Micro LED microdisplay chip

Abstract

The application relates to the technical field of LED display, and discloses a Micro LED micro display chip. The Micro LED micro display chip comprises a driving backboard, a plurality of LED units and a wavelength conversion layer. The plurality of LED units are arranged on the surface of one side of the driving backboard. The LED units emit mixed color light. The mixed color light comprises first color light and second color light. The wavelength conversion layer is arranged on part of the LED units, so as to convert the mixed color light emitted by the corresponding LED units into third color light. The first color light, the second color light and the third color light are all different. At least one LED unit and at least one adjacent LED unit provided with the wavelength conversion layer constitute a full-color pixel point. The application realizes efficient full-color display, improves the light-emitting efficiency, display effect and overall reliability of the Micro LED micro display chip.

Description

Technical Field

[0001] This application belongs to the field of LED display technology, specifically relating to a Micro LED microdisplay chip. Background Technology

[0002] Micro LED, also known as micro light-emitting diode, is a self-emissive display technology that integrates arrayed micron-sized LED units onto an actively addressed driver panel, enabling individual control and illumination to output displayed images.

[0003] In related technologies, Micro LED achieves full-color display by using a color conversion scheme that converts blue light into red and green light. This scheme has relatively low light conversion efficiency, especially when converting blue light to green light, where the green quantum dots have even lower efficiency, leading to a decrease in the luminous efficiency of the Micro LED and affecting the display effect. Furthermore, green quantum dots face reliability issues in high-light-intensity and high-heat environments, impacting the overall reliability of Micro LEDs. Utility Model Content

[0004] This application aims to address at least one of the technical problems existing in the prior art or related technologies.

[0005] Therefore, this application provides a Micro LED microdisplay chip, including: a driving backplane; a plurality of LED units arranged on one side of the surface of the driving backplane, wherein the LED units emit mixed color light, the mixed color light including a first color light and a second color light; a wavelength conversion layer disposed on a portion of the plurality of LED units to convert the mixed color light emitted by the corresponding LED unit into a third color light; wherein the first color light, the second color light and the third color light are all different, and at least one LED unit and at least one adjacent LED unit disposed with the wavelength conversion layer constitute a full-color pixel.

[0006] In one possible implementation, the LED unit includes a first semiconductor layer, an active layer, and a second semiconductor layer; the active layer is formed between the first semiconductor layer and the second semiconductor layer for enabling the LED unit to emit the mixed-color light.

[0007] In one possible implementation, the active layer includes: a first quantum well, wherein multiple pairs of the first quantum well are provided; a second quantum well, wherein multiple pairs of the second quantum well are provided, and multiple pairs of the second quantum well are alternately stacked with multiple pairs of the first quantum well; wherein the first quantum well is used to enable the LED unit to emit the first color light, and the second quantum well is used to enable the LED unit to emit the second color light.

[0008] In one possible implementation, the material of the first quantum well comprises indium gallium nitride, wherein the molar composition of indium in the indium gallium nitride is 5% to 20%; and the material of the second quantum well comprises indium gallium nitride, wherein the molar composition of indium in the indium gallium nitride is 10% to 30%.

[0009] In one possible implementation, the active layer includes: a first quantum well, wherein multiple pairs of the first quantum wells are stacked to form a first quantum well group; a second quantum well, wherein multiple pairs of the second quantum wells are stacked to form a second quantum well group, the second quantum well group being stacked with the first quantum well group; wherein the first quantum well is used to enable the LED unit to emit the first color light, and the second quantum well is used to enable the LED unit to emit the second color light.

[0010] In one possible implementation, the thickness of the first semiconductor layer ranges from 50 nm to 500 nm; the thickness of the active layer ranges from 100 nm to 500 nm; and the thickness of the second semiconductor layer ranges from 500 nm to 5 μm.

[0011] In one possible implementation, the driving backplane includes a driving circuit, which includes a plurality of first contacts and at least one second contact. The plurality of first contacts are disposed below a plurality of LED units in a one-to-one correspondence. The plurality of first contacts are electrically connected to a first semiconductor layer of the plurality of LED units in a one-to-one correspondence. The second semiconductor layers of the plurality of LED units are electrically connected to the second contacts together, so that the driving circuit can drive each LED unit individually.

[0012] In one possible implementation, the Micro LED microdisplay chip further includes: a first conductive layer disposed between the driving backplate and the LED unit, for electrically connecting the first contact with the first semiconductor layer of the corresponding LED unit; and a first electrode layer covering at least the top surface of the plurality of LED units, for electrically connecting the second contact with the second semiconductor layer of the plurality of LED units.

[0013] In one possible implementation, the driving backplane includes a driving circuit comprising a plurality of first contacts and at least one second contact, wherein the first contacts are located between adjacent LED units; wherein the plurality of first contacts are electrically connected to a second semiconductor layer of the plurality of LED units in a one-to-one correspondence, and the first semiconductor layers of the plurality of LED units are electrically connected to the second contact in common, so that the driving circuit can drive each LED unit individually.

[0014] In one possible implementation, the Micro LED microdisplay chip further includes: a second conductive layer disposed between the driving backplate and the plurality of LED units, for electrically connecting the second contact to the first semiconductor layer of the plurality of LED units; and a second electrode layer covering at least the top surface of the LED unit, for electrically connecting the first contact to the second semiconductor layer of the corresponding LED unit.

[0015] In one possible implementation, the Micro LED microdisplay chip further includes: a bonding layer disposed between the driving backplane and the LED units for connecting the driving backplane and the plurality of LED units; and a passivation layer covering at least the plurality of LED units and exposing at least a portion of the top surface of the plurality of LED units.

[0016] In one possible implementation, the Micro LED microdisplay chip further includes: an isolation gate disposed on the driving backplane, having a plurality of grid holes, each of the plurality of grid holes corresponding to a plurality of LED units; wherein the wavelength conversion layer fills a portion of the grid holes among the plurality of grid holes and covers or encloses the corresponding LED units.

[0017] In one possible implementation, the Micro LED microdisplay chip further includes: a blue-green epitaxial structure disposed on the driving backplane, the blue-green epitaxial structure being etched to form a plurality of LED units; the wavelength conversion layer being made of red quantum dots; wherein the first color light includes blue light, the second color light includes green light, and the wavelength conversion layer is used to convert the blue and green light emitted by the corresponding LED units into red light.

[0018] The Micro LED microdisplay chip provided in this application can achieve at least the following technical effects:

[0019] The LED unit of this application emits mixed-color light, which includes a first color light and a second color light. That is, the first and second color lights are directly emitted by the LED unit without light conversion, resulting in more efficient color light. A wavelength conversion layer is disposed on some of the LED units to convert the mixed-color light emitted by the corresponding LED unit into a third color light; specifically, the wavelength conversion layer is used to convert the first and second color lights emitted by the LED unit into the third color light. The first, second, and third color lights are all different. At least one LED unit and at least one adjacent LED unit with a wavelength conversion layer constitute a full-color pixel, achieving efficient monolithic full-color display and improving light conversion efficiency. For example, when the first color light is blue, the second color light is green, and the third color light is red, the green light is directly emitted by the LED unit (the material of the LED unit includes the compound semiconductor InGaN), achieving more efficient green light using the compound semiconductor InGaN itself, avoiding the use of green quantum dots, and improving the luminous efficiency, display effect, and overall reliability of the Micro LED microdisplay chip. Moreover, this application can reduce process complexity, reduce the number of wafer bonding cycles, and achieve higher yield.

[0020] The above general description and the description below are exemplary and illustrative only and are not intended to limit this application. Attached Figure Description

[0021] One or more embodiments are illustrated by way of example with reference to the accompanying drawings. These illustrations and drawings do not constitute a limitation on the embodiments. Elements having the same reference numerals in the drawings are shown as similar elements. The drawings are not to be scaled. And wherein:

[0022] Figure 1 A schematic structural diagram of a Micro LED microdisplay chip provided in one embodiment of this disclosure;

[0023] Figure 2 A schematic planar structural diagram of a portion of the structure of a Micro LED microdisplay chip provided in one embodiment of this disclosure;

[0024] Figure 3 for Figure 2 The illustrated embodiment provides a schematic diagram of the A1-A2 cross-sectional structure.

[0025] Figure 4 A schematic planar structural diagram of a portion of the Micro LED microdisplay chip provided in another embodiment of this disclosure;

[0026] Figure 5 for Figure 4The illustrated embodiment provides a schematic diagram of the B1-B2 cross-sectional structure.

[0027] Figure 6 for Figure 4 A schematic diagram of the C1-C2 cross-sectional structure provided in the embodiment shown;

[0028] Figure 7 A schematic structural diagram of the driving substrate and the first bonding metal layer provided in the embodiments of this disclosure;

[0029] Figure 8 A schematic structural diagram of the substrate, LED epitaxial layer, conductive layer, and second bonding metal layer provided in an embodiment of this disclosure;

[0030] Figure 9 A schematic structural diagram of the first bonding metal layer and the second bonding metal layer fused into a bonding layer, provided for embodiments of this disclosure;

[0031] Figure 10 In order to be in Figure 9 The illustrated embodiment provides a schematic structural diagram of a structure in which multiple LED units are formed.

[0032] Figure 11 In order to be in Figure 10 The illustrated embodiment provides a schematic structural diagram of a structure in which a passivation layer is formed.

[0033] Figure 12 In order to be in Figure 11 The illustrated embodiment provides a schematic structural diagram of the formation of a first electrode layer.

[0034] Figure 13 In order to be in Figure 12 The illustrated embodiment provides a schematic structural diagram of a structure in which a metal layer is formed.

[0035] Figure 14 In order to be in Figure 13 The illustrated embodiment provides a schematic structural diagram of an isolation barrier formed thereon.

[0036] Figure 15 In order to be in Figure 9 The illustrated embodiment provides another schematic structural diagram showing a structure that forms multiple LED units.

[0037] Figure 16 In order to be in Figure 15 The illustrated embodiment provides a schematic structural diagram of a structure in which a passivation layer is formed.

[0038] Figure 17 In order to be in Figure 16 The illustrated embodiment provides a schematic structural diagram of the formation of a second electrode layer.

[0039] Figure 18 In order to be in Figure 17 The illustrated embodiment provides a schematic structural diagram of an isolation barrier formed thereon.

[0040] Figure 19 In order to be in Figure 18 The illustrated embodiment provides a schematic structural diagram of a wavelength conversion layer formed on the structure.

[0041] Figure 20 This is a schematic structural diagram of a display device provided in one embodiment of the present disclosure.

[0042] The reference numerals in the attached figures are as follows:

[0043] 100: Micro LED microdisplay chip; 101: Driver backplane; 102: LED unit; 1021: First semiconductor layer; 1022: Active layer; 1023: Second semiconductor layer; 103: Wavelength conversion layer; 104: First contact; 105: Conductive layer; 1051: First conductive layer; 1052: Second conductive layer; 106: First electrode layer; 1061: Second electrode layer; 107: Bonding layer; 1071: First bonding metal layer; 1072: Second bonding metal layer; 108: Passivation layer; 109: Isolation gate; 110: Grid hole; 111: Substrate; 112: LED epitaxial layer; 113: Metal layer;

[0044] 200: Display device. Detailed Implementation

[0045] To provide a more detailed understanding of the features and technical content of the embodiments of this disclosure, the implementation of the embodiments of this disclosure will be described in detail below with reference to the accompanying drawings. The accompanying drawings are for illustrative purposes only and are not intended to limit the embodiments of this disclosure. In the following technical description, for ease of explanation, several details are used to provide a full understanding of the disclosed embodiments. However, one or more embodiments may still be implemented without these details. In other cases, well-known structures and devices may be simplified in their depiction to simplify the drawings.

[0046] The terms "first," "second," etc., used in the specification, claims, and accompanying drawings of this disclosure are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate for the embodiments of this disclosure described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion.

[0047] In this disclosure, the terms "upper," "lower," "inner," "middle," "outer," "top," and "bottom," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. These terms are primarily for better describing the embodiments of this disclosure and their implementations, and are not intended to limit the indicated devices, elements, or components to having a specific orientation, or to require them to be constructed and operated in a specific orientation. Furthermore, some of the aforementioned terms may be used to indicate other meanings besides orientation or positional relationship; for example, the term "upper" may in some cases indicate a dependency or connection relationship. Those skilled in the art can understand the specific meaning of these terms in this disclosure according to the specific circumstances.

[0048] Furthermore, the terms "set up," "connect," and "fix" should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral structure; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, or it can be an internal connection between two devices, components, or parts. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of this disclosure according to the specific circumstances.

[0049] Unless otherwise stated, the term "multiple" means two or more.

[0050] The term "and / or" describes an association between objects, indicating that three relationships can exist. For example, A and / or B means: A or B, or A and B.

[0051] It should be noted that, unless otherwise specified, the embodiments and features described in the present disclosure can be combined with each other.

[0052] It should be noted that, as used in the embodiments of this disclosure, the term "layer" refers to a portion of material comprising a region having a certain thickness. A layer may extend over the entire lower or upper structure, or may have a extent smaller than that of the lower or upper structure. Furthermore, a layer may be a region of a homogeneous or heterogeneous continuous structure, with a thickness less than the thickness of the continuous structure. For example, a layer may be located between the top and bottom surfaces of a continuous structure, or between any pair of horizontal planes therebetween. A layer may extend horizontally, vertically, and / or along a conical surface.

[0053] It should be noted that the term "micro" (e.g., microdisplay chip) used in the embodiments of this disclosure refers to a descriptive size of certain devices or structures according to embodiments of this application. The term "micro" as used herein is intended to indicate a scale from 0.1 to 100 μm. However, it should be understood that embodiments of this application are not necessarily limited thereto, and certain aspects of the embodiments can be applied to larger and possibly smaller size scales.

[0054] In related technologies, when using inorganic compound semiconductors to achieve red, green, and blue (RGB) tri-color light combining, the RGB vertical stacking structure requires three wafer bonding operations, affecting the device yield. Furthermore, achieving full-color tri-color light combining requires high optical alignment, making the fabrication process complex. When using aluminum gallium indium phosphide (III-V group) semiconductor materials (AlGaInP system) as the red light compound semiconductor, there is also the problem of thermal degradation.

[0055] In view of this, such as Figures 1 to 19 As shown, this disclosure provides a Micro LED microdisplay chip 100. The Micro LED microdisplay chip 100 includes a driving backplane 101, a plurality of LED units 102, and a wavelength conversion layer 103. The plurality of LED units 102 are arranged on one side surface of the driving backplane 101. The LED units 102 emit mixed-color light. The mixed-color light includes a first color light and a second color light. The wavelength conversion layer 103 is disposed on some of the plurality of LED units 102 to convert the mixed-color light emitted by the corresponding LED unit 102 into a third color light. The first color light, the second color light, and the third color light are all different. At least one LED unit 102 and at least one adjacent LED unit 102 with the wavelength conversion layer 103 constitute a full-color pixel.

[0056] In this embodiment, the specific arrangement of the multiple LED units 102 on one side of the surface of the driving backplate 101 is not limited; it can be regular or irregular. For example, the multiple LED units 102 are arranged at intervals on one side of the surface of the driving backplate 101.

[0057] In this embodiment, the LED unit 102 emits mixed-color light, which includes a first color light and a second color light. That is, the first color light and the second color light are directly emitted by the LED unit 102 without light conversion, thus obtaining more efficient color light.

[0058] In this embodiment, the wavelength conversion layer 103 is disposed on a portion of the multiple LED units 102. That is, among the multiple LED units 102, a portion of the LED units 102 are provided with the wavelength conversion layer 103, while another portion of the LED units 102 are not provided with the wavelength conversion layer 103. The projection of the wavelength conversion layer 103 onto the upper surface of the driving backplate 101 can cover the LED units 102 located directly below the wavelength conversion layer 103. The mixed-color light emitted by the LED units 102 located directly below the wavelength conversion layer 103 is converted into a third color light by the wavelength conversion layer 103.

[0059] In this embodiment, the first color light, the second color light, and the third color light are all different, enabling the combination of the three colors to achieve full-color display. For example... Figure 1 As shown, Figure 1 The dashed box at point P illustrates a full-color pixel. At least one LED unit 102 and at least one adjacent LED unit 102 equipped with a wavelength conversion layer 103 constitute a full-color pixel. For example, in two adjacent LED units 102, one LED unit 102 does not have a wavelength conversion layer 103 and directly emits first and second color light. The other LED unit 102 has a wavelength conversion layer 103, which converts the first and second color light emitted by the LED unit 102 into a third color light, forming a full-color pixel. This achieves efficient monolithic full-color display and improves light conversion efficiency.

[0060] In this embodiment, the method of directly emitting mixed-color light by LED unit 102 is combined with the color conversion method of wavelength conversion layer 103. This requires only one wafer bonding operation, reducing the number of wafer bonding operations, achieving higher yield, and enabling full-color display on a single chip. It eliminates the need for high optical alignment, reducing manufacturing complexity. For example, when the third color light is red, the red light is obtained by converting the mixed-color light emitted by LED unit 102 through wavelength conversion layer 103, improving luminous efficiency and stability. Compared to the RGB three-color combination scheme using compound semiconductors, this embodiment obtains red light through color conversion, avoiding the thermal decay and size effects of red compound semiconductors, reducing the number of bonding operations, lowering manufacturing complexity, and increasing device lifespan.

[0061] Optionally, the first color light, the second color light, and the third color light are blue light, green light, and red light, respectively. Alternatively, the first color light, the second color light, and the third color light are green light, blue light, and red light, respectively.

[0062] In this embodiment, blue and green light are directly emitted by LED unit 102, resulting in more efficient blue and green light emission. Red light is obtained by converting the blue and green light emitted by LED unit 102 through wavelength conversion layer 103, thereby improving luminous efficiency and stability.

[0063] Furthermore, the green light is emitted directly from the LED unit 102 without the need for color conversion, resulting in more efficient green light and improved reliability of the green quantum dots in high-intensity and high-heat environments. Compared to related technologies, the direct emission of green light from the LED unit 102 reduces the patterning process required for a single green color conversion, lowers process complexity, and achieves higher yield.

[0064] Alternatively, the wavelength conversion layer 103 can be prepared by an exposure and development process.

[0065] In this embodiment, the driving backplane 101 refers to the material on which subsequent material layers are added. The driving backplane 101 itself may be patterned. The material added to the top of the driving backplane 101 may be patterned or may remain unpatterned. Furthermore, the driving backplane 101 may include a wide variety of semiconductor materials, such as silicon, silicon carbide, gallium nitride, germanium, gallium arsenide, indium phosphide, etc. Alternatively, the driving backplane 101 may be made of a non-conductive material, such as glass, plastic, or sapphire wafer. Further alternatively, the driving backplane 101 may have semiconductor devices or circuits formed therein.

[0066] In some embodiments, such as Figure 3 , Figure 5 and Figure 6 As shown, the LED unit 102 includes a first semiconductor layer 1021, an active layer 1022, and a second semiconductor layer 1023. The active layer 1022 is formed between the first semiconductor layer 1021 and the second semiconductor layer 1023, and the active layer 1022 is used to enable the LED unit 102 to emit mixed color light.

[0067] In this embodiment, the LED unit 102 includes a first semiconductor layer 1021, an active layer 1022, and a second semiconductor layer 1023. The first semiconductor layer 1021 can transmit holes to the active layer 1022, and the second semiconductor layer 1023 can transmit electrons to the active layer 1022. Holes and electrons recombine in the active layer 1022, causing the LED unit 102 to emit mixed-color light.

[0068] In this embodiment, the first semiconductor layer 1021 can be a P-type semiconductor layer. The method of forming the first semiconductor layer 1021 is not limited. For example, the first semiconductor layer 1021 can be formed by doping.

[0069] In this embodiment, the second semiconductor layer 1023 can be an N-type semiconductor layer. The method of forming the second semiconductor layer 1023 is not limited. For example, the second semiconductor layer 1023 can be formed by doping.

[0070] In some embodiments, the active layer 1022 includes a first quantum well and a second quantum well. Multiple pairs of first quantum wells are provided. Multiple pairs of second quantum wells are provided. Multiple pairs of second quantum wells and multiple pairs of first quantum wells are alternately stacked. The first quantum wells are used to enable the LED unit 102 to emit light of a first color, and the second quantum wells are used to enable the LED unit 102 to emit light of a second color.

[0071] In this embodiment, the active layer 1022 includes a first quantum well and a second quantum well, which are disposed between the first semiconductor layer 1021 and the second semiconductor layer 1023 to enable the LED unit 102 to emit mixed-color light. Each pair of first quantum wells includes a well and a barrier. Each pair of second quantum wells includes a well and a barrier.

[0072] In this embodiment, the first quantum well is used to enable the LED unit to emit a first color light, and the second quantum well is used to enable the LED unit to emit a second color light. By alternately stacking multiple pairs of second quantum wells and multiple pairs of first quantum wells, the ability of the first color light and the second color light to emit light simultaneously is enhanced, and the uniformity of light emission is improved.

[0073] Optionally, the active layer 1022 includes a pair of first quantum wells and multiple pairs of second quantum wells. Alternatively, the active layer 1022 includes multiple pairs of first quantum wells and a pair of second quantum wells. Alternatively, the active layer 1022 includes multiple pairs of first quantum wells and multiple pairs of second quantum wells. By stacking the first and second quantum wells, the LED unit 102 can emit mixed-color light.

[0074] In some embodiments, the material of the first quantum well comprises indium gallium nitride (IGN), wherein the molar composition of indium in the IGN is 5% to 20%. The material of the second quantum well comprises IGN, wherein the molar composition of indium in the IGN is 10% to 30%.

[0075] In this embodiment, the material of the first quantum well includes indium gallium nitride (InGaN), in which the molar composition of indium (In) is 5% to 20%. By adjusting the material composition of the first quantum well, the LED unit 102 emits a first color light. For example, the first color light can be blue light.

[0076] In this embodiment, the material of the second quantum well includes indium gallium nitride (InGaN), in which the molar composition of indium (In) is 10% to 30%. By adjusting the material composition of the second quantum well, the LED unit 102 can emit a second color light. For example, the second color light can be green light.

[0077] In some embodiments, the active layer 1022 includes a first quantum well and a second quantum well. Multiple pairs of first quantum wells are stacked to form a first quantum well group. Multiple pairs of second quantum wells are stacked to form a second quantum well group. The second quantum well group is stacked with the first quantum well group. The first quantum well is used to enable the LED unit 102 to emit light of a first color, and the second quantum well is used to enable the LED unit 102 to emit light of a second color.

[0078] Specifically, the first quantum well group and the second quantum well group are disposed between the first semiconductor layer 1021 and the second semiconductor layer 1023 to enable the LED unit 102 to emit mixed color light.

[0079] In this embodiment, the first quantum well is used to enable the LED unit 102 to emit light of a first color, and the second quantum well is used to enable the LED unit 102 to emit light of a second color. The second quantum well group and the first quantum well group are stacked together to reduce the processing difficulty and improve the structural stability.

[0080] In some embodiments, the thickness of the first semiconductor layer 1021 ranges from 50 nm to 500 nm. The thickness of the active layer 1022 ranges from 100 nm to 500 nm. The thickness of the second semiconductor layer 1023 ranges from 500 nm to 5 μm.

[0081] In this embodiment, the thickness of the first semiconductor layer 1021 ranges from 50nm to 500nm, the thickness of the active layer 1022 ranges from 100nm to 500nm, and the thickness of the second semiconductor layer 1023 ranges from 500nm to 5μm, so that the LED unit 102 can effectively inject, transport, and recombine electrons and holes to achieve efficient electro-optical conversion.

[0082] Optionally, the thickness of the first semiconductor layer 1021 is 50nm, 100nm, 200nm, 300nm, 400nm, 500nm, or other values ​​between 50nm and 500nm.

[0083] Optionally, the thickness of the active layer 1022 is 100nm, 200nm, 300nm, 400nm, 500nm or other values ​​between 100nm and 500nm.

[0084] Optionally, the thickness of the second semiconductor layer 1023 is 500 nm, 1 μm, 2 μm, 3 μm, 4 μm, 5 μm or other values ​​between 500 nm and 5 μm.

[0085] Combination Figure 1 , Figure 3 , Figures 10 to 14 As shown, in some embodiments, the driving backplane 101 includes a driving circuit. The driving circuit includes a plurality of first contacts 104 and at least one second contact (not shown in the figure). The plurality of first contacts 104 are disposed below the plurality of LED units 102 in a one-to-one correspondence. The plurality of first contacts 104 are electrically connected to the first semiconductor layer 1021 of the plurality of LED units 102 in a one-to-one correspondence. The second semiconductor layer 1023 of the plurality of LED units 102 is electrically connected to the second contact, so that the driving circuit can drive each LED unit 102 individually.

[0086] Specifically, multiple first contacts 104 are electrically connected to the first semiconductor layers 1021 of multiple LED units 102 in a one-to-one correspondence, and the second semiconductor layers 1023 of multiple LED units 102 are electrically connected to the second contacts, so that the driving circuit is electrically connected to the multiple LED units 102, so that each LED unit 102 can be driven by the driving circuit individually, and each LED unit 102 can emit light individually.

[0087] In practical applications, multiple LED units 102 are electrically connected through a driving circuit, allowing each LED unit 102 to emit light individually. Furthermore, the emission ratio of the first and second color light emitted by each LED unit 102 can be adjusted by controlling the current in the driving circuit.

[0088] In a specific application example, the first contact 104 can be an anode metal contact, and the second contact can be a cathode metal contact. Multiple first contacts 104 correspond one-to-one with and are independently electrically connected to the first semiconductor layers 1021 of multiple LED units 102. The second semiconductor layers 1023 of the multiple LED units 102 are electrically connected to the second contact. The second contact can be a common electrode contact of the multiple LED units 102 to form a common cathode structure. An anode voltage can be applied to each LED unit 102 individually through the first contact 104, providing a separate drive signal to achieve individual control of each LED unit 102 emitting mixed-color light.

[0089] In this embodiment, the driving backplane 101 may be provided with a circuit layer including complementary metal oxide semiconductor (CMOS) devices or thin film field effect transistor (TFT) devices, etc., and these CMOS devices or TFT devices can constitute a driving circuit.

[0090] Combination Figure 1 , Figure 3 as well as Figures 10 to 14 As shown, in some embodiments, the Micro LED microdisplay chip 100 further includes a first conductive layer 1051 and a first electrode layer 106. The first conductive layer 1051 is disposed between the driving backplane 101 and the plurality of LED units 102, and is used to electrically connect the first contact 104 to the first semiconductor layer 1021 of the corresponding LED unit 102. The first electrode layer 106 at least covers the top surface of the plurality of LED units 102, and is used to electrically connect the second contact to the second semiconductor layer 1023 of the plurality of LED units 102.

[0091] In this embodiment, multiple first contacts 104 are located directly below the first semiconductor layer 1021 of multiple LED units 102, and the first contacts 104 are electrically connected to the first semiconductor layer 1021 of the corresponding LED unit 102 through the first conductive layer 1051, so as to realize that the multiple first contacts 104 and the first semiconductor layer 1021 of the multiple LED units 102 are corresponded one-to-one and independently electrically connected.

[0092] In this embodiment, the driving circuit is electrically connected to the first semiconductor layer 1021 of the multiple LED units 102 through the first conductive layer 1051, and the second contact is electrically connected to the second semiconductor layer 1023 of the multiple LED units 102 through the first electrode layer 106. That is, the driving circuit is electrically connected to the multiple LED units 102 through the first conductive layer 1051 and the first electrode layer 106.

[0093] The material of the first conductive layer 1051 is not limited, such as N2Au, ITO, etc. The material of the first electrode layer 106 can be a transparent conductive material, such as ITO, AZO, etc.

[0094] In a specific application example, the first contact 104 can be an anode metal contact, and the second contact can be a cathode metal contact. Multiple first contacts 104 are connected one-to-one and independently to the first semiconductor layers 1021 of multiple LED units 102 via a first conductive layer 1051. The second semiconductor layers 1023 of the multiple LED units 102 are connected to the second contacts via a first electrode layer 106 to form a common cathode structure.

[0095] Optionally, such as Figure 1 , Figure 13 and Figure 14 As shown, the Micro LED microdisplay chip 100 also includes a metal layer 113. The metal layer 113 is disposed on the side of the first electrode layer 106 away from the driving backplate 101. The metal layer 113 is used to connect the first electrode layer 106 and the second contact, so as to realize the common electrical connection of the second semiconductor layer 1023 of the multiple LED units 102 to the second contact.

[0096] In this embodiment, the material of the metal layer 113 may include Cr, Au, Al, Pt, Ag, etc.

[0097] Combination Figures 4 to 6 as well as Figures 15 to 17As shown, in some embodiments, the driving backplane 101 includes a driving circuit. The driving circuit includes a plurality of first contacts 104 and at least one second contact (not shown). The first contacts 104 are located between adjacent LED cells 102. The plurality of first contacts 104 are electrically connected one-to-one with the second semiconductor layers 1023 of the plurality of LED cells 102. The first semiconductor layers 1021 of the plurality of LED cells 102 are electrically connected together to the second contact, so that the driving circuit can drive each LED cell 102 individually.

[0098] In this embodiment, the first contact 104 is located between adjacent LED units 102. That is, for multiple first contacts 104, each first contact 104 is located between two adjacent LED units 102, which facilitates the one-to-one correspondence and independent electrical connection between the second semiconductor layer 1023 of multiple LED units 102 and the multiple first contacts 104. Through the one-to-one correspondence and electrical connection between the second semiconductor layer 1023 of multiple LED units 102 and the multiple first contacts 104, the first semiconductor layer 1021 of multiple LED units 102 is electrically connected to the second contact, so that the driving circuit can drive each LED unit 102 to emit light individually. Furthermore, by controlling the current of the driving circuit, the emission ratio of the first color light and the second color light emitted by each LED unit 102 can be adjusted.

[0099] In a specific application example, the first contact 104 is a cathode metal contact, and the second contact is an anode metal contact. Multiple first contacts 104 correspond one-to-one with and are independently electrically connected to the second semiconductor layers 1023 of multiple LED units 102. The first semiconductor layers 1021 of the multiple LED units 102 are electrically connected to the second contact. The second contact can be a common electrode contact for the multiple LED units 102, forming a common anode structure. A cathode voltage can be applied to each LED unit 102 individually through the first contacts 104, providing a separate drive signal to achieve individual control of each LED unit 102 emitting mixed-color light.

[0100] Combination Figures 4 to 6 as well as Figures 15 to 19 As shown, in some embodiments, the Micro LED microdisplay chip 100 further includes a second conductive layer 1052 and a second electrode layer 1061. The second conductive layer 1052 is disposed between the driving backplane 101 and the plurality of LED units, and is used to electrically connect the second contact to the first semiconductor layer 1021 of the plurality of LED units 102. The second electrode layer 1061 at least covers the top surface of the LED unit 102, and is used to electrically connect the first contact 104 to the second semiconductor layer 1023 of the corresponding LED unit 102.

[0101] In this embodiment, the first contact 104 is located between adjacent LED units 102. The first contact 104 is electrically connected to the second semiconductor layer 1023 of the corresponding LED unit 102 through the second electrode layer 1061, thereby realizing that multiple first contacts 104 are one-to-one corresponded to and independently electrically connected to the second semiconductor layer 1023 of multiple LED units 102.

[0102] In this embodiment, the second contact is electrically connected to the first semiconductor layer 1021 of the multiple LED units 102 through the second conductive layer 1052, and the first contact 104 is electrically connected to the second semiconductor layer 1023 of the corresponding LED unit 102 through the second electrode layer 1061. That is, the driving circuit is electrically connected to the multiple LED units 102 through the second electrode layer 1061 and the second conductive layer 1052.

[0103] The material of the second conductive layer 1052 is not limited, such as N2Au, ITO, etc. The material of the second electrode layer 1061 can be a transparent conductive material, such as ITO, AZO, etc.

[0104] In a specific application example, the first contact 104 is a cathode metal contact, and the second contact is an anode metal contact. Multiple first contacts 104 are individually and independently electrically connected to the second semiconductor layers 1023 of multiple LED units 102 via a second electrode layer 1061. The first semiconductor layers 1021 of the multiple LED units 102 are collectively connected to the second contact via a second conductive layer 1052 to form a common anode structure.

[0105] In some embodiments, such as Figure 1 , Figure 3 , Figure 5 , Figures 11 to 14 as well as Figures 16 to 19 As shown, the Micro LED microdisplay chip 100 also includes a bonding layer 107 and a passivation layer 108. The bonding layer 107 is disposed between the driving backplane 101 and the LED units 102, and is used to connect the driving backplane 101 and the plurality of LED units 102. The passivation layer 108 covers at least the plurality of LED units 102 and exposes at least a portion of the top surface of the plurality of LED units 102, and is used to protect the LED units 102.

[0106] In this embodiment, the bonding layer 107 is disposed between the driving backplate 101 and the LED units 102. Specifically, the bonding layer 107 may be disposed between the driving backplate 101 and the first conductive layer 1051, so as to connect the driving backplate 101 and the multiple LED units 102 through the bonding layer 107. Alternatively, the bonding layer 107 may be disposed between the driving backplate 101 and the second conductive layer 1052, so as to connect the driving backplate 101 and the multiple LED units 102 through the bonding layer 107.

[0107] In this embodiment, the passivation layer 108 covers at least a plurality of LED units 102 and exposes at least a portion of the top surface of the plurality of LED units 102, for the purpose of protecting the LED units 102 and improving the photoelectric performance and reliability of the LED units 102.

[0108] A specific application example, combined with Figure 1 As shown, the passivation layer 108 exposes the top surface of the plurality of LED units 102, that is, the passivation layer 108 exposes the second semiconductor layer 1023 of the plurality of LED units 102, which facilitates the first electrode layer 106 to electrically connect the second contact to the second semiconductor layer 1023 of the plurality of LED units 102.

[0109] Another concrete application example, combined with Figure 6 As shown, the passivation layer 108 exposes the top surface of the plurality of LED units 102, that is, the passivation layer 108 exposes the second semiconductor layer 1023 of the plurality of LED units 102, so as to facilitate the first contact 104 to be electrically connected to the second semiconductor layer 1023 of the corresponding LED unit 102 through the second electrode layer 1061.

[0110] Optionally, the passivation layer 108 may be made of inorganic or organic materials. Inorganic materials include SiO2, AlN, Al2O3, etc. Organic materials include BCB, etc.

[0111] Optionally, the bonding layer 107 may be made of a conductive material, such as a metal or metal alloy.

[0112] In some embodiments, such as Figure 1 , Figure 14 , Figure 18 and Figure 19 As shown, the Micro LED microdisplay chip 100 also includes an isolation gate 109. The isolation gate 109 is disposed on the driving backplane 101. The isolation gate 109 has a plurality of grid holes 110. Each of the plurality of grid holes 110 corresponds to a plurality of LED units 102. The wavelength conversion layer 103 fills a portion of the grid holes 110 and covers or encloses the corresponding LED units 102.

[0113] In this embodiment, an isolation gate 109 is disposed on the drive backplate 101. The isolation gate 109 has multiple grid holes 110, each corresponding to a multiple LED unit 102. For example, the multiple grid holes 110 are arranged around the multiple LED units 102 in a one-to-one correspondence. That is, the one-to-one correspondence between the multiple LED units 102 and the multiple grid holes 110 helps to improve brightness, efficiency, and light color performance, and protects the LED units 102. It is understood that the arrangement of the multiple grid holes 110 is not limited; it can be regular or irregular.

[0114] In this embodiment, the wavelength conversion layer 103 fills a portion of the grid holes 110 and covers the corresponding LED units 102, so that the wavelength conversion layer 103, in its orthogonal projection onto the driving backplate 101, covers the corresponding LED units 102, thereby converting the mixed-color light emitted by the corresponding LED units 102 into a third-color light. By covering the corresponding LED units 102 with the wavelength conversion layer 103, the light emitted from the top and side surfaces of the LED units 102 can be effectively utilized, and the LED units 102 can also be protected, improving yield. Furthermore, by covering the corresponding LED units 102 with the wavelength conversion layer 103, the distance between the wavelength conversion layer 103 and the corresponding LED units 102 can be reduced, thereby improving the light conversion efficiency of the Micro LED microdisplay chip 100.

[0115] In this embodiment, the material of the isolation barrier 109 can be black photoresist, metal, etc. Among them, metals include Cr, Al, Ag, etc.

[0116] In this embodiment, the grid hole 110 can be formed by dry etching, which can etch the sidewall of the grid hole 110 into a bevel and make the angle between the sidewall of the grid hole 110 and the upper surface of the isolation gate 109 obtuse.

[0117] Optionally, the LED unit 102 is located at the center of the grid aperture 110 in which it is located, so as to improve the uniformity of light emission of the LED unit 102.

[0118] Optionally, the Micro LED microdisplay chip 100 may also include a reflective layer. The reflective layer is disposed on the surface of the isolation barrier 109. The reflective layer can block light leakage from the sidewalls of the LED unit 102 and also reflect the light emitted by the LED unit 102, thereby improving the wavelength conversion efficiency of the wavelength conversion layer 103.

[0119] Optionally, such as Figure 1 and Figure 19 As shown, the upper surface of the wavelength conversion layer 103 is flush with or lower than the upper surface of the isolation barrier 109.

[0120] Combination Figure 9 and Figure 10 As shown, in some embodiments, the Micro LED microdisplay chip 100 further includes a blue-green epitaxial structure disposed on a driving backplane, which is etched to form multiple LED units 102. The wavelength conversion layer 103 is made of red quantum dots. The first color light includes blue light, and the second color light includes green light. The wavelength conversion layer is used to convert the blue and green light emitted by the corresponding LED units 102 into red light.

[0121] In this embodiment, the LED epitaxial layer 112 can be a blue-green epitaxial structure, so that the LED unit 102 formed by etching the blue-green epitaxial structure can emit blue and green light. The blue and green light are directly emitted by the LED unit 102 without light conversion, thereby obtaining more efficient blue and green light.

[0122] In this embodiment, the wavelength conversion layer 103 is made of red quantum dots to convert the blue and green light emitted by the LED unit 102 into red light. The red quantum dots can be, for example, InP / CdSe-based quantum dots or perovskite-based quantum dots.

[0123] Optionally, the wavelength range of the first color light is 440 nm to 475 nm. The wavelength range of the second color light is 500 nm to 560 nm. The wavelength range of the third color light is 600 nm to 700 nm.

[0124] In this embodiment, the wavelength range of the first color light is 440nm to 475nm, the wavelength range of the second color light is 500nm to 560nm, and the wavelength range of the third color light is 600nm to 700nm, so that the wavelength conversion layer 103 can convert the mixed color light emitted by the LED unit 102 into the third color light.

[0125] For example, the first color light is blue light. The second color light is green light. The third color light is red light. The LED unit 102 emits blue and green light, which are converted into red light by the wavelength conversion layer 103 to achieve full-color display on a single chip.

[0126] A specific application example:

[0127] The following section uses a common cathode structure as an example to illustrate the structure and fabrication of the Micro LED microdisplay chip 100. It is understood that... Figure 2 This is a planar structural diagram that can be used to illustrate part of the structure of the Micro LED microdisplay chip 100 in this example. Figure 3 This is a cross-sectional view that can be used to illustrate a portion of the structure of the Micro LED microdisplay chip 100 in this example.

[0128] like Figure 7 As shown, a drive backplane 101 is provided. The drive backplane 101 includes a drive circuit having a plurality of first contacts 104 and at least one second contact (not shown). The first contacts 104 are anode metal contacts, and the second contacts are cathode metal contacts. The plurality of first contacts 104 are spaced apart. A first bonding metal layer 1071 is formed on the drive backplane 101. The first bonding metal layer 1071 can be formed by deposition.

[0129] like Figure 8As shown, a substrate 111 is provided. The material of the substrate 111 can be silicon, sapphire, etc. An LED epitaxial layer 112 is grown and formed on the substrate 111. The LED epitaxial layer 112 includes a first semiconductor layer 1021, an active layer 1022, and a second semiconductor layer 1023 stacked together. The first semiconductor layer 1021 is a P-type semiconductor layer, and the second semiconductor layer 1023 is an N-type semiconductor layer. A conductive layer 105 is formed on the LED epitaxial layer 112. A second bonding metal layer 1072 is formed on the conductive layer 105. The second bonding metal layer 1072 can be formed by deposition.

[0130] like Figure 9 As shown, the substrate 111 is flipped so that the second bonding metal layer 1072 fuses with the first bonding metal layer 1071 to form a bonding layer 107, thereby bonding the LED epitaxial layer 112 to the driver backplane 101. Then the substrate 111 is peeled off. The substrate 111 can be peeled off by methods such as laser lift-off, dry etching, wet etching, and mechanical polishing.

[0131] like Figure 10 As shown, the LED epitaxial layer 112 is etched to form a plurality of LED units 102, which are spaced apart. The conductive layer 105 and the bonding layer 107 are etched to expose the upper surface of the driving backplate 101 located between two adjacent LED units 102. Specifically, the conductive layer 105 is etched to form a first conductive layer 1051. The plurality of LED units 102 are located directly above a plurality of first contacts 104, and the first semiconductor layer 1021 of the plurality of LED units 102 is electrically connected to the plurality of first contacts 104 in a one-to-one correspondence through the first conductive layer 1051 and the bonding layer 107.

[0132] like Figure 11 As shown, a passivation layer 108 is formed, which can cover part of the upper surface of the drive backplate 101, the side of the bonding layer 107, the side of the first conductive layer 1051, and the LED unit 102. Through holes are formed in the passivation layer 108 at positions corresponding to the second semiconductor layer 1023 of the plurality of LED units 102 to expose the second semiconductor layer 1023 of the plurality of LED units 102.

[0133] like Figure 12 As shown, a first electrode layer 106 is formed, which may cover the passivation layer 108 and the second semiconductor layer 1023 of the plurality of LED units 102.

[0134] like Figure 13As shown, a metal layer 113 is formed. The metal layer 113 may cover the surface of the first electrode layer 106 located between two adjacent LED units 102. The second semiconductor layer 1023 of the plurality of LED units 102 is electrically connected to the second contact through the first electrode layer 106 and the metal layer 113.

[0135] like Figure 14 As shown, an isolation barrier 109 is formed. The isolation barrier 109 may be disposed on the metal layer 113. The isolation barrier 109 has a plurality of grid holes 110, which surround a plurality of LED units 102 in a one-to-one correspondence.

[0136] like Figure 1 As shown, Figure 1 Can be used to illustrate Figure 14 The structure diagram shows the formation of a wavelength conversion layer 103. The wavelength conversion layer 103 is formed on the isolation gate 109, filling part of the grid holes 110 and covering the corresponding LED unit 102.

[0137] Another specific application example

[0138] The following section uses a common anode structure as an example to illustrate the structure and fabrication of the Micro LED microdisplay chip 100. It should be noted that... Figure 4 This is a planar structural diagram that can be used to illustrate part of the structure of the Micro LED microdisplay chip 100 in this example. Figure 5 and Figure 6 All of these can be used to illustrate a partial structure of the Micro LED microdisplay chip 100 in this example, through cross-sectional views.

[0139] like Figure 7 As shown, a drive backplane 101 is provided. The drive backplane 101 includes a drive circuit having a plurality of first contacts 104 and at least one second contact (not shown). The first contacts 104 are cathode metal contacts, and the second contacts are anode metal contacts. The plurality of first contacts 104 are spaced apart. A first bonding metal layer 1071 is formed on the drive backplane 101. The first bonding metal layer 1071 can be formed by deposition.

[0140] like Figure 8As shown, a substrate 111 is provided. The material of the substrate 111 can be silicon, sapphire, etc. An LED epitaxial layer 112 is grown and formed on the substrate 111. The LED epitaxial layer 112 includes a first semiconductor layer 1021, an active layer 1022, and a second semiconductor layer 1023 stacked together. The first semiconductor layer 1021 is a P-type semiconductor layer, and the second semiconductor layer 1023 is an N-type semiconductor layer. A conductive layer 105 is formed on the LED epitaxial layer 112. A second bonding metal layer 1072 is formed on the conductive layer 105. The second bonding metal layer 1072 can be formed by deposition.

[0141] like Figure 9 As shown, the substrate 111 is flipped so that the second bonding metal layer 1072 fuses with the first bonding metal layer 1071 to form a bonding layer 107, thereby bonding the LED epitaxial layer 112 to the driver backplane 101. Then the substrate 111 is peeled off. The substrate 111 can be peeled off by methods such as laser lift-off, dry etching, wet etching, and mechanical polishing.

[0142] like Figure 15 As shown, the LED epitaxial layer 112 is etched to form a plurality of LED units 102. The plurality of LED units 102 are spaced apart, with first contacts 104 located between two adjacent LED units 102. The conductive layer 105 and the bonding layer 107 are etched to expose the plurality of first contacts 104. Specifically, the conductive layer 105 is etched to form a second conductive layer 1052, which is used to electrically connect the first semiconductor layers 1021 of the plurality of LED units 102 to the second contacts.

[0143] like Figure 16 As shown, a passivation layer 108 is formed, which covers a portion of the upper surface of the drive backplate 101, the side surface of the bonding layer 107, the side surface of the second conductive layer 1052, and the LED units 102. Through-holes are formed in the passivation layer 108 at locations corresponding to the second semiconductor layers 1023 of the plurality of LED units 102 to expose the second semiconductor layers 1023 of the plurality of LED units 102. Through-holes are also formed in the passivation layer 108 at locations corresponding to the plurality of first contacts 104 to expose the plurality of first contacts 104.

[0144] like Figure 17 As shown, a second electrode layer 1061 is formed, which covers the second semiconductor layer 1023, the first contact 104 and a partial passivation layer 108 of the LED unit 102, so that the second semiconductor layer 1023 of the plurality of LED units 102 are electrically connected to the plurality of first contacts 104 in a one-to-one correspondence.

[0145] like Figure 18As shown, an isolation barrier 109 is formed. The isolation barrier 109 has a plurality of grid holes 110, which surround a plurality of LED units 102 in a one-to-one correspondence.

[0146] like Figure 19 As shown, a wavelength conversion layer 103 is formed. The wavelength conversion layer 103 is formed on the isolation gate 109, and the wavelength conversion layer 103 fills part of the grid holes 110 and covers the corresponding LED unit 102.

[0147] like Figures 1 to 20 As shown, this disclosure also provides a display device 200. The display device 200 includes a Micro LED microdisplay chip 100 as described in any of the preceding embodiments.

[0148] In this embodiment, the display device 200 includes a Micro LED microdisplay chip 100, and therefore has all the beneficial effects of the Micro LED microdisplay chip 100 as in any of the previous embodiments, which will not be described again.

[0149] In this embodiment, the Micro LED microdisplay chip 100 or display device 200 can be applied to augmented reality (AR) display devices, virtual reality (VR) display devices, near-eye display (NED) devices, head-up display (HUD) devices, etc.

[0150] The above are merely preferred embodiments of this application and are not intended to limit this application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the protection scope of this application. The above are merely preferred embodiments of this application. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of this application, and these improvements and modifications should also be considered within the protection scope of this application.

Claims

1. A Micro LED micro display chip, characterized in that, include: Drive backplane; Multiple LED units are arranged on one side of the surface of the drive backplate, and the LED units emit mixed color light, which includes a first color light and a second color light; A wavelength conversion layer is disposed on a portion of the LED units among the plurality of LED units to convert the mixed light emitted by the corresponding LED unit into a third color light; The first color light, the second color light, and the third color light are all different, and at least one of the LED units and at least one adjacent LED unit provided with the wavelength conversion layer constitute a full-color pixel. 2.The Micro LED micro display chip of claim 1, wherein, The LED unit includes a first semiconductor layer, an active layer, and a second semiconductor layer; The active layer is formed between the first semiconductor layer and the second semiconductor layer, and is used to enable the LED unit to emit the mixed color light.

3. The Micro LED microdisplay chip according to claim 2, characterized in that, The active layer includes: The first quantum well, wherein multiple pairs of the first quantum well are provided; The second quantum well is provided in multiple pairs, with multiple pairs of the second quantum well and multiple pairs of the first quantum well being stacked alternately; The first quantum well is used to make the LED unit emit the first color light, and the second quantum well is used to make the LED unit emit the second color light.

4. The Micro LED microdisplay chip according to claim 3, characterized in that, The material of the first quantum well includes indium gallium nitride, wherein the molar composition of indium in the indium gallium nitride is 5% to 20%; The material of the second quantum well includes indium gallium nitride, wherein the molar composition of indium in the indium gallium nitride is 10% to 30%. 5.The Micro LED micro display chip of claim 2, wherein, The active layer includes: A first quantum well, wherein multiple pairs of the first quantum wells are stacked to form a first quantum well group; The second quantum well is formed by stacking multiple pairs of the second quantum wells to form a second quantum well group, and the second quantum well group is stacked with the first quantum well group. The first quantum well is used to make the LED unit emit the first color light, and the second quantum well is used to make the LED unit emit the second color light.

6. The Micro LED microdisplay chip according to claim 2, characterized in that, The thickness of the first semiconductor layer ranges from 50 nm to 500 nm; The thickness of the active layer ranges from 100 nm to 500 nm; The thickness of the second semiconductor layer ranges from 500 nm to 5 μm.

7. The Micro LED micro-display chip of claim 2, wherein, The drive backplate includes: The driving circuit includes a plurality of first contacts and at least one second contact, wherein the plurality of first contacts are disposed below the plurality of LED units in a one-to-one correspondence; In this configuration, a plurality of first contacts are electrically connected to a first semiconductor layer of a plurality of LED units in a one-to-one correspondence; the second semiconductor layers of a plurality of LED units are electrically connected to the second contacts in a common manner, so that the driving circuit can drive each LED unit individually. 8.The Micro LED micro display chip of claim 7, wherein, Also includes: A first conductive layer is disposed between the driving backplate and the LED unit, and is used to electrically connect the first contact and the corresponding first semiconductor layer of the LED unit; A first electrode layer, covering at least the top surface of the plurality of LED units, is used to electrically connect the second contact to the second semiconductor layer of the plurality of LED units.

9. The Micro LED microdisplay chip according to claim 2, characterized in that, The drive backplate includes: The driving circuit includes a plurality of first contacts and at least one second contact, wherein the first contacts are located between adjacent LED units; In this configuration, a plurality of first contacts are electrically connected one-to-one with the second semiconductor layers of a plurality of LED units, and the first semiconductor layers of a plurality of LED units are electrically connected together to the second contacts, so that the driving circuit can drive each LED unit individually.

10. The Micro LED microdisplay chip according to claim 9, characterized in that, Also includes: A second conductive layer is disposed between the driving backplate and the plurality of LED units, and is used to electrically connect the second contact and the first semiconductor layer of the plurality of LED units; The second electrode layer, which covers at least the top surface of the LED unit, is used to electrically connect the first contact to the corresponding second semiconductor layer of the LED unit.

11. The Micro LED microdisplay chip according to claim 1, characterized in that, Also includes: A bonding layer is disposed between the driving backplate and the LED unit for connecting the driving backplate and the plurality of LED units; A passivation layer covers at least a plurality of the LED units and exposes at least a portion of the top surface of the plurality of LED units.

12. The Micro LED microdisplay chip according to claim 1, characterized in that, Also includes: An isolation grid is disposed on the drive back plate and has multiple grid holes, each of which corresponds to a multiple of the LED units; The wavelength conversion layer fills a portion of the grid holes in the plurality of grid holes and covers or encloses the corresponding LED unit.

13. The Micro LED microdisplay chip according to claim 1, characterized in that, Also includes: A blue-green light epitaxial structure is disposed on the driving backplate, and the blue-green light epitaxial structure is etched to form a plurality of LED units; The wavelength conversion layer is made of red quantum dots; Wherein, the first color light includes blue light, the second color light includes green light, and the wavelength conversion layer is used to convert the blue light and green light emitted by the corresponding LED unit into red light.

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