Pixel unit and its manufacturing method, microdisplay, pixel-level discrete element

Abstract

This application discloses a pixel unit, a manufacturing method thereof, a microdisplay, and a pixel-level individual element. The pixel unit includes a backplate and a display unit disposed on the backplate, the display unit including a first element layer and a second element layer stacked vertically in a direction away from the backplate, the first element layer including a first compound light-emitting layer and a second compound light-emitting layer adjacent to the first element layer, the second element layer including a color conversion layer and a third compound light-emitting layer adjacent to the first element layer, the color conversion layer being disposed above the first compound light-emitting layer. In this application, the color conversion layer allows compounds with significantly reduced external quantum efficiency to emit color through color conversion, thereby reducing power consumption and improving performance. Furthermore, the pixel unit occupies a smaller horizontal space, which reduces pixel density limitations compared to horizontally arranged pixel units, thereby effectively reducing the reduction in external quantum efficiency caused by size effects, reducing power consumption, improving performance such as brightness, and effectively improving yield.

Description

Technical Field

[0001] This application relates to the technical field of semiconductor devices, and particularly to pixel units, their manufacturing methods, microdisplays, and pixel-level individual elements.

Background Art

[0002] Micro-LED display technology is widely regarded as a next-generation display technology, and holds great potential in the fields of wearable devices and direct displays. Conventional LED red light is based on the AlGaInP material system, and both green light and blue light are based on the InGaN material system. The development of these two material systems has brought great development to applications such as LED lighting and display backlights. However, when directly using conventional LEDs as display pixels and entering a size range from the mm level to the μm level, especially a size of 20 μm or less, the reduction in external quantum efficiency caused by the size effect brings problems to the power consumption and performance of Micro-LEDs, and the red light performance of the AlGaInP system is particularly serious.

[0003] [[ID=​​​​​​

[0005] Therefore, it is necessary to find a semiconductor device that can effectively overcome the above-mentioned drawbacks. [Overview of the project]

[0006] The object of this application is to provide a pixel unit and a method for manufacturing the same, a microdisplay, and a pixel-level discrete element that can effectively reduce the effects of the size effect and effectively address yield loss.

[0007] To achieve the objectives of the present application, according to a first aspect of the present application, a pixel unit for use in a semiconductor element is proposed, comprising: a back plate; and a display unit provided on the back plate, the display unit comprising a first element layer and a second element layer sequentially stacked vertically along a direction away from the back plate, the first element layer comprising a first compound light-emitting layer and a second compound light-emitting layer provided adjacent to the first element layer, the second element layer comprising a color conversion layer and a third compound light-emitting layer provided adjacent to the second element layer, and the color conversion layer provided above the first compound light-emitting layer.

[0008] In a preferred embodiment, the display unit further includes a common cathode provided in the circumferential direction, the common cathode being connected to the first compound light-emitting layer, the second compound light-emitting layer, and the third compound light-emitting layer, respectively, and also connected to an external cathode.

[0009] In a preferred embodiment, the system further includes an enhanced common cathode that is connected to the common cathode and surrounds a first region and a second region that are isolated from each other together with the common cathode, wherein the first compound light-emitting layer and the color conversion layer are laminated in the first region, and the second compound light-emitting layer and the third compound light-emitting layer are laminated in the second region.

[0010] In a preferred embodiment, the first element layer further includes a first bonding layer made of an insulating material, The first bonding layer is provided on the back plate, and the first compound light-emitting layer and the second compound light-emitting layer are each provided on one side of the first bonding layer that is spaced apart from the back plate.

[0011] In a preferred embodiment, the first element layer further includes a first anode electrical connection structure and a second anode electrical connection structure, wherein one end of the first anode electrical connection structure is connected to the first compound light-emitting layer and the other end extends toward the back plate, and the second anode electrical connection structure is connected to the second compound light-emitting layer and the other end extends toward the back plate.

[0012] In a preferred embodiment, the first compound light-emitting layer includes a first P-type ohmic contact layer, a first compound semiconductor layer, and a first N-type ohmic contact layer, which are provided in sequence, wherein the first P-type ohmic contact layer is provided in close contact with the first junction layer and has a larger area than the first compound semiconductor layer, and the first anode electrical connection structure is provided to the side of the first compound semiconductor layer, with a portion of it sequentially penetrating the first P-type ohmic contact layer and the first junction layer.

[0013] In a preferred embodiment, the common cathode includes a first cathode electrical connection structure connected to the first N-type ohmic contact layer.

[0014] In a preferred embodiment, the second element layer further includes a second bonding layer made of a transparent insulating material, the second bonding layer is provided on the first element layer, and the color conversion layer and the third compound light-emitting layer are each provided on one side of the second bonding layer that is spaced apart from the first element layer.

[0015] In a preferred embodiment, the color conversion layer is provided on the second bonding layer, and its projected area on the back plate is larger than the projected area on the back plate of the first compound light-emitting layer.

[0016] In a preferred embodiment, the color conversion layer uses a photochromic material, and the wavelength of the light source of the first compound semiconductor layer is smaller than the wavelength of light from the color conversion layer.

[0017] In a preferred embodiment, the color conversion layer uses at least one of a red photon-quantum dot material or a red phosphor material.

[0018] In a preferred embodiment, the second element layer further includes a third anode electrical connection structure provided on the side of the third compound semiconductor layer, wherein one end of the third anode electrical connection structure is connected to the third compound light-emitting layer and the other end extends toward the back plate.

[0019] In a preferred embodiment, the display unit further includes a first insulating coating layer and a second insulating coating layer, both made of a transparent insulating material, wherein the first insulating coating layer covers the first compound light-emitting layer, the second compound light-emitting layer, the first anode electrical connection structure, the second anode electrical connection structure, a part of the third anode electrical connection structure, and a part of the common cathode, and the second insulating coating layer covers the color conversion layer, the third compound light-emitting layer, a part of the third anode electrical connection structure, and a part of the common cathode.

[0020] In a preferred embodiment, the back plate is provided with a drive circuit, the drive circuit is provided with at least one anode including a first anode, a second anode and a third anode, the first anode electrical connection structure is connected to the first anode, the second anode electrical connection structure is connected to the second anode, and the third anode electrical connection structure is connected to the third anode.

[0021] In a preferred embodiment, the display unit further includes a water vapor barrier layer provided on the surface of the second element layer.

[0022] In a preferred embodiment, the configuration further includes at least four pads, including a cathode pad and at least three anode pads, wherein at least a portion of any one of the at least four pads is provided in the back plate so as to be embedded, the common cathode is connected to the cathode pad, and the first anode electrical connection structure, the second anode electrical connection structure, and the third anode electrical connection structure are each connected to the corresponding anode pad among the at least three anode pads.

[0023] In a preferred embodiment, the element body is provided separately from the back plate, at least four of the pads are provided separately from the back plate, and the pixel-level individual elements further include a shielding support structure that covers the element body and is connected to the back plate.

[0024] In a preferred embodiment, the blocking support structure includes a covering portion and a fixing portion that are connected to each other, the covering portion covering the element body, and the fixing portion being connected to the back plate.

[0025] According to a second embodiment, a manufacturing method for manufacturing the pixel unit described in the first embodiment is provided, comprising: preparing a back plate; bonding a first target compound semiconductor, which has been prepared in advance so as to form a first junction layer, to the back plate; constructing a first compound light-emitting layer and a second compound light-emitting layer, which are provided adjacent to each other so as to form a first element layer; bonding a second target compound semiconductor, which has been prepared in advance so as to form a second junction layer, to one side of the first element layer spaced apart from the back plate; and manufacturing a display unit such that a third compound light-emitting layer and a color conversion layer, which is provided adjacent to the third compound light-emitting layer and above the first compound light-emitting layer, are provided.

[0026] In a preferred embodiment, joining the pre-prepared first target compound semiconductor to the backplane includes coating an insulating material on the entire surface of the backplane where at least one anode is provided, forming at least one through-hole corresponding to at least one of the anodes, manufacturing a first P-type ohmic contact layer on the surface of the first target compound semiconductor, coating an insulating material on the entire surface of the first P-type ohmic contact layer, joining the backplane and the first target compound semiconductor, and removing the substrate of the first target compound semiconductor so that the N-type ohmic contact layer of the first target compound semiconductor is exposed.

[0027] In a preferred embodiment, constructing a first compound light-emitting layer and a second compound light-emitting layer provided adjacent to each other so that a first element layer is formed includes dividing, by patterning etching, the first target compound semiconductor with the N-type ohmic contact layer exposed into the first compound light-emitting layer and the second compound light-emitting layer provided adjacent to each other, coating the entire surfaces of the first compound light-emitting layer and the second compound light-emitting layer so that a first insulating coating layer is formed, patterning etching the first insulating coating layer so that a first anode electrical connection channel, a second anode electrical connection channel, a first cathode electrical connection channel, and a second cathode electrical connection channel are respectively formed, and performing a metal coating on the surface of the first insulating coating layer so that a first anode electrical connection structure, a second anode electrical connection structure, a first cathode electrical connection structure, and a second cathode electrical connection structure are respectively formed.

[0028] In a preferred embodiment, constructing a third compound light-emitting layer and filling to form a color conversion layer provided adjacent to the third compound light-emitting layer includes forming a second target compound semiconductor with an exposed N-type ohmic contact layer in the third compound light-emitting layer by patterning etching; covering the entire surface where the third compound light-emitting layer is located so that a second insulating coating layer is formed; patterning and etching the second insulating coating layer, the second bonding layer, the first insulating coating layer, and the first bonding layer so that a third anode electrical connection channel, a third cathode electrical connection channel, and a first slot are respectively formed; filling the first slot with a color conversion material so that a color conversion layer provided in the second bonding layer is formed; and performing a metal coating on the surface where the second insulating coating layer is located so that a second element layer is formed, thereby forming a third anode electrical connection structure connected to a third anode and a third cathode electrical connection structure connected to a cathode.

[0029] In a preferred embodiment, after the construction of the second element layer is completed, patterning and etching the second element layer and the first element layer so that a reinforced common cathode channel is formed, a part of which is provided between the third compound light-emitting layer and the color conversion layer and a part of which is provided between the first compound light-emitting layer and the second compound light-emitting layer; and performing a metal coating on the surface of the second element layer so that a reinforced common cathode surrounding a first region and a second region connected to the common cathode and isolated from each other together with the common cathode is formed.

[0030] In a preferred embodiment, after the construction of the second element layer is completed, further includes coating a water vapor barrier material on the surface of the second element layer so that a water vapor barrier layer is formed.

[0031] According to a third embodiment, a manufacturing method for manufacturing the pixel unit described in the first embodiment is provided, comprising: preparing a back plate; bonding a pre-prepared first target compound semiconductor to the back plate to construct a first compound light-emitting layer and a second compound light-emitting layer adjacent to each other so as to form a first element layer; bonding a pre-prepared second target compound semiconductor to one side of the first element layer spaced apart from the back plate to construct a third compound light-emitting layer and a color conversion layer adjacent to the third compound light-emitting layer and located above the first compound light-emitting layer so as to form a second element layer.

[0032] In a preferred embodiment, preparing the back plate includes etching a pre-prepared back plate so that at least four cavities are formed; coating the back plate with a sacrificial layer on one side of the back plate where at least four cavities are formed; and constructing on the side of the back plate coated with the sacrificial layer at least four pads, including a cathode pad and at least three anode pads, which are provided in the corresponding cavities such that a portion of each pad is embedded.

[0033] In a preferred embodiment, after the construction of the second element layer is completed, a dielectric material is coated onto the surface of the element body and extends to a portion of the surface of the back plate so that a blocking support structure is formed, and the sacrificial layer is etched on one side of the back plate where the dielectric material is not coated so that at least four of the pads are separated from the back plate, wherein the etching rate ratio between the sacrificial layer and the back plate is greater than 10:1, and the etching rate ratio between the sacrificial layer and the blocking support structure is greater than 10:1.

[0034] According to the fourth aspect, a microdisplay is provided, comprising a microdisplay back plate including a drive circuit, an input interface and an output interface; a display area provided on the microdisplay back plate, the display area including display units included in at least two pixel units according to the first aspect, or display units included in a pixel unit manufactured by the manufacturing method described in the second aspect, arranged in an array; and a peripheral common cathode electrically connected to the common cathode of each of the display units.

[0035] According to the fifth aspect, a pixel-level discrete element is provided, comprising: a discrete element back plate including at least three anode pads and at least one cathode pad; and an element body provided on the discrete element back plate, the element body including a display unit included in at least two of the pixel units described in the first aspect, or a display unit included in a pixel unit manufactured by the manufacturing method described in the third aspect.

[0036] Compared to the prior art, this invention has the following beneficial effects.

[0037] The present invention provides a pixel unit and a method for manufacturing the same, a microdisplay, and a pixel-level discrete element. The pixel unit includes a back plate and a display unit provided on the back plate, which includes a first element layer and a second element layer sequentially stacked vertically along a direction away from the back plate, a first compound light-emitting layer and a second compound light-emitting layer provided adjacent to the first element layer, a color conversion layer and a third compound light-emitting layer provided adjacent to the second element layer, and a display unit in which the color conversion layer is provided above the first compound light-emitting layer. In the present invention, by providing a color conversion layer, the compound light-emitting layer, which has a significantly reduced external quantum efficiency, achieves color emission through color conversion, thereby reducing its power consumption and improving performance. Furthermore, by stacking at least two element layers vertically on the back plate, the pixel unit realizes multicolor display, and because the space occupied by the pixel unit in the horizontal direction is small and there are fewer limitations on pixel density, the decrease in external quantum efficiency caused by the size effect is effectively reduced, power consumption is effectively reduced, performance such as brightness is improved, and yield can be effectively improved.

[0038] Furthermore, by providing the common cathode of this invention in the circumferential direction of the display unit, the area ratio of the cathode in the display unit can be reduced, the area ratio of the light-emitting region can be improved, the effect of size can be reduced, and at the same time, the number of stacked element layers in the vertical direction can be increased or redundant circuits can be formed, effectively preventing optical crosstalk between adjacent pixel units and avoiding light leakage from the color conversion layer.

[0039] Furthermore, the pixel unit according to the present invention further includes an enhanced common cathode surrounding a first region and a second region connected to and isolated from each other by the common cathode, the first compound light-emitting layer and the color conversion layer being laminated in the first region, and the second compound light-emitting layer and the third compound light-emitting layer being laminated in the second region. By providing the enhanced common cathode, electrical enhancement can be effectively achieved, optical crosstalk between adjacent compound light-emitting layers can be effectively prevented, and, more importantly, light overflow of the first compound light-emitting layer can be effectively prevented.

[0040] Furthermore, since the projected area of ​​the color conversion layer on the back plate of the present invention is larger than the projected area of ​​the first compound light-emitting layer on the back plate, light overflow of the first compound light-emitting layer is avoided.

[0041] Furthermore, the color conversion layer of this invention consists of a red quantum dot material, and since the wavelength of the light source of the first compound semiconductor layer is smaller than the wavelength of red light, it not only realizes red light through color conversion in a way that avoids the power consumption and performance defects caused by external quantum effects due to the size effect of the AlGaInP red light system, but also effectively solves the environmental protection problems caused by the GaAs red light system, while simultaneously avoiding the reliability problems of high activity at the extremely large specific surface area of ​​green and blue quantum dots.

[0042] Furthermore, the method for manufacturing a pixel unit according to this application involves passivation and preparation for the next step of bonding by a similar damascene process in the manufacturing of the element, cathode electrical connection, and anode electrical connection. Compared to conventional methods in which an electrical connection structure is constructed by etching a metal layer, this method reduces the difficulty of the electrical connection construction process in a stacked system, and in particular improves the feasibility of using an electrical connection structure for metals that are difficult to dry etch (such as copper).

[0043] Furthermore, this application only needs to achieve at least one of the technical effects described above. [Brief explanation of the drawing]

[0044] [Figure 1] This is a schematic diagram showing the structure of the pixel unit of Example 1 from a top-view angle. [Figure 2] This is a cross-sectional view of the xx section in Figure 1. [Figure 3] This is a cross-sectional view of y1-y1 in Figure 1. [Figure 4] This is a cross-sectional view of y2-y2 in Figure 1. [Figure 5] This is a cross-sectional view of y3-y3 in Figure 1. [Figure 6] This is a schematic diagram showing an exemplary circuit structure of the back panel of Example 1. [Figure 7] This is a schematic diagram showing the circuit structure of one of the element layers in Example 1. [Figure 8] This is a schematic diagram showing an exemplary circuit structure of another back panel of Example 1. [Figure 9] This is a structural diagram showing that a top metal is provided on the surface of the back plate in Example 1. [Figure 10] This is a structural diagram showing that a situ-reflecting mirror is provided on the surface of the back plate in Example 1. [Figure 11] This shows the reflectance data in the visible light wavelength range for an exemplary in-situ reflector in Example 1. [Figure 12] This is a schematic diagram showing the top-view angle structure of a pixel unit including the reinforced common cathode of Example 1. [Figure 13] Figure 12 is a cross-sectional view of the xx section. [Figure 14] This is a cross-sectional view of the xx section of another pixel unit including the reinforced common cathode of Example 1. [Figure 15] This is a cross-sectional view of the xx section of another pixel unit in Example 1. [Figure 16] This is a cross-sectional view of a pixel unit having an optically enhanced structure and an enhanced common cathode in Example 1. [Figure 17] This is a schematic diagram showing an exemplary actual CSP package layout in Example 1. [Figure 18] This is a schematic diagram showing the structure of the microdisplay in Example 2. [Figure 19] This is a schematic diagram showing the arrangement of adjacent pixel units in the microdisplay of Example 2. [Figure 20] This is a cross-sectional view of section AB in Figure 19. [Figure 21] This is a schematic diagram showing an alternative arrangement of adjacent pixel units in the microdisplay of Example 2. [Figure 22] Figure 21 is a cross-sectional view of the CD section. [Figure 23]This is a cross-sectional view showing that a common cathode is shared between adjacent pixel units in Example 2. [Figure 24] This is a top view of the pixel-level discrete element of Example 3. [Figure 25] This is a cross-sectional view in the xx direction in Figure 24. [Figure 26] Figure 24 is a cross-sectional view of section AB. [Figure 27] This is a cross-sectional view of another xx-direction of Example 3 (the sacrificial layer has not been removed and there is no shielding support structure). [Figure 28] This is a top view of the back plate provided with the pad in Example 3. [Figure 29] Figure 28 is a cross-sectional view in the CD direction (including the sacrificial layer and solid pad). [Figure 30] Another cross-sectional view in the CD direction, shown in Figure 28 (including the sacrificial layer and hollow pad). [Modes for carrying out the invention]

[0045] To further clarify the purpose, technical means, and advantages of the present application, the technical means in the embodiments of the present application will be described clearly and completely below with reference to the drawings of the embodiments. Clearly, the embodiments described are only a part of the embodiments of the present application, not all of them. All other embodiments that a person skilled in the art can obtain without creative effort based on the embodiments of the present application are all within the scope of protection of the present application.

[0046] Furthermore, in this description, directions or positional relationships indicated by terms such as "up," "down," "inside," and "outside" are based on the orientation or positional relationships shown in the drawings, and are for the convenience and simplification of the explanation. They do not indicate or imply that the devices or elements mentioned must have a specific orientation, or must be constructed and operate in a specific orientation, and therefore should not be understood as limiting this application. Also, the terms "first" and "second" are used for explanatory purposes only and should not be understood as indicating or implying relative importance, or implicitly indicating the number of technical features indicated. Therefore, features limited as "first" and "second" may explicitly or implicitly include one or more such features. Furthermore, in this description, unless otherwise specified, "multiple" means two or more.

[0047] In this description, unless otherwise explicitly stated or limited, the terms “attachment,” “connection,” and “connection” should be understood in a broad sense. For example, they may be fixed connections, detachable connections, or integral connections. They may be mechanical connections or electrical connections. They may be direct connections, indirect connections via an intermediate medium, or internal communication between two elements. A person skilled in the art will understand the specific meaning of these terms in this application on a case-by-case basis.

[0048] Example 1 As shown in Figures 1-5, this embodiment provides a pixel unit 100 used in a semiconductor device. The pixel unit 100 includes a back plate 10, a display unit 20, and a common cathode 30. The pixel unit 100 according to this embodiment is a vertical stack pixel (VSP). The pixel unit 100 is used in semiconductor devices such as microdisplays and invisible light detectors.

[0049] Note: Figure 1 is a top view of the pixel unit 100, and the dotted lines represent its main internal structure; the same applies to subsequent figures. Figures 2 to 5 are two cross-sectional views of Figure 1 (top view), and each of the subsequent structural diagrams is either a top view or a corresponding cross-sectional view of the current structure. The xx cross-sectional view is a horizontal cross-sectional view of the top view, and the yy cross-sectional view is a vertical cross-sectional view of the top view.

[0050] Specifically, the back plate 10 is provided with a drive circuit. The drive circuit 10 is provided with at least one anode. Exemplary, a circuit diagram of the drive circuit is shown in Figure 6. Note that the circuit diagrams in this embodiment are simplified schematics and all are active drives. The internal circuit of the pixel unit 100 may include active, passive, or semi-passive control circuits. Exemplary, Figure 7 is a circuit diagram of one of the element layers. The anodes in this embodiment may be arranged on the same line, in a V-shape, or in an array. Any of the anodes are located in the middle or at the edge of the back plate 10, and this is not limited to this embodiment.

[0051] Referring to Figures 1-5, the display unit 20 is provided on one side of the back plate 10 where at least one anode is located. The display unit 20 includes a first element layer 40 and a second element layer 50 that are stacked vertically along a direction away from the back plate 10. The first element layer 40 includes an adjacent first compound light-emitting layer 41 and a second compound light-emitting layer 42. The second element layer 50 includes an adjacent color conversion layer 51 and a third compound light-emitting layer 52. The color conversion layer 51 is provided above the first compound light-emitting layer 41.

[0052] Furthermore, any element layer in this embodiment may be a general shape such as a square, hexagon, octagon, or circle, or a combination of shapes, and this embodiment is not further limited to such shapes.

[0053] Of course, in this embodiment, the materials of each compound light-emitting layer used in the display unit 20 may be the same or different. Exemplary combinations are as follows: The color conversion layer 51 is made of a red quantum dot material, and the first compound light-emitting layer 41, the second compound light-emitting layer 42, and the third compound light-emitting layer 52 are made of the same or different light sources other than red light, preferably one of ultraviolet light, blue light, or green light. Here, the wavelength of the light source for the first compound semiconductor layer 412 is smaller than the wavelength of red light. Note that in this embodiment, all compound semiconductor layers refer to quantum well compound semiconductor layers.

[0054] Furthermore, the number of element layers stacked vertically in the display unit 20 is not limited to two layers, but may include three, four, or more layers. It is sufficient to specify that all layers are transparent in the vertical direction of the color conversion layer 51 and do not obstruct the light of the color conversion layer 51 or cause significant light loss.

[0055] For example, if each compound-emitting layer uses a different compound, multi-color display such as full-color display can be achieved. If two or more vertical compound-emitting layers use the same compound, the light irradiation intensity can be enhanced or a redundant structure can be formed. Of course, both embodiments can coexist in the same display unit 20, and this embodiment is not limited to this.

[0056] Furthermore, to achieve multi-color display, the first compound light-emitting layer 41, the second compound light-emitting layer 42, and the third compound light-emitting layer 52 are each connected to different anodes to achieve individual control of light sources of different colors, and the circuit structure is shown in Figure 6. To achieve enhanced light irradiation intensity, for example, the same compound light-emitting layers are connected to the same anode, and the connection configuration can be series or parallel, and the circuit structure is shown in Figure 8.

[0057] For the sake of explanation, this embodiment will be described in more detail using two element layers as an example. Furthermore, RGB full-color display is achieved by using blue light InGaN compound epitaxy for the first compound light-emitting layer 41 and the second compound light-emitting layer 42, green light InGaN compound epitaxy for the third compound light-emitting layer 52, and red light quantum dot material for the color conversion layer 51.

[0058] The back plate 10 in this embodiment may be an active back plate combining one or more of the following: thin-film transistors (TFTs), LTPS low-temperature polysilicon, CMOS integrated circuits, high-mobility transistors (HEMTs), etc.

[0059] In this embodiment, a CMOS integrated circuit backplate is selected. The backplate 10 includes at least one top metal 11 covering at least one anode (Figure 9). Alternatively, the backplate 10 includes a situ reflector 12 provided on its upper surface that covers or exposes at least one anode (Figure 10). The situ reflector 12 may be a metal such as aluminum, gold, or silver, or it may be a Bragg reflective layer in which two or more thin films with different refractive indices are laminated, such as a laminate of silicon oxide and titanium oxide, a laminate of silicon oxide and alumina, or a laminate of silicon oxide and silicon nitride, or it may be an ODR total reflection mirror in which a metal and dielectric are laminated, such as at least one combination such as silver and silicon oxide, aluminum and alumina, or gold and silicon oxide. For example, reflectance data in a part of the visible light wavelength range of a laminate of metallic aluminum 250 nm and silicon oxide 150 nm (target wavelength 620 nm, 1 / 4 is 150 nm) is shown in Figure 11.

[0060] The in-situ reflecting mirror 12 may have a polygonal structure such as a circle, triangle, square, pentagon, hexagon, or octagon, or it may be a combination polygon that avoids anode contacts. The polygon may be inscribed within the pixel boundary, or it may be reduced by a certain length from the boundary.

[0061] In this embodiment, the common cathode 30 is provided in the circumferential direction of the display unit 20. The common cathode 30 is connected to the first compound light-emitting layer 41, the second compound light-emitting layer 42, and the third compound light-emitting layer 52, respectively, and is also connected to an external cathode (not shown). The material of the common cathode 30 is a metal such as Cu or Al.

[0062] Specifically, the common cathode 30 is a metal enclosure frame provided in the circumferential direction 20 of the display unit, and includes a first cathode electrical connection structure 31 connected to the first compound light-emitting layer 41, a second cathode electrical connection structure 32 connected to the second compound light-emitting layer 42, and a third cathode electrical connection structure 33 connected to the third compound light-emitting layer 52.

[0063] More preferably, as shown in Figures 12-14, the pixel unit 100 further includes an enhanced common cathode 60 surrounding a first region 61 and a second region 62 connected to and isolated from each other together with the common cathode 30. Part of the enhanced common cathode 60 is provided between the third compound light-emitting layer 52 and the color conversion layer 51, and part of it is provided between the first compound light-emitting layer 41 and the second compound light-emitting layer 42.

[0064] The first compound light-emitting layer 41 and the color conversion layer 51 are laminated in the first region 61, and the second compound light-emitting layer 42 and the third compound light-emitting layer 52 are laminated in the second region 62. The material of the reinforced common cathode 60 is a metal such as Cu or Al.

[0065] The first element layer 40 further includes a first junction layer 43, a first anode electrical connection structure 44, a second anode electrical connection structure 45, and a first insulating coating layer 46. Here, the first junction layer 43 is provided on the back plate 10, and the first compound light-emitting layer 41 and the second compound light-emitting layer 42 are each provided on one side of the first junction layer 43 spaced apart from the back plate 10. The first anode electrical connection structure 44 has one end connected to the corresponding first anode 13 and the other end connected to the first compound light-emitting layer 41. The second anode electrical connection structure 45 has one end connected to the corresponding second anode 14 and the other end connected to the second compound light-emitting layer 42.

[0066] Furthermore, the first insulating coating layer 46 covers the first compound light-emitting layer 41, the second compound light-emitting layer 42, the first anode electrical connection structure 44, the second anode electrical connection structure 45, and a portion of the common cathode 30. The portion of the common cathode 30 includes, but is not limited to, the first cathode electrical connection structure 31 and the second cathode electrical connection structure 32.

[0067] Here, the first junction layer 43 is made of an insulating material and includes dielectric materials such as SiO2, Si3N4, Al2O3, and AlN, and may also be a semiconductor material such as Si, or an organic material such as SU8 or BCB. The first insulating coating layer 46 is made of a transparent insulating material such as SiO2. All anode electrical connection structures and cathode electrical connection structures are made of corresponding metals such as Cu and Al.

[0068] Furthermore, the first compound light-emitting layer 41 includes a first P-type ohmic contact layer 411, a first compound semiconductor layer 412, and a first N-type ohmic contact layer (not shown), which are provided in sequence. The first P-type ohmic contact layer 411 is provided in close contact with the first junction layer 43, and its area is larger than the area of ​​the first compound semiconductor layer 412. The first anode electrical connection structure 44 is provided to the side of the first compound semiconductor layer 412, and a portion of it sequentially penetrates the first P-type ohmic contact layer 411 and the first junction layer 43 to connect to the corresponding first anode 13. Thus, the first compound light-emitting layer 41 is connected to the first anode 13 via the first anode electrical connection structure 44. Specifically, one end of the first anode electrical connection structure 44 is connected to the first P-type ohmic contact layer 411, and the other end is connected to the first anode 13. Furthermore, the first compound light-emitting layer 41 is connected to the common cathode 30 by connecting the first N-type ohmic contact layer and the first cathode electrical connection structure 31.

[0069] Furthermore, the material of the first P-type ohmic contact layer 411 may be a transparent conductive material such as ITO, or it may be a laminate or alloy of metallic materials such as Au, Ni, Ag, and Mg. The first P-type ohmic contact layer 411 is formed by coating the first compound semiconductor layer 412 with ITO by vapor deposition or sputtering. Preferably, the ITO film thickness is 500 nm and the ohmic contact is formed by high-temperature annealing at 500°C in an N2 environment.

[0070] Furthermore, the second compound light-emitting layer 42 includes a second P-type ohmic contact layer 421, a second compound semiconductor layer 422, and a second N-type ohmic contact layer (not shown), which are provided in sequence. The second P-type ohmic contact layer 421 is provided in close contact with the first junction layer 43, and its area is larger than that of the second compound semiconductor layer 422. The second anode electrical connection structure 45 is provided to the side of the second compound semiconductor layer 422, and a portion of it sequentially penetrates the second P-type ohmic contact layer 421 and the first junction layer 43 to connect to the corresponding second anode. Thus, similarly, the second compound light-emitting layer 42 is connected to the second anode 14 via the second anode electrical connection structure 45. Specifically, one end of the second anode electrical connection structure 45 is connected to the second P-type ohmic contact layer 421, and the other end is connected to the second anode 14. Furthermore, the second compound light-emitting layer 42 is connected to the common cathode 30 by connecting the second N-type ohmic contact layer and the second cathode electrical connection structure 32.

[0071] The second element layer 50 further includes a second junction layer 53, a third anode electrical connection structure 54, and a second insulating coating layer 55. Here, the second junction layer 53 is provided in close contact with the first element layer 40. The color conversion layer 51 and the third compound light-emitting layer 52 are each provided on one side of the second junction layer 53 that is spaced apart from the first element layer 40. Preferably, the projected area of ​​the color conversion layer 51 on the back plate 10 is larger than the projected area of ​​the first compound light-emitting layer 41 on the back plate 10.

[0072] In this embodiment, the color conversion layer 51 is used to obtain a target color light source. Specifically, when light emitted from the first compound light-emitting layer 41 passes through the color conversion layer 51, a target color light source is formed by performing a target color conversion. The color conversion layer 51 uses a photochromic material, preferably at least one of a quantum dot material and a phosphor material. In this embodiment, the color conversion layer 51 is used to form a red light source, so it is preferable that the color conversion layer 51 uses a red quantum dot material or a red phosphor material. Here, the red quantum dot material may be a perovskite red quantum dot (the quantum dot material may be at least one of a CsPdI3 material, an InP material, a CdSe material, or a CdS material). Based on this, the wavelength of the light source of the first compound semiconductor layer 412 is smaller than the wavelength of red light so as to transmit the light from the first compound semiconductor layer 412.

[0073] Here, the second bonding layer 53 is made of a transparent insulating material containing SiO2 or the like. The second insulating coating layer 55 is made of a transparent insulating material containing SiO2 or the like. All anode and cathode electrical connection structures are made of corresponding metals such as Cu and Al.

[0074] Furthermore, the third compound light-emitting layer 52 includes a third P-type ohmic contact layer 521, a third compound semiconductor layer 522, and a third N-type ohmic contact layer (not shown). The third P-type ohmic contact layer 521 is provided in close contact with the second junction layer 53, and its area is larger than that of the third compound semiconductor layer 522. The third anode electrical connection structure 54 is provided to the side of the third compound semiconductor layer 522, and a portion of it sequentially penetrates the third P-type ohmic contact layer 521, the second junction layer 53, and the first junction layer 43 to connect to the corresponding third anode 15. Thus, the third anode electrical connection structure 54 is connected to the third P-type ohmic contact layer 521 at one end and to the third anode 15 at the other end, thereby achieving a connection between the third compound light-emitting layer 52 and the third anode 15. The connection between the third cathode electrical connection structure 33 and the third N-type ohmic contact layer enables the connection between the third compound light-emitting layer 52 and the common cathode 30.

[0075] Furthermore, the second insulating coating layer 55 covers the color conversion layer 51, the third compound light-emitting layer 52, the third anode electrical connection structure 54, and a portion of the common cathode 30. The portion of the common cathode 30 here includes, but is not limited to, the third cathode electrical connection structure 33.

[0076] Preferably, as shown in Figure 14, in order to reduce the absorption and loss of light emitted from the second compound light-emitting layer 42 by the third compound light-emitting layer 52, the projected area of ​​the third compound light-emitting layer 52 on the back plate 10 is smaller than the projected area of ​​the second compound light-emitting layer 42, and the size of each light-emitting layer can be adjusted according to the mixing ratio of different colors.

[0077] For example, as shown in Figure 15, a typical microdisplay element has an element size of 2 μm, taking a monochrome pixel size of 4 μm as an example. When the RGB elements are stacked horizontally, the pixel size is 4 * 12 μm, and when stacked in a V-shape, the pixel size is 8 * 8 μm. Here, the brightness of the red light AlGaInP element is 200,000 nits (approximately 20 mW), the brightness of the green light InGaN element is 3,000,000 nits (approximately 120 mW), and the brightness of the blue light InGaN element is 500,000 nits (approximately 120 mW). The required white light is composed of three colors: red, green, and blue, in the proportions of 35% red light, 50% green light, and 15% blue light. The combined brightness of the white light is greatly affected by the red and blue elements, and the brightness of the red light in particular is significantly insufficient. In one embodiment, the first compound light-emitting layer 41 (backlight source) and the second compound light-emitting layer 42 emit blue light, and the third compound light-emitting layer 52 emits green light. By adjusting and combining the pixel sizes (areas), a better blending ratio can be achieved by increasing the sizes of the first compound light-emitting layer 41 and the second compound light-emitting layer 42 and decreasing the size of the sub-pixel elements of the third compound light-emitting layer 52. The quantum dot material used is a perovskite red quantum dot (the quantum dot material may be CsPdI3 material, InP material, CdSe or CdS material), and the conversion efficiency of the CsPdI3 material exceeds 80%. The pixel size is 5 × 5 μm, the pixel size for blue light as a backlight source is 2.5 × 4 μm, the sub-pixel size for blue light primary color is 1.5 × 4 μm, and the sub-pixel size for green light primary color is 1 × 4 μm. The brightness after color conversion is 1.2 million nits (approximately 240 MW) for red light, 3 million nits (approximately 120 MW) for green light, and 750,000 nits (approximately 180 MW) for blue light, demonstrating that brightness can be significantly increased while simultaneously reducing the pixel size.

[0078] Furthermore, by separating the first compound light-emitting layer 41 and the color conversion layer 51 by a certain distance, thermal isolation is achieved, and a decrease in thermal stability due to direct contact between the photochromic material of the color conversion layer 51 and the backlight source is avoided. This distance can be determined based on the thickness of the second bonding layer 53 and the thickness of the color conversion layer 51, and is not specifically limited in this embodiment. The distance is preferably 0.1 to 5 μm. Of course, the components that realize the thermal isolation effect include, but are not limited to, the first insulating coating layer 46 and the second bonding layer 53.

[0079] Furthermore, the display unit 20 further includes a water vapor barrier layer 70 provided on the surface of the second element layer 50. Specifically, the water vapor barrier layer 70 is made of a transparent dielectric material. The transparent dielectric material includes a single or multilayer inorganic dielectric material such as silicon oxide, silicon nitride, alumina, titanium oxide, or diamond, and may also be an organic dielectric material such as SU8 or polyimide, or a polycrystalline material such as glass or soda. Preferably, the water vapor barrier layer 70 is a Bragg reflective layer formed by lamination of silicon oxide and titanium oxide, but the water vapor barrier layer 70 on the surface of the third compound light-emitting layer 52 is removed by etching. The water vapor barrier layer 70 can act as an optical filter and transmit only the red light wavelength range.

[0080] The pixel unit 100 further includes an optical enhancement structure 80. Specifically, as shown in Figure 16, the optical enhancement structure 80 is laminated on the surface of the water vapor barrier layer 70. The optical enhancement structure 80 may be a polarizer, a lens, or the like. The lens may be an organic material such as SU8 or polyimide, or an inorganic material such as silicon dioxide or alumina.

[0081] Corresponding to the above-mentioned pixel unit 100, this embodiment further provides a method for manufacturing a pixel unit used in a semiconductor device. This manufacturing method includes the following:

[0082] In S1, prepare the back panel.

[0083] Specifically, the back plate may be one or more active back plates such as thin-film transistors (TFTs), LTPS low-temperature polysilicon, CMOS integrated circuits, and high-mobility transistors (HEMTs). A CMOS integrated circuit back plate including at least one anode is selected. Of course, the surface of the back plate is provided with at least one top metal covering the anode, or a situ reflector provided on the surface of the back plate. In this embodiment, it is preferable that a top metal is provided.

[0084] In step S2, a first target compound semiconductor, which has been prepared in advance to form a first junction layer, is bonded to a back plate, and a first compound light-emitting layer and a second compound light-emitting layer are constructed adjacent to each other to form a first element layer. Then, a second target compound semiconductor, which has been prepared in advance to form a second junction layer, is bonded to one side of the first element layer that is spaced apart from the back plate, and a third compound light-emitting layer and a color conversion layer, which is provided adjacent to the third compound light-emitting layer and above the first compound light-emitting layer, are constructed to form a second element layer, thereby manufacturing a display unit.

[0085] Specifically, step S2 includes the following:

[0086] In S21, a pre-prepared first target compound semiconductor is bonded to the back plate, and the following is included.

[0087] In S211, an insulating material (bonding material) is coated over the entire surface of the back plate on which at least one anode is provided, and at least one through hole corresponding to at least one anode is formed.

[0088] In step S212, a first P-type ohmic contact layer is fabricated on the surface of the first target compound semiconductor, and an insulating material (bonding material) is coated over the entire surface of the first P-type ohmic contact layer.

[0089] Preferably, the first target compound semiconductor is an InGaN ternary compound, and its structural diagram may be a single wavelength compound structure such as blue light or green light, as shown in Table 1 or Table 2 below. In this embodiment, the first target semiconductor compound is preferably a blue light compound.

[0090] [Table 1]

[0091] [Table 2]

[0092] The quantum well compound semiconductor layer described above is the compound semiconductor layer of this embodiment. The etching cutoff layer has a constant height ratio with respect to the substrate. The etching cutoff layer is used to protect the remaining compound when removing the substrate.

[0093] Therefore, prior to step S212, the manufacturing method further requires the preparation of the first target compound semiconductor, specifically including the following:

[0094] The substrate is selected to be a blue light InGaN ternary compound made of materials such as Si, sapphire, or Ga2O3.

[0095] A P-type ohmic contact thin film is formed on the P-contact surface. The P-type contact material may be a transparent conductive material such as ITO or ZnO, or it may be a laminate or alloy of metallic materials such as Ni, Au, or Ag. For example, an ITO coating is applied by vapor deposition or sputtering, resulting in an ITO film thickness of 500 nm. The first P-type ohmic contact layer is then formed by high-temperature annealing at 500°C in an N2 environment. Of course, the thickness of the first P-type ohmic contact layer and the conditions for contact layer formation can be adjusted and changed as needed.

[0096] An insulating material is coated over the entire surface of one side of the first P-type ohmic contact layer of the first target compound semiconductor.

[0097] In step S213, the back plate and the first target compound semiconductor are joined. Specifically, the surface of the back plate on which the insulating material is provided is joined to the surface of the first target compound semiconductor on which the insulating material is provided, so that the first bonding layer is formed.

[0098] Preferably, the surface of the insulating material is planarized by CMP (chemical mechanical planarization) (surface roughness after CMP planarization ≤ 10 nm), the surface of the insulating material is activated by a plasma surface so that the surface of the insulating material becomes hydrophilic (the plasma activation method is to treat in an Ar plasma atmosphere with a power of 200 W for 3 minutes), and then the first layer of compound is stacked vertically at a low temperature and the first target compound semiconductor is bonded to the back plate to be integrated.

[0099] For example, in the actual manufacturing process, as shown in Figure 17, a semi-finished compound that is cut and slightly larger (≧10μm) than the display pixel area (Display unit) of the backing plate is used and joined and integrated using a chip-size package. This chip-size package may be a single chip package as shown in a, two chip packages as shown in b, four chip packages as shown in c, nine chip packages as shown in d, etc. In a specific implementation, after completing the P-type ohmic contact and bonding layer using a compound wafer, region screening is performed by testing, and good regions are screened and cut to obtain a semi-finished chip-size package, which are then joined and integrated using rough alignment bonding.

[0100] In step S214, the substrate of the first target compound semiconductor is removed so that the N-type ohmic contact layer of the first target compound semiconductor is exposed.

[0101] Specifically, after bonding is complete, the blue light compound substrate (Si substrate) is thinned by polishing, and the compound Si substrate is completely removed by SF6 polishing or etching (dry etching or wet etching) to expose the N-type ohmic contact layer (GaN compound).

[0102] In S22, a first compound light-emitting layer and a second compound light-emitting layer are constructed adjacent to each other so as to form the first element layer, and the following is included.

[0103] In step S221, the first target compound semiconductor, in which the N-type ohmic contact layer is exposed by patterning etching, is divided into an adjacent first compound light-emitting layer and a second compound light-emitting layer. A portion of the first compound light-emitting layer is etched into a first P-type ohmic contact layer, and a portion of the second compound light-emitting layer is etched into a second P-type ohmic contact layer.

[0104] In step S222, the first compound light-emitting layer and the second compound light-emitting layer are coated over their entire surfaces so that a first insulating coating layer is formed. For example, SiO2 is coated onto the surfaces of the first compound light-emitting layer and the second compound light-emitting layer by atomic layer deposition (ALD) so that a first insulating coating layer is formed.

[0105] In step S223, the first insulating coating layer is patterned and etched so that a first anode electrical connection channel, a second anode electrical connection channel, a first cathode electrical connection channel, and a second cathode electrical connection channel are formed, respectively.

[0106] In S224, a metal coating is applied to the surface of the first insulating coating layer so that a first anode electrical connection structure, a second anode electrical connection structure, a first cathode electrical connection structure, and a second cathode electrical connection structure are formed, respectively. Here, the first anode electrical connection structure is connected to the first anode, the second anode electrical connection structure is connected to the second anode, and the first cathode electrical connection structure and the second cathode electrical connection structure are connected to the cathode, respectively.

[0107] In this embodiment, when manufacturing the elements and constructing the cathode electrical connection structure and anode electrical connection structure, a similar damascene process is used to passivate the elements and prepare for the next step of bonding. Specifically, the similar damascene process involves manufacturing the element layer by patterning etching, then introducing an insulating coating layer, and finally manufacturing the first anode electrical connection structure, the second anode electrical connection structure, the first cathode electrical connection structure, and the second cathode electrical connection structure by patterning deposition or patterning etching.

[0108] In S23, a second target compound semiconductor, which has been prepared in advance so as to form a second junction layer, is bonded to one side separated from the back plate of the first element layer, and the following is included.

[0109] In step S22, after the construction of the first element layer is completed, the second element layer is constructed. Similar to the explanation in step S21, it is first necessary to prepare the second target compound semiconductor for forming the third target compound layer, and in this embodiment, the second target compound semiconductor is a green light system with the structure described above. The bonding process in this step is the same as in step S21, so it will not be repeated here. The second bonding layer is made of a transparent insulating material such as a transparent dielectric material such as SiO2, Si3N4, Al2O3, or AlN, and may also be a light-transmitting semiconductor material such as ultrathin Si, or a transparent organic material such as SU8 or BCB. For example, the second target compound semiconductor is a Si-based green light compound epitaxy.

[0110] In S24, a third compound light-emitting layer is constructed and filled to form a color conversion layer adjacent to the third compound light-emitting layer, and the following is included.

[0111] In step S241, a second target compound semiconductor with an exposed N-type ohmic contact layer is formed on the third compound light-emitting layer by patterning etching, and a portion of the third compound light-emitting layer is etched into the third P-type ohmic contact layer.

[0112] In step S242, the entire surface on which the third compound light-emitting layer is located is covered so that the second insulating coating layer is formed.

[0113] In step S243, the second insulating coating layer, the second bonding layer, the first insulating coating layer, and the first bonding layer are patterned and etched so that the third anode electrical connection channel, the third cathode electrical connection channel, and the first slot are formed, respectively.

[0114] In step S244, the first slot is filled with a color conversion material so that a color conversion layer is formed in the second bonding layer.

[0115] Specifically, the first slot is filled with color conversion material using methods such as spray printing, spin coating, graphics, or engraving, and then the color conversion material is flattened by CMP planarization or scraping.

[0116] In S245, a metal coating is applied to the surface on which the second insulating coating layer is located so that a second element layer is formed, thereby forming a third anode electrical connection structure connected to the third anode and a third cathode electrical connection structure connected to the cathode.

[0117] Similarly, in step 24, the construction of the cathode and anode electrical connection structure is completed by a similar damascene process.

[0118] In S3, an enhanced common cathode is constructed, including the following:

[0119] In S31, the second element layer and the first element layer are patterned and etched so that an enhanced common cathode channel is formed, partly located between the third compound light-emitting layer and the color conversion layer, and partly located between the first compound light-emitting layer and the second compound light-emitting layer.

[0120] In step S32, a metal coating is applied to the surface of the second element layer so that an enhanced common cathode is formed surrounding the first and second regions, which are connected to the common cathode and isolated from each other together with the common cathode.

[0121] In step S4, a water vapor barrier material is coated onto the surface of the second element layer so that a water vapor barrier layer is formed. Specifically, by coating the surface of the second element layer with Al2O3 using the ALD process, a water vapor barrier layer is formed, thereby isolating water vapor and enhancing the stability of the color conversion material.

[0122] Of course, after step S4, the light output can be further controlled by adding structures such as a black matrix (BM), polarizer, and lens to the surface of the water vapor barrier layer. Here, the BM may be a metal or a special black colloid. Polarization can be achieved by a Bragg reflective layer. The Lens may be an inorganic dielectric layer or an organic colloid. In one embodiment, a hemispherical lens structure for light extraction made of SU8 is added.

[0123] In summary, the pixel unit used in the semiconductor element according to this embodiment achieves multicolor display by vertically stacking at least two element layers on the back plate. Compared to a pixel structure where elements are stacked horizontally to achieve full color, the pixel unit occupies less space horizontally in this application, effectively reducing the decrease in external quantum efficiency caused by the size effect, effectively lowering power consumption, and improving performance such as brightness. Furthermore, the yield can be effectively improved by stacking multiple layers vertically. In addition, by providing a color conversion layer, the compound light-emitting layer, which experiences a significant decrease in external quantum efficiency, achieves color emission through color conversion, thereby reducing power consumption and improving performance.

[0124] Furthermore, by providing the common cathode in the circumferential direction of the display unit in this embodiment, the area ratio of the cathode in the display unit can be reduced, the area ratio of the light-emitting region can be improved, the effect of size can be reduced, and at the same time, the number of stacked element layers in the vertical direction can be increased or redundant circuits can be formed, effectively preventing optical crosstalk between adjacent pixel units and avoiding light leakage from the color conversion layer.

[0125] Furthermore, the pixel unit of this embodiment further includes an enhanced common cathode surrounding a first region and a second region connected to and isolated from each other by the common cathode, the first compound light-emitting layer and the color conversion layer are laminated in the first region, and the second compound light-emitting layer and the third compound light-emitting layer are laminated in the second region. By providing the enhanced common cathode, electrical enhancement can be effectively achieved, optical crosstalk between adjacent compound light-emitting layers can be effectively prevented, and, more importantly, light overflow of the first compound light-emitting layer can be effectively prevented.

[0126] Furthermore, since the projected area of ​​the color conversion layer on the back plate in this embodiment is larger than the projected area of ​​the first compound light-emitting layer on the back plate, light overflow of the first compound light-emitting layer is avoided.

[0127] Furthermore, the color conversion layer in this embodiment is made of a red quantum dot material, and since the wavelength of the light source of the first compound semiconductor layer is smaller than the wavelength of red light, it not only realizes red light through color conversion in a way that avoids the power consumption and performance defects caused by external quantum effects due to the size effect of the AlGaInP red light system, but also effectively solves the environmental protection problems caused by the GaAs red light system, while simultaneously avoiding the reliability problems of high activity at the extremely large specific surface area of ​​green and blue quantum dots.

[0128] Furthermore, the manufacturing method for the pixel unit used in the semiconductor device according to this embodiment involves passivation and preparation for the next step of bonding by a similar damascene process during device manufacturing, cathode electrical connection, and anode electrical connection. Compared to conventional methods that construct the electrical connection structure by etching a metal layer, this method reduces the difficulty of the electrical connection construction process in the stacked method, and particularly improves the feasibility of using it as an electrical connection structure for metals that are difficult to dry etch (such as copper).

[0129] Furthermore, this embodiment only needs to achieve at least one of the above technical effects.

[0130] Example 2 According to this embodiment, a microdisplay is provided. As shown in Figure 18, the microdisplay 200 includes a drive back plate 300 which includes at least two drive circuits, an input interface and an output interface, A display area 400 provided on the drive back plate 300, which includes an array of at least two display units 20 according to Embodiment 1 and corresponding common cathodes 30, The system includes a periphery common cathode 500 that is electrically connected to the common cathode 30 of each display unit 20, so that the entire microdisplay 200 acts as a common cathode. The periphery common cathode 500 is a metal surrounding frame structure provided around the display area 400.

[0131] The external I / O interface 600 can be located at any position on the drive back plate 300.

[0132] Furthermore, in this embodiment, the orientation of the array of each pixel unit 100, which is arranged adjacently in an array in the microdisplay 200, is not restricted. In one embodiment, the array of four pixel units 100 is shown in Figures 19 and 20. Here, Figure 20 is a cross-sectional view along the AB section of Figure 19. In another embodiment, the array of four pixel units 100 is shown in Figures 21 and 22. Here, Figure 22 is a cross-sectional view along the CD section of Figure 21. By adjusting the orientation of the array of pixel units 100, the jaggedness of the display edges is improved, or the display is enhanced by borrowing adjacent pixels.

[0133] Furthermore, to further increase the size of the pixel unit 100, the common cathodes 30 of adjacent pixel units 100 are combined and shared. Exemplaryly, cross-sectional views of two adjacent pixel units 100 are shown in Figure 23 below.

[0134] For the specific structure of the microdisplay according to this embodiment and the corresponding technical effects, please refer to the relevant explanation in Embodiment 1, and no further detailed explanation will be provided in this embodiment.

[0135] Example 3 As shown in Figures 24-30, this embodiment provides another pixel unit 100'. The pixel unit 100' includes a back plate 10', at least four pads, a display unit 20', a common cathode 30', an enhanced common cathode 60', and a shielding support structure 70'. Here, the display unit 20' is located above the back plate 10'. The common cathode 30' is provided circumferentially on the display unit 20' and is connected to one of the compound light-emitting layers of any of the element layers of the display unit 20'. At least four pads are provided on the back plate 10' so as to be connected to the display unit 20' and at least a portion of each pad is embedded. The display unit 20' is provided separately from the back plate 10'. The shielding support structure 70' covers the display unit 20' and is connected to the back plate 10'. Note that the structure of the display unit 20' in this embodiment is the same as the structure of the display unit 20 in Embodiment 1. For the remaining explanation of the display unit 20' in this embodiment, please refer to the explanation of the display unit 20 in this embodiment, and it will not be repeated in this embodiment.

[0136] The pixel unit 100' will be described in more detail below, with reference to the diagram.

[0137] The material of the back plate 10' is one of the passive substrates such as silicon, PCB, sapphire, or glass, and an SOI CMOS substrate that completes the single-pixel circuit control switch may also be used. In this embodiment, a silicon-based back plate will be described in more detail as an example.

[0138] Since the pads are used to correspond to the preset electrical connection interfaces of downstream package products, in this embodiment, the pad structure is not limited, and it is preferable that all pad structures are identical in order to simplify the structure and reduce the difficulty of the process. The pads can be solid or hollow, as shown in Figures 28-30.

[0139] Furthermore, at least four pads include one cathode pad 91 and at least three anode pads. Specifically, taking the cathode pad 91 as an example, as shown in Figure 26, it includes a first connecting portion 911 and a needle-piercing portion 912 that are connected to each other. Here, the first connecting portion 911 is provided on the outside of the back plate 10' so as to be connected to the display unit 20', and the needle-piercing portion 912 is provided inside the back plate 10'. The needle-piercing portion 912 may be a vertebral structure, a step-shaped structure, a cylindrical structure, a rectangular parallelepiped structure, etc. Also, one or more alloys or laminates of gold, titanium, tungsten, aluminum and platinum may be used for the pads. Of course, corresponding to the one cathode pad 91 and at least three anode pads described above, at least four corresponding grooves are formed in the back plate 10', and the groove structure formed in the back plate 10' corresponds to the corresponding pad structure. In this embodiment, the back plate 10' and either of the pads are provided separately; that is, the back plate 10' is not in contact with either of the pads.

[0140] Referring again to Figures 24-26, the display unit 20' includes a first element layer 40' and a second element layer 50' stacked vertically along a direction away from the back plate 10'. Furthermore, the first element layer 40' includes an adjacent first compound light-emitting layer 41' and a second compound light-emitting layer 42'. The second element layer 50' includes an adjacent color conversion layer 51' and a third compound light-emitting layer 52'. The color conversion layer 51' is provided above the first compound light-emitting layer 41'. In this way, the first element layer 40' serves as the backlight source for the color conversion layer 81, and the light source lines of the first compound light-emitting layer 41' pass through the color conversion layer 51' and are converted into target light source lines by the color conversion material of the color conversion layer 51', thereby reducing the power consumption of the target light source lines and improving brightness.

[0141] Furthermore, at least three anode pads include a first anode pad 92, a second anode pad 93, and a third anode pad 94. Of course, the number of anode pads N is greater than or equal to the number of compound light-emitting layers in the device layer. The common cathode 30 is connected to the cathode pad 91, the first compound light-emitting layer 41', the second compound light-emitting layer 42', and the third compound light-emitting layer 52', respectively, thereby realizing the connection between each compound light-emitting layer and the cathode pad 91.

[0142] Furthermore, the first element layer 40' further includes a first junction layer 43', a first anode electrical connection structure 44', a second anode electrical connection structure 45', and a first insulating coating layer 46', wherein the first junction layer 43' is made of an insulating material. The first compound light-emitting layer 41' and the second compound light-emitting layer 42' are each provided on one side of the first junction layer 43' spaced apart from the back plate 10'. The first anode electrical connection structure 44' has one end connected to the corresponding first anode pad 92 and the other end connected to the first compound light-emitting layer 41'. The second anode electrical connection structure 45' has one end connected to the corresponding second anode pad 93 and the other end connected to the second compound light-emitting layer 42'.

[0143] The first compound light-emitting layer 41' includes a first P-type ohmic contact layer 411', a first compound semiconductor layer 412', and a first N-type ohmic contact layer (not shown). In this embodiment, the compound semiconductor layer refers to a quantum well compound semiconductor layer. The first P-type ohmic contact layer 411' is provided on the first junction layer 43', and its area is larger than that of the first compound semiconductor layer 412'. Preferably, the first anode electrical connection structure 44' is provided on the side of the first compound semiconductor layer 412', and a part of it sequentially penetrates the first P-type ohmic contact layer 411' and the first junction layer 43' to connect to the first anode pad 92. Here, the material of the first P-type ohmic contact layer 411' may be a transparent conductive material such as ITO, or it may be a laminate or alloy of metallic materials such as Au, Ni, Ag, Mg. The first P-type ohmic contact layer 411' is formed by coating the first compound semiconductor layer 412' with ITO using methods such as vapor deposition or sputtering. Preferably, the ITO film thickness is 500 nm and the ohmic contact is formed by high-temperature annealing at 500°C in an N2 environment.

[0144] The common cathode 30' includes a first cathode electrical connection structure 31'. The connection between the first cathode electrical connection structure 31' and the first N-type ohmic contact layer enables the connection between the first compound light-emitting layer 41 and the cathode pad 91.

[0145] Similarly, the second compound light-emitting layer 42' includes a second P-type ohmic contact layer 421', a second compound semiconductor layer 422', and a second N-type ohmic contact layer (not shown). The second P-type ohmic contact layer 421' is provided on the first junction layer 43', and its area is larger than that of the second compound semiconductor layer 422'. The second anode electrical connection structure 45' is provided on the side of the second compound semiconductor layer 422', and a portion of it sequentially penetrates the second P-type ohmic contact layer 421' and the first junction layer 43' to connect to the corresponding second anode pad 93.

[0146] In this embodiment, the second anode electrical connection structure 45' is provided on the side of the second compound semiconductor layer 422', and the first anode electrical connection structure 44' is provided on the side of the first compound semiconductor layer 412', thereby preventing the electrical connection structures (first anode electrical connection structure 44' and second anode electrical connection structure 45') from obstructing the light-emitting surface.

[0147] Furthermore, the common cathode 30' further includes a second cathode electrical connection structure 32' connected to the second N-type ohmic contact layer, thereby realizing a connection between the second compound light-emitting layer 42' and the cathode pad 91.

[0148] Furthermore, the first insulating coating layer 46' is made of a transparent insulating material such as SiO2. The first insulating coating layer 46' covers the first compound light-emitting layer 41', the second compound light-emitting layer 42', the first anode electrical connection structure 44', the second anode electrical connection structure 45', and a portion of the common cathode 30'. The portion of the common cathode 30' includes, but is not limited to, the first cathode electrical connection structure 31' and the second cathode electrical connection structure 32'.

[0149] Furthermore, the second element layer 50' further includes a second junction layer 53', a third anode electrical connection structure 54', and a second insulating coating layer 55'. Here, the second junction layer 53' is made of a transparent insulating material such as SiO2. The second junction layer 53' is provided on the first element layer 40'. The color conversion layer 51' and the third compound light-emitting layer 52' ​​are each provided on one side of the second junction layer 53' spaced apart from the first element layer 40'. In addition, since the projected area of ​​the color conversion layer 51' on the back plate 10' is larger than the projected area of ​​the first compound light-emitting layer 41' on the back plate 10', overflow of the light source lines of the first compound light-emitting layer 41' is effectively avoided.

[0150] Specifically, the second junction layer 53' is made of silicon nitride, a transparent insulating material. The third compound light-emitting layer 52' ​​includes a third P-type ohmic contact layer 521', a third compound semiconductor layer 522', and a third N-type ohmic contact layer (not shown). The third P-type ohmic contact layer 521' is provided on the second junction layer 53', and its area is larger than that of the third compound semiconductor layer 522'. The third anode electrical connection structure 54' is provided on the side of the third compound semiconductor layer 522', and a portion of it sequentially penetrates the third P-type ohmic contact layer 521', the second junction layer 53', and the first junction layer 43' to connect to the corresponding third anode pad 94. Similarly, the common cathode 30' includes a third cathode electrical connection structure 33', a third cathode electrical connection structure 33', and a third N-type ohmic contact layer, thereby realizing the connection between the third compound light-emitting layer 52' ​​and the cathode pad 91. The second insulating coating layer 55' covers the color conversion layer 51', the third compound light-emitting layer 52', the third anode electrical connection structure 54', and a portion of the common cathode 30'. The portion of the common cathode 30' here includes, but is not limited to, the third cathode electrical connection structure 33'. The second insulating coating layer 55' is made of a transparent insulating material such as SiO2.

[0151] The electrical connection structures of all anodes and common cathodes 30' are made of metallic materials such as Cu and Al.

[0152] Furthermore, the reinforced common cathode 60' is connected to the common cathode 30' and surrounds at least two regions that are isolated from each other together with the common cathode 30'. Each region contains at least one compound light-emitting layer or color conversion layer 51'. The material of the reinforced common cathode 60' is a metal such as Cu or Al, which is a good conductor. In this embodiment, the reinforced common cathode 60' surrounds a first region 61' and a second region 62' that are connected to the common cathode 30' and isolated from each other together with the common cathode 30'. Part of the reinforced common cathode 60' is provided between the third compound light-emitting layer 52' ​​and the color conversion layer 51', and part of it is provided between the first compound light-emitting layer 41' and the second compound light-emitting layer 42'. The first compound light-emitting layer 41' and the color conversion layer 51' are laminated in the first region 61', and the second compound light-emitting layer 42' and the third compound light-emitting layer 52' ​​are laminated in the second region 62'.

[0153] Furthermore, as shown in Figures 24-26, the shielding support structure 70' includes a covering portion 71' and a fixing portion 72' that are connected to each other. The covering portion 71' covers the display unit 20', and the fixing portion 72' is connected to the back plate 10'. The shielding support structure 70' forms a tether structure to fix and connect the display unit 20' to the back plate 10'.

[0154] Specifically, the coating portion 71' covers the display unit 20' and is mainly used to achieve water vapor shielding so that the performance and lifespan of the color conversion layer 51' are not affected after it is eroded by water vapor. The coating portion 71' is made of a transparent dielectric material. The transparent dielectric material includes a single layer or a laminate of inorganic dielectric materials such as silicon oxide, silicon nitride, alumina, titanium oxide, and diamond, and may also be an organic dielectric material such as SU8 or polyimide, or a polycrystalline material such as glass or soda. Preferably, the coating portion 71' is a Bragg reflective layer formed by a laminate of silicon oxide and titanium oxide, but the coating portion 71' on the surface of the third compound emitting layer 52' ​​is removed by etching. The coating portion 71' can act as an optical filter and transmit only the red light wavelength range.

[0155] Furthermore, as shown in Figure 27, the display unit 20' is provided separately from the back plate 10', and at least four pads are also provided separately from the back plate 10'. This separation can be achieved by pre-providing a sacrificial layer between the back plate and at least four pads during the manufacturing process, and then removing the sacrificial layer by etching or other methods after the element stacking is complete and the shielding support structure 70' is formed. Therefore, the pixel unit 100' only requires external force to break the covering portion 71' and the fixing portion 72' during movement, making it easily accessible, and in this structure, the back plate 10' can be reused, thus reducing costs.

[0156] In the exemplary structure, the portion of the blocking support structure 70' provided on the back plate 10' is in complete contact with the back plate 10', and its edge may be flush with, exceed, or recessed from the corresponding edge of the back plate 10', and this embodiment is not limited to this.

[0157] Corresponding to the pixel unit 100' described above, this embodiment further provides a method for manufacturing a pixel unit, which includes the following steps.

[0158] In S1', prepare the back panel.

[0159] Specifically, step S1' includes the following:

[0160] In S11', the pre-prepared back plate is etched so that at least four cavities are formed.

[0161] In S12', a sacrificial layer is coated on one side of the back plate where at least four cavities are formed. The sacrificial layer is formed on the surface of the back plate using silicon oxynitride by coating, thermal oxidation, wet oxidation, etc.

[0162] In S13', on one side of the back plate coated with a sacrificial layer, at least four pads are constructed, each including a cathode pad and at least three anode pads, and provided in the corresponding cavity such that a portion of each pad is embedded.

[0163] The pad in this embodiment is a metal pad and may be an alloy or laminate of one or more of gold, titanium, tungsten, aluminum, and platinum. The manufacturing method includes thermal deposition, sputtering, electroplating, or chemical plating, and the pad may be solid or hollow.

[0164] In S2', a first target compound semiconductor, which has been prepared in advance to form a first junction layer, is bonded to the back plate, and a first compound light-emitting layer and a second compound light-emitting layer are constructed adjacent to each other to form a first element layer. Then, a second target compound semiconductor, which has been prepared in advance, is bonded to one side of the first element layer that is spaced apart from the back plate, and a third compound light-emitting layer and a color conversion layer, which is provided adjacent to the third compound light-emitting layer and above the first compound light-emitting layer, are constructed to form a second element layer.

[0165] At least four pads include a first anode pad, a second anode pad, and a third anode pad.

[0166] Specifically, step S2' includes the following:

[0167] In S21', a pre-prepared first target compound semiconductor is bonded to the back plate, and a first compound light-emitting layer and a second compound light-emitting layer are constructed adjacent to each other so as to form the first element layer.

[0168] In S211', an insulating material is coated over the entire surface of the back plate where at least four pads are provided, and at least one through-hole corresponding to any of the pads is formed.

[0169] In S212', a first P-type ohmic contact layer is fabricated on the surface of the first target compound semiconductor, and an insulating material is coated over the entire surface of the first P-type ohmic contact layer.

[0170] It is preferable to use an InGaN ternary compound as the first target compound semiconductor. Therefore, in this manufacturing method, it is necessary to manufacture the first target compound semiconductor in advance before step S212', and for details, please refer to the explanation in Example 1.

[0171] In S213', the back plate and the first target compound semiconductor are joined together.

[0172] In S214', the substrate of the first target compound semiconductor is removed so that the N-type ohmic contact layer of the first target compound semiconductor is exposed.

[0173] In S215', the first target compound semiconductor, in which the N-type ohmic contact layer is exposed by patterning etching, is divided into an adjacent first compound light-emitting layer and a second compound light-emitting layer. A portion of the first compound light-emitting layer is etched into a first P-type ohmic contact layer, and a portion of the second compound light-emitting layer is etched into a second P-type ohmic contact layer. In this way, the adjacent first compound light-emitting layer and the second compound light-emitting layer are formed. The first compound light-emitting layer includes a first P-type ohmic contact layer, a first compound semiconductor layer, and a first N-type ohmic contact layer, which are sequentially provided in close contact with each other. The second compound light-emitting layer includes a second P-type ohmic contact layer, a second compound semiconductor layer, and a second N-type ohmic contact layer, which are sequentially provided in close contact with each other.

[0174] In S216', the first compound light-emitting layer and the second compound light-emitting layer are coated over their entire surfaces so that a first insulating coating layer is formed. For example, SiO2 is coated onto the surfaces of the first compound light-emitting layer and the second compound light-emitting layer by an atomic layer deposition (ALD) process so that a first insulating coating layer is formed.

[0175] In S217', the first insulating coating layer is patterned and etched so that a first anode electrical connection channel, a second anode electrical connection channel, a first cathode electrical connection channel, and a second cathode electrical connection channel are formed, respectively.

[0176] In S218', a metal coating is applied to the surface of the first insulating coating layer so that the first anode electrical connection structure, the second anode electrical connection structure, the first cathode electrical connection structure, and the second cathode electrical connection structure are formed, respectively.

[0177] In S22', a third compound light-emitting layer is constructed and filled to form a color conversion layer adjacent to the third compound light-emitting layer.

[0178] In S221', a second target compound semiconductor with an exposed N-type ohmic contact layer is formed on the third compound light-emitting layer by patterning etching, and a portion of the third compound light-emitting layer is etched into a third P-type ohmic contact layer. The second target compound semiconductor in this embodiment is a silicon-based green light compound epitaxy, and its structure is described in S212. In this way, the third compound light-emitting layer is formed. The third compound light-emitting layer includes a third P-type ohmic contact layer, a third compound semiconductor layer, and a third N-type ohmic contact layer, which are sequentially provided in close contact.

[0179] In S222', the entire surface on which the third compound light-emitting layer is located is covered so that the second insulating coating layer is formed.

[0180] In S223', the second insulating coating layer, the second bonding layer, the first insulating coating layer, and the first bonding layer are patterned and etched so that the third anode electrical connection channel, the third cathode electrical connection channel, and the first slot are formed, respectively.

[0181] In S224', the first slot is filled with color conversion material so that a color conversion layer is formed in the second bonding layer. Specifically, the first slot is filled with color conversion material by spray printing, spin coating, patterning, embossing, etc., and then the color conversion material is planarized by CMP planarization or scraping.

[0182] In S225', a metal coating is applied to the surface where the second insulating coating layer is located so that a second element layer is formed, thereby forming a third anode electrical connection structure connected to the third anode and a third cathode electrical connection structure connected to the cathode.

[0183] In a preferred embodiment, step S3' is further included after step S2' is completed, and includes constructing an enhanced common cathode, which includes the following:

[0184] In S31', the second element layer and the first element layer are patterned and etched so that an enhanced common cathode channel is formed, partly between the third compound light-emitting layer and the color conversion layer, and partly between the first compound light-emitting layer and the second compound light-emitting layer.

[0185] In S32', a metal coating is applied to the surface of the second element layer so that an enhanced common cathode is formed surrounding the first and second regions, which are connected to the common cathode and isolated from each other together with the common cathode.

[0186] After step S2' or S3' is completed, the manufacturing method further includes step S4' of forming a blocking support structure, and includes the following:

[0187] In S41', a water vapor barrier material is coated onto the surface of the second element layer so that a water vapor barrier layer is formed. The barrier support structure includes a covering part and a fixing part that are connected to each other. The covering part covers the display unit, and the fixing part is connected to the back plate.

[0188] Specifically, the ALD process coats the surface of the second element layer and a portion of the back plate with Al2O3, forming a protective layer that isolates water vapor and enhances the stability of the color conversion material. Simultaneously, the fixed connection between the display unit and the back plate is completed.

[0189] In S42', the sacrificial layer is etched on one side of the back plate surface that is not coated with dielectric material, such that at least four pads are separated from the back plate. The etching rate ratio between the sacrificial layer and the back plate is greater than 10:1, and the etching rate ratio between the sacrificial layer and the shielding support structure is greater than 10:1. Preferably, the gap between the etched back plate and the display unit is 100 nm to 1000 nm, and more preferably 300 nm to 500 nm.

[0190] In summary, according to this embodiment, by providing at least two element layers stacked vertically on the back plate, the size and number of individual pixel elements in the horizontal direction are reduced, thereby avoiding loss of pixel density, reducing the number of chip movements during mass movement, improving accuracy and yield, and simultaneously reducing costs by reducing the number of mass movements. Furthermore, by providing a color conversion layer, the compound light-emitting layer, which has a significantly reduced external quantum efficiency, achieves color emission through color conversion, thereby reducing its power consumption and improving performance, thus enabling full-color display.

[0191] Furthermore, in this embodiment, by providing a common cathode, the area ratio of the cathode in the display unit is reduced, the area ratio of the light-emitting region is improved, the effect of size is reduced, and at the same time, the number of stacked element layers in the vertical direction can be increased or redundant circuits can be formed, effectively preventing optical crosstalk between adjacent pixel units and avoiding light leakage from the color conversion layer.

[0192] Furthermore, the pixel unit in this embodiment is connected to an external circuit based on at least four pads. By sealing the individual elements to the target backplate via pads and making electrical connections, the process can be simplified, and metal welding such as eutectic welding can be avoided so as not to affect the performance of the pixel-level individual elements themselves.

[0193] Furthermore, in this embodiment, the display unit is provided separately from the back plate, and at least four pads are provided separately from the back plate. The pixel-level individual elements further include a shielding support structure that covers the display unit and a portion of the back plate. By providing the shielding support structure, the pixel-level individual elements are protected from color conversion and their performance is prevented from being affected by water vapor erosion. In addition, the structural stability and accessibility for subsequent use are improved by providing the display unit and the back plate separately, and costs are reduced because the back plate can be reused in this structure.

[0194] Furthermore, the pixel unit of this embodiment further includes an enhanced common cathode surrounding a first region and a second region connected to and isolated from each other by the common cathode, the first compound light-emitting layer and the color conversion layer are laminated in the first region, and the second compound light-emitting layer and the third compound light-emitting layer are laminated in the second region. By providing the enhanced common cathode, electrical enhancement can be effectively achieved, optical crosstalk between adjacent compound light-emitting layers can be effectively prevented, and, more importantly, light overflow of the first compound light-emitting layer can be effectively prevented.

[0195] Furthermore, the color conversion layer in this embodiment is made of a red quantum dot material, and since the wavelength of the light source of the first compound semiconductor layer is smaller than the wavelength of red light, it not only realizes red light through color conversion in a way that avoids the power consumption and performance defects caused by external quantum effects due to the size effect of the AlGaInP red light system, but also effectively solves the environmental protection problems caused by the GaAs red light system, while simultaneously avoiding the reliability problems of high activity at the extremely large specific surface area of ​​green and blue quantum dots.

[0196] Furthermore, this embodiment only needs to achieve at least one of the above technical effects.

[0197] Example 4 According to this embodiment, a pixel-level discrete element is provided. This pixel-level discrete element is A back plate of an individual element including at least three anode pads and at least one cathode pad, The element body provided on the back plate of an individual element includes an element body that includes a display unit included in at least two of the pixel units described in Embodiment 3, or an element body that includes a display unit included in a pixel unit manufactured by the manufacturing method described in Embodiment 3.

[0198] All of the above-described technical embodiments can be combined in any way to form any embodiment of the present application, that is, by combining any multiple embodiments, the need for different application scenarios can be met, all of which are within the scope of protection of the present application and will not be repeated here.

[0199] The above is merely a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present application should all be included within the scope of protection of the present application. [Explanation of Symbols]

[0200] 100,100', pixel unit 10,10', backboard 11. Top Metal 12, In-situ reflector 13. First anode 14. Second anode 15. Third anode 20. Display unit 30,30', common cathode 31,31', First cathode electrical connection structure 32,32', Second cathode electrical connection structure 33,33', Third cathode electrical connection structure 40,40', first element layer 41,41', First compound luminescent layer 411,411', 1st P-type ohmic contact layer 412,412', First compound semiconductor layer 42,42', Second compound luminescent layer 421,421', second P-type ohmic contact layer 422,422', second compound semiconductor layer 43,43', 1st bonding layer 44,44', First anode electrical connection structure 45,45', Second anode electrical connection structure 46,46', First insulating coating layer 50,50', second element layer 51,51', color conversion layer 52, 52', third compound luminescent layer 521, 521', 3P-type ohmic contact layer 522,522', third compound semiconductor layer 53,53', 2nd bonding layer 54,54', Third anode electrical connection structure 55,55', second insulating coating layer 60,60', Reinforced common cathode 61,61', 1st area 62,62', second area 70. Water vapor barrier layer 70', Shielding support structure 71', Covered part 72', fixed part 80, Optical reinforcement structure 80', Victim layer 200, Microdisplay 300, drive back plate 400, display area 500, Common surrounding cathode 600, External I / O Interface

Claims

1. A pixel unit used in a semiconductor device, The back panel and A display unit provided on the back plate, comprising a first element layer and a second element layer sequentially stacked vertically along a direction away from the back plate, a first compound light-emitting layer and a second compound light-emitting layer provided adjacent to the first element layer, a color conversion layer and a third compound light-emitting layer provided adjacent to the second element layer, and a display unit wherein the color conversion layer is provided above the first compound light-emitting layer, The first element layer further includes a first anode electrical connection structure and a second anode electrical connection structure provided so as to extend along the stacking direction, The first compound light-emitting layer includes a first P-type ohmic contact layer, a first compound semiconductor layer, and a first N-type ohmic contact layer, which are provided in sequence, wherein the first P-type ohmic contact layer is provided closer to the back plate than the first compound semiconductor layer and the first N-type ohmic contact layer, and its area is larger than the area of ​​the first compound semiconductor layer, and the first anode electrical connection structure is provided to the side of the first compound semiconductor layer, with a portion of it penetrating the first P-type ohmic contact layer. Alternatively, the second compound light-emitting layer includes a second P-type ohmic contact layer, a second compound semiconductor layer, and a second N-type ohmic contact layer arranged sequentially, wherein the second P-type ohmic contact layer is provided closer to the back plate than the second compound semiconductor layer and the second N-type ohmic contact layer, and its area is larger than the area of ​​the second compound semiconductor layer, and the second anode electrical connection structure is provided to the side of the second compound semiconductor layer, with a portion of it penetrating the second P-type ohmic contact layer. A pixel unit characterized by the following features.

2. The display unit further includes a common cathode provided in the circumferential direction, The common cathode is connected to the first compound light-emitting layer, the second compound light-emitting layer, and the third compound light-emitting layer, respectively, and is also connected to an external cathode. The pixel unit according to feature 1.

3. The present invention further includes an enhanced common cathode that is connected to the aforementioned common cathode and surrounds the first and second regions which are isolated from each other together with the aforementioned common cathode, The first compound light-emitting layer and the color conversion layer are provided laminated in the first region. The second compound light-emitting layer and the third compound light-emitting layer are provided laminated in the second region. The pixel unit according to feature 2.

4. The first element layer further includes a first bonding layer made of an insulating material, The first bonding layer is provided on the back plate, The first compound light-emitting layer and the second compound light-emitting layer are each provided on one side of the first bonding layer that is spaced apart from the back plate. The pixel unit according to feature 2.

5. The first anode electrical connection structure is provided with one end connected to the first compound light-emitting layer and the other end extending toward the back plate. The second anode electrical connection structure is provided with one end connected to the second compound light-emitting layer and the other end extending toward the back plate. The pixel unit according to feature 4.

6. The first P-type ohmic contact layer is provided in close contact with the first bonding layer. A portion of the first anode electrical connection structure penetrates the first junction layer. The pixel unit according to feature 5.

7. The common cathode includes a first cathode electrical connection structure connected to the first N-type ohmic contact layer. The pixel unit according to feature 6.

8. The aforementioned second element layer further includes a second bonding layer made of a transparent insulating material, The second junction layer is provided on the first element layer, The color conversion layer and the third compound light-emitting layer are each provided on one side of the second junction layer that is spaced apart from the first element layer. The pixel unit according to feature 6.

9. The color conversion layer is provided on the second bonding layer, and its projected area on the back plate is larger than the projected area on the back plate of the first compound light-emitting layer. The pixel unit according to feature 8.

10. The aforementioned color conversion layer uses a photochromic material, The wavelength of the light source of the first compound semiconductor layer is smaller than the wavelength of light from the color conversion layer. The pixel unit according to feature 9.

11. The aforementioned color conversion layer uses at least one of a red photon quantum dot material or a red phosphor material. The pixel unit according to feature 10.

12. The second element layer further includes a third anode electrical connection structure provided on the side of the third compound light-emitting layer, The third anode electrical connection structure is provided with one end connected to the third compound light-emitting layer and the other end extending toward the back plate. The pixel unit according to feature 8.

13. The display unit further includes a first insulating coating layer and a second insulating coating layer, both made of a transparent insulating material. The first insulating coating layer covers the first compound light-emitting layer, the second compound light-emitting layer, the first anode electrical connection structure, the second anode electrical connection structure, a part of the third anode electrical connection structure, and a part of the common cathode. The second insulating coating layer covers the color conversion layer, the third compound light-emitting layer, a part of the third anode electrical connection structure, and a part of the common cathode. The pixel unit according to feature 12.

14. A drive circuit is provided on the back plate. The drive circuit is provided with anodes including a first anode, a second anode, and a third anode. The first anode electrical connection structure is connected to the first anode, The second anode electrical connection structure is connected to the second anode, The third anode electrical connection structure is connected to the third anode, The pixel unit according to feature 12.

15. The display unit further includes a water vapor barrier layer provided on the surface of the second element layer. The pixel unit according to feature 1.

16. It further includes at least four pads, including a cathode pad and at least three anode pads, At least a portion of one of the four pads is provided in the back plate so as to be embedded, The common cathode is connected to the cathode pad, The first anode electrical connection structure, the second anode electrical connection structure, and the third anode electrical connection structure are each connected to the corresponding anode pad among at least three anode pads. The pixel unit according to feature 12.

17. A manufacturing method for manufacturing a pixel unit according to any one of claims 3 to 15, Prepare the back panel, The manufacturing of a display unit includes bonding a first target compound semiconductor, which has been pre-prepared to form a first bonding layer, to the back plate, constructing a first compound light-emitting layer and a second compound light-emitting layer that are provided adjacent to each other so as to form a first element layer, bonding a second target compound semiconductor, which has been pre-prepared to form a second bonding layer, to one side of the first element layer spaced apart from the back plate, and constructing a third compound light-emitting layer and a color conversion layer provided adjacent to the third compound light-emitting layer and above the first compound light-emitting layer so as to form a second element layer, A manufacturing method characterized by the following features.

18. Bonding the pre-prepared first target compound semiconductor to the back plate is The entire surface of the back plate on which at least one anode is provided is coated with an insulating material, and at least one through hole corresponding to at least one of the anodes is formed. A first P-type ohmic contact layer is fabricated on the surface of the first target compound semiconductor, and an insulating material is coated over the entire surface of the first P-type ohmic contact layer. The back plate and the first target compound semiconductor are joined together. This includes removing the substrate of the first target compound semiconductor so that the N-type ohmic contact layer of the first target compound semiconductor is exposed. The manufacturing method according to claim 17, characterized by the features described above.

19. Constructing a first compound light-emitting layer and a second compound light-emitting layer, which are provided adjacent to each other so as to form the first element layer, By patterning etching, the first target compound semiconductor, in which the N-type ohmic contact layer is exposed, is divided into an adjacent first compound light-emitting layer and a second compound light-emitting layer. The first compound light-emitting layer and the second compound light-emitting layer are covered over their entire surface so that a first insulating coating layer is formed. The first insulating coating layer is patterned and etched so that a first anode electrical connection channel, a second anode electrical connection channel, a first cathode electrical connection channel, and a second cathode electrical connection channel are formed, respectively. The method includes applying a metal coating to the surface of the first insulating coating layer so that a first anode electrical connection structure, a second anode electrical connection structure, a first cathode electrical connection structure, and a second cathode electrical connection structure are each formed therein. The manufacturing method according to claim 18, characterized in that it

20. Constructing a third compound light-emitting layer and a color conversion layer provided adjacent to the third compound light-emitting layer so as to form a second element layer is: By patterning etching, a second target compound semiconductor with an exposed N-type ohmic contact layer is formed on the third compound light-emitting layer, The entire surface on which the third compound light-emitting layer is located is covered so that the second insulating coating layer is formed, The second insulating coating layer, the second bonding layer, the first insulating coating layer, and the first bonding layer are patterned and etched so that a third anode electrical connection channel, a third cathode electrical connection channel, and a first slot are formed, respectively. The first slot is filled with a color conversion material so that a color conversion layer is formed in the second bonding layer, This includes forming a third anode electrical connection structure connected to the third anode and a third cathode electrical connection structure connected to the cathode by applying a metal coating to the surface on which the second insulating coating layer is located so that the second element layer is formed, The manufacturing method according to claim 19, characterized by the features described above.

21. A manufacturing method for manufacturing a pixel unit according to any one of claims 1 to 12 or 16, Prepare the back panel, The method includes bonding a pre-prepared first target compound semiconductor to the back plate to construct a first compound light-emitting layer and a second compound light-emitting layer adjacent to each other so as to form a first element layer, then bonding a pre-prepared second target compound semiconductor to one side of the first element layer spaced apart from the back plate to construct a third compound light-emitting layer and a color conversion layer adjacent to the third compound light-emitting layer and located above the first compound light-emitting layer so as to form a second element layer, A manufacturing method characterized by the following features.

22. Preparing the back panel is Etching a pre-prepared back plate so that at least four cavities are formed, The sacrificial layer is coated on one side of the back plate where at least four of the cavities are formed, The process includes constructing at least four pads on one side of the back plate coated with the sacrificial layer, each pad comprising a cathode pad and at least three anode pads, with a portion of each pad embedded in a corresponding cavity. The manufacturing method according to claim 21, characterized in that it

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