Micro-LED divided by the refractive index.

[0008] Preferably, the isolation passivation layer is made of a high-refractive-index insulating material, including Si3N4 or AlN.

[0009] Preferably, the material of the transparent conductive layer comprises one of indium tin oxide (ITO), fluorine-doped tin oxide (FTO), and Al-doped zinc oxide (AZO).

[0010] In a second aspect of the present application, a preparation method of the thin-film vertical structure red Micro-LED of the first aspect of the present application is provided, comprising the following steps: S1, epitaxial growth of the thin-film vertical structure red Micro-LED on a GaAs substrate, from bottom to top, sequentially comprising an n-AlGaInP layer, a multi-quantum well layer, and a p-GaP layer; S2, depositing a transparent conductive layer and a bonding layer on the surface layer of the epitaxial layer of the thin-film vertical structure red Micro-LED, and bonding with a sapphire substrate having a nitride debonding layer, and then removing the GaAs substrate; S3, etching the epitaxial layer until the p-GaP layer to form a MESA light-emitting region, and then depositing a MESA passivation layer; S4, etching the p-GaP layer until the bonding layer to form an isolation groove between the Micro-LED pixels, and depositing an isolation passivation layer; S5, opening a hole in the passivation layer on the top of the MESA light-emitting region, and evaporating an n-type electrode on the top of the MESA light-emitting region; S6, laser action debonding layer to make it thermally decomposed to realize the debonding between the sapphire substrate and the thin-film vertical structure red Micro-LED, and removing the bonding layer to obtain the thin-film vertical structure red Micro-LED.

[0011] Preferably, in S2, the material of the bonding layer comprises at least one of SiO2, Si3N4, and Al2O3.

[0012] Preferably, in S2, the debonding layer is composed of a sputtered AlN nucleation layer, a medium-temperature GaN layer, a high-temperature GaN layer, and a low-temperature InGaN layer. Among them, low, medium, and high temperature represent the growth temperature of each layer; low temperature represents a growth temperature of 600-700 ℃, medium temperature represents a growth temperature of 800-900 ℃, and high temperature represents a growth temperature higher than 1100 ℃. Under laser irradiation, the InGaN layer is thermally decomposed into In, Ga, and N2, realizing the separation between the thin-film vertical structure red Micro-LED and the sapphire substrate.

[0013] In the process, the thermal decomposition can be realized by laser irradiation. The debonding layer composed of the sputtered AlN nucleation layer, the medium-temperature GaN layer, the high-temperature GaN layer, and the low-temperature InGaN layer can absorb laser with a wavelength of 405 nm or below, reducing the damage of laser irradiation to the epitaxial layer.

[0014] In a third aspect of the present application, a display module of a thin-film vertical structure red Micro-LED based on the first aspect of the present application is provided, comprising: a transparent TFT backplane, a pixel driving circuit; The pixel driving circuit comprises a driving circuit, a thin-film vertical structure red Micro-LED; the driving circuit comprises a source electrode, a drain electrode and a gate electrode; The transparent TFT backplane comprises four insulating layers, namely a top insulating layer in which solder points and source electrode contact points are distributed, a middle insulating layer in which drain electrode leads are distributed, a bottom insulating layer in which a driving circuit is distributed, and a transparent backplane; The n-type electrode of the thin-film vertical structure red Micro-LED is eutectically bonded with the solder points and electrically connected with the drain electrode; The source electrode is electrically connected with the transparent conductive layer of the thin-film vertical structure red Micro-LED through the source electrode contact points.

[0015] Preferably, a transparent resin layer covering the thin-film vertical structure red Micro-LED is arranged on the surface of the transparent TFT backplane.

[0016] Preferably, a single-layer graphene and a transparent conductive material are used as the transparent conductive connection layer to realize the electrical connection between the transparent conductive layer and the source electrode contact points.

[0017] Further preferably, the transparent conductive material comprises one of indium tin oxide, fluorine-doped tin oxide and Al-doped zinc oxide.

[0018] The flexible feature of the single-layer graphene provides a relatively smooth transition for the transparent conductive material on the side wall of the chip or electrode hole, avoiding the film layer fracture between the side wall and the mesa due to the rigid feature of the transparent conductive material itself. Although the single-layer graphene is transparent to red light, its conductivity is poorer than that of the transparent conductive material, so the two can complement each other. This solution solves the technical obstacle that the electrode on the light-emitting side of the chip is difficult to realize electrical connection with the driving circuit board, making integration more convenient.

[0019] Preferably, an insulating layer is deposited on the surface of the transparent TFT backplane to protect the circuit.

[0020] In a fourth aspect of the present application, a preparation and transfer method of a thin-film vertical structure red Micro-LED based on the first aspect of the present application is provided, comprising the following steps: 1) Epitaxial growth of the thin-film vertical structure red Micro-LED on a GaAs substrate, from bottom to top, n-AlGaInP layer, multi-quantum well layer, p-GaP layer; 2) A transparent conductive layer and a bonding layer are deposited on the epitaxial layer of the thin-film vertical structure red Micro-LED, and then bonded to a sapphire substrate with a composite nitride debonding layer. The GaAs substrate is then removed. 3) Etch the epitaxial layer until the p-GaP layer forms the MESA luminescent region, and then deposit the MESA passivation layer; 4) Etch the p-GaP layer (4) until the bonding layer (6) is formed to create isolation trenches between micro LED pixels and deposit an isolation passivation layer; 5) An opening is made in the passivation layer at the top of the MESA light-emitting area, and an n-type electrode is deposited on the top of the MESA light-emitting area; 6) Bond the thin-film vertical structure red Micro-LED wafer to the transparent TFT backplane, and electrically connect the n-type electrode and the drain in the TFT backplane; 7) Laser action on the debonding layer causes it to decompose due to heat, thereby debonding the sapphire substrate and the thin-film vertical structure red Micro-LED and removing the bonding layer; 8) A transparent resin is used to encapsulate the thin-film vertical structure red Micro-LED, and the source electrode of the transparent conductive layer and transparent TFT backplane is etched to expose it; 9) Electrically connect the source of the transparent conductive layer and the transparent TFT backplane, and deposit insulating material to cover the surface of the transparent TFT backplane.

[0021] Based on the above technical solutions, the design concept and principle of this invention are as follows: This invention employs a step-by-step passivation method to achieve full passivation of the MESA light-emitting region and the isolation trench sidewall region. This better suppresses the impact of surface defects on the sidewalls caused by etching during Micro-LED operation on current distribution, thereby improving the chip's luminous efficiency. Simultaneously, this solution combines multiple passivation layers, which facilitates the formation of an optical reflective film, reducing light emission from the sidewalls while enhancing light emission from the Micro-LED's emitting surface. During the Micro-LED transfer process, this invention uses a composite nitride debonding layer to achieve damage-free transfer. In the fabrication of the display module, a combination of a single-layer graphene layer and a transparent conductive layer can be used to achieve a transparent p-type electrode.

[0022] In the process of this invention, a debonding layer is designed to consist of a sputtered AlN nucleation layer, a medium-temperature GaN layer, a high-temperature GaN layer, and a low-temperature InGaN layer. This debonding layer can absorb laser light at wavelengths of 405 nm and below and achieve thermal decomposition, thereby reducing damage to the epitaxial layer from laser irradiation. Existing technologies typically use organic materials such as BCB adhesive as the debonding layer; however, these organic materials are difficult to withstand high temperatures, which can adversely affect micro-LED fabrication processes such as thermal annealing, PECVD deposition, and ALD deposition, which require high-temperature treatment or high wafer cleanliness. In contrast, the debonding layer of this invention is heat-resistant and can be applied to conventional micro-LED fabrication processes, reducing process incompatibility issues caused by the material properties of the debonding layer.

[0023] In addition, the application of transparent conductive electrodes and transparent conductive electrical connection materials improves the light extraction efficiency of thin-film vertical structure red Micro-LED chips, resulting in excellent application effects.

[0024] Compared with the prior art, the present invention has the following advantages and beneficial effects: This invention provides a thin-film vertical structure red light Micro-LED and a display module based on the thin-film vertical structure red light Micro-LED. With its two-step passivation structure of MESA passivation and isolation passivation, it has the advantage of high luminous efficiency in application.

[0025] This invention also provides a method for preparing and transferring thin-film vertical structure red Micro-LEDs. It achieves high-efficiency, low-damage peeling and transfer of Micro-LEDs by using a composite nitride debonding layer. The process of this invention has good adaptability and broad application prospects. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of a thin-film vertical structure red Micro-LED. Figure 2 A schematic diagram of the fabrication process for a thin-film vertical structure red Micro-LED; Figure 3 A schematic diagram illustrating the process of integrating a thin-film vertical structure red Micro-LED with a transparent TFT backplane; Figure 4 A photograph of the back of a vertically structured red Micro-LED after peeling off the thin film; Figure 5 A schematic diagram of the process for encapsulating transparent epoxy resin on the surface of a transparent TFT backplane; Figure 6 A schematic diagram of the process for creating openings in the transparent epoxy resin portion of the transparent TFT backplane surface; Figure 7An integration and display module for thin-film vertical structure red Micro-LEDs; In the above figures: 1: GaAs substrate; 2: n-AlGaInP layer; 3: Multiple quantum well layer; 4: p-GaP layer; 5: Transparent conductive layer; 6: Bonding layer; 7: Debonding layer; 8: Sapphire substrate; 9: MESA light-emitting region; 10: MESA passivation layer; 11: Isolation passivation layer; 12: n-type electrode; 13: Solder joint; 14: Drain lead; 15: Gate; 16: Drain; 17: Source contact point; 18: Source; 19: Top insulating layer; 20: Middle insulating layer; 21: Bottom insulating layer; 22: Transparent backplane; 23: Transparent resin layer; 24: Transparent conductive electrical connection layer; 25: Insulating layer. Detailed Implementation

[0027] The present invention is further illustrated below by way of embodiments, but the invention is not limited to the scope of the embodiments described herein. Experimental methods in the following embodiments that do not specify specific conditions were performed according to conventional methods and conditions, or as selected according to the product instructions.

[0028] Example 1 This embodiment provides a thin-film vertical structure red Micro-LED, the structure of which is as follows: Figure 1 As shown, the thin-film vertical structure red Micro-LED includes: MESA light-emitting region 9, p-GaP layer 4, n-type electrode 12, MESA passivation layer 10, isolation passivation layer 11, and transparent conductive layer 5.

[0029] MESA emitting region 9 consists of an n-AlGaInP layer 2 and a multi-quantum well layer 3, which is located on the mesa of the p-GaP layer 4 and is slightly smaller than the mesa of the p-GaP layer 4; the light-emitting surface of the p-GaP layer 4 is covered with a transparent conductive layer 5.

[0030] MESA passivation layer 10 encloses the top and sidewalls of MESA light-emitting region 9 and the mesa of p-GaP layer 4; the thickness of MESA passivation layer is one-quarter of the emission wavelength of thin-film vertical structure red light Micro-LED divided by the refractive index, and it is made of low refractive index insulating material; isolation passivation layer 11 encloses the surface of MESA passivation layer 10 and the sidewalls of p-GaP layer 4; the thickness of isolation passivation layer is one-quarter of the emission wavelength of thin-film vertical structure red light Micro-LED divided by the refractive index, and it is made of high refractive index insulating material.

[0031] The MESA passivation layer 10 and the isolation passivation layer 11 have holes for connecting the n-AlGaInP layer 2 and the n-type electrode 12, wherein the n-type electrode 12 is plated on the top surface of the n-AlGaInP layer 2.

[0032] Example 2 This embodiment provides a method for fabricating a thin-film vertical structure red Micro-LED, which is epitaxially grown on a GaAs substrate 1. The epitaxial structure consists of an n-AlGaInP layer 2, a multi-quantum-well layer 3, and a p-GaP layer 4. A transparent conductive layer 5, made of ITO or ZnO, covers the surface of the p-GaP layer 4. The epitaxial layer and the sapphire substrate 8 are connected by a bonding layer 6 and a debonding layer 7. The bonding layer is made of insulating materials such as SiO2, Si3N4, Al2O3, or bonding adhesive. The debonding layer 7 consists of a sputtered AlN nucleation layer, a medium-temperature GaN layer, a high-temperature GaN layer, and a low-temperature InGaN layer. Under laser irradiation, the InGaN layer undergoes thermal decomposition into Ga, In, and N2. The aforementioned debonding layer is heat-resistant and can be used in conventional Micro-LED fabrication processes, reducing process incompatibility issues caused by the properties of the debonding layer materials. In addition, the debonding layer can absorb laser light in the 405 nm and below bands and achieve thermal decomposition, which can reduce the damage of laser irradiation to the epitaxial layer.

[0033] like Figure 2 As shown, this embodiment provides a method for fabricating a vertically structured phosphide red-light Micro-LED on a sapphire substrate 8: the steps are as follows: S1. A thin-film vertical structure red light Micro-LED is epitaxially grown on a GaAs substrate 1, consisting of an n-AlGaInP layer 2, a multi-quantum well layer 3, and a p-GaP layer 4 from bottom to top. S2. A transparent conductive layer 5 and a bonding layer 6 are deposited on the surface of the epitaxial layer of the thin film vertical structure red light Micro-LED. The wafer on which the thin film vertical structure red light Micro-LED epitaxial layer is grown is bonded to the sapphire substrate 8 on which the composite nitride debonding layer 7 is grown by hot pressing bonding. The GaAs substrate 1 is peeled off by wet etching. S3. The n-AlGaInP layer 2, the multi-quantum well layer 3 and the p-GaP layer 4 are etched using photolithography and ICP etching processes to form the MESA light-emitting region 9; a MESA passivation layer 10 is deposited on the surface of the MESA light-emitting region 9 and the top surface of the p-GaP layer 4. S4. The MESA passivation layer 10, p-GaP layer 4 and transparent conductive layer 5 are etched using photolithography and ICP etching processes to form isolation trenches between Micro-LED pixels; an isolation passivation layer 11 is deposited on the surface of the MESA light-emitting region 9, the top surface and sidewalls of the p-GaP layer 4 and the isolation trenches. S5. The isolation passivation layer 11 and the MESA passivation layer 10 on the top surface of the MESA light-emitting region 9 are etched using photolithography and ICP etching processes to expose the n-AlGaInP layer 2; an n-type electrode 12 is deposited on the top surface of the exposed n-AlGaInP layer 2 using electron beam evaporation. S6. The debonding layer 7 is thermally decomposed by laser irradiation to achieve debonding between the sapphire substrate 8 and the thin-film vertical structure red light micro-LED, and the bonding layer 6 is removed to obtain the thin-film vertical structure red light micro-LED.

[0034] Example 3 This embodiment provides a display module based on a thin-film vertical structure red micro-LED. The display module includes a transparent TFT backplane and a pixel driving circuit. The pixel driving circuit includes a source 18, a drain 16, a gate 15, and the thin-film vertical structure red micro-LED. The transparent TFT backplane includes four insulating layers: a top insulating layer 19 with solder joints 13 and source contact points 17, a middle insulating layer 20 with drain leads 14, a bottom insulating layer 21 with the driving circuit, and a transparent backplane 22. The n-type electrode 12 of the thin-film vertical structure red micro-LED is eutecticly bonded to the solder joints 13 and electrically connected to the drain 16; the source 18 is electrically connected to the transparent conductive layer 5 of the thin-film vertical structure red micro-LED through the source contact points 17.

[0035] A transparent resin layer 23 covering a thin-film vertical structure red Micro-LED is deposited on the surface of the transparent TFT backplane. The electrical connection between the transparent conductive layer 5 and the source contact 17 is achieved using a monolayer of graphene and a transparent conductive material (e.g., ITO, FTO, AZO, etc.) as the transparent conductive connection layer. The flexibility of the monolayer graphene provides a smoother transition for the transparent conductive material on the chip or electrode hole sidewalls, avoiding film breakage between the sidewalls and mesa due to the rigidity of the transparent conductive material itself. An insulating layer 25 protecting the circuitry is also deposited on the surface of the transparent TFT backplane.

[0036] Example 4 This embodiment provides a method for fabricating and transferring a thin-film vertical structure red Micro-LED to construct a display module, such as... Figure 3 As shown, the sapphire substrate 8 with a thin-film vertical structure red Micro-LED is bonded to a transparent TFT backplane. The steps are as follows: 1) The thin film vertical structure red light Micro-LED is epitaxially grown on GaAs substrate 1, and from bottom to top are n-AlGaInP layer 2, multiple quantum well layer 3, and p-GaP layer 4; 2) A transparent conductive layer 5 and a bonding layer 6 are deposited on the epitaxial layer surface of the thin film vertical structure red light Micro-LED, and bonded to a sapphire substrate 8 with a debonding layer 7 grown with composite nitrides, and then the GaAs substrate 1 is removed. 3) Etch the epitaxial layer until the p-GaP layer 4 is formed to form the MESA light-emitting region 9, and then deposit the MESA passivation layer 10; 4) Etch the p-GaP layer 4 up to the bonding layer 6 to form isolation trenches between Micro-LED pixels, and deposit an isolation passivation layer 11; 5) An opening is made in the passivation layer at the top of the MESA light-emitting region 9, and an n-type electrode 12 is deposited on the top of the MESA light-emitting region 9; 6) Bond the thin-film vertical structure red Micro-LED wafer to the transparent TFT backplane, and electrically connect the n-type electrode 12 and the drain electrode 16 in the TFT backplane; 7) The debonding layer 7 is thermally decomposed by laser irradiation to separate the sapphire substrate 8 from the thin-film vertical structure red-light Micro-LED. The bonding layer 6 is then removed by wet etching. A photograph of the back of the peeled thin-film vertical structure red-light Micro-LED is shown below. Figure 4 As shown, it can be seen that it was completely peeled off without any core particle damage. The debonding layer achieved the non-damaging peeling of the core particles. 8) For example Figure 5 As shown, a transparent resin layer 23 is formed by encapsulating a vertically structured red Micro-LED with a transparent resin encapsulation film. Figure 6 As shown, the transparent conductive layer 5 of the thin-film vertical structure red Micro-LED and the source contact point 17 on the transparent TFT backplane are exposed by etching. 9) For example Figure 7 As shown, a single layer of graphene and a transparent conductive material are used as a transparent conductive electrical connection layer 24 to realize the electrical connection between the transparent conductive layer 5 and the source contact point 17. An insulating layer 25 is deposited on the surface of the transparent TFT backplane to protect the circuit.

[0037] Based on the above scheme, this invention employs a step-by-step passivation method to achieve full passivation of the MESA light-emitting region and the isolation trench sidewall region. This better suppresses the impact of surface defects on the sidewalls caused by etching during Micro-LED operation on current distribution, thereby improving the chip's luminous efficiency. This invention combines multiple passivation layers to form an optical reflective film, enhancing light emission from the Micro-LED light-emitting surface while reducing light emission from the sidewalls. This process exhibits excellent adaptability and has broad application prospects in practical fabrication.

[0038] The preferred embodiments of the present invention have been described in detail above. It should be understood that those skilled in the art can make numerous modifications and variations based on the concept of the present invention without creative effort. Therefore, all technical solutions that can be obtained by those skilled in the art based on the concept of the present invention through logical analysis, reasoning, or limited experimentation on the basis of existing technology should be within the scope of protection defined by the claims.

Claims

1. A thin-film vertical structure red Micro-LED, characterized in that, include: MESA light-emitting region, p-GaP layer, n-type electrode, MESA passivation layer, isolation passivation layer, transparent conductive layer; The MESA emitting region consists of an n-AlGaInP layer and a multi-quantum-well layer, which is located on the p-GaP layer mesa and is smaller than the p-GaP layer mesa; the light-emitting surface of the p-GaP layer is covered with a transparent conductive layer. The MESA passivation layer encapsulates the top and sidewalls of the MESA luminescent region and the p-GaP layer mesa; An isolation passivation layer encapsulates the surface of the MESA passivation layer and the sidewalls of the p-GaP layer; The MESA passivation layer and isolation passivation layer have pathways for connecting the n-AlGaInP layer to the n-type electrode, with the n-type electrode located on the top surface of the n-AlGaInP layer.

2. The thin-film vertical structure red Micro-LED according to claim 1, characterized in that: The MESA passivation layer encapsulates the MESA light-emitting region and the p-GaP mesa. The thickness of the MESA passivation layer is one-quarter of the wavelength of the thin-film vertical structure red light Micro-LED divided by the refractive index. An isolation passivation layer covers the MESA passivation layer and encapsulates the sidewalls of the p-GaP layer. The thickness of the isolation passivation layer is one-quarter of the wavelength of the thin-film vertical structure red light Micro-LED divided by the refractive index.

3. The thin-film vertical structure red Micro-LED according to claim 1, characterized in that: The MESA passivation layer uses a low-refractive-index insulating material, including SiO2 or MgF; the isolation passivation layer uses a high-refractive-index insulating material, including Si3N4 or AlN; the transparent conductive layer is made of one of indium tin oxide, fluorine-doped tin oxide, or Al-doped zinc oxide.

4. A method for fabricating a thin-film vertical structure red Micro-LED as described in any one of claims 1 to 3, characterized in that, Includes the following steps: S1. The thin-film vertical structure red light Micro-LED is epitaxially grown on a GaAs substrate, consisting of an n-AlGaInP layer, a multi-quantum well layer, and a p-GaP layer from bottom to top. S2. A transparent conductive layer and a bonding layer are deposited on the epitaxial layer of the thin-film vertical structure red Micro-LED, and then bonded to a sapphire substrate with a nitride debonding layer. The GaAs substrate is then removed. S3. Etch the epitaxial layer until the p-GaP layer is formed to form the MESA light-emitting region, and then deposit the MESA passivation layer; S4. Etch the p-GaP layer until the bonding layer is formed to create isolation trenches between Micro-LED pixels, and deposit an isolation passivation layer; S5. An opening is made in the passivation layer at the top of the MESA light-emitting area, and an n-type electrode is deposited on the top of the MESA light-emitting area to achieve electrical connection between the n-type electrode and the MESA light-emitting area. S6. Laser treatment debonds the bonding layer, causing it to decompose and thus debonding the sapphire substrate and the thin-film vertical structure red micro-LED. The bonding layer is then removed to obtain the thin-film vertical structure red micro-LED.

5. The method for fabricating a thin-film vertical structure red Micro-LED according to claim 4, characterized in that: In S2, the material of the bonding layer includes at least one of SiO2, Si3N4, and Al2O3.

6. The method for fabricating a thin-film vertical structure red Micro-LED according to claim 4, characterized in that: In S2, the debonding layer consists of a sputtered AlN nucleation layer, a medium-temperature GaN layer, a high-temperature GaN layer, and a low-temperature InGaN layer.

7. A display module based on a thin-film vertical structure red Micro-LED as described in any one of claims 1 to 3, characterized in that, include: Transparent TFT backplane, pixel driving circuit; The pixel driving circuit includes a driving circuit and a thin-film vertical structure red Micro-LED; The driving circuit includes a source, a drain, and a gate; The transparent TFT backplane includes four insulating layers: a top insulating layer with solder joints and source contacts, a middle insulating layer with drain leads, a bottom insulating layer with driving circuitry, and a transparent backplane. The n-type electrode of the thin-film vertical structure red micro-LED is eutectic bonded to the solder joint and electrically connected to the drain electrode; the source electrode is electrically connected to the transparent conductive layer of the thin-film vertical structure red micro-LED through the source electrode contact point.

8. The display module based on thin-film vertical structure red Micro-LED according to claim 7, characterized in that: The surface of the transparent TFT backplane is provided with a transparent resin layer covering a thin-film vertical structure red Micro-LED; an insulating layer is deposited on the surface of the transparent TFT backplane to protect the circuit.

9. The display module based on thin-film vertical structure red Micro-LED according to claim 7, characterized in that: A single layer of graphene and a transparent conductive material are used as a transparent conductive electrical connection layer to achieve electrical connection between the transparent conductive layer and the source contact point.

10. A method for fabricating and transferring a thin-film vertical structure red Micro-LED as described in any one of claims 1 to 3, characterized in that, Includes the following steps: 1) The thin-film vertical structure red light Micro-LED is epitaxially grown on a GaAs substrate, consisting of an n-AlGaInP layer, a multi-quantum well layer, and a p-GaP layer from bottom to top; 2) A transparent conductive layer and a bonding layer are deposited on the epitaxial layer of the thin-film vertical structure red Micro-LED, and then bonded to a sapphire substrate with a composite nitride debonding layer. The GaAs substrate is then removed. 3) Etch the epitaxial layer until the p-GaP layer forms the MESA luminescent region, and then deposit the MESA passivation layer; 4) Etch the p-GaP layer until the bonding layer forms the isolation trench between Micro-LED pixels, and deposit an isolation passivation layer; 5) An opening is made in the passivation layer at the top of the MESA light-emitting area, and an n-type electrode is deposited on the top of the MESA light-emitting area; 6) Bond the thin-film vertical structure red Micro-LED wafer to the transparent TFT backplane, and electrically connect the n-type electrode and the drain in the TFT backplane; 7) Laser action on the debonding layer causes it to decompose due to heat, thereby debonding the sapphire substrate and the thin-film vertical structure red Micro-LED and removing the bonding layer; 8) A transparent resin is used to encapsulate the thin-film vertical structure red Micro-LED, and the source electrode of the transparent conductive layer and transparent TFT backplane is etched to expose it; 9) Electrically connect the source of the transparent conductive layer and the transparent TFT backplane, and deposit insulating material to cover the surface of the transparent TFT backplane.

Images