Micro-LED display device and manufacturing method thereof

Abstract

The application provides a Micro-LED display device and a manufacturing method thereof, wherein the Micro-LED display device comprises: a driving circuit unit, a plurality of pixel units arranged on the driving circuit unit, each pixel unit comprising: a light-emitting unit, the light-emitting unit being provided with three light-emitting structures through a partitioning channel, the three light-emitting structures being ultraviolet light-emitting structures or violet light-emitting structures, white light being obtained through fluorescent powder excitation, after passing through red, green and blue three primary color filters, combined control of a first electrode, a second electrode, a third electrode and a fourth electrode can realize red, green and blue three primary color single color control and color mixing control, the first electrode, the second electrode, the third electrode and the fourth electrode are arranged on the side of a backlight surface at the same time, the light-emitting area of an outlight surface can be increased, and the fourth electrode is connected with a transparent conductive layer through a partitioning channel, current expansion and electric conduction heat capacity can be obviously increased, and then the light-emitting efficiency and reliability of the Micro-LED display device are improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of light emitting diode, more particularly to a Micro-LED display device and a manufacturing method thereof. BACKGROUND

[0002] With the innovation and development of LED technology, Micro-LED display technology has become a new generation of display technology. The traditional LED structure is miniaturized and matrixed, so that the size of each LED chip is reduced to tens of microns or even microns, and each LED pixel point is addressed and driven to emit light. Since the Micro-LED chip micro-display has the advantages of high resolution, high brightness, long service life, wide operating temperature range, strong anti-interference ability, fast response speed and low power consumption, Micro-LED has important application value in high-resolution display, helmet display, augmented reality, high-speed visible light communication, micro-projector, optical genetics and wearable electronics.

[0003] A full-color Micro-LED display screen is assembled by red, green and blue (RGB) Micro-LED chips on a substrate in a certain arrangement. Since the size of the Micro-LED chip is small, a large number of Micro-LED chips need to be transferred to manufacture the full-color Micro-LED display screen, and the process is too complex, which leads to great difficulty in transferring, low yield in mass production, high production cost, poor consistency and other problems. In addition, under the condition of small size chip and small pitch, it is not easy to wire and bond, and the risk of short circuit is also increased, which reduces the reliability of the LED. Therefore, there are great difficulties in realizing the electrode wire bonding technology and the mass transfer process of the display screen. SUMMARY

[0004] Therefore, the present application provides a Micro-LED display device and a manufacturing method thereof to solve the problem that it is not easy to wire and bond under the condition of small size chip and small pitch, and the risk of short circuit is large, which reduces the reliability of the LED. In addition, the manufacturing process is too complex, which leads to great difficulty in mass transfer, low yield in mass production, high production cost, poor consistency and other problems.

[0005] To achieve the above-mentioned purpose, the technical scheme adopted by the present application is as follows:

[0006] A Micro-LED display device, characterized in that it comprises:

[0007] a driving circuit unit;

[0008] a plurality of pixel units arranged on the driving circuit unit, each of the pixel units comprising:

[0009] A light-emitting unit comprises opposite light-out and back surfaces, partition channels arranged through the light-out and back surfaces, and three light-emitting structures spaced by the partition channels;

[0010] A transparent conductive layer, a fluorescent powder and a filter are sequentially stacked on the light-out surface, the filter being a red, green or blue filter;

[0011] The three light-emitting structures are ultraviolet or violet light-emitting structures, and white light is obtained by exciting the fluorescent powder;

[0012] An insulating reflective layer covers part of the back surface and extends to the sidewalls of the light-emitting structures;

[0013] First, second and third electrodes are arranged on the back surface and connected to the three light-emitting structures respectively;

[0014] A fourth electrode is arranged on the side surface of the insulating reflective layer away from the back surface and extends to the partition channels and is connected to the transparent conductive layer;

[0015] The three light-emitting structures each comprise an N-type semiconductor layer, an active region, an electron blocking layer, a P-type semiconductor layer and a P-type contact layer, which are sequentially stacked in the direction from the light-out surface to the back surface.

[0016] Optionally, the fourth electrode comprises an electrode pad and an electrode extension part, the electrode extension part being connected to the transparent conductive layer and the electrode pad, and the electrode pad, the first electrode, the second electrode and the third electrode are on the same horizontal plane away from the side surface of the back surface and are connected to the driving circuit unit.

[0017] Optionally, the three light-emitting structures are a first light-emitting structure, a second light-emitting structure and a third light-emitting structure, wherein the first electrode is connected to the P-type contact layer of the first light-emitting structure, the second electrode is connected to the P-type contact layer of the second light-emitting structure, and the third electrode is connected to the P-type contact layer of the third light-emitting structure.

[0018] Optionally, the active region comprises quantum barrier layers and quantum well layers arranged alternately and periodically, and a quantum barrier layer closest to the electron blocking layer is a first quantum barrier layer, the first quantum barrier layer being an Mg-doped Al x Ga 1-x N layer.

[0019] Optionally, the electron blocking layer comprises a first sub-layer and a second sub-layer stacked together, the first sub-layer being arranged close to the active region and the second sub-layer being arranged away from the active region, and the first sub-layer comprises an Al z Ga 1-zN layers, wherein 0≤z≤1; the second sub-layer comprises periodically and alternately stacked AlGaN layers and GaN layers, and the Al composition of the electron blocking layer gradually decreases in the direction away from the active region, and the Al composition of the first sub-layer is greater than the Al composition of the first quantum barrier layer.

[0020] Optionally, the P-type semiconductor layer comprises periodically and alternately stacked Al a Ga 1-a N layers and Al b Ga 1-b N layers, and the Al a Ga 1-a N layers and the Al b Ga 1-b N layers are δ-doped with Mg at the contact surface, the Al a Ga 1-a N layers and the Al b Ga 1-b N layers have a doping concentration of Mg that is less than the doping concentration of Mg at the contact surface.

[0021] Optionally, the pixel unit further comprises a protective layer covering the sidewalls of the first electrode, the second electrode, the third electrode and the electrode pad and the exposed surface of the electrode extension portion.

[0022] The application further provides a manufacturing method of the Micro-LED display device.

[0023] Step S01: providing an LED epitaxial wafer, the LED epitaxial wafer comprising a buffer layer and a stacked structure which are epitaxially grown on a growth substrate in sequence along a growth direction;

[0024] Step S02: etching the upper surface of the stacked structure to expose the buffer layer and form a separation channel, the stacked structure forming a plurality of independent light-emitting structures through the separation channel, each light-emitting structure being an ultraviolet light-emitting structure or a violet light-emitting structure; every three light-emitting structures constituting a light-emitting unit, the light-emitting unit comprising oppositely arranged light-emitting surfaces and back light surfaces, the light-emitting surfaces being located on the side surface of the buffer layer away from the growth substrate;

[0025] Each light-emitting structure comprises, in sequence along the direction from the light-emitting surface to the back light surface, an N-type semiconductor layer, an active region, an electron blocking layer, a P-type semiconductor layer and a P-type contact layer;

[0026] The three light-emitting structures are a first light-emitting structure, a second light-emitting structure and a third light-emitting structure, respectively;

[0027] Step S03: depositing an insulating reflective layer covering the back light surfaces and extending to the sidewalls of the light-emitting structures.

[0028] Step S04, respectively, on each of the light emitting unit made first electrode, second electrode, third electrode and fourth electrode;

[0029] The first electrode, the second electrode and the third electrode are arranged on the backlight surface and are respectively connected with the three light emitting structures of each of the light emitting units one by one;

[0030] The fourth electrode is arranged on the side surface of the insulating reflective layer away from the backlight surface and extends to the partition channel;

[0031] The first electrode, the second electrode and the third electrode are arranged on the backlight surface and are respectively connected with the three light emitting structures of each of the light emitting units one by one;

[0032] Etching along the upper surface of the insulating reflective layer to expose the P-type contact layer, respectively forming a first electrode manufacturing area on the first light emitting structure, a second electrode manufacturing area on the second light emitting structure, and a third electrode manufacturing area on the third light emitting structure;

[0033] Depositing the first electrode, the second electrode and the third electrode, wherein the first electrode is connected with the P-type contact layer of the first light emitting structure, the second electrode is connected with the P-type contact layer of the second light emitting structure, and the third electrode is connected with the P-type contact layer of the third light emitting structure;

[0034] Step S05, peeling off the growth substrate and the buffer layer to expose the light emitting surface;

[0035] Step S06, growing a transparent conductive layer on the light emitting surface, and the fourth electrode is connected with the transparent conductive layer through the partition channel;

[0036] Step S07, sequentially stacking fluorescent powder and optical filter on the transparent conductive layer, the optical filter being a red, green and blue three primary color filter; the ultraviolet light emitting structure or the violet light emitting structure of each of the light emitting units obtains white light through excitation of the fluorescent powder, and forms a pixel unit after passing through the red, green and blue three primary color filters;

[0037] Step S08, transferring a plurality of the pixel units to the driving circuit unit;

[0038] Specifically, the first electrode, the second electrode, the third electrode and the fourth electrode of each of the pixel units are bonded on the driving circuit unit.

[0039] Optionally, the preparation method of the LED epitaxial wafer comprises:

[0040] Step A01, using MOCVD equipment, growing a buffer layer on the surface of a growth substrate by metal organic chemical vapor deposition method,

[0041] Step A02: Grow an N-type semiconductor layer on the buffer layer;

[0042] Step A03: An active region is grown on the N-type semiconductor layer. The active region includes periodically alternating quantum barrier layers and quantum well layers. The quantum barrier layer closest to the electron blocking layer is the first quantum barrier layer, which is Mg-doped Al. x Ga 1-x N layers;

[0043] Step A04: Grow the electron blocking layer on the active region. The electron blocking layer includes a stacked first sublayer and a second sublayer. The first sublayer is disposed close to the active region, and the second sublayer is disposed away from the active region. The first sublayer includes Al. z Ga 1-z N layers, where 0≤z≤1; the second sub-layer includes periodically alternating Al GaN layers and GaN layers, and along the direction away from the active region, the Al composition of the electron blocking layer gradually decreases, and the Al composition of the first sub-layer is greater than the Al composition of the first quantum barrier layer;

[0044] Step A05: Grow a P-type semiconductor layer on the electron blocking layer, wherein the P-type semiconductor layer comprises periodically alternating Al layers. a Ga 1-a N layer and Al b Ga 1-b N layers, and Al a Ga 1-a N layer and Al b Ga 1-b The contact surface of the N layer is δ-doped with Mg, and Al a Ga 1-a N layer and Al b Ga 1-b The doping concentration of Mg in the N layer is lower than that of Mg at the contact surface.

[0045] Step A06: Grow a P-type contact layer on the P-type semiconductor layer.

[0046] Optionally, the fourth electrode includes an electrode pad and an electrode extension portion, wherein the electrode extension portion connects the transparent conductive layer and the electrode pad; the surfaces of the electrode pad, the first electrode, the second electrode, and the third electrode away from the backlight surface are on the same horizontal plane and are connected to the driving circuit unit.

[0047] Optionally, the pixel unit further includes a protective layer that covers the sidewalls of the first electrode, the second electrode, the third electrode, and the electrode pads, as well as the exposed surface of the electrode extension portion.

[0048] The above technical solution achieves the following results:

[0049] 1. The Micro-LED display device provided by the present invention, by setting a light-emitting unit, the light-emitting unit includes a light-emitting surface and a backlight surface arranged opposite to each other, and a dividing channel arranged through the light-emitting surface and the backlight surface, the light-emitting unit is provided with three light-emitting structures at intervals through the dividing channel. The three light-emitting structures are ultraviolet light-emitting structures or violet light-emitting structures. White light is obtained by excitation by phosphor. After passing through red, green and blue three primary color filters, combined with the control of the first electrode, the second electrode, the third electrode and the fourth electrode, the monochromatic control of red, green and blue three primary colors and its color mixing control can be realized. The first electrode, the second electrode, the third electrode and the fourth electrode are simultaneously arranged on the backlight surface, which can increase the light-emitting area of ​​the light-emitting surface. Moreover, the fourth electrode extends to the dividing channel and connects with the transparent conductive layer, which can significantly increase the current expansion and enhance the heat conduction capability, thereby improving the luminous efficiency and reliability of the Micro-LED display device.

[0050] 2. Furthermore, by setting the active region to include periodically alternating layers of quantum barrier layers and quantum well layers, the quantum barrier layer closest to the electron blocking layer is designated as the first quantum barrier layer, which is Mg-doped Al. x Ga 1-x In the N-layer, Mg can effectively improve the hole injection efficiency and hole transport in the quantum well region, thereby improving the luminous efficiency of Micro-LED display devices.

[0051] 3. Furthermore, by setting an electron blocking layer comprising a stacked first sub-layer and a second sub-layer, with the first sub-layer close to the active region and the second sub-layer far from the active region, the Al composition of the electron blocking layer gradually decreases along the direction away from the active region, thereby improving hole injection efficiency and reducing electron overflow. Moreover, the Al composition of the first sub-layer is greater than that of the first quantum barrier layer in the active region, resulting in a larger band gap difference between the active region and the electron blocking layer. At the same time, it reduces the band tilt of the electron blocking layer, which is more conducive to exerting the electron blocking effect and further improving the luminous efficiency of the Micro-LED display device.

[0052] 4. Furthermore, by setting a P-type semiconductor layer including periodically alternating Al layers... a Ga 1-a N layer and Al b Ga 1-b N layers, and Al a Ga 1-a N layer and Al b Ga 1-b The contact surface of the N layer is δ-doped with Mg, and Al a Ga 1-a N layer and Alb Ga 1-b The doping concentration of Mg in the N layer is lower than that of Mg at the interface, which improves the doping efficiency of Mg and can effectively improve the problem of low P-type doping efficiency in Al GaN materials, especially Al GaN materials with high Al content.

[0053] 5. Furthermore, by setting a fourth electrode including an electrode pad and an electrode extension portion, the electrode extension portion being connected to the transparent conductive layer and the electrode pad; the surfaces of the electrode pad, the first electrode, the second electrode, and the third electrode away from the backlight are on the same horizontal plane and connected to the driving circuit unit, it is possible to make the pixel unit set on the driving circuit unit less prone to defects such as tilting and short circuits.

[0054] 6. The method for fabricating a Micro-LED display device provided in this embodiment is used to prepare a Micro-LED display device. Multiple independent light-emitting structures are formed by etching and stacking structures. Every three light-emitting structures constitute a light-emitting unit. The ultraviolet light-emitting structure or violet light-emitting structure of each light-emitting unit is excited by phosphor to obtain white light. After passing through red, green, and blue primary color filters, it constitutes a pixel unit. Several pixel units are transferred to the driving circuit unit in a single mass transfer, which can effectively solve the problems of high mass transfer difficulty, low mass production yield, high production cost, and poor consistency caused by the overly complex manufacturing process. The first, second, third, and fourth electrodes of each pixel unit are bonded to the driving circuit unit. The electrodes of each pixel unit are set on the backlight side. Each pixel unit only needs to set four bonding points to bond with the driving circuit unit. Compared with the current RGB Micro-LED chip composed of three Micro-LED chips (six electrodes) of red, green, and blue, the electrode wire bonding process is reduced. Moreover, without causing short circuits, the area of ​​each electrode can be increased by adaptive adjustment, making it easier to achieve bonding with the driving circuit unit. Attached Figure Description

[0055] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0056] Figure 1 This is a cross-sectional schematic diagram of a Micro-LED display device provided in an embodiment of the present invention;

[0057] Figure 2 for Figure 1 A schematic diagram of the structure of the light-emitting unit;

[0058] Figure 3 A schematic diagram of a light-emitting structure provided in an embodiment of the present invention;

[0059] Figure 4 A flowchart illustrating a method for manufacturing a Micro-LED display device according to an embodiment of the present invention;

[0060] Figures 5 to 14 for Figure 4 The process cross-sectional diagrams and corresponding top views for each step of the manufacturing method shown are provided.

[0061] Figure 15 This is a schematic diagram of the structure of an LED epitaxial wafer provided in an embodiment of the present invention.

[0062] Explanation of symbols in the diagram:

[0063] 01. Growth substrate; 02. Buffer layer; 03. Stacked structure; 04. First electrode fabrication area; 05. Second electrode fabrication area; 06. Third electrode fabrication area;

[0064] 1. Driving circuit unit; 11. First light-emitting structure; 12. Second light-emitting structure; 13. Third light-emitting structure; 14. Insulating reflective layer; 15. Transparent conductive layer; 20. N-type semiconductor layer; 30. Active region; 31. First quantum barrier layer; 32. Second quantum barrier layer; 33. Quantum well layer; 40. Electron blocking layer; 40a. First sublayer; 40b. Second sublayer; 50. P-type semiconductor layer; 60. P-type contact layer; 100. First electrical... Electrode; 200, Second electrode; 300, Third electrode; 400, Fourth electrode; 410, Electrode pad; 420, Electrode extension section; 500, Phosphor; 510, Red light-excited phosphor; 520, Green light-excited phosphor; 530, Blue light-excited phosphor; 600, Filter; 610, Red filter; 620, Green filter; 630, Blue filter; A, Light-emitting surface; B, Backlight surface; C, Dividing channel; D, Light-blocking section. Detailed Implementation

[0065] To make the content of this invention clearer, the technical solutions in 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, and not all embodiments. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0066] Many specific details are set forth in the following description in order to provide a full understanding of this application. However, this application may also be implemented in other ways different from those described herein. Those skilled in the art can make similar extensions without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.

[0067] Secondly, this application provides a detailed description in conjunction with schematic diagrams. When detailing the embodiments of this application, for ease of explanation, the cross-sectional views illustrating the device structure may be partially enlarged, not adhering to the usual scale. Furthermore, the schematic diagrams are merely examples and should not limit the scope of protection of this application. In addition, actual fabrication should include three-dimensional spatial dimensions of length, width, and depth.

[0068] An embodiment of the present invention provides a Micro-LED display device, such as... Figures 1 to 2 As shown, it includes:

[0069] Drive circuit unit 1;

[0070] Several pixel units are disposed on the driving circuit unit 1, each pixel unit including:

[0071] The light-emitting unit includes a light-emitting surface A and a backlight surface B arranged opposite to each other, and a dividing channel C that passes through the light-emitting surface A and the backlight surface B. The light-emitting unit is provided with three light-emitting structures at intervals through the dividing channel C.

[0072] A transparent conductive layer 15, a phosphor 500, and a filter 600 are sequentially stacked on the light-emitting surface A. The filter 600 is a red, green, and blue three-color filter.

[0073] The three luminescent structures are either ultraviolet luminescent or violet luminescent structures, and white light is obtained by excitation with phosphor 500.

[0074] An insulating reflective layer 14 covers part of the backlight surface B and extends to the sidewalls of each light-emitting structure to reduce mutual interference between the light-emitting structures.

[0075] The first electrode 100, the second electrode 200 and the third electrode 300 are disposed on the backlight surface B and are respectively connected to the three light-emitting structures one by one.

[0076] The fourth electrode 400 is disposed on the side of the insulating reflective layer 14 away from the backlight surface B and extends to the dividing channel C, and is connected to the transparent conductive layer 15.

[0077] The three light-emitting structures each include an N-type semiconductor layer 20, an active region 30, an electron blocking layer 40, a P-type semiconductor layer 50, and a P-type contact layer 60 stacked sequentially along the direction from the light-emitting surface A to the backlight surface B.

[0078] It should be noted that in this embodiment, the first electrode 100, the second electrode 200, and the third electrode 300 are P-type electrodes, and the fourth electrode 400 is a common N-type electrode. According to actual needs, by controlling the first electrode 100, the second electrode 200, the third electrode 300, and the fourth electrode 400, the monochromatic control of the three primary colors of red, green, and blue and their color mixing control can be realized.

[0079] It should be noted that in this embodiment, the fourth electrode 400 is insulated from the three light-emitting structures by an insulating reflective layer 14.

[0080] Optionally, in this embodiment, the fourth electrode 400 includes an electrode pad 410 and an electrode extension portion 420. The electrode extension portion 420 is connected to the transparent conductive layer 15 and the electrode pad 410. The surfaces of the electrode pad 410, the first electrode 100, the second electrode 200 and the third electrode 300 away from the backlight surface B are on the same horizontal plane and are connected to the driving circuit unit 1.

[0081] Optionally, in this embodiment, the three light-emitting structures are a first light-emitting structure 11, a second light-emitting structure 12, and a third light-emitting structure 13, wherein the first electrode 100 is connected to the P-type contact layer 60 of the first light-emitting structure 11, the second electrode 200 is connected to the P-type contact layer 60 of the second light-emitting structure 12, and the third electrode 300 is connected to the P-type contact layer 60 of the third light-emitting structure 13.

[0082] In this embodiment, the three light-emitting structures can be the same size or different sizes, and can be set according to the actual use. This application embodiment does not impose specific restrictions on this.

[0083] In this embodiment, the specific width of the dividing channel C is not limited, and the width of the dividing channel C can be determined according to the actual situation.

[0084] In this embodiment, the specific areas of electrode pad 410, first electrode 100, second electrode 200, and third electrode 300 are not limited and can be set according to actual usage. Optionally, in this embodiment, the vertical projection areas of the first electrode 100, second electrode 200, and third electrode 300 on the driving circuit unit 1 are all smaller than the vertical projection area of ​​the electrode pad 410 on the driving circuit unit 1. Without causing a short circuit, the area of ​​each electrode can be adaptively increased, making it easier to achieve bonding with the driving circuit unit.

[0085] Optionally, in this embodiment, the driving circuit unit 1 consists of a thin-film transistor (TFT) and a storage capacitor.

[0086] Optionally, in this embodiment, the phosphor 500 includes a red light-excited phosphor 510, a green light-excited phosphor 520, and a blue light-excited phosphor 530; the red light-excited phosphor 510, the green light-excited phosphor 520, and the blue light-excited phosphor 530 are respectively disposed on the first light-emitting structure 11, the second light-emitting structure 12, and the third light-emitting structure 13.

[0087] Optionally, in this embodiment, the red, green, and blue primary color filters are a red filter 610, a green filter 620, and a blue filter 630, respectively; the red filter 610, the green filter 620, and the blue filter 630 are respectively covered on the red light-excited phosphor 510, the green light-excited phosphor 520, and the blue light-excited phosphor 530.

[0088] Optionally, in this embodiment, light-blocking portions D are provided between the red light-excited phosphor 510, the green light-excited phosphor 520, and the blue light-excited phosphor 530, as well as between the red filter 610, the green filter 620, and the blue filter 630. The light-blocking portions D are located within the vertical projection range of the dividing channel C, further reducing the mutual interference between the light-emitting structures.

[0089] Optionally, in this embodiment, the N-type semiconductor layer 20 is Si-doped Al. x Ga 1-x The thickness of the N-layer, N-type semiconductor layer 20, ranges from 2 to 4 μm, including the endpoint values.

[0090] Optionally, in this embodiment, the P-type contact layer 60 is a Mg-doped GaN layer, wherein the Mg doping concentration ranges from 1*10⁻⁶. 20 Up to 5*10 20 cm -3 The thickness of the P-type contact layer 60 ranges from 20 to 100 nm, including the endpoint values.

[0091] Optionally, in another embodiment of this application, the active region 30 includes periodically alternating quantum barrier layers and quantum well layers, with the quantum barrier layer closest to the electron blocking layer 40 being a first quantum barrier layer 31, which is Mg-doped Al. x Ga 1-x N layers.

[0092] Optionally, in this embodiment, as Figure 3 As shown, the quantum barrier layer includes a first quantum barrier layer 31 and a second quantum barrier layer 32. The active region 30 is formed by alternating layers of the second quantum barrier layer 32 and the quantum well layer 33 for several periods, with the last period consisting of the first quantum barrier layer 31 and the quantum well layer 33. The second quantum barrier layer 32 is Al. x Ga 1-xN-layer, quantum well layer 33 is Al y Ga 1-y N layers, where 0 <x<1,0<y<1,x> y.

[0093] Optionally, in this embodiment, the number of alternating stacked active regions 30 is 5-8, the thickness of a single quantum well layer is 2-5 nm (including the endpoint value), and the thickness of a single quantum barrier layer is 10-15 nm (including the endpoint value).

[0094] Optionally, in another embodiment of this application, reference is made to... Figure 3 As shown, the electron blocking layer 40 includes a stacked first sublayer 40a and a second sublayer 40b. The first sublayer 40a is disposed close to the active region 30, and the second sublayer 40b is disposed away from the active region 30. The first sublayer 40a includes Al. z Ga 1-z N layers, where 0≤z≤1; the second sublayer 40b includes periodically alternating Al GaN layers and GaN layers, and along the direction away from the active region 30, the Al composition of the electron blocking layer 40 gradually decreases, and the Al composition of the first sublayer 40a is greater than the Al composition of the first quantum barrier layer 31.

[0095] Optionally, in this embodiment, the thickness of the electron blocking layer 40 ranges from 25 to 70 nm, including the endpoint values; the number of alternating stacked cycles of the second sublayer 40b is 5 to 20; the thickness of the first sublayer 40a ranges from 5 to 20 nm, including the endpoint values; and the thickness of the second sublayer 40b ranges from 20 to 50 nm, including the endpoint values.

[0096] Optionally, in another embodiment of this application, the P-type semiconductor layer 50 includes periodically alternating layers of Al. a Ga 1-a N layer and Al b Ga 1-b N layers, and Al a Ga 1-a N layer and Al b Ga 1-b The contact surface of the N layer is δ-doped with Mg, and Al a Ga 1-a N layer and Al b Ga 1-b The doping concentration of Mg in the N-layer is lower than that of Mg at the interface.

[0097] Optionally, in this embodiment, the number of alternating stacked P-type semiconductor layers 50 is 20-50, and the thickness of the P-type semiconductor layer 50 ranges from 20-80 nm, including the endpoint values.

[0098] To further improve the reliability of the Micro-LED display device, optionally, in another embodiment of this application, the pixel unit further includes a protective layer (not shown in the figure), which covers the sidewalls of the first electrode 100, the second electrode 200, the third electrode 300 and the electrode pad 410 and the exposed surface of the electrode extension portion 420.

[0099] like Figure 4 As shown, Figure 4 A flowchart illustrating a method for manufacturing a Micro-LED display device according to an embodiment of the present invention is provided. This method is used to manufacture the Micro-LED display devices described in the above embodiments, and includes the following steps:

[0100] Step S01, as follows Figure 5 As shown, an LED epitaxial wafer is provided, which includes a buffer layer 02 and a stacked structure 03 sequentially epitaxially grown on a growth substrate 01 along the growth direction.

[0101] The stacked structure 03 includes, along the growth direction, an N-type semiconductor layer 20, an active region 30, an electron blocking layer 40, a P-type semiconductor layer 50, and a P-type contact layer 60 stacked sequentially.

[0102] Step S02, as follows Figure 6 As shown, etching is performed along the upper surface of the stacked structure 03 to expose the buffer layer 02 and form a dividing channel C. The stacked structure 03 forms multiple independent light-emitting structures through the dividing channel C. Each light-emitting structure is an ultraviolet light-emitting structure or a violet light-emitting structure. Every three light-emitting structures constitute a light-emitting unit. The light-emitting unit includes a light-emitting surface A and a backlight surface B arranged opposite to each other. The light-emitting surface A is located on the side of the buffer layer 02 away from the growth substrate 01.

[0103] Each light-emitting structure includes, along the direction from the light-emitting surface A to the backlight surface B, an N-type semiconductor layer 20, an active region 30, an electron blocking layer 40, a P-type semiconductor layer 50, and a P-type contact layer 60 stacked sequentially.

[0104] The three light-emitting structures are the first light-emitting structure 11, the second light-emitting structure 12, and the third light-emitting structure 13;

[0105] Step S03, as follows Figure 7 As shown, an insulating reflective layer 14 is deposited, which covers the backlight surface B and extends to the sidewalls of each light-emitting structure to reduce mutual interference between the light-emitting structures.

[0106] Step S04: Fabricate a first electrode 100, a second electrode 200, a third electrode 300 and a fourth electrode 400 on each light-emitting unit;

[0107] The first electrode 100, the second electrode 200 and the third electrode 300 are disposed on the backlight surface B and are respectively connected to the three light-emitting structures of each light-emitting unit.

[0108] The fourth electrode 400 is disposed on the side surface of the insulating reflective layer 14 away from the backlight surface B and extends to the dividing channel C;

[0109] The fabrication of the first electrode 100, the second electrode 200, and the third electrode 300 specifically includes the following steps:

[0110] like Figures 8.1 to 8.2 As shown, where, Figure 8.2 for Figure 8.1 A top view shows that the P-type contact layer 60 is etched along the upper surface of the insulating reflective layer 14, and a first electrode fabrication area 04 is formed on the first light-emitting structure 11, a second electrode fabrication area 05 is formed on the second light-emitting structure 12, and a third electrode fabrication area 06 is formed on the third light-emitting structure 13.

[0111] like Figures 9.1 to 9.2 As shown, where, Figure 9.2 for Figure 9.1 The top view shows the deposition of a first electrode 100, a second electrode 200, and a third electrode 300. The first electrode 100 is connected to the P-type contact layer 60 of the first light-emitting structure 11, the second electrode 200 is connected to the P-type contact layer 60 of the second light-emitting structure 12, and the third electrode 300 is connected to the P-type contact layer 60 of the third light-emitting structure 13.

[0112] Step S05, as follows Figure 10 As shown, the growth substrate 01 and buffer layer 02 are peeled off to expose the smooth surface A;

[0113] Step S06, as follows Figure 11 As shown, a transparent conductive layer 15 is grown on the light-emitting surface A, and the fourth electrode 400 is connected to the transparent conductive layer 15 through the dividing channel C.

[0114] Step S07, as follows Figure 12 As shown, phosphor 500 and filter 600 are sequentially stacked on transparent conductive layer 15. Filter 600 is a red, green and blue three-primary-color filter. The ultraviolet light emission structure or violet light emission structure of each light-emitting unit is excited by phosphor 500 to obtain white light, which is then filtered by red, green and blue three-primary-color filters to form a pixel unit.

[0115] Step S08: Massively transfer several pixel units to driving circuit unit 1;

[0116] Specifically, such as Figure 13As shown, each pixel unit is bonded to the driving circuit unit 1 via the first electrode 100, the second electrode 200, the third electrode 300, and the fourth electrode 400.

[0117] It should be noted that the first electrode 100, the second electrode 200 and the third electrode 300 are P-type electrodes, and the fourth electrode 400 is a common N-type electrode. According to actual needs, by controlling the first electrode 100, the second electrode 200, the third electrode 300 and the fourth electrode 400, the monochromatic control of the three primary colors of red, green and blue and their color mixing control can be realized.

[0118] It should be noted that in this embodiment, the fourth electrode 400 is insulated from the three light-emitting structures by an insulating reflective layer 14.

[0119] Optionally, in this embodiment, the fourth electrode 400 includes an electrode pad 410 and an electrode extension portion 420. The electrode extension portion 420 is connected to the transparent conductive layer 15 and the electrode pad 410. The surfaces of the electrode pad 410, the first electrode 100, the second electrode 200 and the third electrode 300 away from the backlight surface B are on the same horizontal plane and are connected to the driving circuit unit 1.

[0120] In this embodiment, the three light-emitting structures can be the same size or different sizes, and can be set according to the actual use. This application embodiment does not impose specific restrictions on this.

[0121] In this embodiment, the specific width of the dividing channel C is not limited, and the width of the dividing channel C can be determined according to the actual situation.

[0122] In this embodiment, the specific areas of electrode pad 410, first electrode 100, second electrode 200, and third electrode 300 are not limited and can be set according to actual usage. Optionally, in this embodiment, the vertical projection areas of the first electrode 100, second electrode 200, and third electrode 300 on the driving circuit unit 1 are all smaller than the vertical projection area of ​​the electrode pad 410 on the driving circuit unit 1. Without causing a short circuit, the area of ​​each electrode can be adaptively increased, making it easier to achieve bonding with the driving circuit unit.

[0123] Optionally, in this embodiment, the driving circuit unit 1 consists of a thin-film transistor (TFT) and a storage capacitor.

[0124] Optionally, in this embodiment, as Figure 14 As shown, the phosphor 500 includes a red light-excited phosphor 510, a green light-excited phosphor 520, and a blue light-excited phosphor 530; the red light-excited phosphor 510, the green light-excited phosphor 520, and the blue light-excited phosphor 530 are respectively disposed on the first light-emitting structure 11, the second light-emitting structure 12, and the third light-emitting structure 13.

[0125] Optionally, in this embodiment, reference is made to Figure 14 As shown, the red, green, and blue primary color filters are red filter 610, green filter 620, and blue filter 630, respectively; red filter 610, green filter 620, and blue filter 630 are respectively covered on red light-excited phosphor 510, green light-excited phosphor 520, and blue light-excited phosphor 530.

[0126] Optionally, in this embodiment, reference continues to be made to Figure 14 As shown, light-blocking parts D are provided between the red light-excited phosphor 510, the green light-excited phosphor 520, and the blue light-excited phosphor 530, as well as between the red filter 610, the green filter 620, and the blue filter 630. The light-blocking parts D are located within the vertical projection range of the dividing channel C, further reducing the mutual interference between the light-emitting structures.

[0127] To further improve the reliability of Micro-LED chips, optionally, in another embodiment of this application, the pixel unit further includes a protective layer (not shown in the figure), which covers the sidewalls of the first electrode 100, the second electrode 200, the third electrode 300 and the electrode pad 410 and the exposed surface of the electrode extension portion 420.

[0128] Optionally, in another embodiment of this application, such as Figure 15 The diagram shown is a structural schematic of an LED epitaxial wafer provided in an embodiment of the present invention. The method for preparing the LED epitaxial wafer includes:

[0129] Step A01: Using an MOCVD device, a buffer layer 02 is grown on the surface of the growth substrate 01 by metal-organic chemical vapor deposition.

[0130] Optionally, in this embodiment, the temperature inside the reaction chamber is set to 600-1000 degrees Celsius, and aluminum source, gallium source, ammonia and carrier gas are continuously introduced into the reaction chamber to grow buffer layer O2.

[0131] Optionally, in this embodiment, the buffer layer 02 includes an Al GaN layer, and the thickness of the buffer layer 02 ranges from 1 to 3 μm, including the endpoint values.

[0132] Step A02: Grow an N-type semiconductor layer 20 on the buffer layer 02.

[0133] Optionally, in this embodiment, the temperature inside the reaction chamber is set to 1000-1400 degrees Celsius, and aluminum source, gallium source, ammonia and carrier gas are continuously introduced into the reaction chamber to grow an N-type semiconductor layer 20.

[0134] Optionally, in this embodiment, the N-type semiconductor layer 20 is Si-doped Al.x Ga 1-x The thickness of the N-layer, N-type semiconductor layer 20, ranges from 2 to 4 μm, including the endpoint values.

[0135] Step A03: An active region 30 is grown on the N-type semiconductor layer 20. The active region 30 includes periodically alternating quantum barrier layers and quantum well layers. The quantum barrier layer closest to the electron blocking layer 40 is the first quantum barrier layer 31, which is Mg-doped Al. x Ga 1-x N layers.

[0136] Optionally, in this embodiment, as Figure 3 As shown, the quantum barrier layer includes a first quantum barrier layer 31 and a second quantum barrier layer 32. The active region 30 is formed by alternating layers of the second quantum barrier layer 32 and the quantum well layer 33 for several periods, with the last period consisting of the first quantum barrier layer 31 and the quantum well layer 33. The second quantum barrier layer 32 is Al. x Ga 1-x N-layer, quantum well layer 33 is Al y Ga 1-y N layers, where 0 <x<1,0<y<1,x> y.

[0137] Optionally, in this embodiment, the temperature inside the reaction chamber is set to 900-1400 degrees Celsius, and an aluminum source, a gallium source, ammonia gas, and a carrier gas are introduced into the reaction chamber to grow the active region 30.

[0138] Optionally, in this embodiment, the number of alternating stacked active regions 30 is 5-8, the thickness of a single quantum well layer is 2-5 nm (including the endpoint value), and the thickness of a single quantum barrier layer is 10-15 nm (including the endpoint value).

[0139] Step A04: An electron blocking layer 40 is grown on the active region 30. The electron blocking layer 40 includes a stacked first sublayer 40a and a second sublayer 40b. The first sublayer 40a is disposed close to the active region 30, and the second sublayer 40b is disposed away from the active region 30. The first sublayer 40a includes Al. z Ga 1-z N layers, where 0≤z≤1; the second sublayer 40b includes periodically alternating Al GaN layers and GaN layers, and along the direction away from the active region 30, the Al composition of the electron blocking layer 40 gradually decreases, and the Al composition of the first sublayer 40a is greater than the Al composition of the first quantum barrier layer 31.

[0140] Optionally, in this embodiment, the temperature inside the reaction chamber is set to 900-1350°C, and an aluminum source, a gallium source, ammonia gas, and a carrier gas are introduced into the reaction chamber to grow an electron blocking layer 40.

[0141] Optionally, in this embodiment, the thickness of the electron blocking layer 40 ranges from 25 to 70 nm, including the endpoint values; the number of alternating stacked cycles of the second sublayer 40b is 5 to 20; the thickness of the first sublayer 40a ranges from 5 to 20 nm, including the endpoint values; and the thickness of the second sublayer 40b ranges from 20 to 50 nm, including the endpoint values.

[0142] Step A05: Grow a P-type semiconductor layer 50 on the electron blocking layer 40. The P-type semiconductor layer 50 includes periodically alternating Al layers. a Ga 1-a N layer and Al b Ga 1-b N layers, and Al a Ga 1-a N layer and Al b Ga 1-b The contact surfaces of the N-layers are δ-doped with Mg, and Al a Ga 1-a N layer and Al b Ga 1-b The doping concentration of Mg in the N layer is lower than that of Mg at the contact surface.

[0143] Optionally, in this embodiment, the growth temperature of the P-type semiconductor layer 50 is 900°C to 1350°C.

[0144] Optionally, in this embodiment, the number of alternating stacked P-type semiconductor layers 50 is 20-50, and the thickness of the P-type semiconductor layer 50 ranges from 20-80 nm, including the endpoint values.

[0145] Step A06: Grow a P-type contact layer 60 on the P-type semiconductor layer 50.

[0146] Optionally, in this embodiment, the temperature inside the reaction chamber is set to 900-1300℃, and gallium source, ammonia gas, and carrier gas are continuously introduced into the reaction chamber to grow a P-type contact layer 60. The P-type contact layer 60 is a Mg-doped GaN layer, wherein the Mg doping concentration ranges from 1*10⁻⁶. 20 Up to 5*10 20 cm -3 The thickness of the P-type contact layer 60 ranges from 20 to 100 nm, including the endpoint values.

[0147] It should be noted that in this embodiment, high-purity H2 (hydrogen), high-purity N2 (nitrogen), or a mixture of high-purity H2 and high-purity N2 is used as the carrier gas, trimethylgallium (TMGa) and triethylgallium (TEGa) are used as gallium sources, ammonia is used as the nitrogen source, and trimethylaluminum (TMAl) is used as the aluminum source.

[0148] In one embodiment of this application, before forming the buffer layer 02, the growth substrate 01 is placed in the MOCVD reaction chamber, the temperature inside the reaction chamber is set to 1000-1200 degrees Celsius, the chamber pressure is maintained at 100-500 Torr, H2 is introduced, and the chamber is baked at high temperature for 1-10 minutes to remove surface contaminants.

[0149] In one embodiment of this application, after the P-type contact layer 60 is grown, the temperature inside the reaction chamber is set to 800-1100 degrees Celsius, and hydrogen is continuously introduced into the reaction chamber for annealing treatment for 20-30 minutes.

[0150] In summary, the above technical solution achieves the following results:

[0151] 1. The Micro-LED display device provided in this embodiment, by setting a light-emitting unit, includes a light-emitting surface and a backlight surface arranged opposite to each other, and a dividing channel arranged through the light-emitting surface and the backlight surface. The light-emitting unit is provided with three light-emitting structures at intervals through the dividing channel. The three light-emitting structures are ultraviolet light-emitting structures or violet light-emitting structures. White light is obtained by excitation by phosphor. After passing through red, green and blue three primary color filters, combined with the control of the first electrode, the second electrode, the third electrode and the fourth electrode, the monochromatic control of red, green and blue three primary colors and their color mixing control can be realized. The first electrode, the second electrode, the third electrode and the fourth electrode are simultaneously arranged on the backlight surface, which can increase the light-emitting area of ​​the light-emitting surface. Moreover, the fourth electrode extends to the dividing channel and connects with the transparent conductive layer, which can significantly increase the current expansion and enhance the thermal conductivity, thereby improving the luminous efficiency and reliability of the Micro-LED display device.

[0152] 2. Furthermore, by setting the active region to include periodically alternating layers of quantum barrier layers and quantum well layers, the quantum barrier layer closest to the electron blocking layer is designated as the first quantum barrier layer, which is Mg-doped Al. x Ga 1-x In the N-layer, Mg can effectively improve the hole injection efficiency and hole transport in the quantum well region, thereby improving the luminous efficiency of Micro-LED display devices.

[0153] 3. Furthermore, by setting an electron blocking layer comprising a stacked first sub-layer and a second sub-layer, with the first sub-layer close to the active region and the second sub-layer far from the active region, the Al composition of the electron blocking layer gradually decreases along the direction away from the active region, thereby improving hole injection efficiency and reducing electron overflow. Moreover, the Al composition of the first sub-layer is greater than that of the first quantum barrier layer in the active region, resulting in a larger band gap difference between the active region and the electron blocking layer. At the same time, it reduces the band tilt of the electron blocking layer, which is more conducive to exerting the electron blocking effect and further improving the luminous efficiency of the Micro-LED display device.

[0154] 4. Furthermore, by setting a P-type semiconductor layer including periodically alternating Al layers... a Ga 1-a N layer and Al b Ga 1-b N layers, and Al a Ga 1-a N layer and Al b Ga 1-b The contact surface of the N layer is δ-doped with Mg, and Al a Ga 1-a N layer and Al b Ga 1-b The doping concentration of Mg in the N layer is lower than that of Mg at the interface, which improves the doping efficiency of Mg and can effectively improve the problem of low P-type doping efficiency in Al GaN materials, especially Al GaN materials with high Al content.

[0155] 5. Furthermore, by setting a fourth electrode including an electrode pad and an electrode extension portion, the electrode extension portion being connected to the transparent conductive layer and the electrode pad; the surfaces of the electrode pad, the first electrode, the second electrode, and the third electrode away from the backlight are on the same horizontal plane and connected to the driving circuit unit, it is possible to make the pixel unit set on the driving circuit unit less prone to defects such as tilting and short circuits.

[0156] 6. The method for fabricating a Micro-LED display device provided in this embodiment is used to prepare a Micro-LED display device. Multiple independent light-emitting structures are formed by etching and stacking structures. Every three light-emitting structures constitute a light-emitting unit. The ultraviolet light-emitting structure or violet light-emitting structure of each light-emitting unit is excited by phosphor to obtain white light. After passing through red, green, and blue primary color filters, it constitutes a pixel unit. Several pixel units are transferred to the driving circuit unit in a single mass transfer, which can effectively solve the problems of high mass transfer difficulty, low mass production yield, high production cost, and poor consistency caused by the overly complex manufacturing process. The first, second, third, and fourth electrodes of each pixel unit are bonded to the driving circuit unit. The electrodes of each pixel unit are set on the backlight side. Each pixel unit only needs to set four bonding points to bond with the driving circuit unit. Compared with the current RGB Micro-LED chip composed of three Micro-LED chips (six electrodes) of red, green, and blue, the electrode wire bonding process is reduced. Moreover, without causing short circuits, the area of ​​each electrode can be increased by adaptive adjustment, making it easier to achieve bonding with the driving circuit unit.

[0157] Those skilled in the art should understand that, in the disclosure of this invention, the terms "lateral", "longitudinal", "upper", "lower", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, the above terms should not be construed as limiting this invention.

[0158] It should be noted that the various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0159] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A Micro-LED display device, characterized in that, include: Drive circuit unit; A plurality of pixel units are disposed on the driving circuit unit, each pixel unit comprising: A light-emitting unit, comprising a light-emitting surface and a backlight surface arranged opposite to each other, a dividing channel extending through the light-emitting surface and the backlight surface, and three light-emitting structures spaced apart by the dividing channel in the light-emitting unit; A transparent conductive layer, phosphor, and a filter are sequentially stacked on the light-emitting surface, wherein the filter is a red, green, and blue three-primary-color filter; The three light-emitting structures are ultraviolet light-emitting structures or violet light-emitting structures, and white light is obtained by excitation by the phosphor; An insulating reflective layer that covers a portion of the backlight surface and extends to the sidewalls of each of the light-emitting structures; The first electrode, the second electrode, and the third electrode are disposed on the backlight surface and are respectively connected to the three light-emitting structures one by one; The fourth electrode is disposed on the side surface of the insulating reflective layer away from the backlight surface and extends to the dividing channel, and is connected to the transparent conductive layer. All three light-emitting structures include, along the direction from the light-emitting surface to the backlight surface, an N-type semiconductor layer, an active region, an electron blocking layer, a P-type semiconductor layer, and a P-type contact layer stacked sequentially.

2. The Micro-LED display device according to claim 1, characterized in that: The fourth electrode includes an electrode pad and an electrode extension portion, wherein the electrode extension portion connects the transparent conductive layer and the electrode pad; the electrode pad, the first electrode, the second electrode and the third electrode are on the same horizontal plane on the side away from the backlight surface and are connected to the driving circuit unit.

3. The Micro-LED display device according to claim 1, characterized in that: The three light-emitting structures are a first light-emitting structure, a second light-emitting structure, and a third light-emitting structure, wherein the first electrode is connected to the P-type contact layer of the first light-emitting structure, the second electrode is connected to the P-type contact layer of the second light-emitting structure, and the third electrode is connected to the P-type contact layer of the third light-emitting structure.

4. The Micro-LED display device according to claim 1, characterized in that: The active region comprises periodically alternating quantum barrier layers and quantum well layers, with the quantum barrier layer closest to the electron blocking layer being the first quantum barrier layer, which is Mg-doped Al. x Ga 1-x N layers.

5. The Micro-LED display device according to claim 4, characterized in that: The electron blocking layer comprises a stacked first sublayer and a second sublayer, wherein the first sublayer is disposed close to the active region and the second sublayer is disposed away from the active region; the first sublayer comprises Al z Ga 1-z N layers, where 0≤z≤1; the second sub-layer includes periodically alternating AlGaN layers and GaN layers, and along the direction away from the active region, the Al composition of the electron blocking layer gradually decreases, and the Al composition of the first sub-layer is greater than the Al composition of the first quantum barrier layer.

6. The Micro-LED display device according to claim 1, characterized in that: The P-type semiconductor layer comprises periodically alternating layers of Al. a Ga 1-a N layer and Al b Ga 1-b N layers, and the Al a Ga 1-a N layer and the Al b Ga 1-b The contact surface of the N layer is δ-doped with Mg, and the Al a Ga 1-a N layer and the Al b Ga 1-b The doping concentration of Mg in the N layer is lower than that of Mg at the contact surface.

7. The Micro-LED display device according to claim 2, characterized in that: The pixel unit further includes a protective layer that covers the sidewalls of the first electrode, the second electrode, the third electrode, and the electrode pads, as well as the exposed surface of the electrode extension portion.

8. A method for manufacturing a Micro-LED display device, characterized in that, Includes the following steps: Step S01: Provide an LED epitaxial wafer, the LED epitaxial wafer including a buffer layer and a stacked structure sequentially epitaxially grown on a growth substrate along the growth direction; Step S02: Etch along the upper surface of the stacked structure to expose the buffer layer and form a dividing channel. The stacked structure forms multiple independent light-emitting structures through the dividing channel. Each light-emitting structure is an ultraviolet light-emitting structure or a violet light-emitting structure. Every three light-emitting structures constitute a light-emitting unit. The light-emitting unit includes a light-emitting surface and a back-light surface arranged opposite to each other. The light-emitting surface is located on the side of the buffer layer away from the growth substrate. Each of the light-emitting structures comprises, along the direction from the light-emitting surface to the backlight surface, a sequentially stacked N-type semiconductor layer, an active region, an electron blocking layer, a P-type semiconductor layer, and a P-type contact layer; The three light-emitting structures are respectively the first light-emitting structure, the second light-emitting structure, and the third light-emitting structure; Step S03: Deposit an insulating reflective layer that covers the backlight surface and extends to the sidewalls of each of the light-emitting structures; Step S04: Fabricate a first electrode, a second electrode, a third electrode, and a fourth electrode on each of the light-emitting units; The first electrode, the second electrode, and the third electrode are disposed on the backlight surface and are respectively connected to the three light-emitting structures of each light-emitting unit. A fourth electrode is disposed on the side of the insulating reflective layer away from the backlight surface and extends to the dividing channel; The fabrication of the first electrode, second electrode, and third electrode specifically includes the following steps: Etching is performed along the upper surface of the insulating reflective layer to expose the P-type contact layer. A first electrode fabrication area is formed on the first light-emitting structure, a second electrode fabrication area is formed on the second light-emitting structure, and a third electrode fabrication area is formed on the third light-emitting structure. A first electrode, a second electrode, and a third electrode are deposited, wherein the first electrode is connected to the P-type contact layer of the first light-emitting structure, the second electrode is connected to the P-type contact layer of the second light-emitting structure, and the third electrode is connected to the P-type contact layer of the third light-emitting structure. Step S05: Peel off the growth substrate and the buffer layer to expose the light-emitting surface; Step S06: A transparent conductive layer is grown on the light-emitting surface, and the fourth electrode is connected to the transparent conductive layer through the slit channel; Step S07: Phosphor and filter are sequentially stacked on the transparent conductive layer. The filter is a red, green and blue three-primary-color filter. The ultraviolet light emission structure or violet light emission structure of each light-emitting unit is excited by the phosphor to obtain white light, which is then filtered by the red, green and blue three-primary-color filters to form a pixel unit. Step S08: Massively transfer a plurality of the pixel units onto the driving circuit unit; Specifically, each pixel unit is bonded to the driving circuit unit via its first, second, third, and fourth electrodes.

9. The method for manufacturing a Micro-LED display device according to claim 8, characterized in that: The method for preparing the LED epitaxial wafer includes: Step A01: Using an MOCVD (Metal-Organic Chemical Vapor Deposition) device, a buffer layer is grown on the surface of the growth substrate via metal-organic chemical vapor deposition. Step A02: Grow an N-type semiconductor layer on the buffer layer; Step A03: An active region is grown on the N-type semiconductor layer. The active region includes periodically alternating quantum barrier layers and quantum well layers. The quantum barrier layer closest to the electron blocking layer is the first quantum barrier layer, which is Mg-doped Al. x Ga 1-x N layers; Step A04: Grow the electron blocking layer on the active region. The electron blocking layer includes a stacked first sublayer and a second sublayer. The first sublayer is disposed close to the active region, and the second sublayer is disposed away from the active region. The first sublayer includes Al. z Ga 1-z N layers, where 0≤z≤1; the second sub-layer includes periodically alternating AlGaN layers and GaN layers, and along the direction away from the active region, the Al composition of the electron blocking layer gradually decreases, and the Al composition of the first sub-layer is greater than the Al composition of the first quantum barrier layer; Step A05: Grow a P-type semiconductor layer on the electron blocking layer, wherein the P-type semiconductor layer comprises periodically alternating Al layers. a Ga 1-a N layer and Al b Ga 1-b N layers, and the Al a Ga 1-a N layer and the Al b Ga 1-b The contact surface of the N layer is δ-doped with Mg, and the Al a Ga 1-a N layer and the Al b Ga 1-b The doping concentration of Mg in the N layer is lower than that of Mg at the contact surface; Step A06: Grow a P-type contact layer on the P-type semiconductor layer.

10. The method for manufacturing a Micro-LED display device according to claim 8, characterized in that: The fourth electrode includes an electrode pad and an electrode extension portion, wherein the electrode extension portion connects the transparent conductive layer and the electrode pad; the electrode pad, the first electrode, the second electrode and the third electrode are on the same horizontal plane on the side away from the backlight surface and are connected to the driving circuit unit.

11. The method for manufacturing a Micro-LED display device according to claim 10, characterized in that: The pixel unit further includes a protective layer that covers the sidewalls of the first electrode, the second electrode, the third electrode, and the electrode pads, as well as the exposed surface of the electrode extension portion.

Images