Microdisplay device

Abstract

The utility model discloses a micro display device, which belongs to the technical field of semiconductors and comprises a driving wafer and a plurality of display device layers arranged on the driving wafer, and any display device layer comprises sub-pixels. A semiconductor electrode conduction structure is arranged in at least one display device layer, and the semiconductor electrode conduction structure is used for realizing electrode conduction for sub-pixels in the upper display device layer; the semiconductor electrode conduction structure comprises a fence type conduction structure and a cylindrical type conduction structure located in the fence type conduction structure. Based on the technical scheme, through the cylindrical type conduction structure and the fence type conduction structure, the conductivity of the micro-display device is improved, and the limitation of poor conductivity on the application scene of the micro-display device is avoided.

Description

Technical Field

[0001] The utility model relates to the technical field of semiconductors, in particular to a micro display device. Background Art

[0002] Micro LEDs are the core chips of devices such as AR (augmented reality) and VR (virtual reality). Due to their small size, high integration, and self-luminescence, Micro LEDs are considered the best solution compared to technologies such as LCOS (liquid crystal on silicon) and OLED (organic light-emitting diodes) due to their advantages of high resolution, low power consumption, high brightness, and long life.

[0003] In the application of microdisplay devices, they are required to be able to carry large currents and have good electrical conductivity. Therefore, how to improve the electrical conductivity of microdisplay devices urgently requires a new technical solution. Utility Model Content

[0004] The purpose of the utility model is to provide a micro display device with better electrical conductivity.

[0005] In order to achieve the above-mentioned purpose of the utility model, the utility model proposes the following technical solutions:

[0006] A micro display device, comprising a driver wafer and a plurality of display device layers disposed on the driver wafer, wherein any of the display device layers comprises sub-pixels;

[0007] A semiconductor electrode conduction structure is provided in at least one of the display device layers, and the semiconductor electrode conduction structure is used to achieve electrode conduction for sub-pixels in the upper display device layer;

[0008] The semiconductor electrode conductive structure includes a fence-style conductive structure and a column-style conductive structure located inside the fence-style conductive structure.

[0009] In a possible implementation, the fence-style conductive structure includes: a first conductive structure arranged in a horizontal direction and a second conductive structure arranged in a vertical direction;

[0010] The bottom of the second conductive structure is connected to the outer edge of the first conductive structure in the current display device layer to surround the first conductive structure, and the top is connected to the sub-pixel in the upper display device layer, or connected to the bottom of the first conductive structure in the upper display device layer;

[0011] The bottom of the first conductive structure is connected to the anode contact in the driver wafer, or is connected to the top of the second conductive structure in the lower display device layer.

[0012] In a possible implementation, the bottom of the columnar conductive structure is connected to the first conductive structure, and the top is flush with the top of the second conductive structure.

[0013] In a possible implementation, the first conductive structure includes:

[0014] A bonding metal layer and a first ohmic contact layer are vertically stacked in a direction away from the driving wafer.

[0015] In a possible implementation, the thickness of the bonding metal layer is between 10 nm and 1.5 um.

[0016] In a possible implementation, the thickness of the first ohmic contact layer is between 5 nm and 300 nm.

[0017] In a possible implementation, the columnar conductive structure passes through the first ohmic contact layer, and a bottom surface thereof is connected to an upper surface of the bonding metal layer.

[0018] In a possible implementation, the surface area of the columnar conductive structure widens in a direction away from the driver wafer.

[0019] In a possible implementation, the surface area of the columnar conductive structure remains the same along a direction away from the driver wafer.

[0020] In a possible implementation, the micro display device includes more than two display device layers;

[0021] In a display device layer with more than two layers, the semiconductor electrode conductive structure of the display device layer located at the bottom layer includes: a fence-style conductive structure and the column-style conductive structure.

[0022] In a possible implementation, the columnar conductive structure runs through the color compound.

[0023] In a possible implementation, a horizontal dimension of the fence-style conductive structure in the lower display device layer is smaller than or equal to a horizontal dimension of the fence-style conductive structure in the upper display device layer.

[0024] In a possible implementation, the angle of the fence-style conductive structure is between 65 degrees and 115 degrees.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] The microdisplay device includes a driver wafer and a multi-layer display device layer arranged on the driver wafer. Any display device layer includes sub-pixels. At least one display device layer is provided with a semiconductor electrode conduction structure. The semiconductor electrode conduction structure is used to achieve electrode conduction for the sub-pixels in the upper display device layer. The semiconductor electrode conduction structure includes a fence-style conduction structure and a columnar style conduction structure located inside the fence-style conduction structure. Electrode conduction is achieved through a structure combining the columnar style conduction structure and the fence-style conduction structure, thereby increasing the metal volume for anode conduction to improve the conductivity of the microdisplay device.

[0027] Furthermore, the fence-style conductive structure includes: a first conductive structure arranged in the horizontal direction and a second conductive structure arranged in the vertical direction. The first conductive structure includes: a bonding metal layer and a first ohmic contact layer vertically stacked in a direction away from the driving wafer, so that the first conductive structure can be formed by utilizing the bonding structure itself in the display device layer, and the second conductive structure can be formed by utilizing the structure formed by reverse sputtering during the etching process of the first conductive structure, thereby facilitating the preparation of the fence-style conductive structure.

[0028] Furthermore, the columnar style conductive structure passes through the first ohmic contact layer, and its bottom surface is connected to the upper surface of the bonding metal layer, so that the columnar style conductive structure is directly electrically connected to the bonding metal layer without ensuring that ohmic contact is formed with the first ohmic contact layer, thereby increasing the flexibility of material selection for the columnar style conductive structure.

[0029] It should be noted that the present invention only needs to achieve at least one of the above technical effects. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 Schematic diagram of the structure of a micro display device provided in an embodiment of the present application;

[0031] Figure 2 Schematic diagram of the structure of a micro display device provided in an embodiment of the present application;

[0032] Figure 3 Schematic diagram of the structure of a micro display device provided in an embodiment of the present application;

[0033] Figure 4 It is a structural schematic diagram of a micro display device provided in an embodiment of the present application.

[0034] Markings in the figure: 100-driving wafer, 110-anode contact, 200-first display device layer, 210-first sub-pixel, 300-second display device layer, 310-second sub-pixel, 400-third display device layer, 410-third sub-pixel, 500-fence style conductive structure, 510-first conductive structure, 520-second conductive structure, 600-column style conductive structure, 710-bonding metal layer, 720-first ohmic contact layer. DETAILED DESCRIPTION

[0035] To make the purpose, technical solutions, and advantages of the present invention more clear, the following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts shall fall within the scope of protection of the present invention.

[0036] In the description of the present invention, it should be understood that the terms "vertical", "upper", "lower", "top", "side", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention 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 therefore cannot be understood as a limitation on the present invention. In addition, the terms "first" and "second" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "multiple" means two or more.

[0037] In the description of this utility model, it should be noted that, unless otherwise expressly specified or limited, the terms "installed," "connected," and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; mechanical connections, electrical connections; direct connections, indirect connections through an intermediate medium, and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in this utility model based on specific circumstances.

[0038] In order to solve the problem of poor heat dissipation affecting the display effect of the micro-display device, in an embodiment of the present application, a micro-display device is provided that combines a columnar style conductive structure and a fence style conductive structure for anode conduction, thereby improving the electrical and thermal conductivity of the micro-display device and avoiding the impact of poor heat dissipation on the display performance of the micro-display device.

[0039] Combined with reference Figures 1 to 2 An embodiment of the present application provides a micro display device, which includes a driving wafer 100 and a display device layer arranged on the driving wafer 100.

[0040] Among them, any display device layer includes sub-pixels; a semiconductor electrode conduction structure is provided in at least one display device layer, and the semiconductor electrode conduction structure is used to realize electrode conduction for the sub-pixels in the upper display device layer; the semiconductor electrode conduction structure includes a fence style conduction structure 500 and a columnar style conduction structure 600 inside the fence style conduction structure 500.

[0041] For microdisplay devices, poor electrical conductivity will limit the application scenarios of the device. Therefore, in the embodiment of the present application, the semiconductor electrode conduction structure of the microdisplay device adopts a structure that combines a columnar style conduction structure 600 and a fence style conduction structure 500. In this structure, the metal volume used for electrode conduction is relatively large, so this semiconductor electrode conduction structure can have good electrical conductivity.

[0042] It can be understood that the outer periphery of the columnar style conductive structure 600 inside the fence style conductive structure 500 can be in contact with the inner wall of the fence style conductive structure 500, or can be separated from the inner wall of the fence style conductive structure 500 by a certain distance. This application does not impose any restrictions on this.

[0043] It can be understood that when an anode contact 110 is provided in the driving wafer 100, in order to perform anode conduction through the semiconductor electrode conduction structure, the bottom of the semiconductor electrode conduction structure is connected to the anode contact 110 in the driving wafer 100 or another semiconductor electrode conduction structure in the lower display device layer, and the top is connected to the sub-pixel in the upper display device layer or another semiconductor electrode conduction structure.

[0044] It is understood that the present application does not limit the specific number of display device layers on the driver wafer 100. For example, if there are two display device layers, the first display device layer adopts this semiconductor electrode conduction structure; if there are three display device layers, at least one of the first and second display device layers adopts this semiconductor electrode conduction structure.

[0045] Among them, the driver wafer 100 can be an active design that combines one or more of thin film transistors (TFT), low temperature polycrystalline silicon (LTPS), CMOS integrated circuits, high mobility transistors (HEMT), etc. Specifically, the driver wafer 100 is provided with a driver circuit, and the driver circuit is provided with at least one anode contact 110. The driver circuit may include an active, passive, or semi-passive control circuit. All anode contacts 110 included in the driver circuit can be arranged linearly or in an array, and any anode contact 110 is located in the middle or at the edge of the driver wafer 100. This embodiment does not impose any restrictions on this.

[0046] Among them, any display device layer is filled with an insulating layer, and the insulating layer includes materials such as silicon oxide, silicon nitride, SiC, SiCN, PSG, BPSG, polyimide, etc. This application does not limit the specific material of the insulating layer, as long as it is used to achieve the insulating function.

[0047] Each sub-pixel may include: a bonding metal layer 710 , a first ohmic contact layer 720 , an active layer, and a second ohmic contact layer stacked in a direction away from the driving wafer 100 .

[0048] It is understandable that the first ohmic contact layer 720 and the second ohmic contact layer in the present application can be designed to be a P-type ohmic contact layer and an N-type ohmic contact layer, respectively, or can be designed to be an N-type ohmic contact layer and a P-type ohmic contact layer, respectively.

[0049] For example, the sub-pixels are made of compound wafer materials. The structures of some compound wafers are as follows. In some practical applications, the film layers of the compound wafers will be more complex, or there will be cross-use of materials. The material range is not limited. It typically mainly includes P-type material (corresponding to the second ohmic contact layer or the first ohmic contact layer), N-type material (corresponding to the first ohmic contact layer or the second ohmic contact layer), and an MQW quantum well (corresponding to the active layer) sandwiched between the two, and other functional layers:

[0050]

[0051] In one possible implementation, the fence-style conductive structure 500 includes: a first conductive structure 510 arranged in the horizontal direction and a second conductive structure 520 arranged in the vertical direction; the bottom of the second conductive structure 520 is connected to the outer edge of the first conductive structure 510 in the current display device layer to surround the first conductive structure 510, and the top is connected to the sub-pixel in the upper display device layer, or connected to the bottom of the first conductive structure 510 in the upper display device layer; the bottom of the first conductive structure 510 is connected to the anode contact 110 in the driver wafer 100, or connected to the top of the second conductive structure 520 in the lower display device layer.

[0052] In this implementation, the fence-style conductive structure 500 is designed to be composed of a first conductive structure 510 and a second conductive structure 520, and the first conductive structure 510 can be used to electrically connect to the semiconductor electrode conductive structure or the driving wafer 100 in the lower display device layer, and the second conductive structure 520 can be used to electrically connect to the semiconductor electrode conductive structure or sub-pixel in the upper display device layer, thereby realizing the electrode conduction function.

[0053] Furthermore, the bottom of the columnar conductive structure 600 is connected to the first conductive structure 510 , and the top is flush with the top of the second conductive structure 520 , so that the columnar conductive structure 600 is disposed inside the fence conductive structure 500 .

[0054] For example, Figure 1 As shown, the micro display device has a double-layer display device layer: a first display device layer 200 and a second display device layer 300. For the second sub-pixel 310 in the second display device layer 300, a fence-style conductive structure 500 and a columnar-style conductive structure 600 can be correspondingly set at the projection position in the first display device layer 200, and the bottom of the first conductive structure 510 in the fence-style conductive structure 500 is connected to the anode contact 110 in the driving wafer 100, the top of the second conductive structure 520 is connected to this second sub-pixel 310, and the top of the columnar-style conductive structure 600 is also connected to this second sub-pixel 310.

[0055] For example, Figure 2 As shown, the micro display device has three display device layers: a first display device layer 200, a second display device layer 300, and a third display device layer 400. For the second sub-pixel 310 in the second display device layer 300, a fence-style conductive structure 500 and a columnar-style conductive structure 600 can be correspondingly set at the projection position in the first display device layer 200. The bottom of the first conductive structure 510 in the fence-style conductive structure 500 is connected to the anode contact 110 in the driver wafer 100, and the top of the second conductive structure 520 is connected to the second sub-pixel 310. The top of the columnar style conductive structure 600 is also connected to the second sub-pixel 310; for the third sub-pixel 410 in the third display device layer 400, the fence style conductive structure 500 and the columnar style conductive structure 600 can be correspondingly set at the projection position in the first display device layer 200 and the projection position in the second display device layer 300, and the top of the fence style conductive structure 500 and the columnar style conductive structure 600 in the first display device layer 200 are connected to the bottom of the fence style conductive structure 500 in the second display device layer 300.

[0056] Furthermore, the first conductive structure 510 includes a bonding metal layer 710 and a first ohmic contact layer 720 stacked vertically in a direction away from the driver wafer 100. In other words, the first conductive structure 510 is formed by utilizing the inherent bonding structure of the display device layer, thereby facilitating the fabrication of the fence-style conductive structure 500. The thickness of the bonding metal layer 710 is between 10 nm and 1.5 μm, and the thickness of the first ohmic contact layer 720 is between 5 nm and 300 nm.

[0057] In addition, under the above design, the second conductive structure 520 in the fence-style conductive structure 500 can be formed by reverse sputtering during the etching process of the first conductive structure 510, thereby facilitating the preparation of the fence-style conductive structure 500.

[0058] Furthermore, the angle of the fence-style conductive structure is between 65 degrees and 115 degrees. That is, in the fence-style conductive structure, the angle of the second conductive structure 520 relative to the first conductive structure 510 can be within the range of 90°±25°.

[0059] Further, such as Figure 3 As shown, the columnar style conductive structure 600 passes through the first ohmic contact layer 720, and its bottom surface is connected to the upper surface of the bonding metal layer 710. The columnar style conductive structure 600 can be arranged in the fence style conductive structure 500 by using the through-hole and post-metal filling method. In order to electrically connect the columnar style conductive structure 600 with the fence style conductive structure 500, the bottom of the columnar style conductive structure 600 can be connected to the first conductive structure 510 at the bottom of the fence style conductive structure 500. In the design that the first conductive structure 510 includes the bonding metal layer 710 and the first ohmic contact layer 720, since the first ohmic contact layer 720 needs Only metals that can form ohmic contact with it can be electrically connected. Therefore, when designing a through hole, the through hole can be passed through the first ohmic contact layer 720 in the first conductive structure 510, and the bottom surface of the columnar style conductive structure 600 can be connected to the upper surface of the bonding metal layer 710 in the first conductive structure 510, so that the columnar style conductive structure 600 is directly electrically connected to the bonding metal layer 710, thereby avoiding the material limitation of the columnar style conductive structure 600, and it can adopt metals of various material types.

[0060] Furthermore, the surface area of the columnar conductive structure 600 increases in width as it moves away from the driver wafer 100. That is, the columnar conductive structure 600 can be designed to be wide at the top and narrow at the bottom. Since the columnar conductive structure 600 needs to be implemented through a through-hole process, this design facilitates the implementation of the through-hole process. Furthermore, with this wide-at-top-narrow-at-bottom design, the columnar conductive structure 600 has a relatively larger volume, thereby providing better conductive performance.

[0061] Furthermore, the surface area of the pillar-shaped conductive structure 600 can be kept constant in the direction away from the driver wafer 100. That is, the pillar-shaped conductive structure 600 can be designed with the same size from top to bottom, thereby facilitating standardized preparation of the pillar-shaped conductive structure 600 in a miniature size.

[0062] In one possible implementation, the micro display device includes more than two display device layers; among the more than two display device layers, the semiconductor electrode conduction structure located at the bottom display device layer includes: a fence-style conduction structure 500 and a columnar-style conduction structure 600.

[0063] In this implementation, if the number of layers of the micro display device is more than two, that is, there are at least two display device layers, and a semiconductor electrode conduction structure needs to be designed in these display device layers, the semiconductor electrode conduction structure in the bottom display device layer adopts a design that combines the fence style conduction structure 500 and the column style conduction structure 600, so as to achieve the function of carrying large current by utilizing the design that combines the fence style conduction structure 500 and the column style conduction structure 600 in the bottom layer, and adopts a simplified semiconductor electrode conduction structure design in other display device layers to simplify the process implementation.

[0064] For example, in the case where the micro display device includes three display device layers, a design combining a fence style conductive structure 500 and a columnar style conductive structure 600 is adopted in the bottom display device layer, and the second display device layer may be used to achieve electrode conduction by a separate fence style conductive structure 500, a separate columnar style conductive structure 600, or a separate conductive structure of other styles.

[0065] Further, such as Figure 4 As shown, the columnar conductive structure 600 runs through the color compound, so that the columnar conductive structure 600 can be directly prepared after the pixelation is completed according to the existing implementation method.

[0066] Furthermore, the horizontal dimension of the fence-style conductive structure 500 in the lower display device layer is smaller than the horizontal dimension of the fence-style conductive structure 500 in the upper display device layer. Because the display device layers need to be stacked and integrated, and the semiconductor electrode conductive structure in the upper display device layer needs to be aligned with the semiconductor electrode conductive structure in the lower display device layer, to reduce the difficulty of process implementation, the horizontal dimension of the semiconductor electrode conductive structure in the lower display device layer is designed to be smaller than or equal to the horizontal dimension of the semiconductor electrode conductive structure in the upper display device layer.

[0067] In summary, an embodiment of the present application provides a microdisplay device, which includes a driver wafer, a multi-layer display device layer arranged on the driver wafer, any display device layer includes sub-pixels, and at least one display device layer is provided with a semiconductor electrode conduction structure, which is used to achieve electrode conduction for the sub-pixels in the upper display device layer. The semiconductor electrode conduction structure includes a fence-style conduction structure and a columnar style conduction structure located inside the fence-style conduction structure. Electrode conduction is achieved through a structure combining the columnar style conduction structure and the fence-style conduction structure, thereby increasing the metal volume for anode conduction to improve the conductivity of the microdisplay device.

[0068] All of the above optional technical solutions can be combined in any way to form optional embodiments of the present invention, that is, any multiple embodiments can be combined to meet the needs of different application scenarios. They are all within the scope of protection of this application and will not be described in detail here.

[0069] It should be noted that the above is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A micro display device, characterized in that: The micro display device includes a driving wafer and a multi-layer display device layer arranged on the driving wafer, wherein any of the display device layers includes sub-pixels; A semiconductor electrode conduction structure is provided in at least one of the display device layers, and the semiconductor electrode conduction structure is used to achieve electrode conduction for sub-pixels in the upper display device layer; The semiconductor electrode conductive structure includes a fence-style conductive structure and a column-style conductive structure located inside the fence-style conductive structure.

2. The micro display device according to claim 1, wherein: The fence-style conductive structure includes: a first conductive structure arranged in the horizontal direction and a second conductive structure arranged in the vertical direction; The bottom of the second conductive structure is connected to the outer edge of the first conductive structure in the current display device layer to surround the first conductive structure, and the top is connected to the sub-pixel in the upper display device layer, or connected to the bottom of the first conductive structure in the upper display device layer; The bottom of the first conductive structure is connected to the anode contact in the driver wafer, or is connected to the top of the second conductive structure in the lower display device layer.

3. The micro display device according to claim 2, characterized in that The bottom of the columnar conductive structure is connected to the first conductive structure, and the top of the columnar conductive structure is flush with the top of the second conductive structure.

4. The micro display device according to claim 2, characterized in that The first conductive structure includes: A bonding metal layer and a first ohmic contact layer are vertically stacked in a direction away from the driving wafer.

5. The micro display device according to claim 4, characterized in that: The thickness of the bonding metal layer is between 10 nm and 1.5 um.

6. The micro display device according to claim 4, characterized in that The thickness of the first ohmic contact layer is between 5 nm and 300 nm.

7. The micro display device according to claim 4, characterized in that The columnar conductive structure penetrates the first ohmic contact layer, and a bottom surface thereof is connected to the upper surface of the bonding metal layer.

8. The micro display device according to claim 1, wherein: The surface area of the columnar conductive structure widens in a direction away from the driver wafer.

9. The micro display device according to claim 1, characterized in that: The surface area of the pillar-shaped conductive structure remains the same in a direction away from the driver wafer.

10. The micro display device according to claim 1, characterized in that The micro display device includes more than two display device layers; In a display device layer with more than two layers, the semiconductor electrode conductive structure of the display device layer located at the bottom layer includes: a fence-style conductive structure and the column-style conductive structure.

11. The micro display device according to claim 1, wherein: The columnar conductive structure runs through the color compound.

12. The micro display device according to claim 1, wherein: The horizontal size of the fence-style conductive structure in the lower display device layer is smaller than or equal to the horizontal size of the fence-style conductive structure in the upper display device layer.

13. The micro display device according to claim 1, characterized in that The angle of the fence-style conductive structure is between 65 degrees and 115 degrees.

Images