Microdisplay device and method of fabrication

Abstract

The present application relates to a kind of micro display devices and preparation method, micro display device includes driving backplate, and multiple layers of pixel layer are stacked on driving backplate, parent pixel includes multiple subpixels;The bottom end of each subpixel is respectively electrically connected to the corresponding first electrode contact by bottom conductive layer, and the top end of multiple subpixels is interconnected by top conductive layer and forms top common electrode structure;In two subpixels of different pixel layers: the internal channel of one subpixel in lower pixel layer is opened, and the peripheral emission area is formed in the peripheral channel, and the internal channel is for non-common electrode conductive piece to pass through;The light emitted by peripheral emission area at least partially emits via the upper subpixel of non-common electrode conductive piece electrically connected in internal channel.This application also discloses a kind of preparation method of micro display device.The present application can effectively improve the light efficiency and reliability of micro display device, meet the needs of different application scenarios.

Description

Technical Field

[0001] This invention relates to the field of semiconductor technology, and in particular to a microdisplay device and its fabrication method. Background Technology

[0002] Microdisplay devices, characterized by their small size, high resolution, and high brightness, can be applied in numerous fields such as AR / VR devices, automotive displays, medical detection, and smart wearables. Micro-LED and Micro-OLED technologies, in particular, have seen widespread development in recent years. Micro-LED technology, with its advantages of high efficiency, low power consumption, high density, and high stability, is considered one of the most promising next-generation display and light-emitting devices. In the field of microdisplays, to further ensure pixel size and density, multi-color stacking integration is required for color displays. Multi-layer stacked LED devices typically have a driving backplane (with driving circuitry) and multiple layers above it. Pixels are arranged in each layer, and each pixel needs to be electrically connected to the driving backplane. This results in a complex overall structure, significant loss of light-emitting area for each pixel, and difficulty in adjusting the light-emitting area, hindering optimal light distribution. Furthermore, the overall device consumes more power, which is detrimental to the reliability and stability of the LED display. Summary of the Invention

[0003] Therefore, the technical problem to be solved by the present invention is to improve the light efficiency and reliability of micro-display devices in the prior art.

[0004] To address the aforementioned technical problems, the present invention provides a microdisplay device, comprising,

[0005] A drive backplate, wherein a first type of electrode contact is provided on the drive backplate;

[0006] Multiple pixel layers, all of which are stacked sequentially from bottom to top above the driving backplate;

[0007] A mother pixel, wherein the mother pixel comprises a plurality of sub-pixels, and at least two of the sub-pixels are located in different pixel layers;

[0008] The bottom of each sub-pixel is electrically connected to the corresponding first type of electrode contact through the bottom conductive layer, and the tops of multiple sub-pixels are interconnected through the top conductive layer to form a top common electrode structure.

[0009] In two sub-pixels located in different pixel layers, a channel is formed inside the lower pixel layer of one of the sub-pixels, and a peripheral light-emitting area is formed around the channel. A non-common conductive element passes through the channel, and the top end of the non-common conductive element inside the channel is electrically connected to the bottom conductive layer of the other sub-pixel in the upper pixel layer, and the bottom end is electrically connected to the corresponding first type of electrode contact. The light emitted from the peripheral light-emitting area is at least partially emitted through the periphery of the upper sub-pixel electrically connected to the non-common conductive element inside the channel.

[0010] In one embodiment of the present invention, at least two of the sub-pixels in the mother pixel share a top conductive layer, and the sub-pixels sharing the top conductive layer are respectively located in different pixel layers.

[0011] In one embodiment of the present invention, the top conductive layer is separately provided on the top of each of the sub-pixels located in different pixel layers in the mother pixel and is not shared, and the top conductive layer in the same pixel layer is located on the top of the electrically connected sub-pixels.

[0012] In one embodiment of the present invention, the projection area of ​​the upper sub-pixel connected to the non-common conductive element inside the channel on the driving back plate is a first projection area, and the projection area of ​​the peripheral light-emitting area outside the channel on the driving back plate is a second projection area, wherein the first projection area and the second projection area do not overlap at least partially.

[0013] In one embodiment of the present invention, the sub-pixel having a channel and any of the sub-pixels above it connected to the non-common conductive element inside the channel are arranged coaxially; or, the sub-pixel having a channel and at least one of the sub-pixels above it connected to the non-common conductive element inside the channel are arranged off-axis.

[0014] In one embodiment of the present invention, a first insulating filling area is provided inside the channel, and the non-common conductive element inside the channel passes directly through the first insulating filling area.

[0015] In one embodiment of the present invention, a compound semiconductor region is disposed inside the channel, and the non-common conductive element inside the channel passes through the compound semiconductor region.

[0016] In one embodiment of the present invention, in the sub-pixel having a channel, a first inner metal fence is formed inside the channel, the first inner metal fence surrounds the periphery of the non-common conductive element inside the channel, and a first insulating layer covers the inner wall of the peripheral light-emitting area, and the first inner metal fence and the inner wall of the peripheral light-emitting area are insulated and isolated from each other by the first insulating layer.

[0017] In one embodiment of the present invention, the bottom conductive layer is a metal bonding layer.

[0018] In one embodiment of the present invention, the metal bonding layer at the bottom of the sub-pixel with the channel and the first inner metal fence are integrally formed, or the metal bonding layer at the bottom of the sub-pixel with the channel and the first inner metal fence are separately disposed and mutually insulated.

[0019] In one embodiment of the invention, at least one of the sub-pixels is surrounded by a first peripheral metal fence, and the first peripheral metal fence and the outer sidewall of the surrounded sub-pixel are insulated from each other.

[0020] In one embodiment of the invention, the top of the sub-pixel is in contact with an electrically connected top conductive layer, or the top of the sub-pixel and at least a portion of its sidewalls are in contact with an electrically connected top conductive layer.

[0021] In one embodiment of the present invention, a top ohmic contact layer is provided at the top of the sub-pixel, and the top of each sub-pixel is in contact with the corresponding top conductive layer through the top ohmic contact layer.

[0022] In one embodiment of the invention, a metal reinforcement is further included, and at least one of the top conductive layers is electrically connected to the metal reinforcement.

[0023] In one embodiment of the invention, the metal reinforcement is located above the electrically connected top conductive layer.

[0024] In one embodiment of the invention, the metal reinforcement is located below the electrically connected top conductive layer.

[0025] In one embodiment of the invention, the metal reinforcement surrounds the periphery of one of the sub-pixels below the electrically connected top conductive layer.

[0026] In one embodiment of the invention, the bottom end of the metal reinforcement is not lower than the top end of the surrounding sub-pixel.

[0027] In one embodiment of the present invention, the metal reinforcements in different mother pixels can be shared or each can be used independently for their respective mother pixels.

[0028] In one embodiment of the present invention, the driving backplate is divided into a display area, all the mother pixels constitute a pixel array, the projection of the pixel array on the driving backplate is located inside the display area, a second type of electrode contact is provided inside the display area, and / or a second type of electrode contact is provided outside the display area;

[0029] In this configuration, the polarity of the second type of electrode contact is opposite to that of the first type of electrode contact, and the tops of multiple sub-pixels in the mother pixel are all connected to the second type of electrode contact through a top conductive layer to form a top common electrode structure.

[0030] In one embodiment of the invention, a common electrode contact is further included, wherein the second type of electrode contact is electrically connected to the top conductive layer at the top of the plurality of sub-pixels via the common electrode contact.

[0031] In one embodiment of the present invention, at least two of the sub-pixels in the mother pixel share a top conductive layer, and the common electrode conductive member is in direct contact with the shared top conductive layer to achieve electrical connection; or, the common electrode conductive member is electrically connected to the shared top conductive layer through a transition conductive member.

[0032] In one embodiment of the present invention, the top of each of the sub-pixels of at least two different pixel layers in the mother pixel is provided with a separate top conductive layer without sharing it. The common conductive element includes interconnecting conductive portions. Adjacent top conductive layers are interconnected through the interconnecting conductive portions to achieve electrical connection. At least one top conductive layer is in direct contact with the electrically connected interconnecting conductive portion to achieve electrical connection. Alternatively, at least one top conductive layer is electrically connected to the electrically connected interconnecting conductive portion through a metal reinforcement.

[0033] In one embodiment of the present invention, the bottom end of the common electrode is in direct contact with the corresponding second type of electrode contact.

[0034] In one embodiment of the invention, at least one of the sub-pixels is surrounded by a peripheral air gap, the peripheral air gap being annular.

[0035] In one embodiment of the invention, at least one of the sub-pixels is surrounded by a partition wall, the partition wall being a compound semiconductor, and a peripheral air gap is formed between the partition wall and the surrounded sub-pixel.

[0036] In one embodiment of the present invention, a second insulating filling region is further provided around the sub-pixel that is surrounded by the peripheral air gap, and the peripheral air gap is formed inside the second insulating filling region.

[0037] In one embodiment of the present invention, an inner air gap is provided inside the channel, the inner air gap surrounds the periphery of the non-common conductive element inside the channel, and the inner air gap is annular.

[0038] In one embodiment of the present invention, a first insulating filling area is provided inside the channel, and the inner air gap is formed inside the first insulating filling area.

[0039] In one embodiment of the invention, at least two sub-pixels located in different pixel layers emit different colors.

[0040] In one embodiment of the present invention, a lens is provided above the uppermost sub-pixel, and the lens covers at least one of the sub-pixels in the parent pixel.

[0041] This invention also discloses a method for fabricating a microdisplay device, comprising,

[0042] A drive backplane is provided, wherein a first type of electrode contact is provided on the drive backplane;

[0043] A compound semiconductor layer is selected as the pixel layer, and multiple pixel layers are stacked sequentially from bottom to top above the driving backplane. When stacking each pixel layer, the pixel layer is etched to obtain sub-pixels, so that each parent pixel includes multiple sub-pixels, and at least two sub-pixels are located in different pixel layers.

[0044] This ensures that the bottom of each sub-pixel in the mother pixel is electrically connected to the corresponding first type of electrode contact through the bottom conductive layer, and the tops of multiple sub-pixels are interconnected through the top conductive layer to form a top common electrode structure.

[0045] In two sub-pixels located in different pixel layers, a channel is formed inside the lower pixel layer of one of the sub-pixels, and a peripheral light-emitting area is formed around the channel. A non-common conductive element passes through the channel, and the top end of the non-common conductive element inside the channel is electrically connected to the bottom conductive layer of the other sub-pixel in the upper pixel layer, and the bottom end is electrically connected to the corresponding first type of electrode contact. The light emitted from the peripheral light-emitting area is at least partially emitted through the periphery of the upper sub-pixel electrically connected to the non-common conductive element inside the channel.

[0046] In one embodiment of the present invention, when a non-common conductive element passes through the interior of the channel, the preparation method further includes filling the interior of the channel with insulating material to form a first insulating filling region, so that the non-common conductive element passes directly through the first insulating filling region.

[0047] In one embodiment of the present invention, when a non-common conductive element passes through the interior of the channel, the preparation method further includes retaining a portion of the compound semiconductor material inside the channel to form a compound semiconductor region, so that the non-common conductive element passes through the compound semiconductor region.

[0048] The technical solution of the present invention has the following advantages compared with the prior art:

[0049] The microdisplay device described in this invention allows at least two sub-pixels to share a single top conductive layer, simplifying the electrical connection structure and facilitating fabrication. Simultaneously, channels are formed within the corresponding sub-pixels, with an outer light-emitting area around the channels. Non-common conductive components pass through the channels. This structure allows for flexible adjustment of the light-emitting area and position of the sub-pixels, reduces shading of the lower sub-pixel's light-emitting surface, ensures the effective light-emitting area of ​​the lower sub-pixels, reduces energy waste, and achieves optimal light distribution. This effectively improves the luminous efficiency and reliability of the display device and allows its light pattern to meet the needs of different application scenarios. Attached Figure Description

[0050] To make the content of this invention easier to understand, the invention will be further described in detail below with reference to specific embodiments and accompanying drawings.

[0051] Figure 1 This is a schematic diagram of the structure of the first micro-display device of the present invention (two-layer structure);

[0052] Figure 2 yes Figure 1 A schematic diagram (top view) showing the arrangement of sub-pixels in the microdisplay device.

[0053] Figure 3 This is a schematic diagram of the structure of the second type of microdisplay device of the present invention (two-layer structure).

[0054] Figure 4 yes Figure 3 A schematic diagram (top view) showing the arrangement of sub-pixels in the microdisplay device.

[0055] Figure 5 This is a schematic diagram of the structure of the third type of microdisplay device of the present invention (two-layer structure);

[0056] Figure 6 This is a schematic diagram of the structure of the fourth type of microdisplay device of the present invention (two-layer structure).

[0057] Figure 7 yes Figure 1 The diagram shows a possible structure after a lens is installed.

[0058] Figure 8 yes Figure 1 A schematic diagram of another structure after the lens is installed in the shown structure;

[0059] Figure 9 This is a schematic diagram of the structure of the fifth type of microdisplay device of the present invention (three-layer structure).

[0060] Figure 10 This is a schematic diagram (top view) of the arrangement of sub-pixels in a three-layer microdisplay device.

[0061] Figure 11 yes Figure 9 The diagram shows a possible structure after a lens is installed.

[0062] Figure 12 This is a schematic diagram of the structure of the sixth type of microdisplay device of the present invention (three-layer structure).

[0063] Figure 13 yes Figure 12 A schematic diagram (top view) showing the arrangement of sub-pixels in the microdisplay device.

[0064] Figure 14 This is a schematic diagram (top view) of another arrangement of sub-pixels in a three-layer microdisplay device.

[0065] Figure 15 This is a schematic diagram of the bonding between the driving backplate and the first pixel layer in this invention;

[0066] Figure 16 yes Figure 1 The flowchart shown is a fabrication process diagram of the microdisplay device.

[0067] Figure 17 This is a schematic diagram of a pixel layer etching process;

[0068] Figure 18 This is another schematic diagram of the pixel layer structure;

[0069] Figure 19 This is a schematic diagram of the structure of the seventh micro-display device of the present invention;

[0070] Figure 20 This is a schematic diagram of a structure in which the top conductive layer is set independently for the first pixel layer;

[0071] Figure 21 yes Figure 20 A schematic diagram of one form of the structure shown after adding metal reinforcement components;

[0072] Figure 22 yes Figure 20 The diagram shows the structure after the interconnecting conductive parts are connected.

[0073] Figure 23 yes Figure 22 A schematic diagram of the structure shown after the addition of metal reinforcement components;

[0074] Figure 24 This is a schematic diagram of another structure where the top conductive layer is set independently for the first pixel layer;

[0075] Figure 25 yes Figure 20 A schematic diagram of another form of the structure shown after adding metal reinforcement;

[0076] Figure 26 yes Figure 20 A schematic diagram showing the connection between the top conductive layer and the second type of electrode contact in the structure shown.

[0077] Figure 27 A schematic diagram of the structure of the microdisplay device when each pixel layer of the present invention has an independently provided top conductive layer at its top;

[0078] Figure 28 This is a schematic diagram of the structure of the eighth micro-display device of the present invention;

[0079] Figure 29 This is a schematic diagram of the structure of the ninth micro-display device of the present invention;

[0080] Figure 30 This is a schematic diagram of the structure of a sub-pixel in this invention, in which no metal fence is set around its perimeter;

[0081] Figure 31 This is a schematic diagram of a structure in this invention in which a sub-pixel is surrounded by a metal fence.

[0082] Figure 32 This is another structural schematic diagram of a sub-pixel having a metal fence around its perimeter in this invention;

[0083] Figure 33 yes Figure 32 A magnified view of a section at point M1;

[0084] Figure 34 This is a schematic diagram of the structure of the tenth micro-display device of the present invention (with an outer air gap).

[0085] Figure 35 yes Figure 34 A magnified view of a section at point M2;

[0086] Figure 36 This is a schematic diagram of the structure of the eleventh microdisplay device of the present invention;

[0087] Figure 37 This is a schematic diagram of the structure of the twelfth microdisplay device of the present invention;

[0088] Figure 38 This is a schematic diagram of the thirteenth micro-display device of the present invention;

[0089] Figure 39 This is a schematic diagram (top view) of the distribution of the display area in this invention;

[0090] Figure 40 This is a schematic diagram (top view) of the connection between the peripheral electrode contact area and the interface in this invention.

[0091] Figure 41 This is a schematic diagram of the structure of the fourteenth micro-display device of the present invention (with a metal reinforcement).

[0092] Figure 42 This is a schematic diagram of the structure of the fifteenth microdisplay device of the present invention (with a metal reinforcement).

[0093] Figure 43 This is a schematic diagram of the structure of the sixteenth type of microdisplay device of the present invention (with a metal reinforcement).

[0094] Figure 44 This is a schematic diagram of the structure of the seventeenth microdisplay device of the present invention;

[0095] Figure 45 This is a schematic diagram of the structure of the eighteenth micro-display device of the present invention;

[0096] Figure 46 yes Figure 45 A magnified view of a section at point M3;

[0097] Explanation of reference numerals in the instruction manual:

[0098] 10. Drive backplane; 101. First type of electrode contact; 102. Second type of electrode contact; 103. Display area; 104. Peripheral electrode contact area; 105. Interface;

[0099] 20. First pixel layer;

[0100] 30. Second pixel layer;

[0101] 40. Third pixel layer;

[0102] 50. Subpixel; 501. Aperture; 502. Peripheral luminous area;

[0103] 60. Top conductive layer;

[0104] 70. Bottom conductive layer;

[0105] 80. Non-common conductive components;

[0106] 90. Common conductor; 901. Interconnecting conductor;

[0107] 100. First insulation filling area;

[0108] 110. Second insulation filling area;

[0109] 120. Compound semiconductor region;

[0110] 130. First inner metal fence; 140. First outer metal fence; 150. First insulating layer; 160. Second insulating layer; 170. Top ohmic contact layer; 180. Bottom ohmic contact layer; 190. Metal reinforcement; 200. Transition conductive element; 210. Outer air gap; 220. Inner air gap; 230. Etching barrier layer; 240. Second inner metal fence; 250. Lens; 260. Partition wall; Detailed Implementation

[0111] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, so that those skilled in the art can better understand and implement the present invention. However, the embodiments described are not intended to limit the present invention. Obviously, the described embodiments are only some embodiments of this disclosure, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the present disclosure or its application or use.

[0112] In the description of this invention, it should be understood that the terms "vertical," "upper," "lower," "top," "side," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0113] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0114] Traditional LED devices using multi-layer stacking have complex overall structures, resulting in significant loss of light-emitting area for each pixel. This makes it difficult to adjust the light-emitting area and achieve optimal light distribution. Furthermore, the overall device consumes more power, which is detrimental to the reliability and stability of the LED display device. In view of this, this application provides a micro-display device to improve the above-mentioned problems, thereby better ensuring the photoelectric performance and reliability of the LED display device.

[0115] It should be noted that, in this application, the compound semiconductor layer refers to a layer structure with a certain thickness prepared from compound semiconductor materials. Compound semiconductors generally refer to compounds formed from two or more elements, including crystalline inorganic compounds (such as III-V and II-VI compound semiconductors) and oxide semiconductors. The compound semiconductors involved in this application are mainly epitaxial materials for light-emitting diodes, such as InGaN ternary material systems or AlGaInP quaternary material systems, whose emission wavelengths can cover the entire spectrum from ultraviolet, visible, and infrared light. Their substrate materials can be GaN, Si, SiC, Sapphire, GaAs, InP, etc.

[0116] Taking the Micro-LED field as an example, some compound semiconductor materials involved in this application are shown in Table 1. In some practical applications, the film layers of compound semiconductors are more complex, or there are cases where materials are used interchangeably. Typical compound semiconductors mainly include P-type semiconductor materials, N-type semiconductor materials, and MQW active quantum wells and other functional layers (barrier layers, confinement layers, waveguide layers, buffer layers, etc.) sandwiched between the two:

[0117] Table 1. Material Table of Film Layers for Compound Semiconductors

[0118]

[0119] The structure of the microdisplay device of this application will be further described below with reference to the following specific embodiments.

[0120] Example 1

[0121] See Figure 1 This embodiment discloses a multi-layer stacked micro-display device, including at least one mother pixel, each mother pixel having multiple (two or more) sub-pixels. The structure of the above micro-display device is specifically described below using a mother pixel with two sub-pixels as an example. The structure shown in the figure only shows the case of one mother pixel. When there are multiple mother pixels, the internal structure of each mother pixel is basically the same.

[0122] In this invention, the micro-display device has a Z-direction, an X-direction, and a Y-direction, which are perpendicular to each other. The Z-direction is the stacking direction of each layer of sub-pixels, that is, the up and down direction, which can also be understood as the direction away from / closer to the driving backplate. Here, "height" or "up and down" or "top and bottom" are all in the Z-direction.

[0123] In this invention, "bottom end of sub-pixel" refers to the end of the sub-pixel that is close to the driving backplate, and "top end of sub-pixel" refers to the end of the sub-pixel that is away from (away from) the driving backplate.

[0124] It should be noted that the cross-sectional views in the XZ plane in the accompanying drawings of this invention can be schematic diagrams after cutting a single cross section or schematic diagrams after cutting multiple cross sections together, in order to show the connection situation of different electrode contacts.

[0125] The LED display device in this embodiment includes a driving backplate 10 and a mother pixel, the mother pixel including a plurality of sub-pixels 50.

[0126] The driving backplate 10 is a component with a driving circuit. The first type of electrode contact 101 and the second type of electrode contact 102 are the lead-out terminals of the driving circuit, used to electrically connect the driving circuit and the sub-pixel 50. The sub-pixel 50 is a light-emitting element. Through the electrical connection between the driving backplate 10 and the sub-pixel 50, the connection between the sub-pixel 50 and the driving circuit is realized, thereby driving the sub-pixel 50 to emit light. This allows each sub-pixel 50 to be driven individually and emit light independently.

[0127] The aforementioned driving backplane 10 includes, but is not limited to, a CMOS (Complementary Metal Oxide Semiconductor) driving backplane.

[0128] The driving backplate 10 may be provided with a first type of electrode contact 101 and a second type of electrode contact 102. The polarities of the first type of electrode contact 101 and the second type of electrode contact 102 are opposite, with one being the anode and the other the cathode. Understandably, in order to prevent short circuits, the first type of electrode contact 101 and the second type of electrode contact 102 need to be insulated from each other. Through the provision of the first type of electrode contact 101 and the second type of electrode contact 102, the driving backplate 10 can be electrically connected to the sub-pixel 50, thereby controlling the light emission of each sub-pixel using the driving backplate 10.

[0129] Understandably, the two ends of sub-pixel 50 along the Z direction are the bottom and the top, respectively; the bottom and top of sub-pixel 50 are the two ends with opposite polarities. Sub-pixel 50 includes a P-type semiconductor layer, an active layer and an N-type semiconductor layer arranged sequentially along the Z direction. The active layer is used to emit light. The top of sub-pixel 50 is the end where the N-type semiconductor layer is located (or the end where the P-type semiconductor layer is located - anode), and the bottom is the end where the P-type semiconductor layer is located (or the end where the N-type semiconductor layer is located - cathode), which need to be connected to electrode contacts of different polarities respectively.

[0130] See Figure 1 This embodiment discloses a microdisplay device, including a driving backplate 10, a mother pixel, and two pixel layers;

[0131] The drive backplate 10 is provided with a first type of electrode contact 101;

[0132] Two pixel layers are stacked sequentially from bottom to top above the driving backplane to form a two-layer structure. The two stacked pixel layers are the first pixel layer 20 and the second pixel layer 30 from bottom to top.

[0133] The mother pixel has two sub-pixels 50, and the two sub-pixels 50 are located in different pixel layers;

[0134] The bottom of each of the two sub-pixels 50 is electrically connected to the corresponding first type of electrode contact 101 through the bottom conductive layer 70. The tops of the multiple sub-pixels 50 are electrically interconnected through the top conductive layer 60 to form a top common pole structure. That is, the top conductive layers 60 of each sub-pixel 50 in the top common pole structure are electrically connected together and conduct electricity to each other.

[0135] In two sub-pixels 50 located in different pixel layers, a channel 501 is formed inside the lower sub-pixel 50. A peripheral light-emitting area 502 is formed around the channel 501. A corresponding non-common conductive element 80 passes through the channel 501. The top end of the non-common conductive element 80 inside the channel 501 is electrically connected to the bottom conductive layer 70 of the other sub-pixel in the upper pixel layer, and the bottom end is electrically connected to the corresponding first-type electrode contact 101. This means that a sub-pixel 50 in the upper pixel layer can be electrically connected to the corresponding first-type electrode contact 101 through the non-common conductive element 80 penetrating the lower sub-pixel.

[0136] The aforementioned “peripheral light-emitting area” is the area that can emit light after being powered on. To ensure that it emits light normally, the inner wall (side wall) of the peripheral light-emitting area 502 and the non-common conductive component 80 inside the channel are insulated and isolated to avoid the non-common conductive component 80 from directly contacting the inner wall of the peripheral light-emitting area 502, which would cause a short circuit in the peripheral light-emitting area and prevent it from emitting light normally.

[0137] In this design, at least a portion of the light emitted from the peripheral light-emitting area can be emitted through the periphery of the upper sub-pixel connected to the non-common conductive component inside the aperture without being blocked by the upper sub-pixel. This effectively reduces the obstruction of the light-emitting surface of the lower sub-pixel (the sub-pixel area around the aperture is the light-emitting area), increasing the effective light-emitting area of ​​the lower sub-pixel and facilitating the achievement of optimal light distribution. For example... Figure 1 As shown in the figure, the direction of the dashed arrow indicates the light emission direction of the first layer of sub-pixels.

[0138] Furthermore, in this embodiment, two sub-pixels 50 in the mother pixel can share a top conductive layer 60; that is, at least two sub-pixels 50 located in different pixel layers in the mother pixel can share a top conductive layer 60.

[0139] As is understood, in this invention, "upper pixel layer" refers to all pixel layers located above the lowermost pixel layer, while "lower pixel layer" is the pixel layer located below the upper pixel layer. Similarly, "upper sub-pixel" refers to all sub-pixels located above the lowermost sub-pixel, while "lower sub-pixel" is the sub-pixel located below the upper sub-pixel.

[0140] In some implementations, among two sub-pixels located in different pixel layers: the projection area of ​​the upper sub-pixel connected to the non-common conductive element 80 inside the channel 501 on the driving back plate 10 is the first projection area, and the projection area of ​​the peripheral light-emitting area 502 outside the channel on the driving back plate 10 is the second projection area. The first projection area and the second projection area do not overlap at least partially. This method allows at least part of the light emitted from the peripheral light-emitting area to be emitted directly through the periphery of the upper sub-pixel connected to the non-common conductive element inside the channel without being blocked by it. This can effectively reduce the blocking of the light-emitting surface of the lower sub-pixel, increase the effective light-emitting area of ​​the lower sub-pixel, and facilitate the achievement of the best light distribution effect.

[0141] Understandably, the projection of sub-pixel 50 onto the driving backplate 10 refers to the entire area enclosed by the outer edge of the projection.

[0142] The above structure allows the non-common conductive element 80 of the upper sub-pixel to pass through the channel inside at least one lower sub-pixel and be electrically connected to the first type of electrode contact, which can effectively reduce the shading of the light-emitting surface of the lower sub-pixel, increase the effective light-emitting area of ​​the lower sub-pixel, and help achieve the best light distribution effect.

[0143] In addition, it allows at least two sub-pixels to share a single top conductive layer, simplifying the electrical connection structure and making it easier to fabricate;

[0144] Furthermore, the sub-pixel distribution structure described above allows for more flexible design of the light-emitting area of ​​each sub-pixel layer, compensating for the shortcomings of certain sub-pixels being too bright or too dark. For example, by adjusting the size and position of the internal channels of the sub-pixels, the size and position of the peripheral light-emitting area can be flexibly adjusted, thereby achieving adjustment of the light-emitting area and region. This is suitable for different application requirements and makes it easier to adjust the light-emitting area. The structure also facilitates the control of the position of the upper sub-pixels, allowing the upper sub-pixels to be placed at different positions of the lower sub-pixels, thereby controlling the light pattern of the multi-color stacked device to meet the different needs of XR (extended reality) applications.

[0145] The above structure places the upper sub-pixel above the aperture of the lower sub-pixel. Compared to the lower sub-pixel without an aperture, this effectively reduces the obstruction of the light-emitting area of ​​the lower sub-pixel. It also reduces the problem of light blocking and absorption by the metal bonding layer on the lower sub-pixel when the metal bonding layer is placed at the bottom of the upper sub-pixel. This reduces the energy waste of the lower sub-pixel and the phenomenon of the device temperature becoming too high due to energy loss being converted into heat. This effectively increases the light efficiency and reliability of the display device.

[0146] In some implementations, see Figures 1-2 The sub-pixel with the aperture and the upper sub-pixel connected to the non-common conductive element inside the aperture are arranged coaxially (the axes coincide), wherein Figure 1 It can be Figure 2 A sectional view of the middle structure along point AA; or, see [reference]. Figures 3-4 The sub-pixel with the aperture and the upper sub-pixel connected to the non-common conductive component inside the aperture are arranged on opposite axes (the axes do not coincide). Figure 3 It can be Figure 4 A sectional view of the middle structure along point BB. It should be noted that... Figure 2 , Figure 4 In the first pixel layer 20, sub-pixel 50 is denoted as i1, and the first type of electrode contact 101 connected to it is denoted as c1. In the second pixel layer 30, sub-pixel 50 is denoted as i2, and the first type of electrode contact 101 connected to it is denoted as c2.

[0147] In some methods, the projection of the sub-pixel connected to the non-common conductive element inside the aperture on the driving backplate is the first projection area, and the projection area of ​​the sub-pixel with the aperture on the driving backplate is the third projection area. The first projection area can fall completely inside the third projection area. In this case, the area of ​​the first projection area can be smaller than the area of ​​the third projection area. For example, the width (or outer diameter) of the sub-pixel with the aperture along the X direction can be greater than the width (or outer diameter) of the sub-pixel connected to the non-common conductive element inside the aperture along the X direction to better ensure the light emission effect.

[0148] Understandably, the projection of a subpixel onto the driving backplane refers to the entire area enclosed by the outer edge of the projection. For example, the projection of a subpixel with a hole onto the driving backplane refers to the entire area enclosed by the outer edge of the projection, including the hole area.

[0149] When making specific settings, such as Figures 1-4 In the second pixel layer 30, the non-common conductive element 80 of the sub-pixel 50 passes through the sub-pixel 50 in the first pixel layer 20 and is electrically connected to the first type of electrode contact 101. The sub-pixel 50 in the first pixel layer 20 is provided with a channel 501 through which the non-common conductive element 80 passes. (See also...) Figures 1-2 ,in Figure 1 It can be Figure 2 In the cross-sectional view of the structure at AA, the mother pixel has two sub-pixels 50, which are coaxially arranged. At this point, there is at least one first-type electrode contact 101 connected to the first-layer sub-pixel 50; or, see [reference needed]. Figures 3-4 In the second pixel layer 30, the sub-pixels 50 are all set off-axis from the sub-pixels 50 in the first pixel layer 20. At this time, there is no less than one first type of electrode contact 101 connected to the first sub-pixel 50.

[0150] The shape of each sub-pixel 50 is not limited; it can be a circle, ellipse, polygon (triangle, trapezoid, rectangle, etc.) or other shapes.

[0151] In some embodiments, the non-common conductive element 80 inside the channel 501 can penetrate multiple sub-pixels 50 of different pixel layers, and each sub-pixel 50 that is penetrated is provided with a channel 501 through which the corresponding non-common conductive element 80 passes.

[0152] The material of the aforementioned non-common conductive component 80 can be metals such as aluminum (Al), copper (Cu), and tungsten (W) and their corresponding adhesive or barrier layers, such as titanium (Ti), titanium nitride (TiN), tantalum nitride / copper (Ti / Cu), tantalum nitride / copper (TaN / Cu), etc.

[0153] In some implementations, the maximum width (or outer diameter) L1 of the channel along the X direction is greater than or equal to the maximum width (or outer diameter) of the upper sub-pixel connected to the non-common conductive component inside the channel along the X direction. This is to better ensure the light-emitting area of ​​the sub-pixel with the channel, improve the light-emitting effect, and also prevent the light emitted by the lower sub-pixel from being absorbed by the opaque bonding layer of the upper sub-pixel, thus preventing energy loss.

[0154] In some implementations, see Figures 37-38The drive backplate 10 can also be provided with a second type of electrode contact 102, and the polarities of the first type of electrode contact 101 and the second type of electrode contact 102 are opposite. The bottom of each of the multiple sub-pixels 50 in the mother pixel is electrically connected to the corresponding first type of electrode contact 101 through the bottom conductive layer 70, and the top of the multiple sub-pixels 50 is electrically connected to the second type of electrode contact 102 through the top conductive layer 60 to form a top common electrode structure.

[0155] In some embodiments, a first insulating filling area 100 is provided inside the channel 501, and a non-common conductive element 80 inside the channel 501 directly passes through the first insulating filling area 100 and is electrically connected to the first type of electrode contact 101.

[0156] In some embodiments, among two adjacent sub-pixels 50 sharing a top conductive layer 60: the periphery of the upper sub-pixel 50 is provided with a second insulating filling area 110 through which the shared top conductive layer 60 passes.

[0157] The second insulating filling area 110 and the first insulating filling area 100 can be made of the same material.

[0158] In some implementations, the bottom conductive layer 70 at the bottom of the sub-pixel 50 may be a non-metallic conductive layer.

[0159] In some implementations, see Figure 1 The bottom conductive layer 70 at the bottom of the sub-pixel 50 can be a metal bonding layer.

[0160] Furthermore, a metal fence may or may not be provided on the upper part of the metal bonding layer.

[0161] When metal fences are available, they can be installed in the following ways:

[0162] The first type:

[0163] In the sub-pixel 50 with a channel 501: a peripheral light-emitting area 502 is formed in the area surrounding the channel 501. A first inner metal fence 130 is formed inside the channel 501. The first inner metal fence 130 surrounds the non-common conductive element 80 inside the channel 501. A first insulating layer 150 covers the inner wall of the peripheral light-emitting area 502. The first inner metal fence 130 and the inner wall of the peripheral light-emitting area 502 are insulated and isolated by the first insulating layer 150 to avoid direct contact and cause a short circuit inside the peripheral light-emitting area 502.

[0164] Understandably, the inner wall of the peripheral light-emitting area refers to the side wall facing the internal channel, that is, the side wall at its inner peripheral edge. For example, if the peripheral light-emitting area is annular, then the inner wall of the peripheral light-emitting area refers to the inner wall of the annular shape.

[0165] Preferably, the first inner metal fence 130 can be in the form of a ring. In some other cases, it can also be in the form of an arc.

[0166] For example, the first insulating layer 150 may be made of one or more materials selected from silicon oxide, aluminum oxide, silicon nitride, titanium oxide, hafnium oxide, tantalum oxide, niobium oxide, aluminum nitride, or gallium nitride;

[0167] In some designs, the thickness of the first insulating layer 150 can be 5 nm to 2 μm.

[0168] Further, see Figure 31 The metal bonding layer at the bottom of the sub-pixel 50 with the aperture 501 and the first inner metal fence 130 are integrally formed. The metal bonding layer will sputter to form the metal fence during the etching process, thereby achieving integral forming.

[0169] Or, see Figure 32 The metal bonding layer at the bottom of the sub-pixel 50 with the aperture 501 and the first inner metal fence 130 are separately set and insulated from each other; at this time, the first inner metal fence 130 can be fabricated separately to act as a metal reflector, so that the light shining into the aperture 501 can be reflected back through the first inner metal fence 130, thereby better reducing the light loss of the outer light-emitting area 502.

[0170] When the metal bonding layer at the bottom of the sub-pixel 50 with the aperture 501 and the first inner metal fence 130 are separately set, the following preparation method can be adopted: First, a first insulating layer 150 is deposited on the surface of the sub-pixel 50, so that the first insulating layer 150 covers the outer wall and top surface of the peripheral light-emitting area 502 and the inner wall and bottom surface of the aperture 501; then, a metal reflective material is deposited on the outer wall of the first insulating layer 150, and then an etching process is performed to obtain the first inner metal fence 130. The first inner metal fence 130 and the metal bonding layer at its bottom are insulated and isolated by the first insulating layer 150, and the first inner metal fence 130 and the peripheral light-emitting area 502 are also insulated and isolated by the first insulating layer 150.

[0171] The second type:

[0172] At least one sub-pixel 50 is surrounded by a first peripheral metal fence 140, and the first peripheral metal fence 140 and the outer sidewall of the surrounded sub-pixel 50 are insulated from each other.

[0173] Understandably, the outer wall of a subpixel refers to the sidewall at the outer perimeter of the subpixel. For example, if a hole is opened inside the subpixel, making the subpixel ring-shaped, then the outer wall of the subpixel refers to the outer wall of the ring.

[0174] Preferably, the aforementioned first outer metal fence 140 can be in the form of a ring structure. In some other embodiments, it can also be in the form of an arc.

[0175] Furthermore, the outer wall of the sub-pixel 50 surrounded by the first peripheral metal fence 140 is covered with a first insulating layer 150, and the first peripheral metal fence 140 and the surrounding sub-pixel 50 are insulated and isolated from each other by the first insulating layer 150.

[0176] In this embodiment, the metal bonding layer at the bottom of the sub-pixel 50 and the first peripheral metal fence 140 are integrally formed. The metal bonding layer will sputter to form the metal fence during the etching process, thereby achieving integral forming; or, the metal bonding layer at the bottom of the sub-pixel 50 and the first peripheral metal fence 140 are separately set and mutually insulated; the preparation method is basically the same as that of the first inner metal fence 130.

[0177] The aforementioned first outer metal fence 140 can be set around the sub-pixel 50 with the aperture 501, or it can be set around the sub-pixel 50 without the aperture 501.

[0178] When the upper sub-pixel 50 and the adjacent lower sub-pixel 50 share a top conductive layer 60, see [reference] Figure 1 To achieve insulation between the first outer metal fence 140 and the top conductive layer 60 of the upper sub-pixel 50, a second insulating layer 160 can be provided between the first outer metal fence 140 and the top conductive layer 60; the material of the second insulating layer 160 can be the same as that of the first insulating layer 150.

[0179] Understandably, a sub-pixel 50 with a hole 501 can simultaneously have a first inner metal fence 130 and a first outer metal fence 140.

[0180] In some implementations, when there is no metal bonding layer at the bottom of the sub-pixel, the aforementioned first inner metal fence 130 and first outer metal fence 140 may also be provided.

[0181] In some of these implementations, see Figure 19 The top of sub-pixel 50 is provided with a top ohmic contact layer 170, and the top of each sub-pixel 50 is in contact with the corresponding top conductive layer 60 through the top ohmic contact layer 170.

[0182] The aforementioned top ohmic contact layer 170 can also be used as an etching barrier layer 230.

[0183] In some implementations, at least two sub-pixels in a mother pixel located in different pixel layers emit different colors. For example, in a two-layer structure with two pixel layers, the sub-pixels in each pixel layer may emit the same color, while the sub-pixels in different pixel layers emit different colors. Alternatively, one pixel layer may have two sub-pixels with different emission colors, while another pixel layer may have a sub-pixel whose emission color is different from that of at least one sub-pixel in the first layer.

[0184] For example, in some implementations, the sub-pixels 50 in different pixel layers of a multi-layer stacked structure emit different colors to achieve a color configuration.

[0185] For example, in the two-layer structure, the sub-pixels 50 in the first pixel layer 20 and the second pixel layer 30 emit different colors to achieve a dual-color configuration. For instance, the emission colors of each sub-pixel 50 from bottom to top are red and green, or they could be red and blue, or green and blue, etc.

[0186] In this embodiment, each sub-pixel 50 can be made of inorganic compound semiconductor material.

[0187] In some implementations, see Figures 7-8 A lens 250 is provided above the topmost sub-pixel 50, and the lens 250 covers at least one sub-pixel 50.

[0188] Furthermore, the outer surface of lens 250 is curved, see reference. Figure 7 The bottom of the outer surface of lens 250 is in direct contact with the top conductive layer 60 of the uppermost sub-pixel 50.

[0189] Or, see Figure 8 The bottom of the outer surface of lens 250 is connected to the top conductive layer 60 of the uppermost sub-pixel 50 through an insulating medium at bb.

[0190] In this embodiment, both the first insulating filling area 100 and the second insulating filling area 110 can be made of transparent filling material.

[0191] The following explanation uses a mother pixel structure with two sub-pixels of 50 as an example. Figure 1 The method for fabricating the display device shown includes the following steps:

[0192] Step S1: Provide a drive backplate 10, on which first type of electrode contacts 101 are provided;

[0193] And a compound semiconductor layer is selected as the pixel layer. The aforementioned compound semiconductor layer is a layer with a certain thickness prepared using compound semiconductor materials; for example, the compound semiconductor layer here includes an N-type semiconductor layer, an active layer and a P-type semiconductor layer arranged sequentially from top to bottom.

[0194] Step S2: Stack two pixel layers from bottom to top on the driving backplane 10. When stacking each pixel layer, etch the pixel layer to obtain sub-pixels 50, so that each parent pixel includes two sub-pixels 50, and the two sub-pixels 50 are located in different pixel layers. It can be understood that each sub-pixel 50 obtained by etching includes an N-type semiconductor layer, an active layer and a P-type semiconductor layer arranged from top to bottom.

[0195] This ensures that the bottom of each of the multiple sub-pixels 50 in the mother pixel is electrically connected to the corresponding first type electrode contact 101 through the bottom conductive layer 70, and the tops of the multiple sub-pixels 50 are interconnected through the top conductive layer 60 to form a top common electrode structure.

[0196] Furthermore, at least two sub-pixels 50 in the mother pixel share a top conductive layer 60, and the sub-pixels 50 sharing a top conductive layer 60 are located in different pixel layers.

[0197] In this configuration, one of the sub-pixels 50 located in different pixel layers has an opening 501 inside, and a peripheral light-emitting area 502 is formed around the opening 501. A non-common conductive element 80 passes through the opening 501. The top end of the non-common conductive element 80 inside the opening 501 is electrically connected to the bottom conductive layer 70 of the other sub-pixel 50 in the upper pixel layer, and the bottom end is electrically connected to the corresponding first type electrode contact 101. At least part of the light emitted from the peripheral light-emitting area 502 is emitted through the periphery of the upper sub-pixel electrically connected to the non-common conductive element 80 inside the opening 501.

[0198] Step S2, which involves stacking two pixel layers sequentially from bottom to top (Z direction) on the driving backplane 10, may specifically include the following steps:

[0199] Step S201: Refer to Figure 15 The first pixel layer 20 is stacked along the Z direction on the driving backplate 10;

[0200] The first pixel layer 20 has a bottom conductive layer 70 at its bottom. This conductive layer is a metal bonding layer. The first pixel layer 20 and the driving backplate 10 are connected by bonding through the bottom conductive layer 70 to achieve stacking. The bonding method can be thermo-press bonding.

[0201] For example, the aforementioned metal bonding layer can be a combination of metal materials, such as nickel (Ni), tin (Sn), gold (Au), copper (Cu), aluminum (Al), indium tin oxide (ITO), etc. For example, the metal bonding layer can be one or more of the following combinations: Ni and Sn, Au and Sn, Cu and Sn, Au and In, Au and Au, Al and Al, Cu and Cu, or ITO and ITO. The metal bonding layer and the driving backplate 10 may also include an adhesive layer (made of Cr, Ti, Ni, etc.) and a depletion barrier layer (made of Ni, Pt, Cu, etc.). The metal bonding layer on the pixel layer and the driving backplate 10 can be symmetrical or asymmetrical.

[0202] In some preferred embodiments, the aforementioned metal bonding layer can be a multilayer structure stacked sequentially along the height direction, with the layers from bottom to top being a Cr layer (adhesion layer), a Pt layer (barrier depletion layer), an Au layer, a Sn layer, and an Au layer, with thicknesses of 10 nm, 50 nm, 100 nm, 150 nm, and 50 nm, respectively.

[0203] In some designs, a bottom ohmic contact layer 180 is also provided at the bottom of the first pixel layer 20, which is made of a conductive material.

[0204] For example, the bottom ohmic contact layer 180 can be one or more of transparent conductive films such as indium tin oxide (ITO), indium zinc oxide (IZO), indium gallium tin oxide (IGZO), and aluminum-doped zinc oxide (AZO), or one or more of conductive metal materials such as nickel (Ni), chromium (Cr), gold (Au), silver (Ag), zinc (Zn), rhodium (Rh), beryllium (Be), and aluminum (Al), or a composite structure composed of transparent metal oxides and metals; the thickness of the bottom ohmic contact layer 180 is in the range of 1 nm to 500 nm.

[0205] Step S202: See Figure 16 In stage b1, the current pixel layer (compound semiconductor layer) is etched to obtain sub-pixel 50, so as to achieve the independence of sub-pixel 50. It can be understood that the etched sub-pixel 50 includes an N-type semiconductor layer, an active layer and a P-type semiconductor layer arranged sequentially from top to bottom; the thickness of sub-pixel 50 (the distance between the upper surface of the N-type semiconductor layer and the lower surface of the P-type semiconductor layer) is 0.1um to 5um; the width of sub-pixel 50 (X direction) is 0.2um to 80um.

[0206] For example, the angle α of the etched sub-pixel 50 can be 90°±45°, and preferably, the angle α of the sub-pixel 50 can be 90°±20°. Wherein, the angle α of the sub-pixel 50 is the maximum angle between the sidewall of the sub-pixel 50 and the upper surface of the driving backplate 10.

[0207] The above etching process can be carried out using dry etching methods such as ICP and RIE, or wet etching methods such as KOH and HCl.

[0208] Each mother pixel has two sub-pixels 50, and the two sub-pixels 50 are located in different pixel layers.

[0209] In some embodiments, an etching barrier layer 230 is provided at the top of the pixel layer before etching, serving as an etching mask. The etching barrier layer 230 can be a transparent material. It can be an insulating dielectric or a light-transmitting conductive layer material.

[0210] When etching the pixel layer (compound semiconductor layer) to obtain the sub-pixel 50, the corresponding sub-pixel 50 is also subjected to an opening process, so that a channel 501 is formed inside the sub-pixel 50.

[0211] When making a hole, you can do it like this: Figure 16 In stage b1, the bottom of channel 501 can be etched down to the bottom ohmic contact layer 180, or... Figure 17 As shown, etching is first performed up to the P-type semiconductor layer at the bottom of the compound semiconductor layer to keep the semiconductor layer continuous. The etching depth can then be increased until the lower surface of the metal bonding layer is etched.

[0212] Step S203: See Figure 16 In the middle b2 stage, a first insulating layer 150 is deposited on the surface of the current pixel layer, so that the first insulating layer 150 covers the top surface, outer wall and inner wall of the channel 501 of the sub-pixel 50. Then, etching is performed on the periphery of the sub-pixel 50 and inside the channel 501, etching down to the lower surface of the metal bonding layer, so that the first type of electrode contact 101 is exposed inside the channel 501.

[0213] For example, the first insulating layer 150 may be made of one or more materials selected from silicon oxide, aluminum oxide, silicon nitride, titanium oxide, hafnium oxide, tantalum oxide, niobium oxide, aluminum nitride, or gallium nitride;

[0214] In some designs, the thickness of the first insulating layer 150 can be 5 nm to 2 μm.

[0215] During the etching process of the metal bonding layer, a metal fence is sputtered onto the top of the metal bonding layer, at which point the metal fence and the metal bonding layer are integrally formed (see...). Figure 31For example, a first inner metal fence 130 is formed inside the channel 501, and a first outer metal fence 140 is formed around the sub-pixel 50.

[0216] The aforementioned metal fence can also be removed (see...) Figure 30 ).

[0217] In other options, see Figures 32-33 Alternatively, a metal fence can be fabricated separately on the upper part of the metal bonding layer to act as a metal reflector. During fabrication, after depositing the first insulating layer 150, a metal reflective material is deposited, followed by etching to obtain the first inner metal fence 130 and the first outer metal fence 140. The first inner metal fence 130 and the first outer metal fence 140 are insulated from the metal bonding layer at their bottom ends by the first insulating layer 150. The first inner metal fence 130 is also insulated from the inner wall of the outer light-emitting area 502 by the first insulating layer 150, and the first outer metal fence 140 is also insulated from the outer wall of the outer light-emitting area 502 by the first insulating layer 150.

[0218] Step S204: See Figure 16 In the middle b3 stage, insulating material is filled around the sub-pixel 50 with aperture treatment and inside the aperture 501, thereby forming a first insulating filling area 100 inside the aperture 501 and a second insulating filling area 110 around the sub-pixel 50.

[0219] For example, the filling material used in the first insulating filling region 100 and the second insulating filling region 110 may be one or more of silicon oxide, silicon nitride, silicon carbide (SiC), silicon carbon nitride (SiCN), silicon phosphosilicate glass (PSG), borosilicate glass (BPSG) or polyimide.

[0220] Understandably, after insulation filling, the height of the first insulation filling area 100 and the second insulation filling area 110 can be higher than the top of the sub-pixel 50, or flush with the top of the sub-pixel 50, or if the top of the sub-pixel 50 has an etch stop layer 230, it can also be flush with the etch stop layer 230 (see...). Figure 18 ).

[0221] Then, the non-common conductive element 80 is prepared: a hole is made in the first insulating filling area 100 inside the channel 501 and backfilled with metal material to form the non-common conductive element 80, so that the non-common conductive element 80 directly passes through the first insulating filling area 100 and is electrically connected to the first type of electrode contact 101.

[0222] Step S205: See Figure 16 In the middle b4 stage, a second pixel layer 30 is stacked on top of the first pixel layer 20;

[0223] First, repeat steps S202-S203 to complete the fabrication of sub-pixel 50 and the deposition of the first insulating layer 150. Then, the electrode connection at the top of sub-pixel 50 can be performed: See [link / reference]. Figure 16 In the middle b5 stage, the tops of sub-pixels 50 in the second pixel layer 30 and sub-pixels 50 in the first pixel layer 20 are exposed. Then, a top conductive layer 60 is deposited or plated so that the tops of sub-pixels 50 in the second pixel layer 30 and sub-pixels 50 in the first pixel layer 20 are in contact with the top conductive layer 60 to achieve electrical connection. In the structure prepared at this time, sub-pixels 50 in the second pixel layer 30 and sub-pixels 50 in the first pixel layer 20 share a top conductive layer 60.

[0224] Understandably, to expose the top of sub-pixel 50 in the second pixel layer 30 and the top of sub-pixel 50 in the first pixel layer 20, the excess material at the top of the sub-pixel can be removed by etching.

[0225] For example, the top conductive layer 60 is a transparent conductive layer to facilitate light transmission, allowing light emitted from the lower sub-pixel 50 to pass through the top conductive layer 60 and shine upwards. This transparent conductive layer can be one or more combinations of indium tin oxide (ITO), indium zinc oxide (IZO), aluminum-doped zinc oxide (AZO), Al-doped indium tin oxide, Ag-doped indium tin oxide, and Au-doped indium tin oxide.

[0226] When fabricating sub-pixel 50, if an etch barrier layer 230 is provided at the top of sub-pixel 50, and a top ohmic contact layer 170 is provided between the etch barrier layer 230 and the top of sub-pixel 50, and the etch barrier layer 230 is a transparent conductive layer material, then during electrical connection, the etch barrier layer 230 at the top of sub-pixel 50 can be exposed, allowing the exposed area of ​​the etch barrier layer 230 to contact the top conductive layer 60 to achieve electrical connection (see...). Figure 18 Alternatively, the top ohmic contact layer 170 at the top of the sub-pixel 50 can be exposed, allowing the exposed area of ​​the top ohmic contact layer 170 to contact the top conductive layer 60 to achieve electrical connection (see [reference]). Figure 19 );

[0227] When preparing sub-pixels 50 in the second pixel layer 30, after repeating steps S202-S203, refer to... Figures 28-29 First, an insulating material can be filled around the sub-pixel 50 in the second pixel layer 30 to form a second insulating filling area 110. Then, the top conductive layer 60 can be prepared. At this time, holes need to be made in the second insulating filling area 110 of the second pixel layer 30 so that the top conductive layer 60 can contact the top of the sub-pixel 50 in the first pixel layer 20.

[0228] When preparing sub-pixels 50 in the second pixel layer 30, refer to... Figure 1 To achieve insulation between the first peripheral metal fence 140 of the sub-pixel 50 and the sidewall of the top conductive layer 60 in the second pixel layer 30, a second insulating layer 160 can be provided between the first peripheral metal fence 140 and the sidewall of the top conductive layer 60; the material of the second insulating layer 160 can be the same as that of the first insulating layer 150.

[0229] In some embodiments, the thickness of the second insulating layer 160 is 5 nm to 2 μm.

[0230] After completing step S205, lens 250 can be prepared.

[0231] The lens 250 mentioned above is made of insulating material and can be made of materials such as silicon oxide, silicon nitride, aluminum oxide, silicate glass, silicone, electron beam photoresist (PMMA, SU8, etc.).

[0232] During the fabrication of lens 250, an insulating dielectric layer can be backfilled on the upper part of the second pixel layer 30, and the backfilled dielectric layer can be patterned and etched to form lens 250.

[0233] Alternatively, the lens 250 can be prepared by filling with an insulating dielectric material, planarizing it (CMP process), and then patterning it with a coating.

[0234] The LED display device of this embodiment simplifies the electrical connection structure, making it easier to manufacture. It can flexibly adjust the light-emitting area and position of the sub-pixels, which helps to reduce the shading of the light-emitting surface of the lower sub-pixels, increases the effective light-emitting area of ​​the lower sub-pixels, and helps to achieve the best light distribution effect, so that its light pattern meets the needs of different application scenarios. At the same time, it also effectively improves the luminous efficiency and reliability of the display device.

[0235] Example 2

[0236] like Figures 9-14 As shown, the main difference between this embodiment and Embodiment 1 is that the micro-display device in this embodiment has three pixel layers. All pixel layers are stacked sequentially from bottom to top above the driving backplane. At this time, the structure is a three-layer structure. The mother pixel has three sub-pixels 50, which are located in different pixel layers. The three pixel layers from bottom to top are the first pixel layer 20, the second pixel layer 30, and the third pixel layer 40.

[0237] The bottom of each of the three sub-pixels 50 is electrically connected to the corresponding first type electrode contact 101 through the bottom conductive layer 70, and the top of the three sub-pixels is electrically connected to the second type electrode contact 102 through the top conductive layer 60 to form a top common electrode structure.

[0238] In this process, at least two sub-pixels 50 in the mother pixel share a top conductive layer 60, and the sub-pixels 50 that share a top conductive layer 60 are located in different pixel layers.

[0239] In two sub-pixels 50 located in different pixel layers, a channel 501 is formed inside one of the sub-pixels 50 in the lower pixel layer, and an outer light-emitting area 502 is formed around the channel 501. A non-common conductive element 80 passes through the channel 501. The top end of the non-common conductive element 80 inside the channel 501 is electrically connected to the bottom conductive layer of the other sub-pixel 50 in the upper pixel layer, and the bottom end is electrically connected to the corresponding first type of electrode contact.

[0240] The light emitted from the peripheral light-emitting area 502 is at least partially emitted from the periphery of the upper sub-pixel 50 electrically connected to the non-common conductive element inside the aperture 501.

[0241] In some implementations, at least one sub-pixel 50 in the mother pixel has a separate top conductive layer 60 at its top, which is not shared with other sub-pixels 50 in different pixel layers.

[0242] Specifically, the three sub-pixels 50 in the parent pixel can be located in different pixel layers. Only two of these three sub-pixels share a single top conductive layer 60, while the other sub-pixel in a different pixel layer has its own top conductive layer 60 (see the pixel layer structure with a separate top conductive layer 60 for details). Figures 20-24 );

[0243] For example, a separate top conductive layer 60 can be provided at the top of the sub-pixel 50 in the first pixel layer 20 (see [reference]). Figures 20-24 The sub-pixels 50 in the second pixel layer 30 and the third pixel layer 40 share a top conductive layer 60. The two top conductive layers 60 do not share a common layer and can be interconnected through a common conductive element 90.

[0244] The method for fabricating a top conductive layer 60 separately disposed at the top of the sub-pixel 50 in the first pixel layer 20 includes: etching the sub-pixel in the first pixel layer 20, then backfilling the current pixel layer with an insulating medium, and after backfilling, planarizing the top of the first pixel layer 20 to expose the top of the sub-pixel in the pixel layer, and then depositing the top conductive layer 60 to make it contact the exposed area of ​​the top of the sub-pixel to achieve electrical connection, and then depositing an insulating medium on the top of the pixel layer and planarizing it again, and then stacking the upper pixel layer.

[0245] The above method also allows the top conductive layer of a sub-pixel to be located substantially at the top of the sub-pixel when it is set with a separate top conductive layer.

[0246] To enhance current conduction capability, refer to Figure 21 A metal reinforcement 190 can be provided on the top conductive layer 60 at the top of the sub-pixel 50 in the first pixel layer 20.

[0247] Furthermore, the top of the sub-pixel 50 in the first pixel layer 20 can be fully exposed, and the exposed area can be made in contact with the top conductive layer 60 to achieve electrical connection; or, see [reference needed]. Figure 24 This allows the top and part of the sidewalls of the sub-pixel 50 in the first pixel layer 20 to be exposed, and the exposed area to contact the top conductive layer 60 to achieve electrical connection, thereby increasing the current transmission capability and reducing the power consumption of the device.

[0248] When preparing the first pixel layer 20 using the above method, please refer to [reference needed]. Figures 22-23 Furthermore, an interconnecting conductive part 901 can be provided at the top conductive layer 60 at the top of the sub-pixel 50 to serve as an interconnection function for common conductive components, so that two adjacent top conductive layers 60 are interconnected through the interconnecting conductive part 901 to achieve electrical connection.

[0249] In this embodiment, a top conductive layer 60 is in direct contact with the electrically connected interconnect conductive part 901 to achieve electrical connection;

[0250] Alternatively, to enhance current conduction, a top conductive layer 60 can be electrically connected to the interconnecting conductive portion 901 via a metal reinforcement 190. In other embodiments, a separate top conductive layer 60 can be provided at the top of the sub-pixel 50 in the third pixel layer 40, while the sub-pixels 50 in the first pixel layer 20 and the second pixel layer 30 share a single top conductive layer 60, and the two top conductive layers 60 can be interconnected via a common conductive member 90.

[0251] In some implementations, see Figure 9 This allows all three sub-pixels 50 in the mother pixel to share a single top conductive layer 60. The fabrication method of this display device is roughly the same as that of the display device in Embodiment 1, except that the fabrication method of the first pixel layer 20 needs to be repeated when fabricating the second pixel layer 30, which will not be described in detail here.

[0252] Understandably, in the three-layer structure, the non-common conductive component 80 of the third sub-pixel 50 is divided into two segments, one segment is located in the second pixel layer 30, and the other segment is located in the first pixel layer 20. These two segments are prepared in two separate processes, with each end being obtained by opening a hole in the corresponding pixel layer and backfilling it with metal.

[0253] A lens 250 can also be placed above the third pixel layer 40; see reference for details. Figure 11 .

[0254] In some embodiments, the sub-pixel 50 with the aperture and any upper sub-pixel 50 connected to the non-common conductive element inside the aperture are coaxially arranged; or, the sub-pixel 50 with the aperture and at least one upper sub-pixel 50 connected to the non-common conductive element inside the aperture are off-axis arranged.

[0255] For example, the mother pixel has three sub-pixels 50, see [reference] Figures 9-10 The bottommost sub-pixel has a hole. This sub-pixel is coaxially aligned with the sub-pixels of the second layer and also with the sub-pixels of the third layer, meaning that all three sub-pixels are coaxially aligned; or refer to... Figures 12-14 In the second pixel layer 30 and the third pixel layer 40, sub-pixels 50 are both set on opposite axes to sub-pixels 50 in the first pixel layer 20. Figure 12 It can be Figure 13 The diagram shows a cross-sectional view of the structure at point FF. It should be noted that... Figure 10 , Figure 13 and Figure 14 In the first pixel layer 20, sub-pixel 50 is denoted as i1, and the connected first-type electrode contact 101 is denoted as c1. In the second pixel layer 30, sub-pixel 50 is denoted as i2, and the connected first-type electrode contact 101 is denoted as c2. In the third pixel layer 40, sub-pixel 50 is denoted as i3, and the connected first-type electrode contact 101 is denoted as c3. The shape of sub-pixel 50 is not limited; for example... Figure 13 and Figure 14 The shapes of the first layer sub-pixels 50 are different; one is circular and the other is square.

[0256] In some methods, the non-common conductive element inside the channel can penetrate only a sub-pixel in a single pixel layer, or it can penetrate multiple sub-pixels in different pixel layers.

[0257] For example, when making specific settings, refer to Figures 9-10 The non-common conductive element 80 of the sub-pixel 50 in the third pixel layer 40 passes through the sub-pixels 50 in the second pixel layer 30 and the first pixel layer 20 and is electrically connected to the first type of electrode contact 101. The sub-pixels 50 in the second pixel layer 30 and the first pixel layer 20 are provided with a channel 501 for the non-common conductive element 80 to pass through. That is, the non-common conductive element 80 of the upper sub-pixel not only passes through the lowermost sub-pixel, but also passes through at least one sub-pixel between the lowermost sub-pixel and the uppermost sub-pixel.

[0258] Or, see Figures 12-14 The non-common conductive element 80 of the sub-pixel 50 in the third pixel layer 40 only penetrates the sub-pixel 50 in the first pixel layer 20, but not the sub-pixel 50 in the second pixel layer 30. The non-common conductive element 80 of the sub-pixel 50 in the second pixel layer 30 only penetrates the sub-pixel 50 in the first pixel layer 20. Each sub-pixel 50 in the first pixel layer 20 is provided with a channel 501 for the non-common conductive element 80 to pass through. This means that the non-common conductive element 80 of the upper sub-pixel only penetrates the lowermost sub-pixel, but not the other sub-pixels in the middle layer.

[0259] Alternatively, the non-common conductive element 80 of the sub-pixel 50 in the third pixel layer 40 can penetrate only the sub-pixel 50 in the second pixel layer 30, but not the sub-pixel 50 in the first pixel layer 20. Instead, it can penetrate the sub-pixel 50 in the second layer, then penetrate the outer region of the corresponding sub-pixel in the first layer, and finally connect to the corresponding first type of electrode contact 101.

[0260] The shape of each sub-pixel is not limited; it can be a circle, trapezoid, rectangle, or other shapes.

[0261] In some implementations, at least two subpixels located in different pixel layers emit different colors.

[0262] For example, in a three-layer structure, the sub-pixels 50 in the first pixel layer 20, the second pixel layer 30, and the third pixel layer 40 emit different colors to achieve a three-color configuration. For example, the emission colors of each sub-pixel from bottom to top are red, green, and blue, respectively.

[0263] Example 3

[0264] See Figure 27 In this embodiment, the top of the sub-pixels located in different pixel layers within the mother pixel can be provided with a separate top conductive layer 60 instead of sharing one (see the pixel layer structure with a separate top conductive layer 60). Figures 20-24 );

[0265] That is, the top of each sub-pixel in different pixel layers of the mother pixel is set with a separate top conductive layer 60 instead of sharing it, and they can be interconnected with each other through a common conductive component.

[0266] Furthermore, the top conductive layer (the top conductive layer electrically connected to the sub-pixel in the same pixel layer) is located above the corresponding sub-pixel in the electrically connected pixel layer. Here, "above" means located approximately near the top of the sub-pixel. The sub-pixel includes a P-type semiconductor layer, an active layer, and an N-type semiconductor layer arranged sequentially along the Z-direction. Therefore, "above" can be understood as ensuring that the lowest point of the top conductive layer is higher than the upper surface of the active layer in the sub-pixel. For example, see [reference needed]. Figure 20 In the first pixel layer, the entire top conductive layer 60 of the sub-pixel is located above the sub-pixel 50, or, see [link to relevant documentation]. Figure 24 In the first pixel layer, the top conductive layer 60 of the sub-pixel is basically located above the sub-pixel 50, with only the top conductive layer area on the outer periphery of the sub-pixel sidewall being slightly lower.

[0267] For example, see Figure 27 In a two-layer structure with two pixel layers, a top conductive layer 60 can be separately provided at the top of the sub-pixel 50 in the first pixel layer 20 (see [reference]). Figures 20-24 In the second pixel layer 30, a separate top conductive layer 60 is also provided at the top of the sub-pixel 50. The two top conductive layers 60 can be interconnected by an interconnecting conductive part 901, which is part of the common conductive part 90.

[0268] or;

[0269] In a three-layer structure with three pixel layers, a top conductive layer 60 can be separately provided at the top of the sub-pixel 50 in the first pixel layer 20 (see [reference]). Figures 20-24 In the second pixel layer 30 and the third pixel layer 40, each of the sub-pixels 50 is also provided with a separate top conductive layer 60, and the three top conductive layers 60 can be interconnected through a common conductive element 90.

[0270] The method for fabricating a separate top conductive layer 60 at the top of sub-pixel 50 in the first pixel layer includes: etching sub-pixels in the first pixel layer 20, then backfilling the current pixel layer with an insulating medium, planarizing the top of the first pixel layer to expose the top of the sub-pixel, and then depositing the top conductive layer 60 to make it contact the exposed area of ​​the sub-pixel top for electrical connection. Then, an insulating medium can be deposited again on top of the pixel layer and planarized again. Then, the upper pixel layer is stacked. The upper pixel layer can also have its top conductive layer 60 fabricated separately using the same method, i.e., after etching sub-pixels, insulating medium is backfilled, and after backfilling, planarization is performed on the top of the pixel layer to expose the top of the sub-pixel, and then the top conductive layer 60 is deposited to achieve electrical connection. In this process, the insulating medium can be entirely transparent.

[0271] The above-described preparation method also ensures that in a sub-pixel with a separate top conductive layer, the top conductive layer of the sub-pixel is basically located at the top of the sub-pixel.

[0272] In this embodiment, the sub-pixel 50 with the aperture and any sub-pixel 50 above it connected to the non-common conductive element inside the aperture are arranged coaxially; or, the sub-pixel 50 with the aperture and at least one sub-pixel 50 above it connected to the non-common conductive element inside the aperture are arranged off-axis.

[0273] In this embodiment, the structure and arrangement of each sub-pixel can adopt the corresponding forms in Embodiment 1 and Embodiment 2, which will not be repeated here.

[0274] Example 4

[0275] In this embodiment, the non-common conductive element 80 passes through the inside of the channel 501. The top end of the non-common conductive element 80 inside the channel 501 is electrically connected to the bottom conductive layer 70 of another sub-pixel 50 in the upper pixel layer, and the bottom end is electrically connected to the corresponding first type electrode contact 101.

[0276] For example, the bottom corresponding sub-pixel can have a channel 501 inside, and the bottom conductive layer 70 of the upper corresponding sub-pixel can be electrically connected to the corresponding first type electrode contact 101 through a non-common conductive member 80. The non-common conductive member 80 passes through the corresponding channel 501 and is electrically connected to the first type electrode contact 101.

[0277] The non-common conductive component 80 can be penetrated in the following ways:

[0278] The first type: such as Figure 1 As shown, a first insulating filling area 100 is provided inside the channel 501, and the non-common conductive element 80 directly passes through the first insulating filling area 100 and is electrically connected to the first type of electrode contact 101.

[0279] When the first structure described above is prepared, the following preparation method can be used: fill the inside of the channel 501 with insulating material to form a first insulating filling area 100, so that the non-common conductive element 80 directly passes through the first insulating filling area 100 and is electrically connected to the first type of electrode contact 101.

[0280] For example, the filling material used in the first insulating filling region 100 may be one or more of silicon oxide, silicon nitride, silicon carbide (SiC), silicon carbon nitride (SiCN), silicon phosphosilicate glass (PSG), borosilicate glass (BPSG), or polyimide.

[0281] The second type: such as Figures 5-6As shown, a compound semiconductor region 120 is disposed inside the channel 501, and a non-common conductive element 80 passes through the compound semiconductor region 120 and is electrically connected to the first type of electrode contact 101. This method can retain more compound semiconductor material, and compound semiconductor material has good thermal conductivity, which is beneficial to improving the heat dissipation effect of the overall device.

[0282] Understandably, the compound semiconductor region 120 penetrated by the non-common conductive element 80 does not emit light when energized.

[0283] Furthermore, the hole wall of the channel 501 and the internal compound semiconductor region 120 are insulated from each other. For example, insulating material can be filled between the hole wall of the channel 501 and the internal compound semiconductor region 120.

[0284] Furthermore, a metal bonding layer is provided at the bottom of the compound semiconductor region 120. After the non-common conductive component 80 passes through the compound semiconductor region 120, it contacts the first type of electrode contact 101 through the corresponding metal bonding layer to achieve electrical connection.

[0285] Understandably, when the bottom of the compound semiconductor region 120 has a metal bonding layer, a second inner metal fence 240 can be formed on the upper part of the metal bonding layer, and the second inner metal fence 240 is on the periphery of the compound semiconductor region.

[0286] Preferably, the second inner metal fence 240 can be in the form of a ring structure.

[0287] In some embodiments, the compound semiconductor region 120 inside the channel 501 is located inside the first inner metal enclosure 130.

[0288] Furthermore, the second inner metal fence 240 inside the channel 501 is located inside the first inner metal fence 130.

[0289] The second structure described above can be prepared by the following method: a portion of the compound semiconductor material is retained inside the channel 501 to form a compound semiconductor region 120, so that the non-common conductive element 80 passes through the compound semiconductor region 120 and is electrically connected to the first type of electrode contact 101.

[0290] Example 5

[0291] like Figures 34-36 As shown, the main difference between this embodiment and Embodiment 1 is that an air gap is provided in the pixel layer, which is divided into an outer air gap 210 and an inner air gap 220.

[0292] The above-mentioned air gaps can be set in the following ways:

[0293] The first type: such as Figure 34As shown, at least one sub-pixel 50 is surrounded by a peripheral air gap 210. In some preferred embodiments, the peripheral air gap 210 may be annular, such as a circular ring, a square ring, etc., and the specific shape is not limited.

[0294] In some schemes, the sub-pixel 50 with the peripheral air gap 210 is further provided with a first peripheral metal fence 140, and the peripheral air gap 210 is provided between the first peripheral metal fence 140 and the outer wall of the sub-pixel 50.

[0295] In one embodiment, at least one sub-pixel 50 is surrounded by a partition wall 260, which is a compound semiconductor, and an outer air gap 210 is formed between the partition wall 260 and the surrounding sub-pixel 50.

[0296] For example, such as Figure 34 As shown, if the sub-pixel 50 with an outer air gap 210 is further surrounded by a first outer metal fence 140, the partition wall 260 is located inside the first outer metal fence 140.

[0297] In one embodiment, a second insulating filling area 110 is provided around the sub-pixel 50 which is surrounded by an outer air gap 210, and the outer air gap 210 is formed inside the second insulating filling area 110.

[0298] For example, such as Figure 35 As shown, if the sub-pixel 50 with the outer air gap 210 is further surrounded by a first outer metal fence 140, the outer air gap 210 is located inside the first outer metal fence 140.

[0299] The second type: such as Figure 36 As shown, an inner air gap 220 is provided inside the channel 501, and the inner air gap 220 surrounds the periphery of the non-common conductive element 80 inside the channel 501. In some preferred embodiments, the inner air gap 220 may be annular.

[0300] In some embodiments, a first insulating filling region 100 is provided inside the channel 501, and an inner air gap 220 is formed inside the first insulating filling region 100.

[0301] In some ways, such as Figure 6 As shown, a compound semiconductor region 120 is disposed inside the channel 501. A non-common conductive element 80 passes through the compound semiconductor region 120 and is electrically connected to the first type of electrode contact 101. An inner air gap 220 surrounds the periphery of the compound semiconductor region 120. It can be understood that if the periphery of the compound semiconductor region 120 has a first insulating filling region 100, the inner air gap 220 can be formed inside the first insulating filling region 100.

[0302] In some schemes, in the sub-pixel 50 with aperture 501: the area located around the aperture 501 forms an outer light-emitting area 502, and a first inner metal fence 130 is formed inside the aperture 501, which surrounds the non-common conductive element 80 inside the aperture 501.

[0303] Therefore, with the first inner metal fence 130 in place, the inner air gap 220 can be configured as follows:

[0304] One possible solution is: Figure 36 As shown, an inner air gap 220 is provided between the first inner metal fence 130 and the outer light-emitting area 502;

[0305] Furthermore, the space between the first inner metal fence 130 and the outer light-emitting area 502 is also filled by the first insulating filling area 100, and the inner air gap 220 is formed inside the first insulating filling area 100.

[0306] Another option is: such as Figure 6 As shown, a compound semiconductor region 120 is provided inside the channel 501. A non-common conductive element 80 passes through the compound semiconductor region 120 and is electrically connected to the first type of electrode contact 101. An inner air gap 220 surrounds the periphery of the compound semiconductor region 120 and is located between the first inner metal fence 130 and the compound semiconductor region 120.

[0307] This embodiment, by setting an air gap, makes it easier for total internal reflection to occur when light is incident from the high-refractive-index sub-pixel corresponding film layer to the low-refractive-index air gap, thereby achieving optical angle modulation, reducing the light emission divergence angle, achieving light collimation, and thus improving the display brightness and light efficiency of the display device.

[0308] Example 6

[0309] like Figure 39 As shown, in this embodiment, the driving backplate 10 is divided into a display area 103, and all the mother pixels constitute a pixel array. The projection of the pixel array on the driving backplate 10 is located inside the display area 103, which means that the display area 103 is the area where the pixel array projection is located.

[0310] In some embodiments, a second type of electrode contact 102 may also be provided on the drive backplate 10, wherein the polarities of the first type of electrode contact 101 and the second type of electrode contact 102 are opposite.

[0311] In the mother pixel, the bottom of each of the multiple sub-pixels 50 is electrically connected to the corresponding first type electrode contact 101 through the bottom conductive layer 70, and the top of the multiple sub-pixels 50 is electrically connected to the second type electrode contact 102 through the top conductive layer 60 to form a top common electrode structure.

[0312] The second type of electrode contact 102 can be configured in the following ways:

[0313] The first method is to set the second type of electrode contact 102 only inside the display area 103. For example, the second type of electrode contact 102 can be set in the local display area 103 where each mother pixel is projected.

[0314] The second method involves providing second-type electrode contacts 102 only around the periphery of the display area 103. For example, such as... Figure 39 As shown, a peripheral electrode contact area 104 is provided around the display area 103, and the second type of electrode contact 102 can be disposed within the peripheral electrode contact area 104; for example Figure 40 As shown, an interface 105 is also provided around the display area 103, and the peripheral electrode contact area 104 can be electrically connected to the interface 105.

[0315] The third type: both the exterior and interior of the display area 103 are provided with second-type electrode contacts 102.

[0316] In some implementations, such as Figures 37-38 As shown, the microdisplay device also includes a common electrode 90, through which the second type of electrode contacts 102 are electrically connected to the top conductive layer 60 at the top of the plurality of sub-pixels 50 to achieve top common electrode.

[0317] The common electrode 90 is located approximately above the second type of electrode contact 102. The common electrode 90 and the second type of electrode contact 102 can be located together inside the display area 103 or together outside the display area 103.

[0318] In some implementations, see Figure 26 , Figure 37 and Figure 38 The bottom end of the common electrode 90 is in direct contact with the corresponding second type electrode contact 102.

[0319] In a first alternative embodiment, at least two sub-pixels 50 in the mother pixel share a top conductive layer 60, and the common electrode conductive element 90 is in direct contact with the shared top conductive layer 60 to achieve electrical connection; or, the common electrode conductive element 90 is electrically connected to the shared top conductive layer 60 through a transition conductive element 200.

[0320] For example, such as Figure 38As shown, the two sub-pixels 50 share a top conductive layer 60, and this shared top conductive layer 60 is in direct contact with the common electrode conductive element 90 below.

[0321] Or such as Figure 37 As shown, the two sub-pixels 50 share a top conductive layer 60. This shared top conductive layer 60 and the common electrode conductive element 90 below are not in direct contact, but are connected through a transition conductive element 200.

[0322] In some implementations, such as Figure 38 As shown, to further enhance current conduction capability, a metal reinforcement 190 can also be connected to the shared top conductive layer 60.

[0323] In some implementations, multiple mother pixels can share a second type of electrode contact 102, or each mother pixel can independently use its own corresponding second type of electrode contact 102.

[0324] In a second alternative implementation, the top of each of the sub-pixels of at least two different pixel layers in the mother pixel is provided with a separate top conductive layer 60 without sharing it. The common conductive element 90 includes an interconnect conductive part 901, and the two adjacent top conductive layers 60 are interconnected through the interconnect conductive part 901 to achieve electrical connection.

[0325] For example, see Figure 27 In a two-layer structure with two pixel layers, a top conductive layer 60 can be separately provided at the top of the sub-pixel 50 in the first pixel layer 20, and a top conductive layer 60 can also be separately provided at the top of the sub-pixel 50 in the second pixel layer 30. The two top conductive layers 60 can be interconnected by an interconnecting conductive part 901.

[0326] Among them, see Figure 22 An electrical connection is achieved by direct contact between a top conductive layer 60 and the electrically connected interconnect conductive part 901;

[0327] Or, see Figure 23 To enhance current conduction capability, a top conductive layer 60 is electrically connected to the interconnected conductive portion 901 via a metal reinforcement 190.

[0328] Example 7

[0329] In this embodiment, the microdisplay device also includes a metal reinforcement 190, and the top conductive layer 60 is electrically connected to the metal reinforcement 190 to increase the current spreading capability through the metal reinforcement 190.

[0330] In some implementations, at least two sub-pixels 50 in a mother pixel share a top conductive layer 60; the sub-pixels 50 sharing a top conductive layer 60 are located in different pixel layers.

[0331] Among them, such as Figures 41-43 As shown, the shared top conductive layer 60 is electrically connected to the metal reinforcement 190.

[0332] In some schemes, such as Figure 41 As shown, the metal reinforcement 190 is located above the common top conductive layer 60.

[0333] In other options, such as Figures 42-43 As shown, the metal reinforcement 190 is located below the common top conductive layer 60.

[0334] Furthermore, the metal reinforcement 190 surrounds the periphery of a sub-pixel 50 beneath the shared top conductive layer.

[0335] Furthermore, the bottom of the metal reinforcement 190 is not lower than the top of the surrounding sub-pixel 50.

[0336] In the specific fabrication process, when the metal reinforcement 190 is located below the common top conductive layer 60, the metal reinforcement can be inserted into the second insulating filling area 110 surrounding the lower sub-pixel 50.

[0337] In some implementations, the metal reinforcement 190 in different mother pixels can be shared or used independently by their respective mother pixels.

[0338] In other embodiments, the top of a sub-pixel in at least one pixel layer of the mother pixel is provided with a separate top conductive layer, which is not shared with the sub-pixels of other pixel layers. In this case, for the sub-pixel with a separate top conductive layer, a metal reinforcement 190 can also be electrically connected to its top conductive layer 60.

[0339] For example, in some solutions, such as Figure 21 and Figure 27 As shown, the metal reinforcement 190 is located above a top conductive layer 60.

[0340] In other options, such as Figure 25 As shown, the metal reinforcement 190 is located below a top conductive layer 60.

[0341] In some schemes, such as Figure 26 As shown, the bottom end of the common electrode 90 is in direct contact with the corresponding second type of electrode contact.

[0342] Example 8

[0343] In this embodiment, the top of the sub-pixel 50 is in contact with the top conductive layer 60 to achieve electrical connection, which can take the following forms:

[0344] The first type: such as Figure 1 As shown, only the top of the sub-pixel 50 is in contact with the electrically connected top conductive layer 60; at this time, only a part of the top of the sub-pixel can be exposed or fully exposed, and the exposed area can be in contact with the corresponding top conductive layer 60 to achieve electrical connection.

[0345] The second type: See reference Figures 44-46 This arrangement ensures that the top edge and at least part of the sidewalls of the sub-pixel 50 are in contact with the electrically connected top conductive layer 60. In this case, in addition to exposing the top edge of the sub-pixel 50, at least part of its sidewalls are also exposed, thus forming an exposed area that contacts the corresponding top conductive layer 60 to achieve electrical connection. This method increases the electrical contact area, facilitates current spread, and enhances current conduction capability.

[0346] Understandably, in specific settings, one sub-pixel of the mother pixel can use the first type of electrical connection, while other sub-pixels use the second type of electrical connection. Alternatively, all sub-pixels can use the same type of electrical connection. The choice can be made based on actual needs.

[0347] For example, in a two-layer structure, such as Figure 44 As shown, the upper sub-pixel uses the second electrical connection method, with its top and at least part of its sidewalls exposed and in contact with the common top conductive layer 60, while the lower sub-pixel uses the first electrical connection method, exposing only a portion of its top region and making that exposed region in contact with the common top conductive layer 60; and in another way, as Figures 45-46 As shown, the upper sub-pixel adopts the second electrical connection form, with its top j1 and at least part of the sidewall j2 exposed and in contact with the common top conductive layer 60. The lower sub-pixel also adopts the second electrical connection form, exposing a part of the top j1 and part of the sidewall j2, and making the exposed area in contact with the common top conductive layer 60.

[0348] The microdisplay devices of the above embodiments simplify the electrical connection structure, are easier to fabricate, effectively increase the effective light-emitting area of ​​the lower sub-pixels, and are more conducive to the best light distribution effect, thereby effectively improving the light efficiency and reliability of the display device.

[0349] All the above-mentioned optional technical solutions can be combined in any way to form optional embodiments of the present invention. That is, any number of embodiments can be combined to meet the needs of different application scenarios. All of these are within the protection scope of this application and will not be described in detail here.

[0350] It should be noted that the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art can make other variations or modifications based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A microdisplay device, characterized in that: include, A drive backplate, wherein a first type of electrode contact is provided on the drive backplate; Multiple pixel layers, all of which are stacked sequentially from bottom to top above the driving backplate; A mother pixel, wherein the mother pixel comprises a plurality of sub-pixels, and at least two of the sub-pixels are located in different pixel layers; The bottom of each sub-pixel is electrically connected to the corresponding first type of electrode contact through the bottom conductive layer, and the tops of multiple sub-pixels are interconnected through the top conductive layer to form a top common electrode structure. In two sub-pixels located in different pixel layers, a channel is formed inside one of the sub-pixels in the lower pixel layer. An outer light-emitting area is formed around the channel and is part of the sub-pixel itself. A non-common conductive element passes through the channel. The top end of the non-common conductive element inside the channel is electrically connected to the bottom conductive layer of the other sub-pixel in the upper pixel layer, and the bottom end is electrically connected to the corresponding first type of electrode contact. The projection area of ​​the upper sub-pixel connected to the non-common conductive element inside the channel on the driving backplate is a first projection area, and the projection area of ​​the outer light-emitting area outside the channel on the driving backplate is a second projection area. The first projection area and the second projection area do not overlap at least partially, so that the light emitted by the outer light-emitting area is at least partially emitted through the periphery of the upper sub-pixel electrically connected to the non-common conductive element inside the channel.

2. The microdisplay device according to claim 1, characterized in that: At least two of the child pixels in the mother pixel share a top conductive layer, and the child pixels that share a top conductive layer are located in different pixel layers.

3. The microdisplay device according to claim 1, characterized in that: Each of the sub-pixels located in different pixel layers of the mother pixel has its own top conductive layer, and they do not share the same top conductive layer. Furthermore, the top conductive layers in the same pixel layer are all located above the electrically connected sub-pixels.

4. The microdisplay device according to claim 1, characterized in that: The sub-pixel with the aperture and any of the sub-pixels above it connected to the non-common conductive element inside the aperture are arranged coaxially; or, the sub-pixel with the aperture and at least one of the sub-pixels above it connected to the non-common conductive element inside the aperture are arranged off-axis.

5. The microdisplay device according to claim 1, characterized in that: The channel has a first insulating filling area inside, and the non-common conductive element inside the channel passes directly through the first insulating filling area.

6. The microdisplay device according to claim 1, characterized in that: A compound semiconductor region is disposed inside the channel, and the non-common conductive element inside the channel passes through the compound semiconductor region.

7. The microdisplay device according to claim 1, characterized in that: In the sub-pixel with a channel, a first inner metal fence is formed inside the channel. The first inner metal fence surrounds the periphery of the non-common conductive element inside the channel. The inner wall of the peripheral light-emitting area is covered with a first insulating layer. The first inner metal fence and the inner wall of the peripheral light-emitting area are insulated and isolated from each other by the first insulating layer.

8. The microdisplay device according to claim 7, characterized in that: The bottom conductive layer is a metal bonding layer.

9. The microdisplay device according to claim 8, characterized in that: The metal bonding layer at the bottom of the sub-pixel with the channel and the first inner metal fence are integrally formed, or the metal bonding layer at the bottom of the sub-pixel with the channel and the first inner metal fence are separately provided and mutually insulated.

10. The microdisplay device according to claim 1, characterized in that: At least one of the sub-pixels is surrounded by a first peripheral metal fence, and the first peripheral metal fence and the outer wall of the surrounded sub-pixel are insulated from each other.

11. The microdisplay device according to claim 1, characterized in that: The top of the sub-pixel is in contact with the electrically connected top conductive layer, or the top of the sub-pixel and at least part of its sidewalls are in contact with the electrically connected top conductive layer.

12. The microdisplay device according to claim 1, characterized in that: The top of each sub-pixel is provided with a top ohmic contact layer, and the top of each sub-pixel is in contact with the corresponding top conductive layer through the top ohmic contact layer.

13. The microdisplay device according to any one of claims 2 or 3, characterized in that: It also includes a metal reinforcement, at least one of the top conductive layers being electrically connected to the metal reinforcement.

14. The microdisplay device according to claim 13, characterized in that: The metal reinforcement is located above the electrically connected top conductive layer.

15. The microdisplay device according to claim 13, characterized in that: The metal reinforcement is located below the electrically connected top conductive layer.

16. The microdisplay device according to claim 15, characterized in that: The metal reinforcement surrounds the periphery of one of the sub-pixels, which is electrically connected to the top conductive layer.

17. The microdisplay device according to claim 16, characterized in that: The bottom end of the metal reinforcement is not lower than the top end of the surrounding sub-pixel.

18. The microdisplay device according to claim 13, characterized in that: Metal reinforcements in different mother pixels can be shared or used independently by their respective mother pixels.

19. The microdisplay device according to any one of claims 2 or 3, characterized in that: The driving backplate is divided into display areas, and all the mother pixels constitute a pixel array. The projection of the pixel array onto the driving backplate is located inside the display area. The display area is provided with second-type electrode contacts inside and / or the display area is provided with second-type electrode contacts outside. In this configuration, the polarity of the second type of electrode contact is opposite to that of the first type of electrode contact, and the tops of multiple sub-pixels in the mother pixel are all connected to the second type of electrode contact through a top conductive layer to form a top common electrode structure.

20. The microdisplay device according to claim 19, characterized in that: It also includes a common electrode conductor, through which the second type of electrode contacts are electrically connected to the top conductive layer at the top of the plurality of sub-pixels.

21. The microdisplay device according to claim 20, characterized in that: At least two of the child pixels in the mother pixel share a top conductive layer, and the common electrode conductive element is in direct contact with the shared top conductive layer to achieve electrical connection; or, the common electrode conductive element is electrically connected to the shared top conductive layer through a transition conductive element.

22. The microdisplay device according to claim 20, characterized in that: The top of each of the sub-pixels in at least two different pixel layers of the mother pixel is provided with a separate top conductive layer without sharing it. The common conductive element includes an interconnecting conductive portion. Two adjacent top conductive layers are interconnected through the interconnecting conductive portion to achieve electrical connection. At least one top conductive layer is in direct contact with the electrically connected interconnecting conductive portion to achieve electrical connection; or, at least one top conductive layer is electrically connected to the electrically connected interconnecting conductive portion through a metal reinforcement.

23. The microdisplay device according to claim 20, characterized in that: The bottom end of the common electrode is in direct contact with the corresponding second type of electrode contact.

24. The microdisplay device according to claim 1, characterized in that: At least one of the sub-pixels is surrounded by a peripheral air gap, which is annular.

25. The microdisplay device according to claim 24, characterized in that: At least one of the sub-pixels is surrounded by a partition wall, the partition wall being a compound semiconductor, and a peripheral air gap is formed between the partition wall and the surrounding sub-pixel.

26. The microdisplay device according to claim 24, characterized in that: The sub-pixel surrounded by the peripheral air gap is further provided with a second insulating filling area, and the peripheral air gap is formed inside the second insulating filling area.

27. The microdisplay device according to claim 1, characterized in that: An inner air gap is provided inside the channel, which surrounds the non-common conductive component inside the channel and is annular in shape.

28. The microdisplay device according to claim 27, characterized in that: The channel is provided with a first insulating filling area, and the inner air gap is formed inside the first insulating filling area.

29. The microdisplay device according to claim 1, characterized in that... At least two sub-pixels located in different pixel layers emit different colors.

30. The microdisplay device according to claim 1, characterized in that... A lens is provided above the topmost sub-pixel, and the lens covers at least one of the sub-pixels in the parent pixel.

31. A method for fabricating a microdisplay device, characterized in that: include, A drive backplane is provided, wherein a first type of electrode contact is provided on the drive backplane; A compound semiconductor layer is selected as the pixel layer, and multiple pixel layers are stacked sequentially from bottom to top above the driving backplane. When stacking each pixel layer, the pixel layer is etched to obtain sub-pixels, so that each parent pixel includes multiple sub-pixels, and at least two sub-pixels are located in different pixel layers. This ensures that the bottom of each sub-pixel in the mother pixel is electrically connected to the corresponding first type of electrode contact through the bottom conductive layer, and the tops of multiple sub-pixels are interconnected through the top conductive layer to form a top common electrode structure. In two sub-pixels located in different pixel layers, a channel is formed inside one of the sub-pixels in the lower pixel layer. An outer light-emitting area is formed around the channel and is part of the sub-pixel itself. A non-common conductive element passes through the channel. The top end of the non-common conductive element inside the channel is electrically connected to the bottom conductive layer of the other sub-pixel in the upper pixel layer, and the bottom end is electrically connected to the corresponding first type of electrode contact. The projection area of ​​the upper sub-pixel connected to the non-common conductive element inside the channel on the driving backplate is a first projection area, and the projection area of ​​the outer light-emitting area outside the channel on the driving backplate is a second projection area. The first projection area and the second projection area do not overlap at least partially, so that the light emitted by the outer light-emitting area is at least partially emitted through the periphery of the upper sub-pixel electrically connected to the non-common conductive element inside the channel.

32. The method for fabricating a microdisplay device according to claim 31, characterized in that: When the non-common conductive element passes through the channel, the preparation method further includes filling the channel with insulating material to form a first insulating filling area, so that the non-common conductive element passes directly through the first insulating filling area.

33. The method for fabricating a microdisplay device according to claim 31, characterized in that: When the non-common conductive element passes through the inside of the channel, the preparation method further includes retaining a portion of the compound semiconductor material inside the channel to form a compound semiconductor region, so that the non-common conductive element passes through the compound semiconductor region.

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