An epitaxial stacked full-color micro-led micro-display and a manufacturing method thereof

Abstract

The application relates to the fields of semiconductor optoelectronic devices and flat panel display technologies, in particular to an epitaxial stacked full-color Micro-LED micro display screen and a manufacturing method thereof. The display screen comprises a plurality of epitaxial stacked full-color Micro-LED chips arranged in an array, and each chip comprises: a plurality of full-color pixels arranged in an array; each full-color pixel comprises three epitaxial pixel stacks, which are respectively used as three-color stacks; the heights of the stacks are the same, and each stack comprises three-color light-emitting structures stacked in sequence through tunnel junctions; all the epitaxial pixel stacks are arranged in a mosaic distribution; the p-type sub-pixel electrodes of the three-color stacks have different corresponding position relationships and corresponding connection relationships with respect to the corresponding sub-pixel stacks; pixel isolation trenches are provided with n-type sub-pixel electrode stacks corresponding to the three-color stacks; the n-type sub-pixel electrode stacks corresponding to the three-color stacks have different corresponding position relationships and corresponding connection relationships with respect to the corresponding sub-pixel stacks.

Description

Technical Field

[0001] This application relates to the field of semiconductor optoelectronic devices and flat panel display technology, specifically to an epitaxial stacked full-color Micro-LED chip and its manufacturing method. Background Technology

[0002] Microdisplays differ from traditional direct-view displays, primarily used in projection displays such as AR (Augmented Reality) systems. Their size is typically less than 1 inch. Microdisplays generally use the same Micro-LED light-emitting chip structure as direct-view displays. In epitaxial stacked full-color Micro-LED structures, a bottom-up epitaxial growth sequence is typically employed, sequentially fabricating blue, green, and red light-emitting layers and their corresponding carrier injection layers. Tunnel junctions (TJs) are introduced between the light-emitting layers—between the blue and green layers, and between the green and red layers—utilizing their reverse conduction properties to achieve cascading of LED units. After the chip etching process, annealing can activate Mg impurities in the p-GaN layer beneath the tunnel junction, thereby improving carrier injection efficiency.

[0003] To achieve independent driving and control of red, green, and blue sub-pixels, each sub-pixel needs to be electrically isolated. A common cathode (N-type electrode) design is typically used, but the anode (P-type electrode) of each sub-pixel needs to be brought out and controlled independently. This requires stacking different sub-pixels within the same pixel, etching them separately to expose the blue and green light-emitting structures, respectively. The red light-emitting structure, already on top, does not need to be etched. These are then connected to the driving circuit via electrodes. However, because the driving circuit is usually located on the same horizontal plane on the circuit board, while the different color light-emitting structures are at different heights in the stack, the bonding distances between them and the driving circuit differ, requiring different bonding structures. This increases the manufacturing complexity. Furthermore, due to the different bonding structures, the driving requirements and losses between different sub-pixels vary, posing a risk to reliability after aging and potentially causing short circuits due to excessive metal in some areas.

[0004] Therefore, a solution is needed to address the challenges of bonding epitaxial stacked full-color Micro-LED light-emitting chips to the driving circuit chip in epitaxial stacked full-color Micro-LED micro-displays, as well as the reduced reliability risk and even short-circuit risk after aging. Summary of the Invention

[0005] This application provides an epitaxial stacked full-color Micro-LED microdisplay and its manufacturing method to solve the problems of high difficulty in bonding epitaxial stacked full-color Micro-LED chips to the driving circuit in epitaxial stacked full-color Micro-LED microdisplays, and the risk of reduced reliability or even short circuit after aging.

[0006] In one aspect of this application, an epitaxial stacked full-color Micro-LED microdisplay is provided, comprising a plurality of epitaxial stacked full-color Micro-LED chips arranged in an array; the epitaxial stacked full-color Micro-LED chips include: an epitaxial buffer layer; a plurality of full-color Micro-LED pixels arranged in an array on the epitaxial buffer layer; each full-color Micro-LED pixel includes three epitaxial pixel stacks, respectively serving as a red photonic pixel stack, a green photonic pixel stack, and a blue photonic pixel stack; each epitaxial pixel stack has the same height and includes a blue light-emitting structure, a green light-emitting structure, and a red light-emitting structure stacked from the side closest to the epitaxial buffer layer to the side furthest from the epitaxial buffer layer; the blue light-emitting structure, the green light-emitting structure, and the red light-emitting structure are connected sequentially through a tunnel junction; within the scope of the epitaxial stacked full-color Micro-LED microdisplay, all the red photonic pixel stacks, green photonic pixel stacks, and red photonic pixel stacks are connected in an array. The pixel stacks and blue sub-pixel stacks are arranged in a mosaic pattern; each peripheral pixel stack has a p-type sub-pixel electrode of the corresponding color on its top surface; the p-type sub-pixel electrodes of the red, green, and blue sub-pixel stacks have different corresponding positional and connection relationships relative to their respective sub-pixel stacks; each peripheral pixel stack is separated by a grid-like pixel isolation trench, and the pixel isolation trench has n-type sub-pixel electrode stacks corresponding to the red, green, and blue sub-pixel stacks respectively; the n-type sub-pixel electrode stacks corresponding to the red, green, and blue sub-pixel stacks have different corresponding positional and connection relationships relative to their respective sub-pixel stacks; all n-type sub-pixel electrode stacks are arranged in a mosaic pattern; any n-type sub-pixel electrode stack is located on the line connecting adjacent p-type sub-pixel electrodes in different rows corresponding to its own color.

[0007] The epitaxial stacked full-color Micro-LED microdisplay provided in this application stacks different color sub-pixels within the same pixel at the same height. Different sub-pixels are controlled separately by driving electrodes at different positions and with different connection relationships. This allows different color sub-pixels to emit different colors of light, even though their basic light-emitting structures are the same (all containing stacked blue, green, and red light-emitting structures). For example, although the red sub-pixel has the same light-emitting structure as the other two sub-pixels, its driving electrode only drives the red light-emitting structure, thus emitting only red light. The blue and green sub-pixels follow the same principle. Since the epitaxial pixel stacking structure of the three sub-pixels is the same, their heights are also the same. The electrode structures on their top surfaces also have the same height, differing only in their depth and the connection layers. Therefore, when connecting the driving circuit, the electrical connection structures of each sub-pixel can also be of the same height and use the same connection structure. This avoids the reliability reduction and short-circuit risk after aging caused by differences in the electrical connection structures of different sub-pixels. Meanwhile, since the three colors of sub-pixels use the same light-emitting structure, there is no need to perform different structural etching. Although the etching depth of the electrodes is different, requiring one step for each depth, due to the various etching depths at different locations for the n-type and p-type sub-pixel electrodes of the three colors, some etching depths can be designed to be the same. For example, the n-type etching depth for red light and the p-type etching depth for green light are roughly the same, so two grooves can be completed in one step, thus simplifying the process steps and reducing the complexity of the process. With this structure, full-color integration can be completed on the same wafer, significantly reducing the complexity of the process. In addition, the mosaic-style sub-pixel layout, combined with the corresponding stacked arrangement of p-type and n-type sub-pixel electrodes, solves the electrical interconnection and optical crosstalk problems caused by stacked structures. Specifically, by etching grooves into specific epitaxial layers, electrodes for each color pixel are brought out separately, ensuring that the red, green, and blue sub-pixels can be "independently controlled," overcoming the disadvantage of serial structures that cannot be driven separately. Meanwhile, the pixel isolation trenches form an effective "optical isolation dam," which greatly reduces "optical crosstalk" between adjacent pixels, thereby ensuring the color purity and contrast of the displayed image.

[0008] In some embodiments of this application, the red light-emitting structure includes a stacked red n-type contact layer, a red light-emitting layer, and a red electron-blocking layer; the green light-emitting structure includes a stacked green n-type contact layer, a green light-emitting layer, and a green electron-blocking layer; a second tunnel junction is disposed between the green electron-blocking layer and the red n-type contact layer; the blue light-emitting structure includes a stacked blue n-type contact layer, a blue light-emitting layer, and a blue electron-blocking layer; a first tunnel junction is disposed between the blue electron-blocking layer and the green n-type contact layer; and an epitaxial pixel stack. The stack also includes p-type sub-pixel electrodes located on the side of the red light emitting structure away from the epitaxial buffer layer; each p-type sub-pixel electrode includes a contact portion and a p-type first contact portion; the contact portion of the p-type sub-pixel electrode of the red light sub-pixel stack is only located on the surface of the red light emitting structure; the contact portion of the p-type sub-pixel electrode of the green light sub-pixel stack extends into the red light n-type contact layer and is electrically connected to the red light n-type contact layer; the contact portion of the p-type sub-pixel electrode of the blue light sub-pixel stack extends into the green light n-type contact layer and is electrically connected to the green light n-type contact layer.

[0009] In some embodiments of this application, the n-type sub-pixel electrode stack includes a red n-type sub-pixel electrode stack, a green n-type sub-pixel electrode stack, and a blue n-type sub-pixel electrode stack; the n-type sub-pixel electrodes of each color are disposed on top of the corresponding color n-type sub-pixel stack; the red n-type sub-pixel electrode stack includes a blue light-emitting structure, a green light-emitting structure, and a red n-type contact layer stacked on an epitaxial buffer layer; a first tunnel junction is disposed between the blue light-emitting structure and the green light-emitting structure, and a second tunnel junction is disposed between the green light-emitting structure and the red n-type contact layer; the red n-type sub-pixel electrode stack includes a red ... blue light-emitting structure. The primary electrode is disposed on top of the red n-type contact layer and electrically connected to the red n-type contact layer; the green n-type sub-pixel electrode stack includes a blue light-emitting structure and a green n-type contact layer stacked on an epitaxial buffer layer; a first tunnel junction is disposed between the blue light-emitting structure and the green n-type contact layer; the green n-type sub-pixel electrode is disposed on top of the green n-type contact layer and electrically connected to the green n-type contact layer; the blue n-type sub-pixel electrode stack includes a blue n-type contact layer disposed on an epitaxial buffer layer; the green n-type sub-pixel electrode is disposed on top of the blue n-type contact layer and electrically connected to the blue n-type contact layer.

[0010] In some embodiments of this application, the epitaxial stacked full-color Micro-LED chip further includes: a first passivation layer covering the sides and part of the top surface of each epitaxial pixel stack, wherein the contact portion of each p-type sub-pixel electrode penetrates the first passivation layer at its stacking position; a p-type first contact portion of each p-type sub-pixel electrode is disposed at the top of the contact portion; the first passivation layer further covers the sides and part of the top surface of each n-type sub-pixel electrode stack, wherein each n-type sub-pixel electrode includes an n-type first contact portion, and each n-type first contact portion penetrates the first passivation layer at its stacking position; a second passivation layer covering the sides and top surface of the first passivation layer, and the p-type sub-pixel electrode exposed... The second passivation layer has p-type openings on its sides and top surface exposed outside the first passivation layer; a p-type opening is provided on the top of the second passivation layer to expose the p-type first contact portion of the p-type sub-pixel electrode; the second passivation layer also covers the sides of each n-type sub-pixel electrode exposed outside the first passivation layer; an n-type opening is provided on the top of the second passivation layer to expose the n-type first contact portion of the n-type sub-pixel electrode stack; p-type second contact portions are located on the top of the second passivation layer at each epitaxial pixel stack position and are connected to each p-type first contact portion through the p-type openings; n-type second contact portions fill pixel isolation trenches, extend away from the epitaxial buffer layer, and cover each n-type sub-pixel electrode stack, and are connected to each n-type first contact portion through the n-type openings. The epitaxial stacked full-color Micro-LED microdisplay also includes: a driving substrate, which has an effective pixel area, an array of anode contact holes, and anode contact electrodes disposed in the anode contact holes; a cathode contact hole is annularly disposed around the effective pixel area, and a cathode contact electrode is disposed in the cathode contact hole; the driving substrate also has a cathode ring surrounding the effective pixel area, covering and filling the effective pixel area. The cathode contact hole is filled and connected to the cathode contact electrode; a pixel insulating layer is provided on the surface of the driving substrate, which is divided into an array of pixel areas, each pixel area corresponding to an anode contact electrode, and the pixel insulating layer exposes each anode contact electrode; the arrangement of each pixel area corresponds to the arrangement of each epitaxial pixel stack; a p-type third contact portion and an n-type third contact portion are also provided on one side surface of the pixel insulating layer of the driving substrate, the p-type third contact portion is located in each pixel area, connects to the anode contact electrode, and is spaced apart from the n-type third contact portion; the n-type third contact portion is in a grid shape, separating each pixel area and the p-type third contact portion therein, and extends to connect to the outer cathode ring; each p-type third contact portion is connected to each p-type second contact portion, and each n-type third contact portion is connected to each n-type second contact portion, so that the driving substrate and the epitaxial stacked full-color Micro-LED chip are connected as one unit; the gap between the driving substrate and the epitaxial stacked full-color Micro-LED chip is filled with insulating material.The epitaxial stacked full-color Micro-LED microdisplay also includes: a microlens array located on the side of the epitaxial buffer layer of each epitaxial stacked full-color Micro-LED chip facing away from the driving substrate; the microlenses of the microlens array correspond one-to-one with each epitaxial pixel stack.

[0011] The method for manufacturing an epitaxial stacked full-color Micro-LED microdisplay provided in this application forms a p-type sub-pixel electrode whose contact portion, in addition to filling the p-type groove, is also covered with a portion of a first passivation layer. This allows it to partially function as a "back reflective layer," reflecting light emitted towards the substrate back to the light-emitting surface, thereby improving the device's "light extraction efficiency." Furthermore, the arrangement of the microlens array further optimizes the light extraction efficiency and enhances the device's heat dissipation capabilities.

[0012] In some embodiments of this application, the blue light-emitting layer includes a blue InGaN-based multiple quantum well active layer; the green light-emitting layer includes a green InGaN-based multiple quantum well active layer and an AlN layer on the surface of the green InGaN-based multiple quantum well active layer away from the blue light-emitting layer; the red light-emitting layer includes a GaN / InGaN superlattice layer, a blue InGaN-based single quantum well active layer, and a red InGaN-based multiple quantum well active layer stacked together; the color-emitting structure also includes a p-type GaN layer and a p-type electron blocking layer stacked together on the side of the red light-emitting layer away from the red light-emitting layer. + GaN contact layer; red light n-type contact layer is n-type Si-doped GaN or n-type Si-doped AlGaN layer; green light n-type contact layer is n-type Si-doped GaN or n-type Si-doped AlGaN layer; blue light n-type contact layer is n-type Si-doped GaN or n-type Si-doped AlGaN layer; red light electron blocking layer is p-type AlGaN layer; green light electron blocking layer is p-type AlGaN layer; blue light electron blocking layer is p-type AlGaN layer; epitaxial buffer layer is undoped GaN layer; each epitaxial pixel stack and each n-type sub-pixel electrode stack includes an epitaxial buffer layer of partial thickness; the material of each p-type sub-pixel electrode and each n-type sub-pixel electrode stack includes one or more combinations of aluminum, silver, rhodium, zinc, gold, germanium, nickel, chromium, platinum, tin, copper, tungsten, palladium, indium, and titanium.

[0013] In another aspect of this application, a method for manufacturing an epitaxial stacked full-color Micro-LED microdisplay is also provided, comprising the following steps: forming a plurality of columns of epitaxial stacked full-color Micro-LED chips; the step of forming the epitaxial stacked full-color Micro-LED chips includes: providing an epitaxial buffer layer; forming a plurality of full-color Micro-LED pixels arranged in an array on the epitaxial buffer layer; each full-color Micro-LED pixel includes three epitaxial pixel stacks, respectively serving as a red photonic pixel stack, a green photonic pixel stack, and a blue photonic pixel stack; wherein each epitaxial pixel stack has the same height and includes a blue light-emitting structure, a green light-emitting structure, and a red light-emitting structure stacked from the side closest to the epitaxial buffer layer to the side furthest from the epitaxial buffer layer; the blue light-emitting structure, the green light-emitting structure, and the red light-emitting structure are sequentially connected by tunnels. Within the epitaxial stacked full-color Micro-LED microdisplay, all red, green, and blue sub-pixel stacks are arranged in a mosaic pattern. A p-type sub-pixel electrode of the corresponding color is formed on top of each epitaxial pixel stack. Each epitaxial pixel stack is separated by a grid-like pixel isolation trench, in which n-type sub-pixel electrode stacks corresponding to the red, green, and blue sub-pixel stacks are formed. The n-type sub-pixel electrode stacks corresponding to the red, green, and blue sub-pixel stacks have different corresponding positional and connection relationships relative to their respective sub-pixel stacks. All n-type sub-pixel electrode stacks are arranged in a mosaic pattern. Any n-type sub-pixel electrode stack is located on the line connecting adjacent p-type sub-pixel electrodes in different rows corresponding to its own color.

[0014] The epitaxial stacked full-color Micro-LED microdisplay provided in this application stacks different color sub-pixels within the same pixel at the same height. Different sub-pixels are controlled separately by driving electrodes at different positions and with different connection relationships. This allows different color sub-pixels to emit different colors of light, even though their basic light-emitting structures are the same (all containing stacked blue, green, and red light-emitting structures). For example, although the red sub-pixel has the same light-emitting structure as the other two sub-pixels, its driving electrode only drives the red light-emitting structure, thus emitting only red light. The blue and green sub-pixels follow the same principle. Since the epitaxial pixel stacking structure of the three sub-pixels is the same, their heights are also the same. The electrode structures on their top surfaces also have the same height, differing only in their depth and the connection layers. Therefore, when connecting the driving circuit, the electrical connection structures of each sub-pixel can also be of the same height and use the same connection structure. This avoids the reliability reduction and short-circuit risk after aging caused by differences in the electrical connection structures of different sub-pixels. Meanwhile, since the three colors of sub-pixels use the same light-emitting structure, there is no need to perform different structural etching. Although the etching depth of the electrodes is different, requiring one step for each depth, due to the various etching depths at different locations for the n-type and p-type sub-pixel electrodes of the three colors, some etching depths can be designed to be the same. For example, the n-type etching depth for red light and the p-type etching depth for green light are roughly the same, so two grooves can be completed in one step, thus simplifying the process steps and reducing the complexity of the process. With this structure, full-color integration can be completed on the same wafer, significantly reducing the complexity of the process. In addition, the mosaic-style sub-pixel layout, combined with the corresponding stacked arrangement of p-type and n-type sub-pixel electrodes, solves the electrical interconnection and optical crosstalk problems caused by stacked structures. Specifically, by etching grooves into specific epitaxial layers, electrodes for each color pixel are brought out separately, ensuring that the red, green, and blue sub-pixels can be "independently controlled," overcoming the disadvantage of serial structures that cannot be driven separately. Meanwhile, the pixel isolation trenches form an effective "optical isolation dam," which greatly reduces "optical crosstalk" between adjacent pixels, thereby ensuring the color purity and contrast of the displayed image.

[0015] In some embodiments of this application, the steps of providing a support connection layer and forming an array of a plurality of full-color Micro-LED pixels on the support connection layer include: providing an epitaxial buffer layer and forming an array of a plurality of full-color Micro-LED pixels on the epitaxial buffer layer, which includes: providing a growth substrate; forming an epitaxial buffer layer on the growth substrate; forming a blue light-emitting structure on the epitaxial buffer layer; forming a first tunnel junction on the side of the blue light-emitting structure facing away from the growth substrate; forming a green light-emitting structure on the side of the first tunnel junction facing away from the red light-emitting structure; and forming a green light-emitting structure on the side of the green light-emitting structure facing away from the growth substrate. A second tunnel junction is formed on one side of the first tunnel junction; a red light-emitting structure is formed on the side of the second tunnel junction facing away from the green light-emitting structure; thus, a pixel epitaxial structure is formed; p-type grooves of corresponding colors are formed at the positions corresponding to the stacks of each epitaxial pixel in the pixel epitaxial structure; n-type grooves of corresponding colors are formed at predetermined positions; the pixel epitaxial structure is etched to form a grid-like pixel isolation trench, isolating the pixel epitaxial structure into epitaxial pixel stacks with p-type grooves of each color, while n-type sub-pixel electrode stacks with n-type grooves corresponding to each color are formed at corresponding positions in the pixel isolation trench; wherein, the red light-emitting structure The structure includes a stacked red n-type contact layer, a red emitting layer, and a red electron blocking layer; a green emitting structure includes a stacked green n-type contact layer, a green emitting layer, and a green electron blocking layer; a second tunnel junction is provided between the green electron blocking layer and the red n-type contact layer; a blue emitting structure includes a stacked blue n-type contact layer, a blue emitting layer, and a blue electron blocking layer; a first tunnel junction is provided between the blue electron blocking layer and the green n-type contact layer; the red sub-pixel stack does not have p-type grooves; the p-type grooves of the green sub-pixel stack extend into the red n-type contact layer; the p-type grooves of the blue sub-pixel stack extend into the green n-type contact layer. The red n-type sub-pixel electrode stack includes a blue light emitting structure, a green light emitting structure, and a red n-type contact layer stacked on an epitaxial buffer layer; a first tunnel junction is provided between the blue light emitting structure and the green light emitting structure, and a second tunnel junction is provided between the green light emitting structure and the red n-type contact layer; the green n-type sub-pixel electrode stack includes a blue light emitting structure and a green n-type contact layer stacked on an epitaxial buffer layer; a first tunnel junction is provided between the blue light emitting structure and the green n-type contact layer; the blue n-type sub-pixel electrode stack includes a blue n-type contact layer disposed on an epitaxial buffer layer.

[0016] In some embodiments of this application, the method further includes the following steps: forming a first passivation layer, the first passivation layer covering the sides and top surface of each epitaxial pixel stack, and also covering the sides and top surface of each n-type sub-pixel electrode stack; openings in the first passivation layer at the top of each epitaxial pixel stack and the first passivation layer at the top of each n-type sub-pixel electrode stack, the opening positions corresponding to the center of the stack or the position corresponding to the p-type groove on the stack, exposing the underlying film layer; forming contact portions of p-type sub-pixel electrodes corresponding to each color at the top of each epitaxial pixel stack, the contact portions filling each p-type groove and partially covering the first passivation layer; forming p-type sub-images corresponding to each color at the top of each epitaxial pixel stack. The p-type first contact portion of the pixel electrode is located on top of the contact portion of each p-type sub-pixel electrode; an n-type first contact portion of the n-type sub-pixel electrode stack is formed on top of each n-type sub-pixel electrode stack, filling the opening of the first passivation layer and contacting the exposed film layer; wherein, the n-type first contact portion of the red light n-type sub-pixel electrode stack is disposed on top of the red light n-type contact layer and electrically connected to the red light n-type contact layer; the n-type first contact portion of the green light n-type sub-pixel electrode stack is on top of the green light n-type contact layer and electrically connected to the green light n-type contact layer; the n-type first contact portion of the blue light n-type sub-pixel electrode stack is disposed on top of the blue light n-type contact layer and electrically connected to the blue light n-type contact layer.

[0017] The method for manufacturing an epitaxial stacked full-color Micro-LED microdisplay provided in this application forms a p-type sub-pixel electrode whose contact portion is not only filled with a p-type groove, but also covered with a portion of a first passivation layer. This can also serve as a partial "back reflective layer", reflecting light emitted towards the substrate back to the light-emitting surface, thereby improving the "light extraction efficiency" of the device.

[0018] In some embodiments of this application, the method further includes the following steps: forming a second passivation layer covering the first passivation layer, the contact portion of the p-type sub-pixel electrode of each color, and the p-type first contact portion; and the second passivation layer also covering each n-type first contact portion; the second passivation layer opening to expose a portion of the p-type first contact portion and the n-type first contact portion; the exposed portion corresponding to the opening position of the first passivation layer; forming a p-type second contact portion located on top of the second passivation layer at each epitaxial pixel stack position, connecting each p-type first contact portion through a p-type opening; An n-type second contact portion is formed, filling pixel isolation trenches and extending away from the epitaxial buffer layer, and covering the stack of n-type sub-pixel electrodes. It connects to each n-type first contact portion through an n-type opening. Both the p-type second contact portion and each n-type second contact portion extend away from the epitaxial buffer layer, and the top surface of each p-type second contact portion is at the same horizontal position as the top surface of each n-type second contact portion. A driving substrate is provided, which has an effective pixel area. The effective pixel area has an array of anode contact holes, and anode contact electrodes are disposed in the anode contact holes. Point electrodes; the driving substrate has a cathode contact hole arranged in a ring around the effective pixel area, and a cathode contact electrode is disposed in the cathode contact hole; the driving substrate also has a cathode ring, which surrounds the effective pixel area, covers and fills the cathode contact hole, and is connected to the cathode contact electrode; a pixel insulating layer is disposed on the surface of the driving substrate, and the pixel insulating layer is divided into an array of pixel areas, each pixel area corresponding to an anode contact electrode, and the pixel insulating layer exposes each anode contact electrode; the arrangement of each pixel area corresponds to the arrangement of each epitaxial pixel stack; in the driving substrate On one side surface of the pixel insulating layer of the board, p-type third contact portions and n-type third contact portions are formed. The p-type third contact portions are located in each pixel area, connected to the anode contact electrode, and spaced apart from the n-type third contact portions. The n-type third contact portions are in a grid shape, separating each pixel area and the p-type third contact portions therein, and extending to connect to the outer cathode ring. Each p-type third contact portion is connected to each p-type second contact portion, and each n-type third contact portion is connected to each n-type second contact portion, so that the driving substrate and the epitaxial stacked full-color Micro-LED chip are connected as one unit.

[0019] In some embodiments of this application, the following steps are also included: filling the gap between the driving substrate and the epitaxial stacked full-color Micro-LED chip with insulating material; removing the growth substrate on the side of the epitaxial buffer layer of each epitaxial stacked full-color Micro-LED chip facing away from the driving substrate; or, removing the growth substrate on the side of the epitaxial buffer layer of each epitaxial stacked full-color Micro-LED chip facing away from the driving substrate, and then forming a microlens array at the position after the growth substrate is removed, wherein the microlenses of the microlens array correspond one-to-one with each epitaxial pixel stack.

[0020] The method for manufacturing a driving substrate and an epitaxially stacked full-color Micro-LED provided in this application can enhance the heat dissipation capability of the device by removing the growth substrate. Alternatively, by removing the growth substrate and forming a microlens array, the light extraction efficiency can be further optimized. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the specific embodiments of this application or the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0022] Figures 1a-1c This is a schematic diagram of the state at different steps in the formation process of an epitaxial stacked full-color Micro-LED chip;

[0023] Figure 2 This is a schematic diagram showing the state of an epitaxial stacked full-color Micro-LED chip after it is connected to a driving circuit. Figures 3-16b This is a schematic diagram showing the state of each step in the manufacturing process of the chip of the epitaxial stacked full-color Micro-LED microdisplay according to an embodiment of this application; Figures 17a-20 This is a schematic diagram illustrating the process of forming a driver chip by docking the chip of an epitaxial stacked full-color Micro-LED microdisplay with a driver substrate after the chip is manufactured according to an embodiment of this application. Figure 21 This is a schematic diagram showing the mosaic arrangement of the three-color sub-pixels of the chip in an epitaxial stacked full-color Micro-LED microdisplay according to an embodiment of this application. Detailed Implementation

[0024] refer to Figures 1a-1c The formation process of an epitaxial stacked full-color Micro-LED chip first forms... Figure 1a Epitaxial pixel stacking involves stacking blue light-emitting structures 310, green light-emitting structures 320, and red light-emitting structures 330 upwards from substrate 100; subsequently, according to the light-emitting requirements of different sub-pixels, light-emitting structures of the same height are etched to expose them, such as... Figure 1b As shown, etching is performed sequentially until the red light-emitting structure 330 is exposed, then until the green light-emitting structure 320 is exposed, and finally until the blue light-emitting structure 310 is exposed; then, unified packaging and electrode fabrication are performed, as follows. Figure 1c As shown, electrodes e of different heights are packaged and positioned. In this completed chip structure, the electrode heights for each different light-emitting structure are different. (Reference) Figure 2When these sub-pixels are connected to the driving circuit, the structures of different color sub-pixels also differ. The red light-emitting structure 330 of the red sub-pixel has the highest stacking height, therefore its electrical connection structure C-height is the lowest; the blue light-emitting structure 310 of the blue sub-pixel has the lowest stacking height, therefore its electrical connection structure C-height is the highest; and the electrical connection structure C-height of the green light-emitting structure 320 of the green sub-pixel falls in between. This increases the manufacturing complexity, and because of the different bonding structures, the driving requirements and losses between different sub-pixels also differ, thus posing a risk to reliability after aging, and potentially causing short circuits due to excessive metal in some areas.

[0025] Therefore, this application provides an epitaxial stacked full-color Micro-LED microdisplay and its manufacturing method to solve the problems of high difficulty in bonding epitaxial stacked full-color Micro-LED chips to the driving circuit in epitaxial stacked full-color Micro-LED microdisplays, and the risk of reduced reliability or even short circuit after aging.

[0026] This application provides an epitaxial stacked full-color Micro-LED microdisplay, comprising a plurality of epitaxial stacked full-color Micro-LED chips arranged in an array. Each epitaxial stacked full-color Micro-LED chip includes: an epitaxial buffer layer; a plurality of full-color Micro-LED pixels arranged in an array on the epitaxial buffer layer; each full-color Micro-LED pixel includes three epitaxial pixel stacks, respectively serving as a red photonic pixel stack, a green photonic pixel stack, and a blue photonic pixel stack; each epitaxial pixel stack has the same height and includes a blue light-emitting structure, a green light-emitting structure, and a red light-emitting structure stacked from the side closest to the epitaxial buffer layer to the side furthest from the epitaxial buffer layer; the blue light-emitting structure, the green light-emitting structure, and the red light-emitting structure are sequentially connected by a tunnel junction; within the scope of the epitaxial stacked full-color Micro-LED microdisplay, all the red photonic pixel stacks, the green photonic pixel stacks, and the... Blue sub-pixels are stacked in a mosaic pattern; each outer pixel stack has a p-type sub-pixel electrode of the corresponding color on its top surface; the p-type sub-pixel electrodes of the red, green, and blue sub-pixel stacks have different corresponding positional and connection relationships relative to their respective sub-pixel stacks; each outer pixel stack is separated by a grid-like pixel isolation trench, and the pixel isolation trench has n-type sub-pixel electrode stacks corresponding to the red, green, and blue sub-pixel stacks respectively; the n-type sub-pixel electrode stacks corresponding to the red, green, and blue sub-pixel stacks have different corresponding positional and connection relationships relative to their respective sub-pixel stacks; all n-type sub-pixel electrodes are stacked in a mosaic pattern; any n-type sub-pixel electrode stack is located on the line connecting adjacent p-type sub-pixel electrodes in different rows corresponding to its own color.

[0027] This application also provides a method for manufacturing an epitaxial stacked full-color Micro-LED microdisplay, comprising the following steps: forming a plurality of columns of epitaxial stacked full-color Micro-LED chips; the step of forming the epitaxial stacked full-color Micro-LED chips includes: providing an epitaxial buffer layer; forming a plurality of full-color Micro-LED pixels arranged in an array on the epitaxial buffer layer; each full-color Micro-LED pixel includes three epitaxial pixel stacks, respectively serving as a red photonic pixel stack, a green photonic pixel stack, and a blue photonic pixel stack; wherein each epitaxial pixel stack has the same height and includes a blue light-emitting structure, a green light-emitting structure, and a red light-emitting structure stacked from the side closest to the epitaxial buffer layer to the side furthest from the epitaxial buffer layer; the blue light-emitting structure, the green light-emitting structure, and the red light-emitting structure are connected sequentially through a tunnel junction; in the epitaxial stack Within the stacked full-color Micro-LED micro-display, all red, green, and blue sub-pixel stacks are arranged in a mosaic pattern. A p-type sub-pixel electrode of the corresponding color is formed on top of each epitaxial pixel stack. Each epitaxial pixel stack is separated by a grid-like pixel isolation trench, in which n-type sub-pixel electrode stacks corresponding to the red, green, and blue sub-pixel stacks are formed. The n-type sub-pixel electrode stacks corresponding to the red, green, and blue sub-pixel stacks have different corresponding positional and connection relationships relative to their respective sub-pixel stacks. All n-type sub-pixel electrode stacks are arranged in a mosaic pattern. Any n-type sub-pixel electrode stack is located on the line connecting adjacent p-type sub-pixel electrodes in different rows corresponding to its own color.

[0028] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0029] Example 1 This embodiment provides an epitaxial stacked full-color Micro-LED microdisplay, comprising a plurality of epitaxial stacked full-color Micro-LED chips arranged in an array; refer to Figure 20 The epitaxial stacked full-color Micro-LED chips include: 200mm epitaxial buffer layer; Several full-color Micro-LED pixels are arrayed on the epitaxial buffer layer 200; each full-color Micro-LED pixel includes three epitaxial pixel stacks, which are respectively used as red sub-pixel stack R, green sub-pixel stack G and blue sub-pixel stack B; Each epitaxial pixel has the same stack height and includes a blue light emitting structure 310, a green light emitting structure 320, and a red light emitting structure 330 stacked from the side closest to the epitaxial buffer layer 200 to the side furthest from the epitaxial buffer layer; the blue light emitting structure 310, the green light emitting structure 320, and the red light emitting structure 330 are connected in sequence through a tunnel junction. like Figure 21 Within the epitaxial stacked full-color Micro-LED micro-display, all the red photonic pixel stacks R, green photonic pixel stacks G, and blue photonic pixel stacks B are arranged in a mosaic pattern. Each epitaxial pixel stack has a p-type sub-pixel electrode of a corresponding color on its top surface; The p-type sub-pixel electrodes of the red sub-pixel stack R, the green sub-pixel stack G, and the blue sub-pixel stack B have different corresponding positional relationships and corresponding connection relationships relative to their respective sub-pixel stacks; Each epitaxial pixel stack is separated by a grid-like pixel isolation trench, and the pixel isolation trench is provided with n-type sub-pixel electrode stacks corresponding to the red sub-pixel stack, green sub-pixel stack and blue sub-pixel stack respectively; The n-type sub-pixel electrode stacks r, g, and b corresponding to the red sub-pixel stack R, green sub-pixel stack G, and blue sub-pixel stack B have different corresponding positional relationships and corresponding connection relationships relative to the corresponding sub-pixel stacks R, G, and B, respectively. Similarly, Figure 21 All n-type sub-pixel electrodes are stacked in a mosaic pattern. Any stack of n-type sub-pixel electrodes is located on the line connecting adjacent p-type sub-pixel electrodes in different rows corresponding to its own color.

[0030] The epitaxial stacked full-color Micro-LED microdisplay provided in this application stacks different color sub-pixels within the same pixel at the same height. Different sub-pixels are controlled separately by driving electrodes at different positions and with different connection relationships. This allows different color sub-pixels to emit different colors of light, even though their basic light-emitting structures are the same (all containing stacked blue, green, and red light-emitting structures). For example, although the red sub-pixel has the same light-emitting structure as the other two sub-pixels, its driving electrode only drives the red light-emitting structure, thus emitting only red light. The blue and green sub-pixels follow the same principle. Since the epitaxial pixel stacking structure of the three sub-pixels is the same, their heights are also the same. The electrode structures on their top surfaces also have the same height, differing only in their depth and the connection layers. Therefore, when connecting the driving circuit, the electrical connection structures of each sub-pixel can also be of the same height and use the same connection structure. This avoids the reliability reduction and short-circuit risk after aging caused by differences in the electrical connection structures of different sub-pixels. Meanwhile, since the three colors of sub-pixels use the same light-emitting structure, there is no need to perform different structural etching. Although the etching depth of the electrodes is different, requiring one step for each depth, due to the various etching depths at different locations for the n-type and p-type sub-pixel electrodes of the three colors, some etching depths can be designed to be the same. For example, the n-type etching depth for red light and the p-type etching depth for green light are roughly the same, so two grooves can be completed in one step, thus simplifying the process steps and reducing the complexity of the process. With this structure, full-color integration can be completed on the same wafer, significantly reducing the complexity of the process. In addition, the mosaic-style sub-pixel layout, combined with the corresponding stacked arrangement of p-type and n-type sub-pixel electrodes, solves the electrical interconnection and optical crosstalk problems caused by stacked structures. Specifically, by etching grooves into specific epitaxial layers, electrodes for each color pixel are brought out separately, ensuring that the red, green, and blue sub-pixels can be "independently controlled," overcoming the disadvantage of serial structures that cannot be driven separately. Meanwhile, the pixel isolation trenches form an effective "optical isolation dam," which greatly reduces "optical crosstalk" between adjacent pixels, thereby ensuring the color purity and contrast of the displayed image.

[0031] In some embodiments of this application, the red light emitting structure 330 includes a stacked red n-type contact layer, a red light emitting layer, and a red electron blocking layer; The green light emitting structure 320 includes a stacked green n-type contact layer, a green light emitting layer, and a green electron blocking layer; a second tunnel junction 420 is disposed between the green electron blocking layer and the red n-type contact layer; The blue light emitting structure 310 includes a stacked blue n-type contact layer, a blue light emitting layer, and a blue electron blocking layer; a first tunnel junction 410 is disposed between the blue electron blocking layer and the green n-type contact layer; The epitaxial pixel stack also includes p-type sub-pixel electrodes, located on the side of the red light emitting structure 330 away from the epitaxial buffer layer 200; each p-type sub-pixel electrode includes a contact portion and a p-type first contact portion; The contact portion of the p-type sub-pixel electrode of the red sub-pixel stack R is located only on the surface of the red light emitting structure; the contact portion of the p-type sub-pixel electrode of the green sub-pixel stack G extends into the red n-type contact layer and is electrically connected to the red n-type contact layer. The contact portion of the p-type sub-pixel electrode of the blue sub-pixel stack B extends into the green n-type contact layer and is electrically connected to the green n-type contact layer.

[0032] In some embodiments of this application, the n-type sub-pixel electrode stack includes a red n-type sub-pixel electrode stack r, a green n-type sub-pixel electrode stack g, and a blue n-type sub-pixel electrode stack b; the n-type sub-pixel electrode of each color is disposed on top of the n-type sub-pixel stack of the corresponding color. The red n-type sub-pixel electrode stack r includes a blue light emitting structure, a green light emitting structure, and a red n-type contact layer stacked on an epitaxial buffer layer; a first tunnel junction is provided between the blue light emitting structure and the green light emitting structure, and a second tunnel junction is provided between the green light emitting structure and the red n-type contact layer; the red n-type sub-pixel electrode is disposed on top of the red n-type contact layer and is electrically connected to the red n-type contact layer. The green n-type sub-pixel electrode stack g includes a blue light emitting structure and a green n-type contact layer stacked on an epitaxial buffer layer; a first tunnel junction is provided between the blue light emitting structure and the green n-type contact layer; the green n-type sub-pixel electrode is disposed on top of the green n-type contact layer and is electrically connected to the green n-type contact layer. The blue n-type sub-pixel electrode stack b includes a blue n-type contact layer disposed on an epitaxial buffer layer; the green n-type sub-pixel electrode is disposed on top of the blue n-type contact layer and is electrically connected to the blue n-type contact layer.

[0033] In some embodiments of this application, the epitaxial stacked full-color Micro-LED chip further includes: The first passivation layer covers the sides and part of the top surface of each epitaxial pixel stack, and the contact portion of each p-type sub-pixel electrode penetrates the first passivation layer at its own stack position; the p-type first contact portion of each p-type sub-pixel electrode is disposed at the top of the contact portion; the first passivation layer also covers the sides and part of the top surface of each n-type sub-pixel electrode stack, and each n-type sub-pixel electrode includes an n-type first contact portion, and each n-type first contact portion penetrates the first passivation layer at its own stack position. The second passivation layer covers the sides and top surface of the first passivation layer, as well as the sides and top surface of each p-type sub-pixel electrode exposed outside the first passivation layer; a p-type opening is provided at the top of the second passivation layer to expose the p-type first contact portion of the p-type sub-pixel electrode; the second passivation layer also covers the sides of each n-type sub-pixel electrode exposed outside the first passivation layer; an n-type opening is provided at the top of the second passivation layer to expose the n-type first contact portion of the stacked n-type sub-pixel electrodes; p-type second contact portion 612 is located on top of the second passivation layer at the stacking position of each epitaxial pixel, and is connected to each p-type first contact portion through a p-type opening; The n-type second contact portion 622 fills the pixel isolation trench, extends away from the epitaxial buffer layer, and covers the stack of n-type sub-pixel electrodes, and is connected to the n-type first contact portion through the n-type opening; Both the p-type second contact portion 612 and each n-type second contact portion 622 extend away from the outer epitaxial buffer layer 200, and the top surface of each p-type second contact portion 612 and the top surface of each n-type second contact portion 622 are at the same horizontal position.

[0034] Epitaxial stacked full-color Micro-LED microdisplays also include: A driving substrate 21 has an effective pixel area with an array of anode contact holes, each containing an anode contact electrode 23. A cathode contact hole is annularly arranged around the effective pixel area, containing a cathode contact electrode. A cathode ring surrounds the effective pixel area, covering and filling the cathode contact holes, and is connected to the cathode contact electrodes. A pixel insulating layer 22 is formed on the surface of the driving substrate 21, dividing it into arrayed pixel regions, each pixel region... Each pixel has an anode contact electrode 23, and the pixel insulating layer 22 exposes each anode contact electrode 23. The arrangement of each pixel area corresponds to the arrangement of R, G, B of each epitaxial pixel stack. On one side surface of the pixel insulating layer 22 of the driving substrate 21, there are also p-type third contact portions 24 and n-type third contact portions 26. The p-type third contact portions 24 are located in each pixel area, connected to the anode contact electrode 23, and spaced apart from the n-type third contact portions 26. The n-type third contact portions 26 are in a grid shape, separating each pixel area and the p-type third contact portions 24 therein, and extending to connect to the outer cathode ring.

[0035] Each p-type third contact portion 24 is connected to each p-type second contact portion 612, and each n-type third contact portion 26 is connected to each n-type second contact portion 622, so that the driving substrate 21 and the epitaxial stacked full-color Micro-LED chip are connected as one unit; the gap between the driving substrate 21 and the epitaxial stacked full-color Micro-LED chip is filled with insulating material.

[0036] In some embodiments, the epitaxial stacked full-color Micro-LED microdisplay further includes: The microlens array 800 is located on the side of the epitaxial buffer layer 200 of each epitaxial stacked full-color Micro-LED chip facing away from the driving substrate 21; the microlenses of the microlens array 800 correspond one-to-one with each epitaxial pixel stack.

[0037] The method for manufacturing an epitaxial stacked full-color Micro-LED microdisplay provided in this application forms a p-type sub-pixel electrode whose contact portion, in addition to filling the p-type groove, is also covered with a portion of a first passivation layer. This allows it to partially function as a "back reflective layer," reflecting light emitted towards the substrate back to the light-emitting surface, thereby improving the device's "light extraction efficiency." Furthermore, the arrangement of a microlens array can further optimize the light extraction efficiency.

[0038] In some embodiments of this application, the blue light emitting layer includes a blue InGaN-based multiple quantum well active layer; The green light-emitting layer includes a green InGaN-based multi-quantum-well active layer and an AlN layer on the surface of the green InGaN-based multi-quantum-well active layer away from the blue light-emitting layer; The red-emitting layer comprises a stacked GaN / InGaN superlattice layer, a blue-emitting InGaN-based single quantum well active layer, and a red-emitting InGaN-based multi-quantum well active layer; the red-emitting structure also includes a p-type GaN layer and a p-type GaN layer stacked on the side of the red-emitting electron blocking layer away from the red-emitting layer. + GaN contact layer; The red light n-type contact layer is an n-type Si-doped GaN or an n-type Si-doped AlGaN layer; The green n-type contact layer is an n-type Si-doped GaN or an n-type Si-doped AlGaN layer; The blue light n-type contact layer is an n-type Si-doped GaN or an n-type Si-doped AlGaN layer; The red electron blocking layer is a p-type AlGaN layer; The green photoelectron blocking layer is a p-type AlGaN layer; The blue electron blocking layer is a p-type AlGaN layer; The epitaxial buffer layer 200 is an undoped GaN layer; Each epitaxial pixel stack and each n-type sub-pixel electrode stack includes an epitaxial buffer layer of partial thickness; the materials of each p-type sub-pixel electrode and each n-type sub-pixel electrode stack include one or more combinations of aluminum, silver, rhodium, zinc, gold, germanium, nickel, chromium, platinum, tin, copper, tungsten, palladium, indium, and titanium.

[0039] Example 2 This embodiment provides a method for manufacturing an epitaxial stacked full-color Micro-LED microdisplay, including the following steps: Forming several rows of epitaxially stacked full-color Micro-LED chips; the steps for forming epitaxially stacked full-color Micro-LED chips include: Provide an epitaxial buffer layer; A plurality of full-color Micro-LED pixels are formed in an array on an epitaxial buffer layer; each full-color Micro-LED pixel includes three epitaxial pixel stacks, which are respectively used as red sub-pixel stacks, green sub-pixel stacks and blue sub-pixel stacks; Each epitaxial pixel has the same stacking height and includes a blue light emitting structure, a green light emitting structure, and a red light emitting structure stacked from the side closest to the epitaxial buffer layer to the side furthest from the epitaxial buffer layer; the blue light emitting structure, the green light emitting structure, and the red light emitting structure are connected in sequence through a tunnel junction; Within the epitaxial stacked full-color Micro-LED micro-display, all the red, green, and blue sub-pixels are stacked in a mosaic pattern; p-type sub-pixel electrodes of corresponding colors are formed on the top of each epitaxial pixel stack. Each epitaxial pixel stack is separated by a grid-like pixel isolation trench, and n-type sub-pixel electrode stacks corresponding to red sub-pixel stacks, green sub-pixel stacks and blue sub-pixel stacks are formed in the pixel isolation trenches respectively. The n-type sub-pixel electrode stacks corresponding to red, green, and blue sub-pixel stacks have different corresponding positional and connection relationships relative to their respective sub-pixel stacks. All n-type sub-pixel electrodes are stacked in a mosaic pattern. Any stack of n-type sub-pixel electrodes is located on the line connecting adjacent p-type sub-pixel electrodes in different rows corresponding to its own color.

[0040] The epitaxial stacked full-color Micro-LED microdisplay provided in this application stacks different color sub-pixels within the same pixel at the same height. Different sub-pixels are controlled separately by driving electrodes at different positions and with different connection relationships. This allows different color sub-pixels to emit different colors of light, even though their basic light-emitting structures are the same (all containing stacked blue, green, and red light-emitting structures). For example, although the red sub-pixel has the same light-emitting structure as the other two sub-pixels, its driving electrode only drives the red light-emitting structure, thus emitting only red light. The blue and green sub-pixels follow the same principle. Since the epitaxial pixel stacking structure of the three sub-pixels is the same, their heights are also the same. The electrode structures on their top surfaces also have the same height, differing only in their depth and the connection layers. Therefore, when connecting the driving circuit, the electrical connection structures of each sub-pixel can also be of the same height and use the same connection structure. This avoids the reliability reduction and short-circuit risk after aging caused by differences in the electrical connection structures of different sub-pixels. Meanwhile, since the three colors of sub-pixels use the same light-emitting structure, there is no need to perform different structural etching. Although the etching depth of the electrodes is different, requiring one step for each depth, due to the various etching depths at different locations for the n-type and p-type sub-pixel electrodes of the three colors, some etching depths can be designed to be the same. For example, the n-type etching depth for red light and the p-type etching depth for green light are roughly the same, so two grooves can be completed in one step, thus simplifying the process steps and reducing the complexity of the process. With this structure, full-color integration can be completed on the same wafer, significantly reducing the complexity of the process. In addition, the mosaic-style sub-pixel layout, combined with the corresponding stacked arrangement of p-type and n-type sub-pixel electrodes, solves the electrical interconnection and optical crosstalk problems caused by stacked structures. Specifically, by etching grooves into specific epitaxial layers, electrodes for each color pixel are brought out separately, ensuring that the red, green, and blue sub-pixels can be "independently controlled," overcoming the disadvantage of serial structures that cannot be driven separately. Meanwhile, the pixel isolation trenches form an effective "optical isolation dam," which greatly reduces "optical crosstalk" between adjacent pixels, thereby ensuring the color purity and contrast of the displayed image.

[0041] In some embodiments of this application, the steps of providing a support connection layer and forming an array of full-color Micro-LED pixels on the support connection layer include: refer to Figure 3 The steps of providing an epitaxial buffer layer and forming an array of full-color Micro-LED pixels on the epitaxial buffer layer include: Provide growth substrate 101; An epitaxial buffer layer 200 is formed on the growth substrate; A blue light-emitting structure 310 is formed on the epitaxial buffer layer; A first tunnel junction 410 is formed on the side of the blue light-emitting structure facing away from the growth substrate; A green light-emitting structure 320 is formed on the side of the first tunnel junction opposite to the red light-emitting structure. A second tunnel junction 420 is formed on the side of the green light-emitting structure opposite to the first tunnel junction. A red light emitting structure 330 is formed on the side of the second tunnel junction opposite to the green light emitting structure; This completes the pixel epitaxial structure; refer to Figure 4a and Figure 4b , Figure 4a This is a top view showing the preset positions of each pixel region. The dashed squares in the figure indicate the preset positions of the corresponding color sub-pixels, and the dashed circles indicate the preset positions of the corresponding contact layers or the corresponding p-shaped grooves. Figure 4b for Figure 4a A cross-sectional view of the position of the pp section line; p-shaped grooves of corresponding colors are formed at the positions of the stacked epitaxial pixels in the pixel epitaxial structure; however, the sub-pixel stacks corresponding to the red light emitting structure do not form p-shaped grooves. Figure 5a The dashed circle in the middle only indicates the location where the contact layer is to be formed; refer to Figure 5a and Figure 5b , Figure 5b for Figure 5a A cross-sectional view of the position of the n-section line; forming an n-shaped groove of the corresponding color at the preset corresponding position; refer to Figure 6a and Figure 6b ,as well as Figure 7a and Figure 7b ; Figure 6b for Figure 6a A cross-sectional view showing the location of the PP section line. Figure 7b for Figure 7a A cross-sectional view at the position of the nn section line; etching the pixel epitaxial structure to form a grid-like pixel isolation trench, isolating the pixel epitaxial structure into epitaxial pixel stacks R, G, B with p-type grooves of various colors, while n-type sub-pixel electrode stacks r, g, b with n-type grooves of various colors are formed at corresponding positions in the pixel isolation trench; wherein the epitaxial buffer layer 200 is also etched with a portion of its thickness, constituting part of the epitaxial pixel stacks of various colors and the n-type sub-pixel electrode stacks.

[0042] Among them, the comparison Figure 4b For the annotation, please refer to Figure 6a and Figure 6b : The red light emitting structure includes a stacked red n-type contact layer 331, a red light emitting layer 332, and a red electron blocking layer 333; The green light emitting structure includes a stacked green n-type contact layer 321, a green light emitting layer 322, and a green electron blocking layer 323; a second tunnel junction 420 is provided between the green electron blocking layer 323 and the red n-type contact layer 331. The blue light emitting structure includes a stacked blue n-type contact layer 311, a blue light emitting layer 312, and a blue electron blocking layer 313; a first tunnel junction 410 is provided between the blue electron blocking layer 313 and the green n-type contact layer 321. Red sub-pixels are stacked without p-shaped grooves in the R region; The p-type groove of the green photonic pixel stack G extends into the red n-type contact layer 331; The p-type groove of the blue sub-pixel stack B extends into the green n-type contact layer 321; refer to Figure 7a and Figure 7b : The red n-type sub-pixel electrode stack r includes a blue light emitting structure 310, a green light emitting structure 320 and a red n-type contact layer 331 stacked on the epitaxial buffer layer 200; A first tunnel junction 410 is provided between the blue light emitting structure 310 and the green light emitting structure 320, and a second tunnel junction 420 is provided between the green light emitting structure 320 and the red light n-type contact layer 331. The green n-type sub-pixel electrode stack g includes a blue light emitting structure 310 and a green n-type contact layer 321 stacked on the epitaxial buffer layer 200; A first tunnel junction 410 is provided between the blue light emitting structure 310 and the green light n-type contact layer 321; The blue n-type sub-pixel electrode stack b includes a blue n-type contact layer 311 disposed on the epitaxial buffer layer 200.

[0043] Optional, see reference Figure 8a and Figure 8b , Figure 8b for Figure 8a Cross-sectional view of the pp section line position: After the above steps, H in the etched epitaxial structure can be removed by thermal annealing to activate Mg atoms in the stacked epitaxial layer and form a good p-type GaN layer.

[0044] In some embodiments of this application, the following steps are also included: refer to Figure 9a and Figure 9b ,as well as Figure 10a and Figure 10b ; Figure 9b for Figure 9aA cross-sectional view showing the location of the PP section line. Figure 10b for Figure 10a Cross-sectional view of the position of the nn section line: A first passivation layer 500 is formed, which covers the sides and top surfaces of each epitaxial pixel stack R, G, B, and also covers the sides and top surfaces of each n-type sub-pixel electrode stack r, g, b. Openings are made in the first passivation layer 500 on top of each epitaxial pixel stack R, G, B and the first passivation layer 500 on top of each n-type sub-pixel electrode stack r, g, b. The opening positions correspond to the center of the stack or the position corresponding to the p-type groove on the stack, exposing the underlying film layer. refer to Figure 11a and Figure 11b ,as well as Figure 12a and Figure 12b ; Figure 11b for Figure 11a A cross-sectional view showing the location of the PP section line. Figure 12b for Figure 12a Cross-sectional view of the position of the nn section line: A contact portion 610 corresponding to each color of the p-type sub-pixel electrode is formed on the top of each epitaxial pixel stack. The contact portion 610 fills each p-type groove and partially covers the first passivation layer 500. A p-type first contact portion 611 corresponding to each color p-type sub-pixel electrode is formed on top of each p-type sub-pixel electrode R, G, B stack. It is located on top of the contact portion 610 of each p-type sub-pixel electrode, fills the opening of the first passivation layer 500, and is in contact with the exposed film layer. An n-type first contact portion 621 of the n-type sub-pixel electrode stack is formed on top of each n-type sub-pixel electrode stack r, g, b, filling the opening of the first passivation layer 500 and contacting the exposed film layer. In this configuration, the n-type first contact portion 621 of the red n-type sub-pixel electrode stack r is disposed on top of the red n-type contact layer 331 and is electrically connected to the red n-type contact layer 331; the n-type first contact portion 621 of the green n-type sub-pixel electrode stack g is disposed on top of the green n-type contact layer 321 and is electrically connected to the green n-type contact layer 321; and the n-type first contact portion 621 of the blue n-type sub-pixel electrode stack b is disposed on top of the blue n-type contact layer 311 and is electrically connected to the blue n-type contact layer 311.

[0045] The method for manufacturing an epitaxial stacked full-color Micro-LED microdisplay provided in this application forms a p-type sub-pixel electrode whose contact portion is not only filled with a p-type groove, but also covered with a portion of a first passivation layer. This can also serve as a partial "back reflective layer", reflecting light emitted towards the substrate back to the light-emitting surface, thereby improving the "light extraction efficiency" of the device.

[0046] Optionally, a chip can be formed by stacking three sub-pixel electrodes in the same row, including the R, G, and B color sub-pixel stack. The first passivation layer 500 and epitaxial buffer layer 200 between adjacent chips are removed, exposing the growth substrate 101 and forming chip isolation channels between the chips. The n-type sub-pixel electrode stack in the channel portion can be selected and diced together with the three-color sub-pixel stack into the same chip, or excluded from the diced chip portion, depending on the display requirements of the chip.

[0047] In some embodiments of this application, the following steps are also included: refer to Figure 13a and Figure 13b ,as well as Figure 14a and Figure 14b ; Figure 13b for Figure 13a A cross-sectional view showing the location of the PP section line. Figure 14b for Figure 14a Cross-sectional view of the position of the nn section line: A second passivation layer 700 is formed, covering the first passivation layer 500, the contact portion 610 of the p-type sub-pixel electrode of each color, and the p-type first contact portion 611; and the second passivation layer 700 also covers each n-type first contact portion 621. The second passivation layer 700 has an opening, forming a p-type opening at the corresponding position of each epitaxial pixel stack and an n-type opening at the corresponding position of the n-type sub-pixel electrode stack, exposing a portion of the p-type first contact portion 611 and the n-type first contact portion 621; the exposed portion corresponds to the opening position of the first passivation layer 500. refer to Figure 15a and Figure 15b ,as well as Figure 16a and Figure 16b ; Figure 15b for Figure 15a A cross-sectional view showing the location of the PP section line. Figure 16b for Figure 16a Cross-sectional view of the position of the nn section line: A p-type second contact portion 612 is formed and located on top of the second passivation layer 700 at the stacking position of each epitaxial pixel, and is connected to each p-type first contact portion 611 through a p-type opening; An n-type second contact portion 622 is formed, which fills the pixel isolation trench, extends in a direction away from the epitaxial buffer layer 200, and covers each n-type sub-pixel electrode stack, and is connected to each n-type first contact portion 621 through an n-type opening; Both the p-type second contact portion 612 and each n-type second contact portion 622 extend away from the outer epitaxial buffer layer, and the top surface of each p-type second contact portion 612 and the top surface of each n-type second contact portion 622 are at the same horizontal position. Optionally, it also includes chip dicing, which involves dicing each chip into a single chip from the aforementioned chip isolation channel location.

[0048] refer to Figure 17a and Figure 17b , Figure 17a A top view showing the process steps of driving the substrate. Figure 17b for Figure 17a Cross-sectional view of the position of the dd section line: A driving substrate 21 is provided, which has an array of anode contact holes, each containing an anode contact electrode 23. A cathode contact hole is annularly arranged around the area containing the anode contact holes, each containing a cathode contact electrode (the cathode contact holes and cathode contact electrodes are not shown in the figure). The driving substrate also has a cathode ring 25 surrounding the area containing the anode contact holes, covering and filling the cathode contact holes, and connected to the cathode contact electrodes. A pixel insulating layer 22 is provided on the surface of the driving substrate 21, dividing it into an array of pixel regions, each corresponding to an anode contact electrode 23. The pixel insulating layer 22 exposes each anode contact electrode 23. The arrangement of each pixel region corresponds to the arrangement of each stack of epitaxial pixels. On one side surface of the pixel insulating layer 22 of the driving substrate 21, p-type third contact portions 24 and n-type third contact portions 26 are formed. The p-type third contact portions 24 are located in each pixel area, connected to the anode contact electrode 23, and spaced apart from the n-type third contact portions 26. The n-type third contact portions 26 are in a grid shape, separating each pixel area and the p-type third contact portions 24 therein, and extending to connect to the outer cathode ring 25 (connection details refer to...). Figure 17a , Figure 17b (The portion connecting the n-type third contact 26 to the cathode ring 25 is not shown in the image). refer to Figure 18 Each p-type third contact portion 24 is connected to each p-type second contact portion 612, and each n-type third contact portion 26 is connected to each n-type second contact portion 622, so that the driving substrate 21 and the epitaxial stacked full-color Micro-LED chip are connected as one unit.

[0049] In some embodiments of this application, the following steps are also included: refer to Figure 19 Insulating material (insulating layer not labeled) is filled in the gap between the driving substrate and the epitaxial stacked full-color Micro-LED chip. refer to Figure 20On the side of the epitaxial buffer layer of each epitaxial stacked full-color Micro-LED chip facing away from the driving substrate, the growth substrate 101 is removed; or, on the side of the epitaxial buffer layer 200 of each epitaxial stacked full-color Micro-LED chip facing away from the driving substrate, the growth substrate 101 is removed, and then a microlens array 800 is formed at the position after the growth substrate 101 is removed, and the microlenses of the microlens array 800 correspond one-to-one with each epitaxial pixel stack.

[0050] The method for manufacturing a driving substrate and an epitaxially stacked full-color Micro-LED provided in this application can enhance the heat dissipation capability of the device by removing the growth substrate. Alternatively, by removing the growth substrate and forming a microlens array, the light extraction efficiency can be further optimized.

[0051] After forming the microlens array, the driver chip for the epitaxial stacked full-color Micro-LED chips is fabricated. For the die-to-die fabrication process, bonding is now complete, allowing for subsequent display module fabrication and ultimately, the display screen manufacturing process. For the die-to-wafer fabrication process, the driver chip is then diced and tested before the display module fabrication, completing the display screen manufacturing process.

[0052] Although embodiments of this application have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of this application, and all such modifications and variations fall within the scope defined by the appended claims.

Claims

1. An epitaxial stacked full-color Micro-LED micro-display screen, characterized in that, It includes several epitaxially stacked full-color Micro-LED chips arranged in an array; the epitaxially stacked full-color Micro-LED chips include: Epitaxial buffer layer; The epitaxial buffer layer has a plurality of full-color Micro-LED pixels arranged in an array; each full-color Micro-LED pixel includes three epitaxial pixel stacks, which are respectively used as red photonic pixel stacks, green photonic pixel stacks and blue photonic pixel stacks; Each of the aforementioned epitaxial pixel stacks has the same height and includes a blue light emitting structure, a green light emitting structure, and a red light emitting structure stacked from the side closest to the epitaxial buffer layer to the side furthest from the epitaxial buffer layer; the blue light emitting structure, the green light emitting structure, and the red light emitting structure are connected sequentially through a tunnel junction; Within the scope of the epitaxial stacked full-color Micro-LED micro-display, all the red photonic sub-pixels, green photonic sub-pixels, and blue photonic sub-pixels are stacked in a mosaic-like arrangement. Each of the aforementioned epitaxial pixel stacks has a p-type sub-pixel electrode of a corresponding color on its top surface; The p-type sub-pixel electrodes of the red sub-pixel stack, the green sub-pixel stack, and the blue sub-pixel stack have different corresponding positional relationships and corresponding connection relationships relative to the corresponding sub-pixel stacks; Each of the epitaxial pixel stacks is spaced apart by a grid-like pixel isolation trench, and the pixel isolation trench is provided with n-type sub-pixel electrode stacks corresponding to the red sub-pixel stack, the green sub-pixel stack and the blue sub-pixel stack respectively; The n-type sub-pixel electrode stacks of the corresponding red sub-pixel stacks, green sub-pixel stacks, and blue sub-pixel stacks have different corresponding positional relationships and corresponding connection relationships relative to the corresponding sub-pixel stacks; All the n-type sub-pixel electrodes are stacked in a mosaic pattern. Any of the n-type sub-pixel electrode stacks are located on the line connecting adjacent p-type sub-pixel electrodes in different rows corresponding to their own colors.

2. The epitaxial stacked full-color Micro-LED microdisplay according to claim 1, characterized in that, The red light emitting structure includes a stacked red n-type contact layer, a red light emitting layer, and a red electron blocking layer; The green light-emitting structure includes a stacked green n-type contact layer, a green light-emitting layer, and a green electron-blocking layer; a second tunnel junction is provided between the green electron-blocking layer and the red n-type contact layer; The blue light emitting structure includes a stacked blue n-type contact layer, a blue light emitting layer, and a blue electron blocking layer; a first tunnel junction is provided between the blue electron blocking layer and the green n-type contact layer; The epitaxial pixel stack also includes a p-type sub-pixel electrode, located on the side of the red light emitting structure away from the epitaxial buffer layer; Each of the p-type sub-pixel electrodes includes a contact portion and a p-type first contact portion; The contact portion of the p-type sub-pixel electrode of the red light sub-pixel stack is located only on the surface of the red light emitting structure; The contact portion of the p-type sub-pixel electrode of the green sub-pixel stack extends into the red n-type contact layer and is electrically connected to the red n-type contact layer; The contact portion of the p-type sub-pixel electrode of the blue light sub-pixel stack extends into the green light n-type contact layer and is electrically connected to the green light n-type contact layer.

3. The epitaxial stacked full-color Micro-LED micro-display screen according to claim 2, characterized in that, The n-type sub-pixel electrode stack includes a red n-type sub-pixel electrode stack, a green n-type sub-pixel electrode stack, and a blue n-type sub-pixel electrode stack; the n-type sub-pixel electrode of each color is disposed on top of the n-type sub-pixel stack of the corresponding color; The red n-type sub-pixel electrode stack includes a blue light emitting structure, a green light emitting structure, and a red n-type contact layer stacked on the epitaxial buffer layer; a first tunnel junction is provided between the blue light emitting structure and the green light emitting structure, and a second tunnel junction is provided between the green light emitting structure and the red n-type contact layer; the red n-type sub-pixel electrode is disposed on top of the red n-type contact layer and is electrically connected to the red n-type contact layer; The green n-type sub-pixel electrode stack includes a blue light emitting structure and a green n-type contact layer stacked on the epitaxial buffer layer; a first tunnel junction is provided between the blue light emitting structure and the green n-type contact layer; the green n-type sub-pixel electrode is disposed on top of the green n-type contact layer and is electrically connected to the green n-type contact layer. The blue n-type sub-pixel electrode stack includes a blue n-type contact layer disposed on the epitaxial buffer layer; the green n-type sub-pixel electrode is disposed on top of the blue n-type contact layer and is electrically connected to the blue n-type contact layer.

4. The epitaxial stacked full-color Micro-LED microdisplay according to claim 3, characterized in that, The epitaxial stacked full-color Micro-LED chip also includes: A first passivation layer covers the sides and part of the top surface of each of the epitaxial pixel stacks, and the contact portion of each of the p-type sub-pixel electrodes penetrates the first passivation layer at its stacking position; a p-type first contact portion of each of the p-type sub-pixel electrodes is disposed at the top of the contact portion; the first passivation layer also covers the sides and part of the top surface of each of the n-type sub-pixel electrode stacks, and each of the n-type sub-pixel electrodes includes an n-type first contact portion, and each of the n-type first contact portions penetrates the first passivation layer at its stacking position; A second passivation layer covers the sides and top surface of the first passivation layer, as well as the sides and top surface of each p-type sub-pixel electrode exposed outside the first passivation layer; a p-type opening is provided at the top of the second passivation layer to expose the p-type first contact portion of the p-type sub-pixel electrode; the second passivation layer also covers the sides of each n-type sub-pixel electrode exposed outside the first passivation layer; an n-type opening is provided at the top of the second passivation layer to expose the n-type first contact portion of the stacked n-type sub-pixel electrodes; The p-type second contact portion is located on top of the second passivation layer at the stacked position of each of the epitaxial pixels, and is connected to each of the p-type first contact portions through the p-type opening; The n-type second contact portion fills the pixel isolation trench, extends away from the epitaxial buffer layer, and covers each of the n-type sub-pixel electrode stacks, and is connected to each of the n-type first contact portions through the n-type opening; Both the p-type second contact portion and each of the n-type second contact portions extend away from the epitaxial buffer layer, and the top surface of each p-type second contact portion and the top surface of each n-type second contact portion are at the same horizontal position. The epitaxial stacked full-color Micro-LED microdisplay also includes: A driving substrate has an effective pixel area with an array of anode contact holes, each containing an anode contact electrode. A cathode contact hole is annularly arranged around the effective pixel area, containing a cathode contact electrode. The driving substrate also has a cathode ring surrounding the effective pixel area, covering and filling the cathode contact holes, and connected to the cathode contact electrodes. A pixel insulating layer is formed on the surface of the driving substrate, divided into arrays... Each pixel region corresponds to one anode contact electrode, and the pixel insulating layer exposes each anode contact electrode. The arrangement of each pixel region corresponds to the arrangement of each stack of epitaxial pixels. A p-type third contact portion and an n-type third contact portion are also provided on one side of the pixel insulating layer of the driving substrate. The p-type third contact portion is located in each pixel region, connects to the anode contact electrode, and is spaced apart from the n-type third contact portion. The n-type third contact portion is in a grid shape, which separates each pixel region and the p-type third contact portion therein, and extends to connect to the outer cathode ring. Each of the p-type third contact portions is correspondingly connected to each of the p-type second contact portions, and each of the n-type third contact portions is correspondingly connected to the n-type second contact portions, so that the driving substrate and the epitaxial stacked full-color Micro-LED chip are connected as one unit; the gap between the driving substrate and the epitaxial stacked full-color Micro-LED chip is filled with insulating material. The epitaxial stacked full-color Micro-LED microdisplay further includes: a microlens array located on the side of the epitaxial buffer layer of each epitaxial stacked full-color Micro-LED chip facing away from the driving substrate; the microlenses of the microlens array correspond one-to-one with each of the epitaxial pixel stacks.

5. The epitaxial stacked full-color Micro-LED microdisplay according to claim 4, characterized in that, The blue light-emitting layer includes a blue light-emitting InGaN-based multi-quantum-well active layer; The green light emitting layer includes a green InGaN-based multi-quantum well active layer and an AlN layer on the surface of the green InGaN-based multi-quantum well active layer away from the blue light emitting layer; The red light emitting layer comprises a stacked GaN / InGaN superlattice layer, a blue light InGaN-based single quantum well active layer, and a red light InGaN-based multi-quantum well active layer; the red light emitting structure further comprises a p-type GaN layer and a p-type GaN layer stacked on the side of the red light blocking layer away from the red light emitting layer. + GaN contact layer; The red light n-type contact layer is an n-type Si-doped GaN or an n-type Si-doped AlGaN layer; The green n-type contact layer is an n-type Si-doped GaN or an n-type Si-doped AlGaN layer; The blue light n-type contact layer is an n-type Si-doped GaN or an n-type Si-doped AlGaN layer; The red light electron blocking layer is a p-type AlGaN layer; The green photoelectron blocking layer is a p-type AlGaN layer; The blue light blocking layer is a p-type AlGaN layer; The epitaxial buffer layer is an undoped GaN layer; each epitaxial pixel stack and each n-type sub-pixel electrode stack includes the epitaxial buffer layer with a partial thickness; The materials of each of the p-type sub-pixel electrodes and each of the n-type sub-pixel electrode stacks include one or more combinations of aluminum, silver, rhodium, zinc, gold, germanium, nickel, chromium, platinum, tin, copper, tungsten, palladium, indium, and titanium.

6. A method for manufacturing an epitaxial stacked full-color Micro-LED microdisplay, characterized in that, Includes the following steps: Several rows of epitaxially stacked full-color Micro-LED chips are formed; The steps for forming the epitaxial stacked full-color Micro-LED chip include: Provide an epitaxial buffer layer; A plurality of full-color Micro-LED pixels are formed in an array on the epitaxial buffer layer; each full-color Micro-LED pixel includes three epitaxial pixel stacks, which are respectively used as red photonic pixel stacks, green photonic pixel stacks and blue photonic pixel stacks; Each of the aforementioned epitaxial pixels has the same stacking height and includes a blue light emitting structure, a green light emitting structure, and a red light emitting structure stacked from the side closest to the epitaxial buffer layer to the side furthest from the epitaxial buffer layer; the blue light emitting structure, the green light emitting structure, and the red light emitting structure are connected sequentially through a tunnel junction; Within the range of the epitaxial stacked full-color Micro-LED micro-display, all the red, green, and blue sub-pixels are arranged in a mosaic pattern; a p-type sub-pixel electrode of the corresponding color is formed on the top of each epitaxial pixel stack. Each of the epitaxial pixel stacks is spaced by a grid-like pixel isolation trench, and n-type sub-pixel electrode stacks corresponding to the red sub-pixel stack, the green sub-pixel stack and the blue sub-pixel stack are formed in the pixel isolation trench; The n-type sub-pixel electrode stacks of the corresponding red sub-pixel stacks, green sub-pixel stacks, and blue sub-pixel stacks have different corresponding positional relationships and corresponding connection relationships relative to the corresponding sub-pixel stacks; All the n-type sub-pixel electrodes are stacked in a mosaic pattern. Any of the n-type sub-pixel electrode stacks are located on the line connecting adjacent p-type sub-pixel electrodes in different rows corresponding to their own colors.

7. The method for manufacturing an epitaxial stacked full-color Micro-LED microdisplay according to claim 6, characterized in that, The steps of providing the epitaxial buffer layer and forming an array of full-color Micro-LED pixels on the epitaxial buffer layer include: Provide a growth substrate; An epitaxial buffer layer is formed on the growth substrate; A blue light-emitting structure is formed on the epitaxial buffer layer; A first tunnel junction is formed on the side of the blue light-emitting structure opposite to the growth substrate; A green light-emitting structure is formed on the side of the first tunnel junction opposite to the red light-emitting structure; A second tunnel junction is formed on the side of the green light-emitting structure opposite to the first tunnel junction. A red light-emitting structure is formed on the side of the second tunnel junction opposite to the green light-emitting structure; This completes the pixel epitaxial structure; A p-shaped groove of corresponding color is formed at the position corresponding to the stacking of each epitaxial pixel in the pixel epitaxial structure; an n-shaped groove of corresponding color is formed at a preset corresponding position; The pixel epitaxial structure is etched to form a grid-like pixel isolation trench, which isolates the pixel epitaxial structure into an epitaxial pixel stack with p-type grooves of various colors. At the same time, n-type sub-pixel electrode stacks with n-type grooves of various colors are formed at corresponding positions in the pixel isolation trench. in, The red light emitting structure includes a stacked red n-type contact layer, a red light emitting layer, and a red electron blocking layer; The green light-emitting structure includes a stacked green n-type contact layer, a green light-emitting layer, and a green electron-blocking layer; a second tunnel junction is provided between the green electron-blocking layer and the red n-type contact layer; The blue light emitting structure includes a stacked blue n-type contact layer, a blue light emitting layer, and a blue electron blocking layer; a first tunnel junction is provided between the blue electron blocking layer and the green n-type contact layer; The red photon sub-pixel stack does not have a p-shaped groove; The p-type grooves of the green photonic sub-pixels extend into the red n-type contact layer; The p-type grooves of the blue sub-pixels extend into the green n-type contact layer; The red n-type sub-pixel electrode stack includes a blue light emitting structure, a green light emitting structure, and a red n-type contact layer stacked on the epitaxial buffer layer; A first tunnel junction is provided between the blue light emitting structure and the green light emitting structure, and a second tunnel junction is provided between the green light emitting structure and the red light n-type contact layer; The green n-type sub-pixel electrode stack includes a blue light emitting structure and a green n-type contact layer stacked on the epitaxial buffer layer; a first tunnel junction is provided between the blue light emitting structure and the green n-type contact layer; The blue n-type sub-pixel electrode stack includes a blue n-type contact layer disposed on the epitaxial buffer layer.

8. The method for manufacturing an epitaxial stacked full-color Micro-LED microdisplay according to claim 7, characterized in that, It also includes the following steps: A first passivation layer is formed, which covers the sides and top surface of each of the epitaxial pixel stacks, and also covers the sides and top surface of each of the n-type sub-pixel electrode stacks; An opening is formed in the first passivation layer at the top of each epitaxial pixel stack and the first passivation layer at the top of each n-type sub-pixel electrode stack, with the opening position corresponding to the center of the stack or the position corresponding to the p-type groove on the stack, exposing the underlying film layer. A contact portion corresponding to each color of the p-type sub-pixel electrode is formed on top of each of the epitaxial pixel stacks. The contact portion fills each of the p-type grooves and partially covers the first passivation layer. A p-type first contact portion corresponding to each color of the p-type sub-pixel electrode is formed on top of the stack of each epitaxial pixel, and is located on top of the contact portion of each p-type sub-pixel electrode; An n-type first contact portion of the n-type sub-pixel electrode stack is formed on top of each of the n-type sub-pixel electrode stacks, filling the opening of the first passivation layer and contacting the exposed film layer. Specifically, the n-type first contact portion of the red n-type sub-pixel electrode stack is disposed on top of the red n-type contact layer and is electrically connected to the red n-type contact layer; the n-type first contact portion of the green n-type sub-pixel electrode stack is disposed on top of the green n-type contact layer and is electrically connected to the green n-type contact layer; and the n-type first contact portion of the blue n-type sub-pixel electrode stack is disposed on top of the blue n-type contact layer and is electrically connected to the blue n-type contact layer.

9. The method for manufacturing an epitaxial stacked full-color Micro-LED microdisplay according to claim 7, characterized in that, It also includes the following steps: A second passivation layer is formed, covering the first passivation layer, the contact portion of the p-type sub-pixel electrode of each color, and the p-type first contact portion; and the second passivation layer also covers each n-type first contact portion; The second passivation layer has an opening that exposes a portion of the p-type first contact portion and the n-type first contact portion; the exposed portion corresponds to the opening position of the first passivation layer. A p-type second contact portion is formed, located on top of the second passivation layer at the stacked position of each of the epitaxial pixels, and connected to each of the p-type first contact portions through the p-type opening; An n-type second contact portion is formed, which fills the pixel isolation trench, extends away from the epitaxial buffer layer, and covers each of the n-type sub-pixel electrode stacks, and is connected to each of the n-type first contact portions through the n-type opening; Both the p-type second contact portion and each of the n-type second contact portions extend away from the epitaxial buffer layer, and the top surface of each p-type second contact portion and the top surface of each n-type second contact portion are at the same horizontal position. A driving substrate is provided, wherein the driving substrate has an effective pixel area, the effective pixel area has an array of anode contact holes, and an anode contact electrode is disposed in the anode contact holes; the driving substrate has a cathode contact hole arranged in a ring around the effective pixel area, and a cathode contact electrode is disposed in the cathode contact hole; the driving substrate also has a cathode ring surrounding the effective pixel area, covering and filling the cathode contact holes, and connected to the cathode contact electrode; a pixel insulating layer is disposed on the surface of the driving substrate, the pixel insulating layer is divided into an array of pixel regions, each pixel region corresponding to one anode contact electrode, and the pixel insulating layer exposes each anode contact electrode; the arrangement of each pixel region corresponds to the arrangement of each stack of epitaxial pixels. A p-type third contact portion and an n-type third contact portion are formed on the pixel insulating layer side surface of the driving substrate. The p-type third contact portion is located in each pixel area, connected to the anode contact electrode, and spaced apart from the n-type third contact portion. The n-type third contact portion is in a grid shape, separating each pixel area and the p-type third contact portion therein, and extending to connect to the outer cathode ring. Each of the p-type third contact portions is connected to each of the p-type second contact portions, and each of the n-type third contact portions is connected to the n-type second contact portions, so that the driving substrate and the epitaxial stacked full-color Micro-LED chip are integrated into one unit.

10. The method for manufacturing an epitaxial stacked full-color Micro-LED microdisplay according to claim 9, characterized in that, It also includes the following steps: An insulating material is filled between the driving substrate and the epitaxial stacked full-color Micro-LED chip; On the side of the epitaxial buffer layer of each of the epitaxial stacked full-color Micro-LED chips facing away from the driving substrate, the growth substrate is removed; or, On the side of the epitaxial buffer layer of each of the epitaxial stacked full-color Micro-LED chips facing away from the driving substrate, the growth substrate is removed, and then a microlens array is formed at the position after the growth substrate is removed. The microlenses of the microlens array correspond one-to-one with each of the epitaxial pixel stacks.

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