Micro-display device with integrated reflective dome and method for manufacturing micro-display device

Abstract

The present invention relates to the technical field of semiconductors, and disclosed are a micro-display device with an integrated reflective dome and a method for manufacturing the micro-display device. The micro-display device comprises a driving wafer; and a display module, wherein the display module is arranged on the driving wafer, the display module comprises a pixel unit and a first micro-lens structure covering the pixel unit, the projection of the top of the pixel unit on the driving wafer is located in the outer contour of the projection of the bottom of the first micro-lens structure on the driving wafer, and the periphery of the bottom of the first micro-lens structure is covered with a reflective material so as to form a reflective dome of the first micro-lens structure. On the basis of the technical solution provided in the present application, a reflective dome structure is integrated within a micro-lens, thereby enhancing the performance of the micro-lens in converging emitted light and preventing optical crosstalk.

Description

Microdisplay device with integrated reflective dome and its fabrication method

[0001] This application claims priority to Chinese Patent Application No. 2024109322269, filed on July 12, 2024, entitled “Microdisplay Device with Integrated Reflective Dome and Method for Fabrication Thereof”, the entire contents of which are incorporated herein by reference. Technical Field

[0002] This invention relates to the field of semiconductor technology, and in particular to a micro-display device with an integrated reflective dome and its fabrication method. Background Technology

[0003] As a next-generation display technology, Micro-LED technology has advantages over LCD and OLED, including high electro-optical conversion efficiency, low power consumption, good stability, long lifespan, no size development limitations, and short switching time.

[0004] Micro-LED has great potential in both wearable devices and direct-view displays. However, in current applications, optical waveguides are often used to couple Micro-LED chips to the final display. Due to the high optical loss of the optical waveguide path and the collimated light input characteristics, the industry usually configures microlenses on the Micro-LED chip to improve the coupling efficiency between the Micro-LED chip and the optical waveguide system.

[0005] However, based on existing microlens technology, the brightness of Micro-LEDs at the display end is still not satisfactory. Therefore, there is an urgent need for a new microlens fabrication scheme that can improve optical performance, further converge the emission angle, and meet the luminous efficiency requirements of Micro-LEDs. Summary of the Invention

[0006] The purpose of this invention is to provide a micro-display device with an integrated reflective dome and its fabrication method, which can improve optical performance, further converge the emission angle, and meet the luminous efficiency requirements of Micro-LED.

[0007] To achieve the above-mentioned objectives, the present invention proposes the following technical solution:

[0008] On one hand, a microdisplay device integrating a reflective dome is provided, the microdisplay device comprising:

[0009] Driven wafer;

[0010] The display module is disposed on the driving wafer and includes: a pixel unit and a first microlens structure overlaid on the pixel unit. The projection of the top of the pixel unit on the driving wafer is located within the outer contour of the projection of the bottom of the first microlens structure on the driving wafer, and the bottom of the first microlens structure is covered with a reflective material to form a reflective dome of the first microlens structure.

[0011] In one possible implementation, the display module further includes:

[0012] An insulating layer is disposed below the first microlens structure and surrounds the pixel unit;

[0013] The insulating layer includes a reflective dome target surrounding the pixel unit, with the top of the reflective dome target connected to the bottom of the reflective dome.

[0014] In one possible implementation, the reflective dome is formed by backsplashing of the reflective dome target.

[0015] In one possible implementation, the distance between the reflective dome target and the pixel unit is not greater than 1 / 2 pixel spacing and not less than 1 / 4 pixel spacing;

[0016] The pixel spacing refers to the distance between the center points of two adjacent pixel units.

[0017] In one possible implementation, the projection of the bottom of the first microlens structure onto the driving wafer is located within the outer contour of the projection of the top of the reflective dome target onto the driving wafer, and the horizontal distance between the reflective dome target and the first microlens structure is not less than 0 and not greater than 1 / 2 pixel spacing.

[0018] The pixel spacing refers to the distance between the center points of two adjacent pixel units.

[0019] In one possible implementation, the top height of the reflective dome target is greater than the top height of the pixel unit.

[0020] In one possible implementation, the surface of the pixel unit and the surface of the driving wafer are covered with a continuous common cathode;

[0021] The bottom of the reflective dome target is connected to the side of the common cathode away from the driving wafer.

[0022] In one possible implementation, the reflective dome target is spaced apart from the first microlens structure, and the reflective dome simultaneously covers the outer periphery of the bottom of the first microlens structure and the insulating layer between the first microlens structure and the reflective dome target.

[0023] In one possible implementation, the driving wafer is further provided with a cathode contact, and the reflective dome target is connected to the top of the cathode contact and the bottom of the reflective dome.

[0024] In one possible implementation, the N-type semiconductor at the top of the pixel unit extends toward the side where the reflective dome target is located. The reflective dome target includes a first part of the target, one end of which is connected to a corresponding cathode contact, and the other end of which is connected to the bottom of the reflective dome. The sidewall of the first part of the target is connected to the sidewall of the N-type semiconductor layer at the top of the pixel unit.

[0025] or,

[0026] The N-type semiconductor at the top of the pixel unit extends toward the side where the reflective dome target is located. The reflective dome target includes a second part target and a third part target. One end of the second part target is connected to the corresponding cathode contact, and the other end of the second part target is connected to a portion of the lower surface of the third part target. Another portion of the lower surface of the third part target is connected to the upper surface of the N-type semiconductor layer at the top of the pixel unit. A portion of the upper surface of the third part target is connected to the bottom of the reflective dome. The sidewall of the second part target is connected to the sidewall of the N-type semiconductor layer at the top of the pixel unit.

[0027] In one possible implementation, the surface of the pixel unit and the surface of the driving wafer are covered with a continuous common cathode;

[0028] The bottom of the reflective dome target is spaced from the side of the common cathode away from the driving wafer.

[0029] In one possible implementation, the insulating layer further includes another lower resonant cavity surrounding the pixel unit, the bottom of which is connected to the side of the common cathode away from the driving wafer, and the top height of the lower resonant cavity is not higher than the bottom height of the reflective dome.

[0030] In one possible implementation, the height of the reflective dome is less than one-third of the height of the first microlens structure.

[0031] In one possible implementation, the thickness of the reflective dome is between 100 nm and 300 nm.

[0032] In one possible implementation, the display module further includes:

[0033] A second microlens structure is disposed over the first microlens structure and the reflective dome.

[0034] In one possible implementation, the reflective material is a metallic material.

[0035] On the other hand, a method for fabricating a microdisplay device is also provided, the method being used to fabricate the microdisplay device as described above, the method comprising:

[0036] Prepare the driver wafer;

[0037] A display module is integrated on the driving wafer. The display module is disposed on the driving wafer and includes: a pixel unit and a first microlens structure overlaid on the pixel unit. The projection of the top of the pixel unit on the driving wafer is located within the outer contour of the projection of the bottom of the first microlens structure on the driving wafer. The bottom of the first microlens structure is covered with a reflective material to form a reflective dome of the first microlens structure.

[0038] In one possible implementation, integrating the display module on the driving wafer includes:

[0039] Pixel units are fabricated on the driving wafer;

[0040] Prepare a reflective dome target material surrounding the pixel unit;

[0041] A dielectric deposition is performed around the pixel unit to form a first dielectric layer, the top of which is higher than the top of the reflective dome target.

[0042] The first dielectric layer is etched by an ion beam to form an insulating layer around the pixel unit, the first microlens structure, and the reflective dome. The top of the reflective dome target is connected to the bottom of the reflective dome. The reflective dome is formed by back sputtering of the reflective dome target during the ion beam etching process.

[0043] In one possible implementation, the ion beam etching of the first dielectric layer to form the insulating layer surrounding the pixel unit, the first microlens structure, and the reflective dome includes:

[0044] A photoresist layer is deposited on top of the first dielectric layer, and the photoresist layer is aligned with the pixel unit;

[0045] The first dielectric layer is subjected to photolithography and plasma etching through the photoresist layer to expose the reflective dome target and obtain the insulating layer and the columnar structure above the pixel unit;

[0046] The columnar structure is morphologically transformed by ion beam etching to form the first microlens structure and the reflective dome.

[0047] In one possible implementation, integrating the display module on the driving wafer includes:

[0048] An insulating layer is wrapped around the outside of each pixel unit;

[0049] A display module having the pixel units is connected to a driving wafer, and the driving wafer is provided with cathode contacts;

[0050] The top of the pixel unit is exposed, and the top of the reflective dome target is electrically connected to the N-type semiconductor layer. The bottom of the reflective dome target is connected to the cathode contact, and the reflective dome target surrounds the pixel unit.

[0051] A dielectric layer is deposited over the pixel unit to form a second dielectric layer;

[0052] The second dielectric layer is etched by an ion beam to form the first microlens structure and the reflective dome. The top of the reflective dome target is connected to the bottom of the reflective dome. The reflective dome is formed by back sputtering of the reflective dome target during the ion beam etching process.

[0053] In one possible implementation, integrating the display module on the driving wafer includes:

[0054] Pixel units are fabricated on the driving wafer;

[0055] A dielectric deposition is performed around the pixel unit to form the insulating layer;

[0056] The insulating layer is patterned and etched to form a trench structure surrounding the pixel unit;

[0057] Metal is deposited on the trench structure to construct the reflective dome target;

[0058] A dielectric layer is deposited over the insulating layer to form a third dielectric layer;

[0059] The third dielectric layer is etched by an ion beam to form the first microlens structure and the reflective dome. The top of the reflective dome target is connected to the bottom of the reflective dome. The reflective dome is formed by back sputtering of the reflective dome target during the ion beam etching process.

[0060] In one possible implementation, the method further includes, prior to forming the third dielectric layer:

[0061] A continuous common cathode is disposed on the surface of the pixel unit and the surface of the driving wafer;

[0062] A lower resonant cavity is prepared surrounding the pixel unit, the bottom of which is connected to the side of the common cathode away from the driving wafer.

[0063] In one possible implementation, the method further includes:

[0064] A second microlens structure is fabricated by dielectric deposition on the first microlens structure and the reflective dome.

[0065] Compared with the prior art, the present invention has the following beneficial effects:

[0066] A microdisplay device with an integrated reflective dome is provided, wherein pixel units are stacked on a driving wafer, a first microlens structure is aligned with the pixel units, and a reflective material is coated around the bottom of the first microlens structure to form a reflective dome of the first microlens structure. By integrating the reflective dome structure, the emission angle of the microdisplay device is further converged, and the optical performance of the microdisplay device is improved.

[0067] Furthermore, an insulating layer is provided around the pixel unit, and a reflective dome target surrounding the pixel unit is provided in the insulating layer. The top of the reflective dome target is connected to the bottom of the reflective dome, thereby effectively fabricating the reflective dome corresponding to the first microlens structure by using the reflective dome target for back sputtering. Attached Figure Description

[0068] Figure 1 is a schematic diagram of the structure of a microdisplay device provided in an embodiment of this application;

[0069] Figure 2 is a schematic diagram of the structure of a micro-display device with different reflective dome angles provided in the embodiments of this application;

[0070] Figure 3 is a schematic diagram of the structure of a micro-display device with different heights of reflective dome targets provided in the embodiments of this application;

[0071] Figure 4 is a schematic diagram of a microdisplay device with a second microlens structure provided in an embodiment of this application;

[0072] Figure 5 is a schematic diagram of the emission angles of different micro-display devices provided in the embodiments of this application;

[0073] Figure 6 is a schematic diagram of crosstalk performance for different microdisplay devices provided in the embodiments of this application;

[0074] Figure 7 is a flowchart of a method for fabricating a micro-display device provided in an embodiment of this application;

[0075] Figure 8 is a schematic diagram of a micro-display device fabricated with a reflective dome target provided in an embodiment of this application;

[0076] Figure 9 is a schematic diagram of a microdisplay device with a first dielectric layer provided in an embodiment of this application;

[0077] Figure 10 is a schematic diagram of a micro-display device with a photoresist layer provided in an embodiment of this application;

[0078] Figure 11 is a schematic diagram of a micro-display device with a columnar structure provided in an embodiment of this application;

[0079] Figure 12 is a schematic diagram of another micro-display device provided in an embodiment of this application;

[0080] Figure 13 is a schematic diagram of another microdisplay device provided in an embodiment of this application;

[0081] Figure 14 is a schematic diagram of another micro-display device provided in an embodiment of this application;

[0082] Figure 15 is a schematic diagram of another microdisplay device provided in the embodiments of this application.

[0083] Reference numerals: 100-Driver wafer, 200-Display module, 10-Pixel unit, 11-Bonding metal layer, 12-Compound pixel, 13-Passivation layer, 14-Common cathode, 15-N-type semiconductor layer, 16-P-type semiconductor layer, 20-First microlens structure, 30-Reflective dome, 40-Insulating layer, 50-Reflective dome target, 51-First part target, 52-Second part target, 53-Third part target, 60-Second microlens structure, 70-First dielectric layer, 80-Photoresist layer, 91-Cathode contact, 92-Lower resonant cavity, 93-Anode contact, 94-Anode metal component. Detailed Implementation

[0084] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of the embodiments of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0085] 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.

[0086] 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.

[0087] Traditional microlens fabrication methods suffer from insufficient emission angle convergence and inadequate protection against optical crosstalk.

[0088] To avoid the above problems, this application proposes a technical solution of integrating a reflective dome structure inside a microlens, which can improve the convergence angle of the microlens and prevent optical crosstalk.

[0089] Example 1

[0090] First, this application provides a micro-display device with an integrated reflective dome, as shown in Figure 1. The micro-display device includes:

[0091] A driving wafer 100; a display module 200, the display module 200 being disposed on the driving wafer 100, the display module 200 including: a pixel unit 10, a first microlens structure 20 covering the pixel unit 10, the projection of the top of the pixel unit 10 onto the driving wafer 100 being located within the outer contour of the projection of the bottom of the first microlens structure 20 onto the driving wafer 100, and a reflective material being covered around the bottom of the first microlens structure 20 to form a reflective dome 30 of the first microlens structure 20.

[0092] In this embodiment of the application, a display module 200 is disposed on a driving wafer 100. The display module 200 includes a pixel unit 10 and a first microlens structure 20 stacked along a direction away from the driving wafer 100. Around the bottom of the first microlens structure 20, a reflective dome 30 made of reflective material is covered. The presence of the reflective dome 30 can, on the one hand, further converge the emission angle of the micro-display device, and on the other hand, it has a light reflection effect, which can reflect the light that is incident on the bottom of the first microlens structure 20 and emit it from the middle part of the first microlens structure 20, thereby improving the brightness of the micro-display device.

[0093] The driving wafer 100 can be an active design combining one or more of the following: thin-film transistor (TFT), low-temperature polysilicon (LTPS), CMOS integrated circuit, high-mobility transistor (HEMT). Specifically, the driving wafer 100 is provided with a driving circuit, which has at least one anode contact. The driving circuit may include active, passive, or semi-passive control circuitry. All anode contacts included in the driving circuit can be linearly arranged or arrayed. Any anode contact can be located in the middle or at the edge of the driving wafer 100; this embodiment does not impose any restrictions on this.

[0094] The reflective material corresponding to the reflective dome 30 can be a metallic material, such as Au, Al, Ag or other alloy materials with good reflective properties, or other materials with reflective properties, such as Bragg dielectric reflective layers.

[0095] The pixel unit 10 may be as shown in FIG1, comprising: a bonding metal layer 11 and a compound pixel 12 stacked along a direction away from the driving wafer 100; a passivation layer 13 deposited on the sidewalls of the pixel unit 10; and a common cathode 14 deposited on the surface of the passivation layer 13 and the top of the pixel unit 10.

[0096] Furthermore, the passivation layer 13 can be a single layer or a stack of dielectric layers such as aluminum oxide, silicon nitride, or silicon oxide. The common cathode 14 can be a transparent conductive film, which can be one or more of ITO (Indium Tin Oxide) film, AZO (Antimony doped Zinc Oxide) film, ATO (Antimony doped Tin Oxide) film, and FTO (Fluorine doped Tin Oxide) film. The transparent conductive film can also be formed by depositing a thin metal (such as Al, Au, Ag) on ​​the ITO surface and then annealing it to form metal-doped ITO, so as to enhance the current transport capability of the common cathode 14.

[0097] The first microlens structure 20 is a spherical or conical structure, bulging outwards from the driving wafer 100. The bottom of the first microlens structure 20 contacts the top of the pixel unit 10, and the surface dimension corresponding to the bottom of the first microlens structure 20 is not smaller than the surface dimension of the top of the pixel unit 10, so that the first microlens structure 20 can effectively converge the light emitted from the pixel unit 10. The first microlens structure 20 can be made of organic high-temperature resistant materials (≥200℃) such as SU8 or polyimide, or inorganic materials such as silicon oxide, silicon nitride, or aluminum oxide, including inorganic silicon oxide or oxides prepared using PSG (phosphate glass), BPSG (borophosphosilicate glass) processes, or deposition sources such as TEOS (tetraethoxysilane) or TEPO (triethyl phosphate).

[0098] The reflective dome 30 surrounds the bottom outer periphery of the first microlens structure 20. Specifically, the inner edge of the reflective dome 30 is in close contact with the first microlens structure 20, while the outer edge is determined by its own thickness. It can be understood that, because the reflective dome 30 is attached to the bottom outer periphery of the first microlens structure 20, its outer edge can have a certain angle with the horizontal surface. Specifically, the angle of the reflective dome 30 is between 90° and 180°. The larger the angle, the stronger the emission angle convergence effect and the smaller the emission angle, as shown in Figure 2. By controlling the corresponding angle of the reflective dome 30, the effect of the microlens converging the emission angle can be optimized.

[0099] Furthermore, the height of the reflective dome 30 is less than one-third the height of the first microlens structure 20. By designing the height of the reflective dome 30, an excessively tall reflective dome 30 is avoided from excessively restricting the emission angle of the microdisplay device. Furthermore, the thickness of the reflective dome 30 is between 100nm and 300nm. Within this range, the reflective dome 30 has sufficient thickness to adhere to the outer periphery of the bottom of the first microlens structure 20, while also avoiding excessive thickness that would result in material waste.

[0100] For example, the height of the first microlens structure 20 is 1.8 μm, the height of the reflective dome 30 is 0.7 μm, and the thickness is 150 nm. In one possible implementation, as shown in FIG1, the display module 200 further includes: an insulating layer 40, which is disposed below the first microlens structure 20 and surrounds the pixel unit 10; wherein, the insulating layer 40 is provided with a reflective dome target 50 surrounding the pixel unit 10, and the top of the reflective dome target 50 is connected to the bottom of the reflective dome 30.

[0101] In this implementation, the first microlens structure 20 is supported by the insulating layer 40 in the display module 200, allowing the first microlens structure 20 to be stacked above the pixel unit 10. Specifically, the bottom of the first microlens structure 20 contacts the surface of the insulating layer 40 away from the driving wafer 100. A vertically extending reflective dome target 50 is disposed in the insulating layer 40, and the reflective dome target 50 surrounds the pixel unit 10. The top of the reflective dome target 50 is exposed on the surface of the insulating layer 40 away from the driving wafer 100 and is connected to the bottom of the reflective dome 30. Furthermore, the reflective dome target 50 provides the base material for the fabrication of the reflective dome 30; the fabrication of the reflective dome 30 requires fabrication based on this structure.

[0102] Optionally, the reflective dome 30 is formed by back sputtering of the reflective dome target 50. Specifically, the top of the reflective dome target 50 is exposed on the surface of the insulating layer 40 away from the driving wafer 100. Its top is formed by back sputtering during the ion beam etching process, creating a reflective dome 30 surrounding the bottom of the first microlens structure 20, resulting in a reflective dome 30 that is thicker at the bottom and thinner at the top. The reflective dome target 50 can be Au, Al, Ag, or other alloy materials with good reflective properties; this application does not limit the specific material of the reflective dome 30. It is understood that since the reflective dome 30 is formed by back sputtering of the reflective dome target 50, the specific material of the reflective dome 30 is the same as that of the reflective dome target 50.

[0103] Furthermore, as shown in Figure 1, the distance between the reflective dome target 50 and the pixel unit 10 is denoted as P. P is no greater than 1 / 2 pixel spacing and no less than 1 / 4 pixel spacing; where pixel spacing refers to the distance between the center points of two adjacent pixel units 10. By designing the distance between the sidewall of the reflective dome target 50 and the sidewall of the pixel unit 10, a reasonable spacing is maintained between the reflective dome target 50 and the pixel unit 10. This avoids the distribution density of the pixel unit 10 being affected when the spacing is too large, and also avoids the reflective dome target 50 affecting the optical or electrical performance of the pixel unit 10 when the spacing is too small.

[0104] Furthermore, the projection of the bottom of the first microlens structure 20 onto the driving wafer 100 lies within the outer contour of the projection of the top of the reflective dome target 50 onto the driving wafer 100. As shown in FIG1, the horizontal distance between the reflective dome target 50 and the first microlens structure 20 is marked as D, where D is not less than 0 and not greater than 1 / 2 pixel spacing; wherein, pixel spacing refers to the distance between the center points of two adjacent pixel units 10. Furthermore, as shown in FIG1, the reflective dome target 50 and the first microlens structure 20 are spaced apart, and the reflective dome 30 simultaneously covers the outer periphery of the bottom of the first microlens structure 20 and the insulating layer 40 between the first microlens structure 20 and the reflective dome target 50.

[0105] In order for the reflective dome 30 formed by backsputtering of the reflective dome target 50 to surround the outer periphery of the first microlens structure 20, the projection of the bottom of the first microlens structure 20 on the driving wafer 100 is designed to be located within the projection of the top of the reflective dome target 50 on the driving wafer 100. The horizontal spacing between the sidewall of the reflective dome target 50 and the sidewall of the first microlens structure 20 is designed so that the reflective dome 30 has sufficient space in the horizontal direction to be formed by backsputtering.

[0106] Furthermore, the top height of the reflective dome target 50 is greater than the top height of the pixel unit 10. On the one hand, since the top height of the reflective dome target 50 is the same as the top height of the insulating layer 40, if the top height of the reflective dome target 50 is too low, the insulating layer 40 will also be lower than the top of the pixel unit 10. Therefore, the top height of the reflective dome target 50 is designed to be greater than the top height of the pixel unit 10. Correspondingly, the insulating layer 40 is also designed to completely surround the pixel unit 10, providing insulation protection for the pixel unit 10. On the other hand, the reflective dome target 50 has a reflective effect on the light emitted from the pixel unit 10. By using a reflective dome target 50 with a height greater than the top height of the pixel unit 10, the reflection effect can be guaranteed.

[0107] Furthermore, the height of the reflective dome target 50 can be 1 to 5 times the height of the pixel unit 10. It can be understood that the height of the reflective dome target 50 is inversely proportional to the emission angle; the higher the reflective dome target 50, the stronger the emission angle convergence effect and the smaller the emission angle, as shown in Figure 3. By controlling the height of the reflective dome target 50, the effect of the microlens in converging the emission angle can be optimized.

[0108] Furthermore, a continuous common cathode 14 is formed on the surface of the pixel unit 10 and the surface of the driving wafer 100; the bottom of the reflective dome target 50 is connected to the side of the common cathode 14 away from the driving wafer 100. In the micro-display pixel, each pixel unit 10 is cathode interconnected through the common cathode 14, and the bottom of the reflective dome target 50 is directly connected to the common cathode 14, which can improve the current spreading capability of the common cathode 14.

[0109] In one possible implementation, the display module 200 further includes a second microlens structure 60, which is disposed over the first microlens structure 20 and the reflective dome 30.

[0110] As shown in Figure 4, after the first microlens structure 20 is fabricated, a second microlens structure 60 can be formed by covering it with another layer of transparent medium material, thereby flexibly adjusting the microlens size to improve the microlens performance.

[0111] The second microlens structure 60 can be made of organic high-temperature resistant materials such as SU8 or polyimide (≥200℃), or inorganic materials such as silicon oxide, silicon nitride, or aluminum oxide, including inorganic silicon oxide or oxides prepared using PSG (phosphate glass), BPSG (borophosphosilicate glass) processes, or deposition sources such as TEOS (tetraethoxysilane) or TEPO (triethyl phosphate). The second microlens structure 60 can be made of the same material as the first microlens structure 20, or it can be made of a different material; this application does not impose any restrictions on this.

[0112] It is understandable that the reflective dome microlens corresponding to the above structure significantly outperforms other microlenses in terms of convergent emission angle and anti-crosstalk performance. In one example, on the same Micro LED microdisplay chip substrate, Figure 5 shows the emission angle of other microlenses (upper part of Figure 5, ±28°) and the emission angle of the reflective dome microlens corresponding to the embodiment of this application (lower part of Figure 5, ±18°). Figure 6 shows the crosstalk performance of other microlenses (upper part of Figure 6) and the reflective dome microlens corresponding to the embodiment of this application (lower part of Figure 6). The reflective dome microlens is significantly better than other microlenses in both cases.

[0113] In summary, the embodiments of this application provide a micro-display device with an integrated reflective dome, which stacks pixel units on a driving wafer, aligns a first microlens structure with the pixel units, and coats the bottom of the first microlens structure with a reflective material to form a reflective dome of the first microlens structure. By integrating the reflective dome structure, the emission angle of the micro-display device is further converged, and the optical performance of the micro-display device is improved.

[0114] Furthermore, an insulating layer is provided around the pixel unit, and a reflective dome target surrounding the pixel unit is provided in the insulating layer. The top of the reflective dome target is connected to the bottom of the reflective dome, thereby effectively fabricating the reflective dome corresponding to the first microlens structure by using the reflective dome target for back sputtering.

[0115] The fabrication method of the microdisplay device corresponding to the structure described in the above embodiments will be described below. As shown in Figure 7, the fabrication method of the microdisplay device may include the following steps:

[0116] Step S1: Prepare the driver wafer.

[0117] Specifically, the driver wafer includes anode contacts in the vertical direction, and an insulating medium is disposed around the anode contacts.

[0118] Step S2: Integrate a display module on the driver wafer. The display module is located on the driver wafer and includes: a pixel unit and a first microlens structure covered on the pixel unit. The projection of the top of the pixel unit on the driver wafer is located within the outer contour of the projection of the bottom of the first microlens structure on the driver wafer. The bottom of the first microlens structure is covered with a reflective material to form a reflective dome of the first microlens structure.

[0119] In one possible implementation, step S2 specifically includes:

[0120] S211: Fabricate pixel units on the driver wafer.

[0121] The specific fabrication process for the pixel unit can be described as follows:

[0122] (1) The compound wafer and the driving wafer are bonded together by a bonding metal layer.

[0123] Specifically, bonding metals are deposited on the surfaces of both the compound wafer and the driving wafer. The bonding metals on the surfaces of the two wafers are then used to form a bonding metal layer, and the two wafers are integrated together by wafer-level thermo-pressing bonding.

[0124] (2) Patterning etching is performed on the compound wafer to obtain pixel units.

[0125] Specifically, after exposing the N-type ohmic contact layer in the compound wafer, the compound wafer is patterned into pixels using semiconductor photolithography and etching processes, with the P-type ohmic contact layer in the compound wafer as the etching stop layer. The completed pixel units correspond to the anode contacts in the driving wafer.

[0126] (3) Passivate the device surface and prepare a common cathode layer.

[0127] After completing the patterning etching of the pixel unit, sidewall passivation and common cathode current extension are further introduced to form a passivation layer and a common cathode, so as to complete the fabrication of N-type ohmic contact and common cathode.

[0128] S212: Prepare a reflective dome target material surrounding the pixel unit.

[0129] Specifically, as shown in Figure 8, a reflective dome target 50 is fabricated on the microdisplay device on which the common cathode 14 has been fabricated, and it is patterned and distributed between the pixel units 10. The fabrication method can be lift-off, electroplating, patterning etching, etc., and the target material can be Au, Al, Ag, or other alloy materials with good reflective properties. In one embodiment, the reflective dome target is fabricated by lift-off, and its height is approximately 1.2 times that of the pixel unit.

[0130] S213: Dielectric deposition is performed around the pixel unit to form a first dielectric layer, the top of the first dielectric layer being higher than the top of the reflective dome target.

[0131] Specifically, as shown in Figure 9, a transparent dielectric material for constituting microlenses is prepared on the surface of the microdisplay device. This material can be organic materials such as SU8 and polyimide (≥200℃), which are resistant to high temperatures; or inorganic materials such as silicon oxide, silicon nitride, and aluminum oxide. Specifically, inorganic silicon oxide or oxides prepared using PSG (phosphate glass), BPSG (borophosphosilicate glass) processes, or deposition sources such as TEOS (tetraethoxysilane) and TEPO (triethyl phosphate) form the first dielectric layer 70. Further, the first dielectric layer 70 is planarized, for example, by spin-coating organic materials and CMP (chemical mechanical polishing) inorganic materials, to facilitate subsequent processing.

[0132] S214: Ion beam etching is performed on the first dielectric layer to form an insulating layer around the pixel unit, a first microlens structure, and a reflective dome.

[0133] The top of the reflective dome target is connected to the bottom of the reflective dome, which is formed by back sputtering of the reflective dome target during the ion beam etching process.

[0134] Furthermore, S214 specifically includes:

[0135] (1) A photoresist layer is deposited on top of the first dielectric layer, and the photoresist layer is aligned with the pixel unit.

[0136] Specifically, as shown in Figure 10, photolithography is performed on the surface of the first dielectric layer 70 to form a photoresist mask directly above the pixel unit 10, i.e., a photoresist layer 80 is deposited.

[0137] (2) The first dielectric layer is photolithographically etched and plasma-etched through a photoresist layer to expose the reflective dome target and obtain the columnar structure above the insulating layer and pixel unit.

[0138] Specifically, as shown in Figure 11, the micro-display device is subjected to plasma etching. After etching, the first dielectric layer 70 is obtained as a columnar structure of transparent dielectric material and an insulating layer 40. It should be noted that after plasma etching, the distance D between the edge of the columnar structure and the center of the reflective dome target is greater than 0 and less than 1 / 2 pixel pitch. Pixel pitch refers to the distance between the center points of two adjacent pixel units.

[0139] Furthermore, the thickness of the columnar structure is less than or equal to the distance between the edges of two adjacent pixel units, so that a groove structure is formed between the pixel units. The groove structure can provide sufficient space for subsequent etching of the columnar structure.

[0140] (3) The columnar structure is morphologically transformed by ion beam etching to form the first microlens structure and the reflective dome.

[0141] Specifically, as shown in Figure 1, the microdisplay device undergoes ion beam etching to transform the transparent dielectric material from a columnar structure to a spherical or conical structure, forming a first microlens structure 20. Simultaneously, a reflective dome target 50 is etched, and a reflective dome 30 is formed around the first microlens structure 20 via back sputtering. The angle of the reflective dome 30 can be between 90° and 180°. Furthermore, the distance D between the lower edge of the first microlens structure 20 and the center of the reflective dome target 50 must be greater than 0 and less than half the pixel pitch. The pixel pitch refers to the distance between the center points of two adjacent pixel units.

[0142] Understandably, based on the above microlens fabrication scheme, heating and reflow are not required, thus avoiding the problems of poor stability and consistency in the traditional heating and reflow process for microlens fabrication.

[0143] It is understandable that, in addition to the microlens fabrication scheme shown in the above steps, other implementation schemes can also be used to fabricate microlenses, as long as it is ensured that during the fabrication process of microlenses, while the morphology of the microlenses is changed by ion beam etching, the reflective dome 30 around the lower edge of the first microlens structure 20 is simultaneously formed by back sputtering.

[0144] In one possible implementation, after step S214, the following step may be further performed: depositing a medium on the first microlens structure and the reflective dome to prepare the second microlens structure.

[0145] In this implementation, as shown in Figure 4, after forming the first microlens structure 20 through the columnar structure, a transparent medium material can be further covered to form the second microlens structure 60. The size of the microlens can be flexibly adjusted by the thickness of the transparent medium material, making mass production operations convenient.

[0146] In summary, the fabrication method of the micro-display device provided in this application embodiment offers a method for fabricating a micro-display device with an integrated reflective dome. This method involves stacking pixel units on a driving wafer, aligning a first microlens structure with these pixel units, and covering the bottom periphery of the first microlens structure with a metal material to form a reflective dome. By integrating the reflective dome structure, the emission angle of the micro-display device is further reduced, thereby improving the optical performance of the micro-display device.

[0147] Furthermore, an insulating layer is provided around the pixel unit, and a reflective dome target surrounding the pixel unit is provided in the insulating layer. The top of the reflective dome target is connected to the bottom of the reflective dome, thereby effectively fabricating the reflective dome corresponding to the first microlens structure by using the reflective dome target for back sputtering.

[0148] Example 2

[0149] The difference between this embodiment and Embodiment 1 is that, in this embodiment, a cathode contact is also provided on the driving wafer, and the reflective dome target surrounds the pixel unit and is also connected to the top of the cathode contact and the bottom of the reflective dome. Since the reflective dome target is connected to the top of the cathode contact, it also has the function of cathode communication. Furthermore, the pixel unit includes a P-type semiconductor layer, an N-type semiconductor layer, and an active layer located between the P-type and N-type semiconductor layers, with the N-type semiconductor layer located at the top of the pixel unit. The reflective dome target is also connected to the N-type semiconductor layer at the top of the pixel unit, thereby enabling the pixel unit to conduct with the cathode contact on the driving wafer through this reflective dome target, thus achieving cathode contact.

[0150] In one example, as shown in Figure 12, the N-type semiconductor layer 15 extends toward the side where the reflective dome target 50 is located. The reflective dome target 50 includes a first part target 51. One end of the first part target 51 is connected to the corresponding cathode contact 91, and the other end of the first part target 51 is connected to the bottom of the reflective dome 30. The sidewall of the first part target 51 is connected to the sidewall of the N-type semiconductor layer 15 at the top of the pixel unit 10.

[0151] In one example, as shown in Figure 13, the N-type semiconductor layer 15 extends toward the side where the reflective dome target 50 is located. The reflective dome target 50 includes a second part target 52 and a third part target 53. One end of the second part target 52 is connected to the corresponding cathode contact 91, and the other end of the second part target 52 is connected to a portion of the lower surface of the third part target 53. Another portion of the lower surface of the third part target 53 is connected to the upper surface of the N-type semiconductor layer 15 at the top of the pixel unit 10. A portion of the upper surface of the third part target 53 is connected to the bottom of the reflective dome 30. The sidewall of the second part target 52 is connected to the sidewall of the N-type semiconductor layer 15 at the top of the pixel unit 10.

[0152] When the cathode connection function is achieved through the reflective dome target 50, the above structure does not require a separate common cathode to be set outside the N-type semiconductor layer 15. Instead, the reflective dome target 50 is directly set on the side of the N-type semiconductor layer 15 to connect with it to achieve cathode connection, thereby exposing the N-type semiconductor layer 15. This avoids the devices used for cathode connection from blocking the light-emitting area of ​​the pixel unit 10, greatly improving the light-emitting brightness of the pixel unit 10, achieving better light-emitting efficiency, improving reliability, and also making full use of the N-type semiconductor layer 15, reducing the waste of manufacturing materials and saving costs.

[0153] The fabrication method of the microdisplay device corresponding to the structure described in the above embodiments will be described below. As shown in Figure 7, the fabrication method of the microdisplay device may include the following steps:

[0154] Step S1: Prepare the driver wafer.

[0155] Specifically, the driver wafer includes an anode contact, and an insulating medium is disposed around the anode contact.

[0156] Step S2: Integrate a display module on the driver wafer. The display module is located on the driver wafer and includes: a pixel unit and a first microlens structure covered on the pixel unit. The projection of the top of the pixel unit on the driver wafer is located within the outer contour of the projection of the bottom of the first microlens structure on the driver wafer. The bottom of the first microlens structure is covered with a reflective material to form a reflective dome of the first microlens structure.

[0157] In one possible implementation, step S2 specifically includes:

[0158] S221: An insulating layer is wrapped around the outside of each pixel unit.

[0159] Specifically, S221 may include:

[0160] (1) Preparation of compound wafers.

[0161] After fabrication, the compound wafer includes a substrate, and an N-type semiconductor layer, a compound pixel (also known as an active layer), and a P-type semiconductor layer formed sequentially along the direction away from the substrate.

[0162] (2) The compound wafer is processed to obtain pixel units corresponding to the anode contacts, and an insulating layer is prepared to form a display module.

[0163] Specifically, after the pixel unit is fabricated, a dielectric deposition is performed around the pixel unit to form an insulating layer. The insulating layer is attached to the sidewall of the pixel unit, and the N-type semiconductor layer of the pixel unit is exposed to the outside of the pixel unit.

[0164] S222: Connects a display module with pixel units to a driver wafer, the driver wafer having cathode contacts.

[0165] As shown in Figure 12 or Figure 13, after the display module 200 and the driving wafer 100 are connected, the P-type semiconductor layer 16 of the pixel unit 10 is electrically connected to the corresponding anode contact 93 on the driving wafer 100 through the anode metal component 94, thereby achieving anode connection. For example, one end of the anode metal component 94 can be in contact with the P-type semiconductor 16, and the other end can be in contact with the corresponding anode contact 93 on the driving wafer 100, thereby achieving electrical connection.

[0166] S223: Expose the N-type semiconductor layer at the top of the pixel unit, electrically connect the top of the reflective dome target to the N-type semiconductor layer, connect the bottom of the reflective dome target to the cathode contact, and the reflective dome target surrounds the pixel unit.

[0167] S224: Perform dielectric deposition on top of the pixel unit to form a second dielectric layer.

[0168] S225: Ion beam etching is performed on the second dielectric layer to form a first microlens structure and a reflective dome. The top of the reflective dome target is connected to the bottom of the reflective dome. The reflective dome is formed by back sputtering of the reflective dome target during the ion beam etching process.

[0169] The specific implementation of S225 can be similarly referred to the specific implementation of S214, and will not be repeated here.

[0170] Example 3

[0171] The difference between this embodiment and Embodiment 1 is that, as shown in FIG14, the surface of the pixel unit 10 and the surface of the driving wafer 100 are covered with a continuous common cathode 14, and the bottom of the reflective dome target 50 is spaced from the side of the common cathode 14 away from the driving wafer 100. With this design, the material required for the reflective dome target 50 structure can be reduced, thereby reducing process costs.

[0172] In one example, as shown in Figure 15, the insulating layer 40 also includes another lower resonant cavity 92 surrounding the pixel unit 10. The bottom of the lower resonant cavity 92 is connected to the side of the common cathode 14 away from the driving wafer 100, and the top height of the lower resonant cavity 92 is no higher than the bottom height of the reflective dome 30. The reflective dome target 50 and the lower resonant cavity 92 form a resonant cavity combination structure. Through the resonant cavity combination structure, optical isolation is achieved between pixel units, which can effectively avoid crosstalk problems between adjacent pixel units and enhance the optical resonance of the micro-display device.

[0173] Furthermore, the reflective dome target 50 and the lower resonant cavity 92 are spaced apart by a certain distance in the horizontal direction. The outer contour of the projection of the reflective dome target 50 onto the driving wafer 100 can be within or outside the outer contour of the projection of the lower resonant cavity 92 onto the driving wafer 100.

[0174] The center distance between the lower resonant cavity 92 and the pixel unit 10 is greater than the center distance between the lower resonant cavity 92 and the pixel unit 10, or the center distance between the reflective dome target 50 and the pixel unit 10 is less than the center distance between the lower resonant cavity 92 and the pixel unit 10.

[0175] Furthermore, the bottom height of the reflective dome target 50 is not higher than the top height of the lower resonant cavity 20. With the bottom height of the reflective dome target 50 not higher than the top height of the lower resonant cavity 20, the reflective dome target 50 and the lower resonant cavity 20 are designed to be connected or further intersecting in the vertical direction, so that the resonant cavity combination formed by the reflective dome target 50 and the lower resonant cavity 92 can completely surround the pixel unit 10 in the vertical direction, thereby enabling complete control over the light emitted by the pixel unit 10.

[0176] The fabrication method of the microdisplay device corresponding to the structure described in the above embodiments will be described below. As shown in Figure 7, the fabrication method of the microdisplay device may include the following steps:

[0177] Step S1: Prepare the driver wafer.

[0178] Specifically, the driver wafer includes anode contacts in the vertical direction, and an insulating medium is disposed around the anode contacts.

[0179] Step S2: Integrate a display module on the driver wafer. The display module is located on the driver wafer and includes: a pixel unit and a first microlens structure covered on the pixel unit. The projection of the top of the pixel unit on the driver wafer is located within the outer contour of the projection of the bottom of the first microlens structure on the driver wafer. The bottom of the first microlens structure is covered with a reflective material to form a reflective dome of the first microlens structure.

[0180] In one possible implementation, step S2 specifically includes:

[0181] S231: Fabricate pixel units on the driving wafer.

[0182] The specific implementation of S231 can be similarly referred to the specific implementation of S211, and will not be repeated here. During the fabrication of the pixel unit, after completing the patterning etching of the pixel unit, the process further includes sidewall passivation and common cathode current extension to form a passivation layer and a common cathode, thereby completing the fabrication of the N-type ohmic contact and the common cathode.

[0183] S232: Dielectric deposition is performed around the pixel unit to form an insulating layer.

[0184] S233: Pattern the insulating layer to form a trench structure around the pixel unit.

[0185] The bottom of the trench structure is spaced from the side of the common cathode away from the driving wafer.

[0186] S234: Metal deposition is performed on the trench structure to construct a reflective dome target.

[0187] S235: Dielectric deposition is performed on top of the insulating layer to form a third dielectric layer.

[0188] S236: Ion beam etching is performed on the third dielectric layer to form the first microlens structure and the reflective dome. The top of the reflective dome target is connected to the bottom of the reflective dome. The reflective dome is formed by back sputtering of the reflective dome target during the ion beam etching process.

[0189] The specific implementation of S236 can be similarly referred to the specific implementation of S214, and will not be elaborated here.

[0190] 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.

[0191] It should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A micro-display device integrating a reflective dome, characterized in that, The microdisplay device includes: Driven wafer; The display module is disposed on the driving wafer and includes: a pixel unit and a first microlens structure overlaid on the pixel unit. The projection of the top of the pixel unit on the driving wafer is located within the outer contour of the projection of the bottom of the first microlens structure on the driving wafer, and the bottom of the first microlens structure is covered with a reflective material to form a reflective dome of the first microlens structure.

2. The microdisplay device according to claim 1, characterized in that, The display module also includes: An insulating layer is disposed below the first microlens structure and surrounds the pixel unit; The insulating layer includes a reflective dome target surrounding the pixel unit, with the top of the reflective dome target connected to the bottom of the reflective dome.

3. The microdisplay device according to claim 2, characterized in that, The reflective dome is formed by the reflective dome target material through a reverse sputtering process.

4. The microdisplay device according to claim 2, characterized in that, The distance between the reflective dome target and the pixel unit is not greater than 1 / 2 pixel spacing and not less than 1 / 4 pixel spacing; The pixel spacing refers to the distance between the center points of two adjacent pixel units.

5. The microdisplay device according to claim 2, characterized in that, The projection of the bottom of the first microlens structure onto the driving wafer is located within the outer contour of the projection of the top of the reflective dome target onto the driving wafer, and the horizontal distance between the reflective dome target and the first microlens structure is not less than 0 and not greater than 1 / 2 pixel distance. The pixel spacing refers to the distance between the center points of two adjacent pixel units.

6. The microdisplay device according to claim 2, characterized in that, The top height of the reflective dome target is greater than the top height of the pixel unit.

7. The microdisplay device according to claim 2, characterized in that, The surface of the pixel unit and the surface of the driving wafer are covered with a continuous common cathode; The bottom of the reflective dome target is connected to the side of the common cathode away from the driving wafer.

8. The microdisplay device according to claim 2, characterized in that, The reflective dome target is spaced apart from the first microlens structure, and the reflective dome simultaneously covers the bottom outer periphery of the first microlens structure and the insulating layer between the first microlens structure and the reflective dome target.

9. The microdisplay device according to claim 2, characterized in that, The driving wafer is also provided with a cathode contact, and the reflective dome target is connected to the top of the cathode contact and the bottom of the reflective dome.

10. The microdisplay device according to claim 9, characterized in that, The N-type semiconductor at the top of the pixel unit extends toward the side where the reflective dome target is located. The reflective dome target includes a first part of the target, one end of which is connected to a corresponding cathode contact, and the other end of which is connected to the bottom of the reflective dome. The sidewall of the first part of the target is connected to the sidewall of the N-type semiconductor layer at the top of the pixel unit. or, The N-type semiconductor at the top of the pixel unit extends toward the side where the reflective dome target is located. The reflective dome target includes a second part target and a third part target. One end of the second part target is connected to the corresponding cathode contact, and the other end of the second part target is connected to a portion of the lower surface of the third part target. Another portion of the lower surface of the third part target is connected to the upper surface of the N-type semiconductor layer at the top of the pixel unit. A portion of the upper surface of the third part target is connected to the bottom of the reflective dome. The sidewall of the second part target is connected to the sidewall of the N-type semiconductor layer at the top of the pixel unit.

11. The microdisplay device according to claim 2, characterized in that, The surface of the pixel unit and the surface of the driving wafer are covered with a continuous common cathode; The bottom of the reflective dome target is spaced from the side of the common cathode away from the driving wafer.

12. The microdisplay device according to claim 11, characterized in that, The insulating layer also includes another lower resonant cavity surrounding the pixel unit. The bottom of the lower resonant cavity is connected to the side of the common cathode away from the driving wafer. The top height of the lower resonant cavity is not higher than the bottom height of the reflective dome.

13. The microdisplay device according to claim 1, characterized in that, The height of the reflective dome is less than 1 / 3 of the height of the first microlens structure.

14. The microdisplay device according to claim 1, characterized in that, The thickness of the reflective dome is between 100nm and 300nm.

15. The microdisplay device according to claim 1, characterized in that, The display module also includes: A second microlens structure is disposed over the first microlens structure and the reflective dome.

16. The microdisplay device according to claim 1, characterized in that, The reflective material is a metallic material.

17. A method for fabricating a microdisplay device, characterized in that, The method is used to prepare the microdisplay device as described in any one of claims 1 to 16, the method comprising: Prepare the driver wafer; A display module is integrated on the driving wafer. The display module is disposed on the driving wafer and includes: a pixel unit and a first microlens structure overlaid on the pixel unit. The projection of the top of the pixel unit on the driving wafer is located within the outer contour of the projection of the bottom of the first microlens structure on the driving wafer. The bottom of the first microlens structure is covered with a reflective material to form a reflective dome of the first microlens structure.

18. The method according to claim 17, characterized in that, The integration of the display module on the driving wafer includes: Pixel units are fabricated on the driving wafer; Prepare a reflective dome target material surrounding the pixel unit; A dielectric deposition is performed around the pixel unit to form a first dielectric layer, the top of which is higher than the top of the reflective dome target. The first dielectric layer is etched by an ion beam to form an insulating layer around the pixel unit, the first microlens structure, and the reflective dome. The top of the reflective dome target is connected to the bottom of the reflective dome. The reflective dome is formed by back sputtering of the reflective dome target during the ion beam etching process.

19. The method according to claim 18, characterized in that, The step of ion beam etching the first dielectric layer to form the insulating layer around the pixel unit, the first microlens structure, and the reflective dome includes: A photoresist layer is deposited on top of the first dielectric layer, and the photoresist layer is aligned with the pixel unit; The first dielectric layer is subjected to photolithography and plasma etching through the photoresist layer to expose the reflective dome target and obtain the insulating layer and the columnar structure above the pixel unit; The columnar structure is morphologically transformed by ion beam etching to form the first microlens structure and the reflective dome.

20. The method according to claim 17, characterized in that, The integration of the display module on the driving wafer includes: An insulating layer is wrapped around the outside of each pixel unit; A display module having the pixel units is connected to a driving wafer, and the driving wafer is provided with cathode contacts; The top of the pixel unit is exposed, and the top of the reflective dome target is electrically connected to the N-type semiconductor layer. The bottom of the reflective dome target is connected to the cathode contact, and the reflective dome target surrounds the pixel unit. A dielectric layer is deposited over the pixel unit to form a second dielectric layer; The second dielectric layer is etched by an ion beam to form the first microlens structure and the reflective dome. The top of the reflective dome target is connected to the bottom of the reflective dome. The reflective dome is formed by back sputtering of the reflective dome target during the ion beam etching process.

21. The method according to claim 17, characterized in that, The integration of the display module on the driving wafer includes: Pixel units are fabricated on the driving wafer; A dielectric deposition is performed around the pixel unit to form the insulating layer; The insulating layer is patterned and etched to form a trench structure surrounding the pixel unit; Metal is deposited on the trench structure to construct the reflective dome target; A dielectric layer is deposited over the insulating layer to form a third dielectric layer; The third dielectric layer is etched by an ion beam to form the first microlens structure and the reflective dome. The top of the reflective dome target is connected to the bottom of the reflective dome. The reflective dome is formed by back sputtering of the reflective dome target during the ion beam etching process.

22. The method according to claim 21, characterized in that, Before forming the third dielectric layer, the method further includes: A continuous common cathode is disposed on the surface of the pixel unit and the surface of the driving wafer; A lower resonant cavity is prepared surrounding the pixel unit, the bottom of which is connected to the side of the common cathode away from the driving wafer.

23. The method according to claim 18, characterized in that, The method further includes: A second microlens structure is fabricated by dielectric deposition on the first microlens structure and the reflective dome.

24. The method according to claim 17, characterized in that, The reflective material is a metallic material.

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