Intermediate state microdisplay device and microdisplay device

Abstract

The utility model discloses an intermediate state micro-display device and a micro-display device, and relates to the technical field of semiconductors. The intermediate state micro display device includes: a driving wafer; the display module comprises at least two pixel units arranged on the driving wafer, the at least two pixel units protrude in the direction away from the driving wafer, the surface of the display module is covered with a first dielectric layer made of a transparent dielectric material, and the surface of the display module is covered with a second dielectric layer made of a transparent dielectric material. The first dielectric layer comprises a columnar structure covering the top of the pixel unit, the columnar structure is used for forming a first micro lens covering the top of the pixel unit through ion beam etching, and the first micro lens is etched into a spherical structure or a conical structure. Based on the technical scheme provided by the invention, the preparation of the micro lens does not need to carry out a traditional process of etching after melting a micro lens morphology mask, also does not need to execute a surface planarization and hot reflux process, and is simple in process and high in yield.

Description

Technical Field

[0001] The utility model relates to the technical field of semiconductors, in particular to an intermediate-state microdisplay device and a microdisplay device. Background Art

[0002] Currently, the form of optical waveguide is mostly used to couple with Micro-LED chips. Due to the relatively high optical loss of the optical waveguide optical path and the characteristic of requiring collimated light input, the brightness at the display end is not satisfactory. Therefore, a microlens is usually configured on the Micro-LED chip to improve the coupling efficiency between the Micro-LED chip and the optical waveguide system.

[0003] The preparation schemes of traditional microlenses include photoresist reflow, etching, printing, laser direct writing, droplet wetting, nanoimprinting, etc. Except for the etching scheme, they are basically organic materials. The organic materials have poor heat resistance and anti-mechanical deformation performance. The etching scheme combines the photoresist reflow scheme to prepare the microlens morphology, and uses etching to transfer the pattern, transferring the microlens morphology to the inorganic material. In this scheme, the molten etching structure is prone to deformation, resulting in yield problems, and the preparation and planarization processes of inorganic materials are complex and require high requirements.

[0004] Therefore, there is an urgent need to provide a new preparation scheme for microlenses that can avoid the above defects. Summary of the Utility Model

[0005] The purpose of the utility model is to provide an intermediate-state microdisplay device and a microdisplay device, which do not need to perform the process of etching after masking the morphology of the traditional molten microlens, nor do they need to perform surface planarization and thermal reflow processes, with simple processes and high yield.

[0006] To achieve the above utility model purpose, the utility model proposes the following technical solutions:

[0007] On the one hand, an intermediate-state microdisplay device for microlens preparation is provided. The intermediate-state microdisplay device includes:

[0008] A driving wafer;

[0009] A display module, the display module includes at least two pixel units disposed on the driving wafer, the at least two pixel units protrude away from the driving wafer, and the surface of the display module is covered with a first dielectric layer composed of a transparent dielectric material. The first dielectric layer includes columnar structures covering the tops of the pixel units, and the columnar structures are used for ion beam etching to form first microlenses covering the tops of the pixel units. The first microlenses are etched into spherical structures or conical structures.

[0010] In a possible implementation, the first dielectric layer further includes:

[0011] A groove structure, which is filled between two adjacent pixel units, and the groove structure encloses a filling gap between two adjacent pixel units.

[0012] In a possible implementation, the depth of the filling gap is not less than 1 micron, and the width of the filling gap is not less than 0.5 micron.

[0013] In a possible implementation, the thickness of the first dielectric layer is not greater than the pixel pitch, and the pixel pitch is the distance between the edges of two adjacent pixel units.

[0014] In a possible implementation, the thickness of the first dielectric layer is not less than 0.5 micron.

[0015] In a possible implementation, the width of the columnar structure is not less than the width of the active layer in the pixel unit.

[0016] On the other hand, a microdisplay device is provided. The microdisplay device is prepared by the intermediate-state microdisplay device as described in the above aspect. The microdisplay device includes:

[0017] A driving wafer;

[0018] A display module, which includes at least two pixel units disposed on the driving wafer. The at least two pixel units protrude away from the driving wafer. The surface of the display module is covered with a first microlens made of a transparent dielectric material. The first microlens is etched into a spherical structure or a conical structure. The first microlens is formed by ion beam etching of a columnar structure covering the top of the pixel unit.

[0019] In a possible implementation, the microdisplay device further includes:

[0020] A second microlens, which is covered on the outer surface of the first microlens.

[0021] Compared with the prior art, the present utility model has the following beneficial effects:

[0022] A middle - state micro - display device for micro - lens preparation is provided. A display module is arranged on a driving wafer, and a first dielectric layer composed of a transparent dielectric material is covered on the surface of the display module. The first dielectric layer includes columnar structures deposited on top of pixel units. These columnar structures can be directly transformed into first micro - lenses with spherical or conical structures through ion beam etching. The micro - lenses are made of all - inorganic materials, with high temperature resistance, strong resistance to mechanical deformation, and do not require the process of etching after the topography mask of traditional molten micro - lenses, nor do they need to perform surface planarization and thermal re - flow processes. The process is simple and has a high yield.

[0023] Furthermore, the size of the micro - lens can be flexibly adjusted by continuously covering a transparent dielectric material on the first micro - lens, which is convenient for mass production operations. Description of the Drawings

[0024] Figure 1 It is a schematic structural diagram of a middle - state micro - display device provided in an embodiment of the present application;

[0025] Figure 2 It is a schematic structural diagram of a micro - display device provided in an embodiment of the present application;

[0026] Figure 3 It is a schematic structural diagram of a micro - display device provided in an embodiment of the present application;

[0027] Figure 4 It is a schematic structural diagram of a pixel unit provided in an embodiment of the present application;

[0028] Figure 5 It is a schematic diagram of the light - emitting parameters of a micro - display device provided in an embodiment of the present application;

[0029] Figure 6 It is a flowchart of a method for preparing a micro - display device provided in an embodiment of the present application;

[0030] Figure 7 It is a schematic structural diagram of a micro - display device with a third dielectric layer provided in an embodiment of the present application;

[0031] Figure 8 It is a schematic structural diagram of a micro - display device with part of the third dielectric layer removed provided in an embodiment of the present application;

[0032] Figure 9 It is a schematic structural diagram of a micro - display device with part of the bonding metal layer removed provided in an embodiment of the present application;

[0033] Figure 10 It is a schematic structural diagram of a micro - display device with a passivation layer and a common cathode provided in an embodiment of the present application;

[0034] Figure 11 It is a schematic structural diagram of an intermediate state microdisplay device provided in an embodiment of the present application;

[0035] Figure 12 It is a schematic structural diagram of a microdisplay device prepared with a photoresist layer provided in an embodiment of the present application;

[0036] Figure 13 It is a schematic structural diagram of a microdisplay device after the first dielectric layer is processed provided in an embodiment of the present application.

[0037] Reference numerals:

[0038] 100 - driving wafer, 200 - display module, 10 - pixel unit, 11 - bonding metal layer, 12 - compound pixel, 13 - second dielectric layer, 14 - passivation layer, 15 - common cathode, 16 - common cathode metal, 20 - first dielectric layer, 21 - columnar structure, 22 - groove structure, 30 - first microlens, 40 - second microlens, 50 - photoresist layer. Detailed implementation manners

[0039] To make the objectives, technical solutions and advantages of the present utility model clearer, the technical solutions in the embodiments of the present utility model will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present utility model. Apparently, the described embodiments are only a part rather than all of the embodiments of the present utility model. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present utility model without creative efforts shall fall within the protection scope of the present utility model.

[0040] In the description of the present utility model, it should be understood that the orientation or positional relationships indicated by the terms "vertical", "upper", "lower", "top", "side", "inner", "outer", etc. are based on the orientation or positional relationships shown in the drawings, and are only for the convenience of describing the present disclosure and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation of the present utility model. In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present utility model, unless otherwise specified, the meaning of "a plurality" is two or more.

[0041] In the description of the present utility model, it should be noted that unless otherwise clearly specified and defined, the terms "installation", "connection", and "coupling" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to specific circumstances.

[0042] The preparation schemes of traditional microlenses have various defects, such as:

[0043] (1) When preparing microlenses using the photoresist melting scheme, the lenses are all organic structures under this scheme, and the temperature resistance and mechanical deformation resistance of the materials are poor; such as Patent CN117008226 A.

[0044] (2) When preparing microlenses using the imprinting scheme, the lenses are also organic structures under this scheme. In addition to the poor temperature resistance and mechanical properties of the materials, an additional imprinting template needs to be prepared, the process is relatively cumbersome, and problems such as adhesion are likely to occur during demolding after imprinting, resulting in low yield; such as Patent CN1977189A, CN114913558A.

[0045] (3) When preparing microlenses using the etching scheme, combining the photoresist melting scheme to prepare the microlens morphology, and using etching to transfer the pattern, the microlens morphology is transferred to quartz. This scheme has high process requirements and is relatively complex. The molten etching structure is prone to lens deformation, resulting in low yield; such as Patent CN115343788A.

[0046] In order to avoid the above problems, in the embodiments of the present application, a technical scheme for preparing microlenses is proposed, in which a transparent dielectric material is deposited to form a columnar structure on a pixel unit, and then the columnar structure is etched by an ion beam.

[0047] Next, the device structure proposed in the present application will be described.

[0048] First, the embodiments of the present application provide an intermediate-state microdisplay device for microlens preparation, as Figure 1 shown, the intermediate-state microdisplay device includes:

[0049] Drive wafer 100; display module 200, the display module 200 includes at least two pixel units 10 disposed on the drive wafer 100, the at least two pixel units 10 protrude away from the drive wafer 100, and the surface of the display module 200 is covered with a first dielectric layer 20 made of a transparent dielectric material. The first dielectric layer 20 includes a columnar structure 21 covering the top of the pixel unit 10. The columnar structure 21 is used for ion beam etching to form a first microlens 30 covering the top of the pixel unit 10, and the first microlens 30 is etched into a spherical structure or a conical structure.

[0050] In the embodiment of the present application, a display module 200 is disposed on the drive wafer 100, and the surface of the display module 200 is covered with a first dielectric layer 20 made of a transparent dielectric material. The first dielectric layer 20 includes a columnar structure 21 deposited on the top of the pixel unit 10, and this columnar structure 21 is utilized to form the microlens. Specifically, this columnar structure 21 can be directly etched by an ion beam to further transform into a first microlens 30 with a spherical structure or a conical structure.

[0051] Among them, the drive wafer 100 can be an active design combined with one or more of thin film transistors (TFTs), low temperature polysilicon (LTPS), CMOS integrated circuits, high electron mobility transistors (HEMTs), etc. Specifically, the drive wafer 100 is provided with a drive circuit, the drive circuit is provided with at least one anode contact, and the drive circuit can include an active, passive, or semi - passive control circuit. All the anode contacts included in the drive circuit can be linearly arranged or array - arranged, and any anode contact is located in the middle or on the edge of the drive wafer 100, and this embodiment does not limit this.

[0052] Among them, ion beam etching (IBE) is a micro - nano processing technology. Through the chemical reaction and physical impact effect of the ion beam, it can remove part of the material on the surface of the material, thereby realizing the etching and processing of the material. Ion beam etching is a direct etching technology. The ion beam accurately aims at the surface of the material and etches the material through the interaction between ions and the atoms on the surface of the material. Therefore, high - precision processing can be achieved. Specifically in this application, the etching shape can be controlled to precisely process the columnar structure 21 into the first microlens 30 with a spherical structure or a conical structure as shown in Figure 2 the first microlens 30 with a spherical structure or a conical structure.

[0053] Among them, the first dielectric layer 20 can specifically be inorganic silicon oxide, silicon nitride, aluminum oxide, etc., including PSG (phosphate glass), BPSG (borophosphosilicate glass) processes or inorganic silicon oxides or nitrogen oxides prepared using deposition sources such as TEOS (tetraethyl orthosilicate), TEPO (triethyl phosphate).

[0054] Among them, the pixel unit 10 can be as Figure 4 shown, which includes, stacked in the direction away from the driving wafer 100: a bonding metal layer 11, a compound pixel 12, the compound pixel 12 is filled with a second dielectric layer 13 around it, and during the ion beam etching process of the bonding metal layer 11, it is re-sputtered and deposited on the side wall of the second dielectric layer 13 to form a metal fence. A passivation layer 14 is deposited on the surface of the driving wafer 100 and the side wall of the metal fence, and a common cathode 15 is deposited on the surface of the passivation layer 14 and the surface of the compound pixel 12. On the common cathode 15 on the surface of the driving wafer 100, a common cathode metal 16 is prepared.

[0055] Among them, the second dielectric layer 13 can specifically be inorganic silicon oxide, silicon nitride, aluminum oxide, etc., including PSG (phosphate glass), BPSG (borophosphosilicate glass) process or inorganic silicon oxide or nitrogen oxide prepared by deposition sources such as TEOS (tetraethyl orthosilicate), TEPO (triethyl phosphate). The material of the second dielectric layer 13 and the above-mentioned first dielectric layer 20 can be the same or different, and the present application does not limit this. The passivation layer 14 can be a single layer or a stack of dielectric layers such as aluminum oxide, silicon nitride, and silicon oxide. The common cathode 15 can adopt a transparent conductive film, and the transparent conductive film can be one or a combination of ITO (Indium Tin Oxide) film, AZO (Antimony doped Zinc Oxide) film, ATO (Antimony doped Tin Oxide) film, FTO (Fluorine doped Tin Oxide) film. The transparent conductive film can also be a metal-doped ITO formed by annealing after plating a thin metal (such as Al, Au, Ag) on the surface of ITO to enhance the current transmission ability of the common cathode 15.

[0056] In the embodiment of the present application, since the pixel unit 10 protrudes above the surface of the driving wafer 100, when the first dielectric layer 20 is covered on the surface of the display module 200, the first dielectric layer 20 further includes: a groove structure 22, the groove structure 22 is filled between two adjacent pixel units 10, and the groove structure 22 encloses the filling gap between two adjacent pixel units 10. It can be understood that the groove structure 22 generally presents as a depression toward the driving wafer 100 side, so that there is a filling gap between two adjacent columnar structures 21. The specific structural shape of the groove structure 22 is associated with the side wall shape of the pixel unit 10 and the surface shape of the driving wafer 100. The filling gap enclosed by the groove structure can be in the style of being larger at the upper part and smaller at the lower part.

[0057] In a possible implementation, the depth of the filling gap is not less than 1 micron, and the width of the filling gap is not less than 0.5 micron. To ensure the processing space for ion beam etching of the columnar structure 21, therefore, there needs to be a sufficient spacing between two adjacent columnar structures 21, that is, the filling gap needs to have a certain scale of topography. Its depth is specifically the distance from the top of the columnar structure 21 to the bottom of the filling gap, which needs to be not less than 1 micron, and its width is specifically the longest distance in the horizontal direction, which needs to be not less than 0.5 micron.

[0058] In a possible implementation, the thickness of the first dielectric layer 20 is not greater than the pixel pitch, and the pixel pitch is the distance between the edges of two adjacent pixel units 10. When depositing the first dielectric layer 20, the thickness of the first dielectric layer 20 can be controlled, specifically that the thickness of the first dielectric layer 20 is not greater than the pixel pitch formed between the edges of two adjacent pixel units 10, so as to obtain a filling gap that meets the conditions and the required columnar structure 21. Among them, the thickness of the first dielectric layer 20 can specifically refer to the thickness of the columnar structure 21 in the first dielectric layer 20.

[0059] In a possible implementation, the thickness of the first dielectric layer 20 is not less than 0.5 micron. Since the first dielectric layer 20 needs to have a certain thickness to prepare the microlens structure subsequently, therefore, the thickness of the first dielectric layer 20 is designed to be not less than 0.5 micron. Among them, the thickness of the first dielectric layer 20 can specifically refer to the thickness of the columnar structure 21 in the first dielectric layer 20.

[0060] In a possible implementation, the width of the columnar structure 21 is not less than the width of the active layer in the pixel unit 10. To ensure that the first microlens 30 above the pixel unit 10 can converge the light emitted by the active layer, therefore, the width of the columnar structure 21 is designed to be not less than the width of the active layer in the pixel unit 10, so that the first microlens 30 prepared through this columnar structure 21 can effectively process the outgoing light and improve the optical performance.

[0061] Based on the structure of the above intermediate-state microdisplay device, a final microdisplay device can be further prepared, such as Figure 2 shown, the microdisplay device includes:

[0062] Drive the wafer 100; a display module 200, the display module 200 includes at least two pixel units 10 disposed on the drive wafer 100, and at least two pixel units 10 protrude away from the drive wafer 100. The surface of the display module 200 is covered with a first microlens 30 made of a transparent dielectric material. The first microlens 30 is etched into a spherical structure or a conical structure. The first microlens 30 is formed by ion beam etching of a columnar structure 21 covering the top of the pixel unit 10.

[0063] After directly performing ion beam etching on the columnar structure 21 on the pixel unit 10 as shown in Figure 1 , it can be transformed into the first microlens 30 with a spherical structure or a conical structure as shown in Figure 2 .

[0064] It can be understood that in the conventional technical solutions for preparing microlenses, such as photoresist reflow, etching, printing, laser direct writing, droplet wetting, nanoimprinting, etc., except for the etching solution, they are basically organic materials, and the organic materials have poor heat resistance and anti-mechanical deformation performance. The etching and in-situ growth solutions are to prepare the microlens morphology in combination with the photoresist reflow solution, use etching to transfer the pattern, and transfer the microlens morphology to the inorganic material. In the solution, the molten etching structure is prone to deformation, resulting in yield problems. The preparation and planarization processes of inorganic materials are complex, and the process difficulty and yield challenges are large. In the present application, after the transparent dielectric material is deposited, the microlens is prepared by ion beam etching the columnar structure 21, without the need for the process of etching after masking the conventional molten microlens morphology, nor the need to perform surface planarization and thermal reflow processes, and the process is simple and the yield is high.

[0065] In a possible implementation manner, the microdisplay device further includes: a second microlens 40, and the second microlens 40 is covered on the outer surface of the first microlens 30.

[0066] As shown in Figure 3 , subsequently, another layer of transparent dielectric material can be covered to form a third dielectric layer to add the second microlens 40, so as to flexibly control the microlens size and improve the microlens performance.

[0067] Among them, the third dielectric layer can specifically be inorganic silicon oxide, silicon nitride, aluminum oxide, etc., including PSG (phosphate glass), BPSG (borophosphosilicate glass) process or inorganic silicon oxide or nitrogen oxide prepared by deposition sources such as TEOS (tetraethoxysilane), TEPO (triethyl phosphate). The second microlens 40 can be the same material as the first microlens 30 or different materials, and the present application does not limit this.

[0068] It is understandable that the present application does not limit the thickness of the second microlens 40. In addition, on the basis of the second microlens 40, one or more additional layers of transparent dielectric material can be further coated to form a new microlens structure.

[0069] Exemplarily, through the above-mentioned microlens, as Figure 5 shown, the emission angle of the microdisplay device converges from 105° ( Figure 5 left, without microlens) to 50° ( Figure 5 right, with microlens).

[0070] In summary, the embodiments of the present application provide an intermediate-state microdisplay device for microlens preparation, which sets a display module on a driving wafer. The surface of the display module is covered with a first dielectric layer composed of a transparent dielectric material. The first dielectric layer includes columnar structures deposited on top of pixel units. These columnar structures can be directly transformed into spherical or conical first microlenses through ion beam etching. The microlenses are all-inorganic materials, with high temperature resistance and strong resistance to mechanical deformation. Moreover, there is no need for the process of etching after the topography mask of traditional fused microlenses, nor the need to perform surface planarization and thermal reflow processes. The process is simple and the yield is high.

[0071] Furthermore, the microlens size can be flexibly adjusted by continuously coating transparent dielectric material on the first microlens, which facilitates mass production operations.

[0072] Next, a method for preparing the microdisplay device corresponding to the above-described structure will be described.

[0073] As Figure 6 shown, the method for preparing the microdisplay device may include the following steps:

[0074] Step S1: Prepare a display module on a driving wafer. The display module includes at least two pixel units disposed on the driving wafer, and the at least two pixel units protrude away from the driving wafer.

[0075] In this step, protruding pixel units are prepared on the driving wafer. The present application does not limit whether the top surface of the protruding pixel units is flat. It can be flat or have certain undulations. Further, the driving wafer may have anode contacts, and the pixel units in the display module are correspondingly arranged with the anode contacts in the driving wafer. One pixel unit can correspond to one anode contact or multiple anode contacts.

[0076] Among them, the specific preparation steps of the display module can be as follows:

[0077] (1) Prepare a second dielectric layer on the compound pixel surface and remove the second dielectric layer on the surface of the bonding metal layer.

[0078] As shown Figure 7 in the figure, a transparent dielectric material is deposited on the surface of the compound pixel 12 to prepare the second dielectric layer 13. As shown Figure 8 in the figure, the device is subjected to plasma etching, and the second dielectric layer 13 on the surface of the bonding metal layer 11 is removed by using the anisotropy of plasma etching.

[0079] (2) Remove the bonding metal layer between the pixel units.

[0080] As shown Figure 9 in the figure, the device is subjected to ion beam etching to remove the bonding metal layer 11 between the pixel units. During the ion beam etching process, metal atoms form re-sputter and deposit on the sidewalls of the second dielectric layer 13 to form a metal fence.

[0081] (3) Passivate the surface of the device and prepare a common cathode.

[0082] As shown Figure 10 in the figure, after the patterning etching of the pixel units is completed, sidewall passivation and common cathode current spreading are further introduced to form a passivation layer 14 and a common cathode 15 to complete the preparation of the N-type ohmic contact and the common cathode.

[0083] (4) Prepare the common cathode metal.

[0084] As shown Figure 4 in the figure, a common cathode metal 16 is prepared on the common cathode between adjacent pixel units. The preparation method can be lift off, electroplating, patterning etching, etc., and the present application does not limit this. Further, the top height of the common cathode metal 16 is not higher than the top height of the compound pixel.

[0085] Step S2: Deposit a transparent dielectric material on the display module to form a columnar structure on the top of each pixel unit.

[0086] In this step, taking the raised pixel units in the display module as a guide, a transparent dielectric material is deposited above them. The deposited first dielectric layer includes columnar structures on the top of each pixel unit.

[0087] In a possible implementation manner, step S2 may specifically include: depositing a transparent dielectric material on the display module and controlling the thickness of the transparent dielectric material to be less than the pixel pitch to form a first dielectric layer; wherein, the pixel pitch is the distance between the edges of two adjacent pixel units, and the first dielectric layer includes continuous columnar structures and groove structures. The groove structures are structures filled between two adjacent pixel units, and the groove structures enclose the filling gaps between two adjacent pixel units.

[0088] In this implementation, since the filling of the transparent dielectric material has the characteristic that the filling of the plane is faster than that of the sidewalls, when the thickness of the transparent dielectric material is controlled to be less than or equal to the pixel pitch, the required groove structure will be formed between the pixel units after filling, and the groove structure can provide sufficient space for the subsequent etching of the columnar structure.

[0089] Further, if the thickness of the transparent dielectric material is greater than the pixel pitch, after forming the first dielectric layer, the following steps need to be further performed: A photoresist layer is covered above the top of the columnar structure, and the width of the photoresist layer is smaller than the width of the columnar structure; the first dielectric layer is lithographed and plasma-etched through the photoresist layer to obtain a columnar structure with a limited surface size.

[0090] In this implementation, when the thickness of the formed first dielectric layer 20 is greater than the pixel pitch, the Figure 11 shown structure is obtained, and the corresponding columnar structure spacing is small, which is not suitable for direct ion beam etching. Therefore, as Figure 12 、 13 shown, after covering the photoresist layer 50, lithography can be performed followed by plasma etching to obtain a columnar structure with a limited surface size. It can be understood that when the surface size of the columnar structure is limited, no planarization treatment is required, and no complex processes such as heating and reflux are required after lithography.

[0091] Among them, for the columnar structure with a limited surface size, the depth of the corresponding filling gap is not less than 1 micron, and the width is not less than 0.5 micron.

[0092] Step S3: Perform ion beam etching on the columnar structure to etch it into a spherical structure or a conical structure to form a first microlens covering the top of the pixel unit.

[0093] In this step, the device is subjected to ion beam etching to transform the transparent dielectric material from a columnar structure into a spherical structure or a conical structure to form a first microlens.

[0094] In a possible implementation, after forming the first microlens, the following steps are further included: Depositing the transparent dielectric material on the display module again to construct a second microlens above the first microlens.

[0095] In this implementation, after forming the first microlens through the columnar structure, the transparent dielectric material can continue to be covered, and the size of the microlens can be flexibly adjusted by the thickness of the transparent dielectric material, which is convenient for mass production operations.

[0096] In summary, in the method for manufacturing a microdisplay device provided by the embodiments of the present application, a display module is disposed on a driving wafer, and a first dielectric layer composed of a transparent dielectric material is disposed on the surface of the display module. The first dielectric layer includes columnar structures deposited on top of pixel units. These columnar structures can be directly transformed into first microlenses in the shape of spherical structures or conical structures through ion beam etching. The microlenses are made of all-inorganic materials, have high temperature resistance and strong resistance to mechanical deformation, and do not require the process of etching after the topography mask of traditional molten microlenses, nor do they require surface planarization and thermal reflow processes. The process is simple and has a high yield.

[0097] Furthermore, the size of the microlenses can be flexibly adjusted by continuously covering the first microlenses with a transparent dielectric material, which facilitates mass production operations.

[0098] Any combination of the above all optional technical solutions can form an optional embodiment of the present invention, that is, any number of embodiments can be combined to meet the requirements of different application scenarios, and all are within the protection scope of the present application, and will not be elaborated herein one by one.

[0099] It should be noted that the above are only the preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. An intermediate state micro display device for preparing a micro lens, characterized in that: The intermediate state micro display device comprises: Driver wafer; A display module, the display module includes at least two pixel units arranged on the driving wafer, the at least two pixel units protrude in a direction away from the driving wafer, the surface of the display module is covered with a first dielectric layer composed of a transparent dielectric material, the first dielectric layer includes a columnar structure covering the top of the pixel unit, the columnar structure is used to form a first microlens covering the top of the pixel unit through ion beam etching, and the first microlens is etched into a spherical structure or a conical structure.

2. The intermediate state micro display device according to claim 1, characterized in that: The first dielectric layer further comprises: A groove structure is filled between two adjacent pixel units, and the groove structure encloses a filling gap between two adjacent pixel units.

3. The intermediate state micro display device according to claim 2, characterized in that: The depth of the filling gap is not less than 1 micron, and the width of the filling gap is not less than 0.5 micron.

4. The intermediate state micro display device according to claim 1, characterized in that: The thickness of the first dielectric layer is not greater than a pixel pitch, where the pixel pitch is the distance between edges of two adjacent pixel units.

5. The intermediate state micro display device according to claim 1, characterized in that: The thickness of the first dielectric layer is not less than 0.5 micrometers.

6. The intermediate state micro display device according to claim 1, characterized in that: The width of the columnar structure is not less than the width of the active layer in the pixel unit.

7. A micro display device, characterized in that: The micro display device is prepared by the intermediate state micro display device according to any one of claims 1 to 6, and the micro display device comprises: Driver wafer; A display module, wherein the display module comprises at least two pixel units arranged on the driving wafer, wherein the at least two pixel units protrude in a direction away from the driving wafer, wherein the surface of the display module is covered with a first microlens made of a transparent dielectric material, wherein the first microlens is etched into a spherical structure or a conical structure, and wherein the first microlens is formed by ion beam etching a columnar structure covering the top of the pixel unit.

8. The micro display device according to claim 7, characterized in that: The micro display device also includes: A second microlens is disposed on an outer surface of the first microlens.

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