Micro LED Display Chip and Its Preparation Method

Abstract

The embodiments of this specification provide a Micro LED display chip and a method for manufacturing the same. The Micro LED display chip includes: a substrate, on the surface of which there are provided a plurality of independent first electrode structures; an LED epitaxial layer disposed on the substrate, the LED epitaxial layer having a plurality of LED units arranged in an array, each LED unit including a plurality of micro LED modules respectively electrically connected to the same first electrode structure so that the LED unit can be independently driven by the first electrode structure, and the micro LED modules respectively include a first doped semiconductor layer, an active layer, and a second doped semiconductor layer stacked; wherein, there is a gap between the micro LED modules of the LED unit, and a wavelength conversion material capable of changing the color of light is disposed in the gap, and the same wavelength conversion material is disposed in different LED units. A wavelength conversion material capable of changing the color of light is disposed between the micro LED modules, realizing displays of different colors, meeting the requirements of different scenarios, and improving the applicability of the MicroLED display chip.

Description

Technical Field

[0001] This specification relates to the field of display technologies, and particularly to a Micro LED display chip and a method for manufacturing the same. Background Art

[0002] Compared with traditional diode display technologies, Micro LED display technologies feature array and miniaturization. The size of Micro LEDs can reach the micron level or even smaller. Micro light-emitting diodes not only have the characteristic of small volume, but also have advantages such as high brightness, low power consumption, fast response, long lifespan, and high light efficiency. Compared with organic light-emitting display technologies and liquid crystal display technologies, micro light-emitting diode display technologies have good application prospects in frontier display fields such as automotive head-up displays and AR / VR glasses. However, how to provide corresponding multi-color or full-color micro light-emitting diode light-emitting devices according to different usage scenario requirements has always been a problem hindering the development of the industry. Summary of the Invention

[0003] In view of this, multiple embodiments of this specification are dedicated to providing a Micro LED display chip and a method for manufacturing the same, which is beneficial to improving the applicability of the Micro LED display chip.

[0004] An embodiment of this specification provides a Micro LED display chip, including: a substrate, on the surface of which multiple independent first electrode structures are provided; an LED epitaxial layer, disposed on the substrate, the LED epitaxial layer having multiple LED units arranged in an array, and one LED unit corresponding to one of the first electrode structures; each LED unit includes multiple micro LED modules respectively electrically connected to the same first electrode structure, so that the LED unit can be independently driven by the first electrode structure, and the micro LED modules respectively include a first doped semiconductor layer, an active layer, and a second doped semiconductor layer stacked; wherein, there is a gap between the micro LED modules of the LED unit, and a wavelength conversion material capable of changing the color of light is disposed in the gap, and the same wavelength conversion material is disposed in different LED units.

[0005] An embodiment of this specification provides a method for fabricating a Micro LED display chip, including: providing a substrate, wherein a plurality of independent first electrode structures are disposed on the surface of the substrate; providing an LED epitaxial layer, the LED epitaxial layer including a plurality of spaced-apart micro LED modules, the micro LED modules including a first doped semiconductor layer, an active layer, and a second doped semiconductor layer stacked; wherein the first doped semiconductor layer of the micro LED module is an integral structure; filling a wavelength conversion material capable of changing the color of light between the micro LED modules such that the same wavelength conversion material is disposed between different micro LED modules; bonding the LED epitaxial layer after filling the wavelength conversion material to the substrate; wherein the second doped semiconductor layer of some of the micro LED modules is bonded to the first electrode structure of the substrate; each micro LED module bonded to a first electrode structure forms an LED unit, such that the micro LED modules of each LED unit are electrically connected to the same first electrode structure respectively, so that the LED unit can be independently driven by the first electrode structure.

[0006] An embodiment of this specification provides a method for fabricating a Micro LED display chip, including: providing a substrate; wherein a plurality of independent first electrode structures are disposed on the surface of the substrate; bonding an LED epitaxial layer on the substrate, the LED epitaxial layer including a plurality of spaced-apart micro LED modules, the micro LED modules including a first doped semiconductor layer, an active layer, and a second doped semiconductor layer stacked; wherein the first doped semiconductor layer of the plurality of spaced-apart micro LED modules is an integral structure; the second doped semiconductor layer of some of the micro LED modules is bonded to the first electrode structure of the substrate; etching the LED epitaxial layer to form a plurality of independent micro LED modules, the first doped semiconductor layers of adjacent micro LED modules being mutually separated, the active layers of adjacent micro LED modules being mutually separated, and the second doped semiconductor layers of adjacent micro LED modules being mutually separated; wherein each micro LED module bonded to a first electrode structure forms an LED unit; at least filling a wavelength conversion material capable of changing the color of light between the micro LED modules; wherein the same wavelength conversion material is disposed in different LED units.

[0007] The Micro LED display chip provided by the embodiments of this specification has a gap between the micro LED modules of the LED units, and a wavelength conversion material capable of changing the color of light is arranged in the gap, which can improve the luminous efficiency of the wavelength conversion material, and at the same time can achieve displays of different colors, can meet the requirements of different scenarios, and improve the applicability of the Micro LED display chip. The same wavelength conversion material is arranged in different LED units, which matches the characteristics of the small size of the LED units, is beneficial to reducing the preparation difficulty and improving the yield. In addition, the LED unit includes a plurality of micro LED modules, and the use of the micro LED modules can further reduce the size of the LED unit, which is beneficial to improving the resolution and broadening the applicable scenarios. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 Shown is a top view structural schematic diagram of a Micro LED display chip provided by an embodiment.

[0009] Figure 2 Shown is a cross-sectional view structural schematic diagram of a Micro LED display chip provided by an embodiment.

[0010] Figure 3 Shown is a cross-sectional view structural schematic diagram of a Micro LED display chip provided by an embodiment.

[0011] Figure 4 Shown is a cross-sectional view structural schematic diagram of a Micro LED display chip provided by an embodiment.

[0012] Figure 5 Shown is a top view structural schematic diagram of a Micro LED display chip provided by an embodiment.

[0013] Figure 6 Shown is a cross-sectional view structural schematic diagram of a Micro LED display chip provided by an embodiment.

[0014] Figure 7 Shown is a cross-sectional view structural schematic diagram of a Micro LED display chip provided by an embodiment.

[0015] Figures 8a - 8h Shown are structural schematic diagrams of a Micro LED display chip at different stages during the preparation process provided by an embodiment.

[0016] Figures 9a - 9f Shown are structural schematic diagrams of a Micro LED display chip at different stages during the preparation process provided by an embodiment.

[0017] Figures 10a - 10mShown is a schematic structural diagram of different stages in the preparation process of a Micro LED display chip provided by an embodiment. Specific embodiments

[0018] Next, with reference to the accompanying drawings in some embodiments of the specification, the technical solutions in some embodiments of the specification will be clearly and completely described. Obviously, the described embodiments are only a part of the embodiments of the specification, rather than all the embodiments. Based on the embodiments in this specification, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the scope of this specification.

[0019] The meaning of "on..." in this specification should be interpreted in the broadest sense, such that "on..." not only means "directly on something", but also means "on something" including intermediate components or layers therebetween.

[0020] The term "layer" used in this specification refers to a portion of material including a region having a certain thickness. A layer can extend over the entire underlying or overlying structure, or can have an extent less than the extent of the underlying or overlying structure. In addition, a layer can be a region of a homogeneous or heterogeneous continuous structure, the thickness of which is less than the thickness of the continuous structure. For example, a layer can be located between the top and bottom surfaces of a continuous structure or between any pair of horizontal planes therebetween. A layer can extend horizontally, vertically, and / or along a tapered surface. A layer can include multiple layers. For example, a semiconductor layer can include one or more doped or undoped semiconductor layers and can have the same or different materials.

[0021] The term "Micro LED" used in this specification refers to the descriptive dimensions of certain structures according to the embodiments of this specification. The term "micro" used in this specification is intended to represent a scale of 0.1 to 100 μm. However, it should be understood that the embodiments of this specification are not necessarily limited thereto, and certain aspects of the embodiments can be applicable to larger and possibly smaller size scales.

[0022] Please refer to Figure 1 、 Figure 2 and Figure 3 。 Figure 2 is Figure 1 a schematic cross-sectional structural diagram along line A-A' in Figure 1 In , the contour portion of the first electrode structure 210 blocked by the LED unit is represented by a dashed line. Figure 1The wavelength conversion material 400 is not shown. Embodiments of this specification provide a Micro LED display chip. The Micro LED display chip may include: a substrate 100, on the surface of which a plurality of independent first electrode structures 210 are provided; an LED epitaxial layer 300 disposed on the substrate 100, the LED epitaxial layer 300 having a plurality of LED units 310 arranged in an array, and one of the LED units 310 corresponding to one of the first electrode structures 210; each of the LED units 310 includes a plurality of micro-LED modules 311 respectively electrically connected to the same first electrode structure 210, so that the LED unit 310 can be independently driven by the first electrode structure 210. The micro-LED modules 311 respectively include a first doped semiconductor layer 3111, an active layer 3112, and a second doped semiconductor layer 3113 which are stacked; wherein, there is a gap between the micro-LED modules 311 of the LED unit 310, and a wavelength conversion material 400 capable of changing the color of light is disposed in the gap, and the same wavelength conversion material 400 is disposed in different LED units 310.

[0023] In some embodiments, the substrate 100 may be a Complementary Metal-Oxide-Semiconductor (CMOS) substrate, may be a Thin Film Transistor (TFT) substrate, or may be a Liquid Crystal on Silicon (LCOS) substrate. The substrate 100 may include semiconductor materials. For example, silicon, silicon carbide, gallium nitride, germanium, gallium arsenide, indium phosphide. The substrate 100 may include non-conductive materials. For example, glass, sapphire. The substrate 100 may include a driving circuit, and the driving circuit may be used to drive the LED unit 310. The driving circuit may be an active matrix driving circuit or may be a passive matrix driving circuit. The first electrode structure 210 may be electrically connected to the driving circuit to meet the requirement of the LED unit 310 being independently driven.

[0024] In some embodiments, the plurality of independent first electrode structures 210 may be spaced apart from each other.

[0025] Please refer to Figure 3 . In some embodiments, the LED epitaxial layer 300 is disposed on the substrate 100. The LED epitaxial layer 300 is located on the side of the substrate 100 having the first electrode structure 210, and the first electrode structure 210 may be located between the substrate 100 and the LED epitaxial layer 300. The LED epitaxial layer 300 has a plurality of LED units 310 arranged in an array. The plurality of LED units 310 may be arranged in multiple rows and multiple columns.

[0026] In some embodiments, there is a gap between the micro-LED modules 311 of the LED unit 310. Along the direction perpendicular to the plane where the substrate 100 is located, the depth of the gap is less than or equal to the height of the micro-LED module 311. When the depth of the gap is equal to the height of the micro-LED module 311, the micro-LED modules 311 are independent of each other. Please refer to Figure 2 . In some embodiments, the multiple LED units 310 can be independently arranged. When the depth of the gap is less than the height of the micro-LED module 311, the micro-LED modules 311 are connected to each other. Please refer to Figure 3 . In some embodiments, the multiple LED units 310 can be connected to each other. Please refer to 1 and Figure 2 . Each LED unit 310 can include multiple micro-LED modules 311. Each LED unit 310 can include one row and multiple columns of micro-LED modules 311; alternatively, each LED unit 310 can include one column and multiple rows of micro-LED modules 311; alternatively, each LED unit 310 can include multiple rows and multiple columns of micro-LED modules 311. The micro-LED modules 311 of each LED unit 310 can be arranged in an array, and the Micro LED display chip can include multiple LED units 310 arranged in an array.

[0027] Please refer to Figure 2 . In some embodiments, one LED unit 310 corresponds to one first electrode structure 210. The orthographic projection of the LED unit 310 on the corresponding first electrode structure 210 can cover a partial area of the first electrode structure 210, and the orthographic projection of the micro-LED modules 311 included in the LED unit 310 on the corresponding first electrode structure 210 can be partially or entirely located within the first electrode structure 210. The LED unit 310 includes multiple micro-LED modules 311 that are electrically connected to the same first electrode structure 210 respectively, so that the LED unit 310 can be independently driven by the first electrode structure 210. The micro-LED module 311 can be electrically connected to the first electrode structure 210 in a direct contact manner. Please refer to Figure 4The micro-LED module 311 can be electrically connected to the first electrode structure 210 in an indirect connection manner through the bonding module 510. The material of the bonding module 510 can include at least one of metal, conductive adhesive, and metal oxide. The metal can be at least one of materials such as aluminum (Al), copper (Cu), platinum (Pt), chromium (Cr), titanium (Ti), germanium (Ge), nickel (Ni), etc. The metal oxide can be indium tin oxide. In some embodiments, the bonding material 500 can include a stacked contact metal layer and a bonding metal layer. The contact metal layer can be used to contact the micro-LED module 311. In some embodiments, the thickness range of the contact metal layer is 1-100 nm. Preferably, the thickness range of the contact metal layer is 5-10 nm. In some embodiments, the material of the contact metal layer is at least one of ITO or NiAu. In some embodiments, the thickness range of the bonding metal layer is 100 nm-100 μm. Preferably, the thickness range of the bonding metal layer is 1-2 μm. In some embodiments, the material of the bonding metal layer is at least one of Cu, Sn, Au, In. A plurality of micro-LED modules 311 are electrically connected to the first electrode structure 210, so that the LED unit 310 can be independently driven by the first electrode structure 210.

[0028] In some embodiments, the first electrode structure 210 can be made of a conductive material. Specifically, it can be at least one of metal and conductive adhesive. The metal can be at least one of materials such as aluminum (Al), copper (Cu), platinum (Pt), chromium (Cr), titanium (Ti), germanium (Ge), nickel (Ni), etc.

[0029] Please refer to Figure 3 The micro-LED module 311 respectively includes a first doped semiconductor layer 3111, an active layer 3112, and a second doped semiconductor layer 3113 which are stacked. The active layer 3112 is located between the first doped semiconductor layer 3111 and the second doped semiconductor layer 3113, and the second doped semiconductor layer 3113 can be located on the side of the active layer 3112 close to the substrate 100. The micro-LED module 311 can be electrically connected to the first electrode structure 210 through the second doped semiconductor layer 3113.

[0030] In some embodiments, the first doped semiconductor layer 3111 may be an N-type semiconductor structure or may be a P-type semiconductor layer; correspondingly, the second doped semiconductor layer 3113 may be a P-type semiconductor structure or may be an N-type semiconductor layer. The N-type semiconductor layer or the P-type semiconductor layer may include II-VI group materials. For example, zinc selenide (ZnSe). The N-type semiconductor layer or the P-type semiconductor layer may include III-V nitride compounds materials. For example, gallium nitride (GaN), aluminum nitride (AlN), indium nitride (InN), indium gallium nitride (InGaN), aluminum gallium nitride (AlGaN), or aluminum indium gallium nitride (AlInGaN). The first doped semiconductor layer 3111 and the second doped semiconductor layer 3113 may include different dopants. For example, the N-type semiconductor layer may include dopants such as silicon or germanium. The P-type semiconductor layer may include dopants such as magnesium or carbon. The N-type semiconductor layer and the P-type semiconductor layer may be a single-layer structure or may include multiple layers. The active layer 3112 may include quantum well (QW) materials, may be a single quantum well layer, may include multiple quantum well (MQW) layers, or may include a structure formed by alternately laminating quantum well layers and barrier layers.

[0031] In some embodiments, the LED unit 310 includes a plurality of micro-LED modules 311, and some of the micro-LED modules 311 are circumferentially coated with a light conversion material. For the LED unit 310, some of the micro-LED modules 311 may be circumferentially coated with a light conversion material, or all of the micro-LED modules 311 may be circumferentially coated with a light conversion material. For a plurality of LED units 310, at least one of the micro-LED modules 311 in the micro-LED modules 311 of each LED unit 310 may be circumferentially coated with a light conversion material.

[0032] In some embodiments, the micro-LED module 311 may have a bottom surface close to the substrate 100 and a top surface opposite to the substrate 100. The surface between the top surface and the bottom surface of the micro-LED module 311 may be the circumferential surface of the micro-LED module 311. The circumferential coating of the micro-LED module 311 with a light conversion material may be that the light conversion material is in contact with the circumferential surface of the micro-LED module 311. The circumferential coating of the micro-LED module 311 with a light conversion material may be that the light conversion material surrounds the circumferential surface of the micro-LED module 311. Along the direction perpendicular to the bottom surface of the micro-LED module 311, a part of the height of the micro-LED module 311 is circumferentially coated with a light conversion material or the entire height is coated with a light conversion material. The circumferential surfaces of the micro-LED modules 311 of the LED unit 310 are all coated with a light conversion material. This is beneficial to improving the light conversion efficiency and increasing the light output area.

[0033] In some embodiments, there is a gap between the micro-LED modules 311 of the LED unit 310, and a wavelength conversion material 400 capable of changing the color of light is disposed within the gap. It can be in the direction perpendicular to the plane where the substrate 100 is located, and the wavelength conversion material 400 is disposed within at least the depth range of the gap between the micro-LED modules 311. The gap between the micro-LED modules 311 can be entirely filled with the wavelength conversion material 400, which is beneficial to enhancing the wavelength conversion efficiency and improving the lifespan of the LED unit 310.

[0034] In some embodiments, the light conversion material can be a quantum dot material or a phosphor. The light conversion material is used to convert the color of the light emitted by the LED unit 310. For example, the light conversion material can be used to convert the light of the first color emitted by the micro-LED module 311 into the light of the second color, thereby adjusting the light output color of the LED unit 310. It can be understood that there is a corresponding relationship between the wavelength and color of light. The same wavelength conversion material 400 is provided in different LED units 310. The wavelength conversion material 400 in the LED unit 310 can be a single wavelength conversion material 400 or a mixed wavelength conversion material 400. The wavelength conversion materials 400 included in multiple LED units 310 are the same. The wavelength conversion material can be formed by a single process, which is beneficial to reducing the process difficulty, adapting to the characteristics of the small size of the LED unit 310, and improving the yield.

[0035] The Micro LED display chip provided by the embodiments of this specification has a wavelength conversion material capable of changing the color of light disposed between the micro-LED modules, so that different color displays can be realized, the requirements of different scenarios can be met, and the applicability of the Micro LED display chip can be improved. The same wavelength conversion material is provided in different LED units, which matches the characteristics of the small size of the LED unit, is beneficial to reducing the preparation difficulty and improving the yield. In addition, the LED unit includes multiple micro-LED modules. By using the micro-LED modules, the size of the LED unit can be further reduced, which is beneficial to improving the resolution and broadening the applicable scenarios.

[0036] In some embodiments, the wavelength conversion material 400 includes a color mixing quantum dot material; wherein, the color mixing quantum dot material includes quantum dot materials of at least two colors. For example, the color mixing quantum dot material may include at least two of the following: a red light quantum dot material, a green light quantum dot material, and a blue light quantum dot material. The color mixing quantum dot material may include quantum dot materials of three colors. The color mixing quantum dot material includes a variety of quantum dot materials of different colors, thereby being able to reduce the process difficulty while increasing the adaptation range. The light emitted by the micro-LED module 311 may be blue light. The light after passing through the wavelength conversion material 400 from the light emitted by the micro-LED module 311 may be mixed light. The color mixing quantum dot material can improve the light extraction color gamut of the Micro LED display chip and can meet the multi-color full-color requirements.

[0037] In some embodiments, the wavelength conversion material 400 includes a single-color quantum dot material. The single-color quantum dot material may include one of the following: a red light quantum dot material, a green light quantum dot material, a blue light quantum dot material, and a yellow light quantum dot material. The red light quantum dot material can change the light emitted by the micro-LED module 311 into red, the green light quantum dot material can change the light emitted by the micro-LED module 311 into green, the blue light quantum dot material can change the light emitted by the micro-LED module 311 into blue, and the yellow light quantum dot material can change the light emitted by the micro-LED module 311 into yellow. The color of the light emitted by the LED module may be the same as or different from the color changed by the wavelength conversion material 400.

[0038] Please refer to Figure 4 or Figure 6 . In some embodiments, the Micro LED display chip may include: a filter layer 900, including a plurality of filter units 910 corresponding to the LED units 310. The filter layer 900 can allow light with wavelengths within a certain range to pass through, while intercepting light in the remaining wavelength ranges. Or rather, the filter layer 900 can enable light of a color corresponding to a wavelength within a certain range to pass through. Thus, by setting the filter layer 900, the color purity can be improved and the display effect can be enhanced. The LED unit 310 may be located between the filter layer 900 and the substrate 100. The orthographic projection of the filter unit 910 on the LED unit 310 may cover the LED unit 310. There may be gaps between the plurality of filter units 910. An absorbing unit may be provided between the filter units 910, and the absorbing unit can solve the problem of light crosstalk between adjacent LED units 310.

[0039] In some embodiments, the filter layer 900 may be a filter layer 900 of a single color. The filter layer 900 may extend continuously, and the orthographic projection of the filter layer 900 on the LED unit 310 may cover the area between the LED unit 310 and the LED unit 310. It can be applicable to pure color display, simplify the manufacturing process, and improve the color purity.

[0040] In some embodiments, the light passing through the wavelength conversion material 400 is mixed light having at least two colors; the filter unit 910 includes a first filter unit 911 and a second filter unit 912; wherein, the colors of the light allowed to pass through by the first filter unit 911 and the second filter unit 912 are different from each other. For example, the mixed light includes red light and green light, and correspondingly, the colors of the light allowed to pass through by the first filter unit 911 and the second filter unit 912 can be red light and green light respectively.

[0041] Please refer to Figure 5 and Figure 6 . Figure 6 is Figure 5 a schematic cross-sectional structure diagram along line B-B' in []. In the figure, the micro LED module 311 is respectively covered by a first filter unit 911, a second filter unit 912 and a third filter unit 913, and the micro LED module 311 is shown by a dotted line. In some embodiments, the light passing through the wavelength conversion material 400 is mixed light; the filter unit 910 includes a first filter unit 911, a second filter unit 912 and a third filter unit 913; wherein, the colors of the light allowed to pass through by the first filter unit 911, the second filter unit 912 and the third filter unit 913 are different from each other. In some embodiments, the colors of the light allowed to pass through by the first filter unit 911, the second filter unit 912 and the third filter unit 913 are different from each other, and are all selected from: red light, green light or blue light. In some embodiments, the filter unit 910 includes a first filter unit 911, a second filter unit 912 and a third filter unit 913; the second filter unit 912 is adjacent to both the first filter unit 911 and the third filter unit 913, and the filter unit 910 has at least one first filter unit 911, one second filter unit 912 and one third filter unit 913 as a repeating unit, and multiple repeating units can be arranged in an array. For example, Figure 5 two repeating units are exemplified in []. The filter layer includes filter units of different colors, so that light of different colors can be allowed to pass through, which is beneficial to the full-color display of the Micro LED display chip.

[0042] Please refer to Figure 7. In some embodiments, the substrate 100 is provided with a second electrode structure 220 having an opposite electrical property to the first electrode structure 210; the first doped semiconductor layer 3111 in the micro-LED module 311 of the LED unit 310 is an integral structure and is electrically connected to the second electrode structure 220; the second doped semiconductor layers 3113 of the micro-LED modules 311 in the LED unit 310 are respectively electrically connected to the same first electrode structure 210. Along the direction perpendicular to the substrate 100, at least a part of the thickness of the first doped semiconductor layer 3111 of the micro-LED module 311 may be interconnected with adjacent micro-LED modules 311, forming an integral structure of the first doped semiconductor layer 3111 of the micro-LED modules 311 in the LED unit 310. The second doped semiconductor layers 3113 of the LED unit 310 may be respectively and independently electrically connected to the corresponding first electrode structures 210. The first doped semiconductor layer 3111 being an integral structure and electrically connected to the second electrode structure 220 is beneficial to reducing the process difficulty and the driving difficulty.

[0043] . In some embodiments, at least one second electrode structure connecting member may be provided, and the second electrode structure connecting member is used to electrically connect the second electrode structure 220 and the first doped semiconductor layer 3111. The second electrode structure connecting member may extend along the depth direction of the interval between the micro-LED modules 311 on the surface of a micro-LED module 311 not electrically connected to the first electrode structure 210. It can be understood that this micro-LED module 311 not electrically connected to the first electrode structure 210 is not used for light emission and can provide support for the electrical connection between the second electrode structure 220 and the first doped semiconductor layer 3111. In some embodiments, the second electrode structure connecting member may be formed by the same process as the bonding material 500. The first electrode structure 210 and the second electrode structure 220 may be formed by the same process.

[0044] Please refer to Figure 3。In some embodiments, there are also redundant micro-LED modules 312 between multiple LED units 310 that are not electrically connected to the first electrode structure 210. The redundant micro-LED modules 312 respectively include a first doped semiconductor layer 3111, an active layer 3112, and a second doped semiconductor layer 3113 that are stacked. The first doped semiconductor layer 3111 of the redundant micro-LED module 312 and the first doped semiconductor layer 3111 of the micro-LED module 311 of the LED unit 310 are an integral structure. Since the redundant micro-LED module 312 is not electrically connected to the first electrode structure 210, the redundant micro-LED module 312 cannot be driven. The redundant micro-LED modules 312 between the LED units 310 can be one or multiple. The redundant micro-LED module 312 can include a first doped semiconductor layer 3111, an active layer 3112, and a second doped semiconductor layer 3113 that are stacked, and the second doped semiconductor layer 3113 is close to the substrate 100. There can be redundant micro-LED modules 312 between multiple LED units 310. The redundant micro-LED modules 312 can be connected through the first doped semiconductor layer 3111, and the first doped semiconductor layer 3111 of the redundant micro-LED module 312 can be connected to the first doped semiconductor layers 3111 of multiple LED units 310. The Micro LED display chip includes the redundant micro-LED module 312, which can reduce the process difficulty. The fact that the first doped semiconductor layer 3111 of the redundant micro-LED module 312 and the first doped semiconductor layers 3111 of multiple LED units 310 are an integral structure is beneficial to reducing the driving difficulty of the LED units 310. In some embodiments, there may be no redundant micro-LED modules 312 between multiple LED units 310, and the first doped semiconductor layer 3111 of the micro-LED module 311 in the LED unit 310 is an integral structure.

[0045] Please refer to Figure 6 and Figure 7 。In some embodiments, the substrate 100 may include a first electrode contact 110, and the first electrode structure 210 can be electrically connected to the driving circuit through the first electrode contact 110. The first electrode contact 110 can be exposed on the surface of the substrate 100, which is convenient for realizing the electrical connection between the LED unit 310 and the first electrode contact 110, thereby realizing the independent driving of the LED unit 310. The first electrode structures 210 can be arranged in one-to-one correspondence with the first electrode contacts 110. The orthographic projection of the first electrode structure 210 on the substrate 100 can cover the first electrode contact 110. In some embodiments, the substrate 100 may further include a second electrode contact 120, and the second electrode structure 220 can be electrically connected to the driving circuit through the second electrode contact 120.

[0046] Please refer to Figure 2。In some embodiments, the spacing makes the multiple micro-LED modules 311 included in the LED unit 310 independent of each other. The first doped semiconductor layers 3111 of adjacent micro-LED modules 311 are separated from each other, the active layers 3112 of adjacent micro-LED modules 311 are separated from each other, and the second doped semiconductor layers 3113 of adjacent micro-LED modules 311 are separated from each other.

[0047] In some embodiments, the spacing makes the multiple micro-LED modules 311 included in the LED unit 310 independent of each other, and the spacing is filled with the wavelength conversion material 400. Among the multiple micro-LED modules 311 included in the LED unit 310, the wavelength conversion material 400 is completely filled between adjacent micro-LED modules 311, which is beneficial to improving the lifespan and light conversion rate.

[0048] Please refer to Figure 4 。In some embodiments, a planarization structure 710 is provided between adjacent LED units 310. The planarization structure 710 makes the LED epitaxial layer 300 form a planarized surface facing away from the substrate. The planarization structure 710 planarizes the micro-LED modules 311 included in the multiple LED units 310 to form a planarized surface facing away from the substrate 100. By planarizing the micro-LED modules 311, it is beneficial to eliminate the height difference between independent LED modules and facilitate the improvement of the continuity and stability of subsequent film layers. In some embodiments, the material of the planarization structure 710 may include a light-absorbing material, for example, an organic black matrix photoresist; or, the material of the planarization structure 710 may include a light-filtering material, for example, a color filter photoresist. It can prevent light crosstalk between adjacent LED units 310 and is beneficial to improving the display effect.

[0049] In some embodiments, the material of the planarization structure 710 at least includes one of the following: organic black matrix photoresist, color filter photoresist, polyimide, damascene glue, OC glue, SU8 photoresist or benzocyclobutene (BCB).

[0050] Please refer to Figure 4 。In some embodiments, a common electrode layer 800 having an opposite electrical property to the first electrode structure 210 is provided on the planarized surface, and the first doped semiconductor layer 3111 of the micro-LED module 311 is electrically connected to the common electrode layer 800. The common electrode layer 800 can be provided on the surface of the micro-LED module 311. Correspondingly, the common electrode layer 800 is electrically connected to the multiple micro-LED modules 311. It is beneficial to reduce the process difficulty and driving difficulty. The material of the common electrode layer 800 can be a conductive material and can be a transparent material. For example, it can be indium tin oxide.

[0051] In some embodiments, the substrate 100 is provided with a second electrode structure 220 having an opposite electrical property to the first electrode structure 210, and the common electrode layer 800 is electrically connected to the second electrode structure 220. The second electrode structure 220 may be located on the surface of the substrate 100, and the second electrode structure 220 may be electrically connected to the driving circuit. The substrate 100 may include a second electrode contact 120, and the second electrode contact 120 is electrically connected to the driving circuit and the second electrode structure 220 for driving the LED unit 310. The electrical property of the first electrode structure 210 may be negative, and the electrical property of the second electrode structure 220 may be positive.

[0052] In some embodiments, the micro-LED modules 311 respectively include a first doped semiconductor layer 3111, an active layer 3112, and a second doped semiconductor layer 3113 which are stacked; wherein, the first doped semiconductor layer 3111 is independently electrically connected to the common electrode layer 800, and the second doped semiconductor layer 3113 is independently electrically connected to the corresponding first electrode structure 210. The first doped semiconductor layers 3111 of the micro-LED modules 311 may be all electrically connected to the common electrode layer 800, and the second doped semiconductor layers 3113 are respectively electrically connected to the corresponding first electrode structures 210.

[0053] The embodiments of the present specification provide a method for manufacturing a Micro LED display chip. The method for manufacturing the Micro LED display chip may include the following steps.

[0054] Step S110: Provide a substrate 100, wherein a plurality of independent first electrode structures 210 are provided on the surface of the substrate 100.

[0055] Please refer to Figure 8a . In some embodiments, the plurality of independent first electrode structures 210 are spaced apart from each other. The material of the first electrode structure 210 may be a conductive material. Specifically, it may include at least one of metal, conductive glue, and metal oxide. The metal may be at least one of materials such as aluminum (Al), copper (Cu), platinum (Pt), chromium (Cr), titanium (Ti), germanium (Ge), nickel (Ni), etc. The metal oxide may be indium tin oxide. The substrate 100 may include a driving circuit, and the first electrode structure 210 may be electrically connected to the driving circuit. Figure 8a The driving circuit is not shown in

[0056] Please refer to Figure 8a . In some embodiments, the substrate 100 may include a first electrode contact 110, and the first electrode structure 210 may be electrically connected to the driving circuit through the first electrode contact 110. The first electrode structures 210 may be provided in one-to-one correspondence with the first electrode contacts 110. The orthographic projection of the first electrode structure 210 on the substrate 100 may cover the first electrode contact 110.

[0057] In some embodiments, the substrate 100 is provided with a second electrode structure 220 having an opposite electrical property to the first electrode structure 210. The material of the second electrode structure 220 may be a conductive material. Specifically, it may include at least one of a metal, a conductive adhesive, and a metal oxide. In some embodiments, the substrate 100 may include a second electrode contact 120, and the second electrode structure 220 may be electrically connected to the driving circuit through the second electrode contact 120.

[0058] Step S120: Provide an LED epitaxial layer 300, where the LED epitaxial layer 300 includes a plurality of spaced-apart micro-LED modules 311, and the micro-LED modules 311 include a first doped semiconductor layer 3111, an active layer 3112, and a second doped semiconductor layer 3113 that are stacked; wherein, the first doped semiconductor layer 3111 of the micro-LED module 311 is an integral structure.

[0059] In some embodiments, the LED epitaxial layer 300 includes a plurality of spaced-apart micro-LED modules 311, and at least the second doped semiconductor layers 3113 of the micro-LED modules 311 are independent of each other. The LED epitaxial layer 300 including a plurality of spaced-apart micro-LED modules 311 may mean that the second doped semiconductor layers 3113 are spaced apart; or, it may mean that the second doped semiconductor layers 3113 are spaced apart and at least part of the thickness of the active layer 3112 is spaced apart; or, it may mean that the second doped semiconductor layers 3113 are spaced apart, the active layer 3112 is spaced apart, and part of the thickness of the first doped semiconductor layer 3111 is spaced apart. The thickness direction refers to the stacking direction of the first doped semiconductor layer 3111 and the active layer 3112.

[0060] Please refer to Figure 8b 、 Figure 8c and Figure 8d。In some embodiments, the step of providing the LED epitaxial layer 300 may include: providing a semiconductor layer 300a; wherein the semiconductor layer 300a includes a first doped semiconductor layer 3111, an active layer 3112, and a second doped semiconductor layer 3113 which are stacked; wherein a bonding material 500 is provided on the semiconductor layer 300a; etching the bonding material 500 to form a plurality of independent bonding modules 510; etching the semiconductor layer 300a to form a plurality of micro-LED modules 311; wherein, among the plurality of spaced micro-LED modules 311, the first doped semiconductor layer 3111 is an integral structure; the micro-LED modules 311 correspond to the bonding modules 510. In some embodiments, the bonding material 500 may include a metal material. The bonding material 500 may include a stacked contact metal layer and a bonding metal layer. The contact metal layer is used to contact the semiconductor layer 300a and may be in contact with the second doped semiconductor layer 3113. In some embodiments, the thickness range of the contact metal layer is 1-100 nm. Preferably, the thickness range of the contact metal layer is 5-10 nm. In some embodiments, the material of the contact metal layer is at least one of ITO or NiAu. In some embodiments, the thickness range of the bonding metal layer is 100 nm - 100 μm. Preferably, the thickness range of the bonding metal layer is 1-2 μm. In some embodiments, the material of the bonding metal layer is at least one of Cu, Sn, Au, In. The bonding module 510 can be used to improve the bonding force between the LED epitaxial layer 300 and the substrate 100 when they are bonded. The bonding material is a conductive material, which can meet the requirement of electrically connecting the micro-LED module 311 and the first electrode structure 210.

[0061] Please refer to Figure 8b and Figure 8c 。In some embodiments, by etching the bonding material 500, a part of the bonding material 500 in some areas is removed to form a plurality of independent bonding modules 510. The micro-LED modules 311 correspond to the bonding modules 510. The bonding modules 510 are independent of each other and there are intervals between the bonding modules 510. A mask can be provided on the bonding material 500, and a part of the bonding material 500 is removed through the mask.

[0062] Please refer to Figure 8c and Figure 8d。In some embodiments, after etching the bonding material 500 to form a plurality of independent bonding modules 510, the semiconductor layer 300a may be etched to form the LED epitaxial layer 300. By etching the semiconductor layer 300a, a part of the LED epitaxial layer 300 with a part of the thickness in some regions is removed to form a plurality of spaced micro-LED modules 311, and the LED epitaxial layer 300 is obtained. Among them, at least a part of the thickness of the first doped semiconductor layer 3111 of the etched semiconductor layer 300a is not etched, and the first doped semiconductor layer 3111 with an integral structure is formed. The first doped semiconductor layer 3111 has an integral structure, and the first doped semiconductor layer 3111 connects the micro-LED modules 311, which is beneficial to improving the stability of the LED epitaxial layer 300 and reducing the risk of detachment during and after the bonding of the LED epitaxial layer 300 to the substrate 100. The micro-LED module 311 corresponds to the bonding module 510, and the orthographic projection of the bonding module 510 on the micro-LED module 311 may be located within the micro-LED module 311. When etching the semiconductor layer 300a, the bonding module 510 may be used as a mask. In some embodiments, providing the semiconductor layer 300a includes providing the semiconductor layer 300a disposed on the first substrate 300-1.

[0063] In some embodiments, the step of providing the LED epitaxial layer 300 includes: providing a semiconductor layer 300a; wherein, the semiconductor layer 300a includes a first doped semiconductor layer 3111, an active layer 3112, and a second doped semiconductor layer 3113 which are stacked; etching the semiconductor layer 300a to form a plurality of micro-LED modules 311; wherein, in the plurality of spaced micro-LED modules 311, the first doped semiconductor layer 3111 is an integral structure; the micro-LED module 311 corresponds to the bonding module 510; the method further includes: attaching a bonding material 500 to the second doped semiconductor layer 3113 of the micro-LED module 311; wherein, the bonding material 500 is used for bonding with the substrate 100. After obtaining the LED epitaxial layer 300, the bonding material 500 is attached to the second doped semiconductor layer 3113 of the micro-LED module 311, and the bonding material 500 can be located on the surface of the second doped semiconductor layer 3113 of the micro-LED module 311 on the side facing away from the first doped semiconductor layer 3111. The bonding material 500 can be a conductive material. The bonding material 500 can be located in a partial area of the surface of the second doped semiconductor layer 3113 on the side facing away from the first doped semiconductor layer 3111, and can overlap with the surface of the second doped semiconductor layer 3113 on the side facing away from the first doped semiconductor layer 3111. A mask can be used to attach the bonding material 500 to the second doped semiconductor layer 3113. Specifically, the mask opening can correspond to the micro-LED module 311, so that the bonding material 500 can be attached to the second doped semiconductor layer 3113. The bonding material 500 can be formed by evaporation coating.

[0064] Step S130: Fill a wavelength conversion material 400 capable of changing the color of light between the micro-LED modules 311 so that the same wavelength conversion material 400 is provided between different micro-LED modules 311.

[0065] In some embodiments, the substrate 100 is provided with a second electrode structure 220, and the second electrode structure 220 has an opposite electrical property to the first electrode structure 210. The second electrode structure 220 is used for electrically connecting with the first doped semiconductor layer 3111. Please refer to Figure 8e . In some embodiments, the wavelength conversion material 400 capable of changing the color of light can be filled in the space between the micro-LED modules 311 by at least one of processes such as coating, inkjet printing, and evaporation coating. The height of the light conversion material can be less than the depth of the space between the micro-LED modules 311, or can be equal to the depth of the space between the micro-LED modules 311. The wavelength conversion material 400 can be in contact with the circumferential surface of the micro-LED module 311.

[0066] In some embodiments, the light conversion material may be a quantum dot material or may be a phosphor. The light conversion material is used to convert the color of the light emitted by the LED module. The wavelength conversion material 400 may be a single wavelength conversion material 400 or may be a hybrid wavelength conversion material 400. By setting the same wavelength conversion material 400 between different LED modules, the wavelength conversion material 400 filled between the micro-LED modules can be formed by one process. The integration process of the same wavelength conversion material is beneficial to reducing the process difficulty, matching the characteristic of the small size of the LED module, and is beneficial to improving the yield of the Micro LED display chip.

[0067] Step S140: Bond the LED epitaxial layer 300 after filling the wavelength conversion material 400 to the substrate 100; wherein, the second doped semiconductor layer 3113 of some of the micro-LED modules 311 is bonded to the first electrode structure 210 of the substrate 100; each micro-LED module 311 bonded to the first electrode structure 210 forms an LED unit 310, so that the micro-LED modules 311 of each LED unit 310 are electrically connected to the same first electrode structure 210 respectively, so that the LED unit 310 can be independently driven by the first electrode structure 210.

[0068] Please refer to Figure 8f . In some embodiments, a plurality of independent first electrode structures 210 are provided on the surface of the substrate 100. When the LED epitaxial layer 300 is bonded to the substrate 100, the second doped semiconductor layer 3113 of some of the micro-LED modules 311 is bonded to the first electrode structure 210 of the substrate 100, and the micro-LED module 311 bonded to the first electrode structure 210 is electrically connected to the first electrode structure 210. The micro-LED modules 311 bonded to the same first electrode structure 210 form an LED unit 310, and the micro-LED modules 311 of each LED unit 310 are electrically connected to the same first electrode structure 210 respectively, so that the LED unit 310 can be independently driven by the first electrode structure 210. The second doped semiconductor layer 3113 of the micro-LED module 311 can be bonded to the first electrode structure 210 of the substrate 100 through a bonding module 510. There may be at least one micro-LED module 311 that is not bonded to the first electrode structure 210 between adjacent first electrode structures 210. The number of micro-LED modules 311 bonded to each first electrode structure 210 may be multiple, and the multiple micro-LED modules 311 may be arranged in a row, or may be arranged in a column, or may be arranged in a multi-row and multi-column array. The micro-LED modules 311 bonded to the same first electrode structure 210 form an LED unit 310. The multiple independent first electrode structures 210 correspond to multiple LED units 310.

[0069] In some embodiments, a second electrode structure 220 is provided on the substrate 100, and the micro-LED module 311 corresponding to the second electrode structure 220 is bonded to the second electrode structure 220.

[0070] Please refer to Figure 8g . In some embodiments, when a semiconductor layer 300a is provided on the first substrate 300-1, after the LED epitaxial layer 300 filled with the wavelength conversion material 400 is bonded to the substrate 100, the first substrate 300-1 can be removed. At least one of methods such as mechanical peeling, laser peeling, and etching can be used to remove the first substrate 300-1.

[0071] The method for manufacturing a Micro LED display chip provided by the embodiments of this specification can form a Micro LED display chip that can emit an expected color according to requirements by filling a wavelength conversion material 400 that can change the color of light between the micro-LED modules 311, thereby improving adaptability. By providing the same wavelength conversion material 400 between different micro-LED modules 311 and preparing the wavelength conversion material 400 through an integrated process, the wavelength conversion material 400 is formed in the intervals between the micro-LED modules 311, which conforms to the characteristics of the small size of the micro-LED modules 311 and is beneficial to improving the yield and reducing the difficulty. Since the first doped semiconductor layer 3111 is an integral structure, the bonding force between adjacent film layers can be improved based on the integral first doped semiconductor layer 3111. By providing an LED epitaxial layer 300 including a plurality of spaced micro-LED modules 311, bonding the LED epitaxial layer 300 to the substrate 100, and the micro-LED modules 311 bonded to the first electrode structure 210 form an LED unit 310, there is no need to pre-define the LED unit 310, which reduces the requirement for alignment accuracy and can satisfy the connection between the micro-LED modules 311 and the first electrode structure 210, and is beneficial to the improvement of the manufacturing yield.

[0072] Please refer to Figure 8h . In some embodiments, the method for manufacturing a Micro LED display chip may include: attaching a filter layer 900 on the LED epitaxial layer 300; wherein, the filter layer 900 includes a plurality of filter units 910 corresponding to the LED units 310.

[0073] In some embodiments, the filter unit 910 includes a first filter unit 911 and a second filter unit 912, and the colors of light allowed to pass through the first filter unit 911 and the second filter unit 912 are different. Thus, a multi-color display can be formed.

[0074] In some embodiments, the light passing through the wavelength conversion material 400 is mixed-color light; the filter unit 910 further includes a first filter unit 911, a second filter unit 912, and a third filter unit 913; wherein, the colors of the light allowed to pass through by the first filter unit 911, the second filter unit 912, and the third filter unit 913 are different from each other. The colors of the light allowed to pass through by the first filter unit 911, the second filter unit 912, and the third filter unit 913 are different from each other, and are all selected from: red light, green light, or blue light. The second filter unit 912 is adjacent to both the first filter unit 911 and the third filter unit 913. For specific content, reference may be made to the above description of the Micro LED display chip, which will not be elaborated here.

[0075] Please refer to Figure 8g and Figure 9a . In some embodiments, the micro LED modules 311 in the LED epitaxial layer 300 that are not bonded to the first electrode structure 210 are redundant micro LED modules 312. The method for manufacturing a Micro LED display chip may include: etching a part of the first doped semiconductor layer 3111 of the LED epitaxial layer 300 to form a plurality of independent micro LED modules 311. Etching a part of the first doped semiconductor layer 3111 of the LED epitaxial layer 300 to form a plurality of independent micro LED modules 311, and the etching depth may be greater than or equal to the thickness of the first doped semiconductor layer 3111 of the integrally connected part of the micro LED modules 311 to form a plurality of independent micro LED modules 311. Among the plurality of independent micro LED modules 311, the first doped semiconductor layers 3111 of adjacent micro LED modules 311 are mutually separated, the active layers 3112 of adjacent micro LED modules 311 are mutually separated, and the second doped semiconductor layers 3113 of adjacent micro LED modules 311 are mutually separated. This is beneficial to reducing the film layer thickness and preventing crosstalk between the LED units 310 caused by the integrally structured first doped semiconductor layer 3111.

[0076] In some embodiments, the method for manufacturing a Micro LED display chip may include: removing the redundant micro LED modules 312. Since the redundant micro LED modules 312 are not bonded to the first electrode structure 210, there is a gap between the micro LED modules 311 and the substrate 100. Removing the redundant micro LED modules 312 is beneficial to improving the stability of the Micro LED display chip. The redundant micro LED modules 312 may be located between adjacent LED units 310. Adjacent LED units 310 may include micro LED modules 311 that are not connected to the first electrode structure 210, may include light conversion materials, and the redundant micro LED modules 312 and the light conversion materials connected to the redundant micro LED modules 312 may be removed.

[0077] In some embodiments, after forming a plurality of independent micro-LED modules 311 by etching a portion of the first doped semiconductor layer 3111 of the LED epitaxial layer 300, redundant micro-LED modules 312 can be removed. Alternatively, only the redundant micro-LED modules 312 can be removed. The first doped semiconductor layers 3111 of the plurality of micro-LED modules 311 included in the LED unit are of an integral structure. At this time, there is no need to remove the first doped semiconductor layer 3111 connecting the plurality of micro-LED modules 311 included in the LED unit, which is beneficial to improving the stability of the LED unit.

[0078] Please refer to Figure 9a , Figure 9b , Figure 9c and Figure 9d . In some embodiments, the step of removing the redundant micro-LED modules 312 in the LED epitaxial layer 300 that are not bonded to the first electrode structure 210 may include: disposing an etching photoresist layer 600 on the LED epitaxial layer 300; wherein, the etching photoresist layer 600 is provided with openings corresponding to the redundant micro-LED modules 312 that are not bonded to the first electrode structure 210; etching away the redundant micro-LED modules 312 corresponding to the openings; and removing the etching photoresist layer 600. A whole layer of etching photoresist material can be disposed on the LED epitaxial layer 300, and then the etching photoresist material that does not cover the LED unit 310 is removed to form an etching photoresist layer 600 provided with openings corresponding to the redundant micro-LED modules 312. The etching photoresist layer 600 can be formed by using a mask provided with openings corresponding to the LED unit 310. Correspondingly, the etching photoresist layer 600 is provided with openings corresponding to the redundant micro-LED modules 312 that are not bonded to the first electrode structure 210. The redundant micro-LED modules 312 corresponding to the openings can be etched away by using a dry etching process or a wet etching process.

[0079] Please refer to Figure 9d . In some embodiments, the method for manufacturing a Micro LED display chip may include: forming a planarization structure 710 between the LED units 310; wherein, the planarization structure 710 makes the LED epitaxial layer 300 form a planarized surface facing away from the substrate 100. A planarization material filled between the LED units 310 and covering the LED units 310 can be formed, and then the planarization material is removed until the LED units 310 are exposed to form a planarization structure, and the planarization structure 710 planarizes the micro-LED modules 311 of the LED epitaxial layer 300. Or a planarization structure 710 can be formed only between the LED units 310, specifically by using a mask. The material of the planarization structure 710 at least includes one of the following: organic black matrix photoresist, color filter photoresist, polyimide, damascene glue, OC glue, SU8 photoresist, or benzocyclobutene.

[0080] Please refer to Figure 9e 。In some embodiments, a common electrode layer 800 having an opposite electrical property to the first electrode structure 210 is formed based on the planarized surface; wherein, the first doped semiconductor layer 3111 of the micro-LED module 311 is electrically connected to the common electrode layer 800. A plurality of LED units 310 are arranged at intervals, and the common electrode layer 800 can simplify the driving. The common electrode layer 800 can be prepared by an evaporation process or a deposition process. The material of the common electrode layer 800 can be a transparent conductive material. It can be a transparent metal oxide. For example, the material of the common electrode layer 800 is indium tin oxide.

[0081] In some embodiments, the common electrode layer 800 can be electrically connected to the second electrode structure 220. The second doped semiconductor layer 3113 of the micro-LED module 311 is electrically connected to the first electrode structure 210, and the first doped semiconductor layer 3111 of the micro-LED module 311 is electrically connected to the second electrode structure 220. The first electrode structure 210 and the second electrode structure 220 can be electrically connected to a driving circuit to realize independent driving of the LED units 310. The substrate 100 can include a first electrode contact 110, and the first electrode structure 210 can be electrically connected to the driving circuit through the first electrode contact 110. The substrate 100 can include a second electrode contact 120, and the second electrode structure 220 can be electrically connected to the driving circuit through the second electrode contact 120.

[0082] Refer to Figure 9f 。In some embodiments, when the common electrode layer 800 having an opposite electrical property to the first electrode structure 210 is formed on the planarized surface, a filter layer 900 can be provided on the side of the common electrode layer 800 facing away from the substrate 100. The filter layer 900 is a whole-surface structure and can cover each LED unit 310. Or the filter layer 900 can include a plurality of filter units 910 corresponding to the LED units 310. The filter layer 900 can be formed by a deposition process or can be formed by laminating a pre-formed filter film.

[0083] In some embodiments, the light after passing through the wavelength conversion material 400 is a mixed-color light having at least two colors; the filter unit 910 includes a first filter unit 911 and a second filter unit 912; wherein, the colors of the light allowed to pass through by the first filter unit 911 and the second filter unit 912 are different.

[0084] In some embodiments, the light passing through the wavelength conversion material 400 is mixed-color light; the filter unit 910 further includes a first filter unit 911, a second filter unit 912, and a third filter unit 913; wherein, the colors of the light allowed to pass through by the first filter unit 911, the second filter unit 912, and the third filter unit 913 are different from each other. In some embodiments, the colors of the light allowed to pass through by the first filter unit 911, the second filter unit 912, and the third filter unit 913 are different from each other, and are all selected from: red light, green light, or blue light. In some embodiments, the second filter unit 912 is adjacent to both the first filter unit 911 and the third filter unit 913.

[0085] The embodiments of the present specification provide a method for manufacturing a Micro LED display chip. The method for manufacturing a Micro LED display chip may include the following steps.

[0086] Step S210: Provide a substrate 100; wherein, a plurality of independent first electrode structures 210 are provided on the surface of the substrate 100.

[0087] Please refer to Figure 10a . In some embodiments, the plurality of independent first electrode structures 210 are spaced apart from each other. The material of the first electrode structure 210 may be a conductive material. Specifically, it may include at least one of metal, conductive adhesive, and metal oxide. The metal may be at least one of materials such as aluminum (Al), copper (Cu), platinum (Pt), chromium (Cr), titanium (Ti), germanium (Ge), nickel (Ni), etc. The metal oxide may be indium tin oxide. The substrate 100 may include a driving circuit, and the first electrode structure 210 may be electrically connected to the driving circuit.

[0088] In some embodiments, the substrate 100 may include first electrode contacts 110, and the first electrode structure 210 may be electrically connected to the driving circuit through the first electrode contacts 110. The first electrode structures 210 may be provided in one-to-one correspondence with the first electrode contacts 110. The orthographic projection of the first electrode structure 210 on the substrate 100 may cover the first electrode contacts 110.

[0089] In some embodiments, the substrate 100 is provided with a second electrode structure 220 having an opposite electrical property to the first electrode structure 210. The material of the second electrode structure 220 may be a conductive material. Specifically, it may include at least one of metal, conductive adhesive, and metal oxide. In some embodiments, the substrate 100 may include second electrode contacts 120, and the second electrode structure 220 may be electrically connected to the driving circuit through the second electrode contacts 120.

[0090] Step S220: Bond the LED epitaxial layer 300 on the substrate 100. The LED epitaxial layer 300 includes a plurality of spaced-apart micro-LED modules 311. The micro-LED module 311 includes a first doped semiconductor layer 3111, an active layer 3112, and a second doped semiconductor layer 3113 which are stacked. Among them, the first doped semiconductor layers 3111 of the plurality of spaced-apart micro-LED modules 311 are of an integral structure. The second doped semiconductor layer 3113 of some of the micro-LED modules 311 is bonded to the first electrode structure 210 of the substrate 100.

[0091] Please refer to Figure 10b , Figure 10c and Figure 10d . In some embodiments, before bonding the LED epitaxial layer 300 on the substrate 100, it may include: providing the LED epitaxial layer 300, the LED epitaxial layer 300 including a plurality of spaced-apart micro-LED modules 311, the micro-LED module 311 including a first doped semiconductor layer 3111, an active layer 3112, and a second doped semiconductor layer 3113 which are stacked. Among them, the first doped semiconductor layers 3111 of the plurality of spaced-apart micro-LED modules 311 are of an integral structure. The step of providing the LED epitaxial layer 300 may include providing a semiconductor layer 300a. Among them, the semiconductor layer 300a includes a first doped semiconductor layer 3111, an active layer 3112, and a second doped semiconductor layer 3113 which are stacked. Among them, a bonding material 500 is provided on the semiconductor layer 300a. Etch the bonding material 500 to form a plurality of independent bonding modules 510. Etch the semiconductor layer 300a to form a plurality of spaced-apart micro-LED modules 311, obtaining the LED epitaxial layer 300. Among them, in the plurality of spaced-apart micro-LED modules 311, the first doped semiconductor layer 3111 is of an integral structure. The micro-LED module corresponds to the bonding module.

[0092] In some embodiments, after obtaining the LED epitaxial layer 300, it may be possible to: attach a bonding material 500 to the second doped semiconductor layer 3113 of the micro-LED module 311. Among them, the bonding material 500 is used for bonding with the substrate 100.

[0093] Please refer to Figure 10e . In some embodiments, the second doped semiconductor layer 3113 of some of the micro-LED modules 311 is bonded to the first electrode structure 210 of the substrate 100. Between adjacent first electrode structures 210, there may be corresponding parts of the micro-LED modules 311 that are not bonded to the first electrode structure 210. The micro-LED modules 311 corresponding to the second electrode structure 220 may be bonded to the second electrode structure 220.

[0094] Step S230: Etch a part of the first doped semiconductor layer 3111 of the LED epitaxial layer 300 to form a plurality of independent micro-LED modules 311. The first doped semiconductor layers of adjacent micro-LED modules are separated from each other, the active layers of adjacent micro-LED modules are separated from each other, and the second doped semiconductor layers of adjacent micro-LED modules are separated from each other. Wherein, each micro-LED module 311 bonded to the first electrode structure 210 forms an LED unit 310.

[0095] Please refer to Figure 10e and Figure 10f . In some embodiments, the LED epitaxial layer 300 is disposed on the first substrate 300-1. The first substrate 300-1 can be removed before etching a part of the first doped semiconductor layer 3111 of the LED epitaxial layer 300 to form a plurality of independent micro-LED modules 311.

[0096] In some embodiments, a dry etching process or a wet etching process can be used to remove a part of the first doped semiconductor layer 3111 of the LED epitaxial layer 300. At least the first doped semiconductor layer 3111 of the part connecting the micro-LED modules 311 can be removed, so as to form a plurality of independent micro-LED modules 311. The micro-LED modules 311 bonded to the same first electrode structure 210 form an LED unit 310. The micro-LED module 311 bonded to the first electrode structure 210 can electrically connect the micro-LED module 311 to the first electrode structure 210, so that the LED unit 310 can be independently driven by the first electrode structure 210.

[0097] Step S240: Fill at least a wavelength conversion material 400 capable of changing the color of light between the micro-LED modules 311. The same wavelength conversion material 400 is disposed in different LED units 310.

[0098] In some embodiments, at least a wavelength conversion material 400 capable of changing the color of light is filled between the micro-LED modules 311. The surface of the wavelength conversion material 400 facing away from the substrate 100 can be located within the interval between adjacent micro-LED modules 311, or the surface of the wavelength conversion material 400 facing away from the substrate 100 can cover the micro-LED modules 311. In the case where the surface of the wavelength conversion material 400 facing away from the substrate 100 covers the micro-LED modules 311, a part of the thickness of the wavelength conversion material 400 can be removed until the micro-LED modules 311 are exposed. The same wavelength conversion material 400 is disposed in different LED units 310. Filling a wavelength conversion material 400 capable of changing the color of light between the micro-LED modules 311 by one process conforms to the characteristics of the small size of the micro-LED modules 311, which is beneficial to reducing the preparation difficulty and improving the preparation yield.

[0099] The manufacturing method of the Micro LED display chip provided by the embodiments of this specification can reduce the crosstalk between LED units by bonding an LED epitaxial layer on a substrate and then etching a part of the first doped semiconductor layer of the LED epitaxial layer to form a plurality of independent micro LED modules. By filling a wavelength conversion material 400 that can change the color of light between the micro LED modules 311, the wavelength conversion material can be selected according to requirements to form a Micro LED display chip that can emit the expected color, improving adaptability. By setting the same wavelength conversion material 400 between different micro LED modules, it conforms to the characteristics of small LED unit size, which is beneficial to improving the yield and reducing the difficulty.

[0100] Please refer to Figure 10f and Figure 10g . In some embodiments, before at least filling the wavelength conversion material 400 that can change the color of light between the micro LED modules 311, the manufacturing method of the Micro LED display chip may further include: removing redundant micro LED modules 312 that are not bonded to the first electrode structure 210; wherein, the redundant micro LED modules 312 are the micro LED modules 311 in the LED epitaxial layer 300 that are not bonded to the first electrode structure 210. The redundant micro LED modules 312 that are not bonded to the first electrode structure 210 can be removed by a dry etching process or a wet etching process, and the micro LED modules 311 bonded to the first electrode structure 210 are retained.

[0101] Please refer to Figure 10h and Figure 10i . In some embodiments, the step of at least filling the wavelength conversion material 400 that can change the color of light between the micro LED modules 311 may include: filling the wavelength conversion material 400 between the micro LED modules 311 and between the LED units 310 until the wavelength conversion material 400 completely coats the micro LED modules 311 included in the LED unit 310; etching the wavelength conversion material 400 until the top surface of the first doped semiconductor layer 3111 of the micro LED module 311 is exposed. In this case, the gaps between the multiple micro LED modules 311 included in the LED unit 310 are completely filled with the wavelength conversion material 400, which is beneficial to increasing the setting range of the wavelength conversion material 400 and improving the light conversion efficiency.

[0102] Please refer to Figure 10l。In some embodiments, a common electrode layer 800 having an opposite electrical property to the first electrode structure 210 may be formed on the micro-LED module 311; wherein, the first doped semiconductor layer 3111 of the micro-LED module 311 is electrically connected to the common electrode layer 800; wherein, the space enclosed by the common electrode layer 800, the first electrode structure 210 and the micro-LED module 311 is filled with the wavelength conversion material 400. The common electrode layer 800 can be prepared by an evaporation process or a deposition process. The material of the common electrode layer 800 can be a transparent conductive material. It can be a transparent metal oxide. For example, it can be indium tin oxide. In some embodiments, the wavelength conversion material 400 can be retained between the LED units, reducing the process and making the surfaces between the LED units flat, which is beneficial to improving the stability of the common electrode layer 800. The driving difficulty can be reduced through the common electrode layer 800. The space enclosed by the common electrode layer 800, the first electrode structure 210 and the micro-LED module 311 is filled with the wavelength conversion material 400, which can improve the light conversion efficiency and the life of the Micro LED display chip.

[0103] Please refer to Figure 10j and Figure 10k 。In some embodiments, before forming the common electrode layer 800 having an opposite electrical property to the first electrode structure 210 on the micro-LED module 311, the method further includes: etching the wavelength conversion material 400 between the LED units 310; forming a planarization structure 710 between the LED units 310; wherein, the planarization structure 710 makes the micro-LED module form a planarized surface facing away from the substrate 100; correspondingly, the common electrode layer 800 having an opposite electrical property to the first electrode structure 210 is formed on the planarized surface. Etching the wavelength conversion material 400 between the LED units 310 may include: disposing an etching photoresist layer 600 on the micro-LED module 311; wherein, the etching photoresist layer 600 is provided with openings corresponding to the LED units 310; etching away the wavelength conversion material 400 corresponding to the openings. The wavelength conversion material 400 corresponding to the openings can be etched away by a dry etching process or a wet etching process. In some embodiments, the etching photoresist layer 600 can be removed after etching away the wavelength conversion material 400 corresponding to the openings. In some embodiments, a planarization structure 710 can be formed between the LED units 310; wherein, the planarization structure 710 planarizes the micro-LED module 311 of the LED epitaxial layer 300 to form a planarized surface facing away from the substrate 100. Please refer to Figure 10m 。In some embodiments, a filter layer 900 can be attached to the common electrode layer 800; wherein, the filter layer 900 includes a plurality of filter units 910 corresponding to the LED units 310.

[0104] In some embodiments, the light passing through the wavelength conversion material 400 is mixed light having at least two colors; the light filtering unit 910 includes a first light filtering unit 911 and a second light filtering unit 912; wherein, the colors of the light allowed to pass through by the first light filtering unit 911 and the second light filtering unit 912 are different from each other.

[0105] In some embodiments, the light passing through the wavelength conversion material 400 is mixed light; the light filtering unit 910 further includes a first light filtering unit 911, a second light filtering unit 912 and a third light filtering unit 913; the second light filtering unit 912 is adjacent to both the first light filtering unit 911 and the third light filtering unit 913; wherein, the colors of the light allowed to pass through by the first light filtering unit 911, the second light filtering unit 912 and the third light filtering unit 913 are different from each other. In some embodiments, the colors of the light allowed to pass through by the first light filtering unit 911, the second light filtering unit 912 and the third light filtering unit 913 are different from each other and are all selected from: red light, green light or blue light. For specific content, reference may be made to the above description of the Micro LED display chip, which will not be elaborated herein.

[0106] Each of the multiple embodiments in this specification emphasizes the parts different from other embodiments. The embodiments can be mutually explained by reference. Any combination of the multiple embodiments in this specification by those skilled in the art based on general technical knowledge is covered by the disclosure of this specification.

[0107] The technical features of the above embodiments can be combined arbitrarily. For the sake of concise description, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope described in this specification.

[0108] The above are only some embodiments in this specification and are not intended to limit this specification. Any modification, equivalent replacement, etc. made within the spirit and principle of this specification shall be included in the disclosure scope of this specification.

Claims

1. A Micro LED display chip, characterized in that, Comprising: A substrate with a plurality of independent first electrode structures disposed on its surface; An LED epitaxial layer disposed on the substrate, the LED epitaxial layer having a plurality of LED units arranged in an array, and one of the LED units corresponding to one of the first electrode structures; Each of the LED units includes a plurality of micro-LED modules respectively electrically connected to the same first electrode structure so that the LED unit can be independently driven by the first electrode structure, and each of the micro-LED modules includes a first doped semiconductor layer, an active layer, and a second doped semiconductor layer stacked; Wherein, there is a gap between the micro-LED modules of the LED unit and a wavelength conversion material capable of changing the color of light is disposed in the gap, and the same wavelength conversion material is disposed in different LED units; the gap extends a predetermined distance in a direction towards the first doped semiconductor layer from a side of the second doped semiconductor layer away from the first doped semiconductor layer, and the predetermined distance is less than or equal to the thickness of the micro-LED module in the extending direction of the gap; Wherein, the first doped semiconductor layers of the micro-LED modules in the LED unit are of an integral structure; or, The first doped semiconductor layers, the active layers, and the second doped semiconductor layers of adjacent micro-LED modules in the LED unit are all mutually separated.

2. The Micro LED display chip according to claim 1, wherein The substrate is provided with a second electrode structure having an opposite electrical property to the first electrode structure; The integral first doped semiconductor layer is electrically connected to the second electrode structure; The second doped semiconductor layers of the micro-LED modules in the LED unit are respectively electrically connected to the same first electrode structure.

3. The Micro LED display chip according to claim 2, characterized in that, There are also redundant micro-LED modules between the plurality of LED units that are not electrically connected to the first electrode structure, and each of the redundant micro-LED modules includes a first doped semiconductor layer, an active layer, and a second doped semiconductor layer stacked, and the first doped semiconductor layer of the redundant micro-LED module is of an integral structure with the first doped semiconductor layer of the micro-LED module of the LED unit.

4. The Micro LED display chip according to claim 1, wherein The wavelength conversion material includes a color mixing quantum dot material; wherein, the color mixing quantum dot material includes at least two kinds of quantum dot materials; or, the wavelength conversion material includes a single-color quantum dot material.

5. The Micro LED display chip according to claim 1, characterized in that, Also comprising: A filter layer including a plurality of filter units corresponding to the LED units.

6. The Micro LED display chip according to claim 5, wherein, The light passing through the wavelength conversion material is a mixed color light having at least two colors; the filter unit at least includes a first filter unit and a second filter unit; wherein, the colors of light allowed to pass through by the first filter unit and the second filter unit are different.

7. The Micro LED display chip according to claim 1, wherein The gap is filled with the wavelength conversion material.

8. The Micro LED display chip according to claim 1, characterized in that, A planarization structure is disposed between adjacent LED units, and the planarization structure makes the LED epitaxial layer form a planarized surface facing away from the substrate.

9. The Micro LED display chip according to claim 8, wherein, A common electrode layer having an opposite electrical property to the first electrode structure is disposed on the planarized surface, and the first doped semiconductor layer of the micro-LED module is electrically connected to the common electrode layer.

10. A method for preparing a Micro LED display chip, characterized in that, Comprising: Provide a substrate, wherein a plurality of independent first electrode structures are provided on the surface of the substrate; Provide an LED epitaxial layer; the LED epitaxial layer includes a plurality of spaced micro-LED modules, and each micro-LED module includes a first doped semiconductor layer, an active layer, and a second doped semiconductor layer which are stacked; wherein, the first doped semiconductor layer of the micro-LED module is an integral structure; the spacing extends a predetermined distance in a direction towards the first doped semiconductor layer from a surface of the second doped semiconductor layer away from the first doped semiconductor layer, and the predetermined distance is less than the thickness of the micro-LED module in the extending direction of the spacing; Fill a wavelength conversion material capable of changing the color of light between the micro-LED modules so that the same wavelength conversion material is provided between different micro-LED modules; Bond the LED epitaxial layer after filling the wavelength conversion material to the substrate; wherein, the second doped semiconductor layer of some of the micro-LED modules is bonded to the first electrode structure of the substrate; each micro-LED module bonded to the first electrode structure forms an LED unit, so that the micro-LED modules of each LED unit are electrically connected to the same first electrode structure respectively, so that the LED unit can be independently driven by the first electrode structure.

11. The method according to claim 10, characterized in that, The step of providing the LED epitaxial layer includes: Provide a semiconductor layer; wherein, the semiconductor layer includes a first doped semiconductor layer, an active layer, and a second doped semiconductor layer which are stacked; wherein, a bonding material is provided on the semiconductor layer; Etch the bonding material to form a plurality of independent bonding modules; Etch the semiconductor layer to form a plurality of the micro-LED modules; wherein, among the plurality of spaced micro-LED modules, the first doped semiconductor layer is an integral structure; the micro-LED modules correspond to the bonding modules.

12. The method according to claim 10, wherein It further includes: Attach a filter layer on the LED epitaxial layer; wherein, the filter layer includes a plurality of filter units corresponding to the LED units.

13. A method for preparing a Micro LED display chip, characterized in that, It includes: Provide a substrate; wherein, a plurality of independent first electrode structures are provided on the surface of the substrate; Bond an LED epitaxial layer on the substrate, the LED epitaxial layer includes a plurality of spaced micro-LED modules, and each micro-LED module includes a first doped semiconductor layer, an active layer, and a second doped semiconductor layer which are stacked; wherein, the first doped semiconductor layer of the plurality of spaced micro-LED modules is an integral structure; the second doped semiconductor layer of some of the micro-LED modules is bonded to the first electrode structure of the substrate; the spacing extends a predetermined distance in a direction towards the first doped semiconductor layer from a surface of the second doped semiconductor layer away from the first doped semiconductor layer, and the predetermined distance is less than the thickness of the micro-LED module in the extending direction of the spacing; Etch the LED epitaxial layer to form a plurality of independent micro-LED modules, wherein the first doped semiconductor layers of adjacent micro-LED modules are mutually separated, the active layers of adjacent micro-LED modules are mutually separated, and the second doped semiconductor layers of adjacent micro-LED modules are mutually separated; wherein, each micro-LED module bonded to the first electrode structure forms an LED unit; At least fill the wavelength conversion material capable of changing the color of light between the micro-LED modules; wherein, the same wavelength conversion material is provided in different LED units.

14. The method according to claim 13, wherein Before at least filling the wavelength conversion material capable of changing the color of light between the micro-LED modules, the method further includes: Removing redundant micro-LED modules that are not bonded to the first electrode structure; wherein, the redundant micro-LED modules are the micro-LED modules in the LED epitaxial layer that are not bonded to the first electrode structure.

15. The method according to claim 14, wherein The step of at least filling the wavelength conversion material capable of changing the color of light between the micro-LED modules includes: Filling the wavelength conversion material between the micro-LED modules and between the LED units until the wavelength conversion material completely covers the micro-LED modules included in the LED unit; Etching the wavelength conversion material until the top surface of the first doped semiconductor layer of the micro-LED module is exposed.

16. The method according to claim 15, wherein Further includes: Forming a common electrode layer with an opposite electrical property to the first electrode structure on the micro-LED module; wherein, the first doped semiconductor layer of the micro-LED module is electrically connected to the common electrode layer; wherein, the space surrounded by the common electrode layer, the first electrode structure and the micro-LED module is filled with the wavelength conversion material.

17. The method according to claim 16, wherein Before forming a common electrode layer with an opposite electrical property to the first electrode structure on the micro-LED module, the method further includes: Etching the wavelength conversion material between the LED units; Forming a planarization structure between the LED units; wherein, the planarization structure makes the LED epitaxial layer form a planarized surface facing away from the substrate; Correspondingly, forming the common electrode layer with an opposite electrical property to the first electrode structure on the planarized surface.

18. The method according to claim 16, wherein Further includes: Attaching a filter layer to the common electrode layer; wherein, the filter layer includes a plurality of filter units corresponding to the LED units.

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