Method for manufacturing weakened structure, method for manufacturing micro-led display

Abstract

This invention discloses a method for fabricating a weakened structure and a method for fabricating a micro-light-emitting diode (LED) display. The weakened structure includes a first support structure, and the method for fabricating the first support structure includes the steps of: forming an adhesive layer on a micro-light-emitting diode and / or a transient substrate; transferring the micro-light-emitting diode to the transient substrate, wherein the micro-light-emitting diode is bonded to the transient substrate through the adhesive layer; and etching the adhesive layer to form the first support structure, wherein the first support structure is mesh-like and surrounds the micro-light-emitting diode. The method for fabricating a weakened structure and a method for fabricating a micro-light-emitting diode display provided by this invention can improve the yield of mass transfer.

Description

Technical Field

[0001] This invention belongs to the field of semiconductor manufacturing technology, and specifically relates to a method for fabricating a weakened structure and a method for fabricating a micro light-emitting diode display. Background Technology

[0002] Micro LED displays are a new generation of display technology that offers advantages over liquid crystal displays, including higher brightness, better luminous efficiency, and lower power consumption.

[0003] In the transfer process of micro-LEDs, they can be transferred onto the display substrate using methods such as electrostatic force, van der Waals force, magnetic force, laser selective transfer, fluid transfer, and direct transfer. However, in selective pickup of micro-LEDs, the micro-LEDs are bonded to the substrate via adhesive. Before the transfer structure picks up the LEDs, the adhesive needs to be etched to facilitate pickup. However, the etching width cannot be precisely controlled during etching, which can easily damage the micro-LEDs and affect the yield of mass transfer. Summary of the Invention

[0004] In view of the shortcomings of the prior art, the purpose of this application is to provide a method for fabricating a weakened structure and a method for fabricating a micro-light-emitting diode display, which aims to solve the problem of the inability to precisely control the etching of the adhesive material between the substrate and the micro-light-emitting diode.

[0005] To solve the above-mentioned technical problems, the present invention is achieved through the following technical solution:

[0006] This invention provides a method for manufacturing a weakening structure, wherein the weakening structure includes a first supporting structure, and the method for manufacturing the first supporting structure includes the following steps:

[0007] A binder layer is formed on the micro light-emitting diode and / or transient substrate;

[0008] The micro-light-emitting diode is transferred to a transient substrate, and the micro-light-emitting diode is bonded to the transient substrate through the adhesive layer; and

[0009] The adhesive layer is etched to form a first support structure, which is mesh-like and surrounds the micro-light-emitting diode.

[0010] The above-mentioned method for fabricating the weakened structure involves etching the adhesive layer into a mesh shape to support the micro-light-emitting diode. Furthermore, the etching process of the adhesive is easy to control, which can improve the yield of mass transfer.

[0011] Optionally, the adhesive layer is made of organosilicon compounds.

[0012] Optionally, the silicon content in the adhesive layer is 20% to 85%. This ensures that the first support structure formed after etching is a mesh structure and has a suitable mesh density. This avoids the situation where the first support structure is insufficient to support the micro-LED when the silicon content is too low, or where the adhesion between the first support structure and the micro-LED is too strong when the silicon content is too high, preventing the transfer structure from picking up the micro-LED.

[0013] Optionally, the material of the adhesive layer includes groups containing carbon, hydrogen, and nitrogen.

[0014] Optionally, the step of forming the first support structure includes: dry etching the adhesive layer, wherein the etching gas is oxygen or chlorine.

[0015] Optionally, the material of the first support structure is silicon oxide.

[0016] The material configuration of the adhesive layer and the first support structure described above ensures that, apart from the substance forming the first support structure, the substance in the adhesive layer reacts with the etching gas to generate a substance that is easy to remove. After etching is completed, only the solid and mesh-like first support structure remains.

[0017] Optionally, the weakening structure further includes a second support structure, and when the micro-light-emitting diode is bonded to the transient substrate, the second support structure is located between the two electrodes of the micro-light-emitting diode.

[0018] The second support structure described above further supports the micro-light-emitting diode, ensuring its stability.

[0019] Optionally, the step of forming the second support structure includes:

[0020] An oxide layer is formed on the transient substrate; and

[0021] The oxide layer is etched to form the second support structure;

[0022] The radial dimension of the second support structure is smaller than the distance between the two electrodes of the micro-LED.

[0023] Optionally, the material of the second support structure is silicon oxide.

[0024] Optionally, when the micro-LED is bonded to the transient substrate, the second support structure is at a predetermined distance from the micro-LED. This ensures that there is no adhesive force between the second support structure and the micro-LED, thereby guaranteeing high yield during mass production.

[0025] Based on the same inventive concept, this application also provides a method for manufacturing a micro light-emitting diode display, including:

[0026] Provide a substrate;

[0027] Multiple micro light-emitting diodes are formed on the substrate;

[0028] The micro-light-emitting diode is transferred to the transient substrate, and the micro-light-emitting diode is bonded to the transient substrate through an adhesive layer;

[0029] Etching the adhesive layer to form a first support structure, the first support structure being mesh-like and surrounding the micro-light-emitting diode; and

[0030] The micro light-emitting diodes are transferred onto the display substrate.

[0031] The above-described method for manufacturing a micro-light-emitting diode display can support the micro-light-emitting diode by etching the adhesive layer into a mesh. Furthermore, the etching process of the adhesive is easy to control, which can improve the yield of mass transfer.

[0032] Optionally, the transfer structure is an elastic stamp, and the material of the elastic stamp is polydimethylsiloxane.

[0033] Optionally, the step of forming the micro light-emitting diode includes:

[0034] A first semiconductor layer is formed on the substrate;

[0035] A light-emitting layer is formed on the first semiconductor layer;

[0036] A second semiconductor layer is formed on the light-emitting layer;

[0037] A transparent conductive layer is formed on the second semiconductor layer;

[0038] Deposit a first electrode on the first semiconductor layer; and

[0039] A second electrode is deposited on the second semiconductor layer.

[0040] Optionally, the step of forming the micro light-emitting diode further includes depositing a reflective layer on the second semiconductor layer and the transparent conductive layer.

[0041] Optionally, the step of forming the micro light-emitting diode further includes: forming a first conductive channel and a second conductive channel on the reflective layer, wherein the first conductive channel is in contact with the first semiconductor layer and the second conductive channel is in contact with the transparent conductive layer.

[0042] Optionally, the step of forming the first conductive channel and the second conductive channel includes:

[0043] A photoresist layer is deposited on the reflective layer;

[0044] An opening is formed on the photoresist layer; and

[0045] The reflective layer is etched using the photoresist layer as a mask.

[0046] The angle between the sidewall of the opening and the reflective layer is greater than 90 degrees.

[0047] The above process ensures that the resulting electrode has a large radial dimension, which facilitates welding.

[0048] Of course, any product implementing this invention does not necessarily need to achieve all of the advantages described above at the same time. Attached Figure Description

[0049] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0050] Figure 1 This is a flowchart illustrating a method for manufacturing a micro-light-emitting diode display according to the present invention.

[0051] Figure 2 This is a structural diagram of the first photoresist layer formed on the semiconductor epitaxial layer in this invention.

[0052] Figure 3 This is a structural diagram of a recess formed on a semiconductor epitaxial layer in this invention.

[0053] Figure 4 for Figure 3 Top view.

[0054] Figure 5 This is a structural diagram of the second photoresist layer formed on the semiconductor epitaxial layer in this invention.

[0055] Figure 6 This is a structural diagram of trenches formed on a semiconductor epitaxial layer in this invention.

[0056] Figure 7 for Figure 6 Top view.

[0057] Figure 8 This is a schematic diagram of the structure of the third photoresist layer in this invention.

[0058] Figure 9 This is a schematic diagram of the transparent conductive layer in this invention.

[0059] Figure 10 for Figure 9 Top view.

[0060] Figure 11 This is a schematic diagram of the structure of the fourth photoresist layer in this invention.

[0061] Figure 12 This is a schematic diagram of the reflective layer in this invention.

[0062] Figure 13 for Figure 12 Top view.

[0063] Figure 14 This is a schematic diagram of the structure of the fifth photoresist layer in this invention.

[0064] Figure 15 This is a schematic diagram of the electrode structure in this invention.

[0065] Figure 16 for Figure 15 Top view.

[0066] Figure 17 This is a schematic diagram of the structure of the first adhesive layer in this invention.

[0067] Figure 18 This is a schematic diagram of the structure of the second adhesive layer in this invention.

[0068] Figure 19 This is a schematic diagram of the structure in this invention where the micro-light-emitting diode is transferred to the transient substrate.

[0069] Figure 20 This is a schematic diagram of the micro-light-emitting diode structure after substrate stripping in this invention.

[0070] Figure 21 This is a schematic diagram of the first support structure in this invention.

[0071] Figure 22 This is a schematic diagram of the mass transfer in this invention.

[0072] Figure 23 This is a schematic diagram of the support layer in this invention.

[0073] Figure 24 This is a schematic diagram of the second support structure in this invention.

[0074] Figure 25 This is a schematic diagram of the structure in which a second adhesive layer is formed on the second support structure in this invention.

[0075] Figure 26 This is a schematic diagram of the structure for transferring a micro-light-emitting diode to a transient substrate in another embodiment of the present invention.

[0076] Figure 27 This is a schematic diagram of the micro-light-emitting diode structure after substrate stripping in another embodiment of the present invention.

[0077] Figure 28 This is a schematic diagram of the first and second support structures of the present invention.

[0078] Figure 29 This is a schematic diagram of mass transfer in another embodiment of the present invention.

[0079] Figure 30 This is a schematic diagram of the structure of the micro-light-emitting diode display in this invention.

[0080] Explanation of reference numerals in the attached figures:

[0081] 10 Substrate; 100 Micro LED; 100a Red Micro LED; 100b Green Micro LED; 100c Blue Micro LED; 11 Semiconductor Epitaxial Layer; 111 First Semiconductor Layer; 112 Light Emitting Layer; 113 Second Semiconductor Layer; 114 Recess; 115 Trench; 116 Transparent Conductive Layer; 117 Reflective Layer; 118 First Conductive Channel; 119 Second Conductive Channel; 120 Electrode; 121 First Electrode; 122 Second Electrode; 21 First Photoresist Layer; 22 Second Photoresist Layer; 23 Third Photoresist Layer Layer; 24 Fourth photoresist layer; 25 Fifth photoresist layer; 201 First opening; 202 Second opening; 203 Third opening; 204 Fourth opening; 205 Fifth opening; 206 Sixth opening; 207 Seventh opening; 30 Transient substrate; 31 Adhesive layer; 311 First adhesive layer; 312 Second adhesive layer; 313 First support structure; 314 Second support structure; 315 Support layer; 40 Transfer structure; 50 Display substrate; 501 Substrate; 502 Circuit layer; 503 Planarization layer; 504 Protective layer; 505 Protective substrate. Detailed Implementation

[0082] To facilitate understanding of this application, a more complete description will be provided below with reference to the accompanying drawings. Preferred embodiments of this application are shown in the drawings. However, this application can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a more thorough and complete understanding of the disclosure of this application.

[0083] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein in the specification of this application is for the purpose of describing particular embodiments only and is not intended to be limiting of this application.

[0084] In the description of this invention, it should be understood that the terms "center," "upper," "lower," "front," "rear," "left," and "right," etc., indicating orientation or positional relationships, are based on the orientation or positional relationships shown in the accompanying drawings and are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or component referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0085] Please see Figure 22 As shown, a micro-light-emitting diode (LED) display may include a display substrate 50 and a plurality of micro-light-emitting diodes 100 disposed on the display substrate 50. A driving circuit is disposed on the display substrate 50 to drive the micro-light-emitting diodes 100. The plurality of micro-light-emitting diodes 100 are electrically connected to the driving circuit, and the plurality of micro-light-emitting diodes 100 are arranged in a matrix on the display substrate 50 to form the display area of ​​the micro-light-emitting diode display. Micro-light-emitting diode displays have advantages such as long lifespan, high contrast, high resolution, fast response speed, wide viewing angle, rich colors, ultra-high brightness, and low power consumption. For example, they can be applied to televisions, laptops, monitors, mobile phones, watches, wearable displays, automotive devices, virtual reality (VR) devices, augmented reality (AR) devices, portable electronic devices, game consoles, or other electronic devices.

[0086] Please see Figures 2 to 22 As shown, in the manufacturing process of a micro-light-emitting diode (LED) display, multiple LEDs 100 can be formed on a substrate 10. For example, a semiconductor epitaxial layer 11 is deposited on the substrate 10, and the LEDs 100 are formed through steps such as exposure and development, etching, and metal deposition. Different substrate materials can be used depending on the type of LED 100 formed. For example, an ultraviolet-emitting LED 100 can be made of gallium nitride (GaN), and the substrate 10 of this LED 100 is typically a heteroepitaxial substrate on sapphire, a self-supporting gallium nitride substrate made using hydride vapor phase epitaxy, or an ammonothermal method. For LEDs 100 of other colors, gallium arsenide (GaAs), gallium phosphide (GaP) substrates, or substrates made of other materials can be used. Multiple LEDs 100 are disposed on the same substrate 10 to form an array of LEDs 100. After sorting and selection, the micro-LEDs 100 are transferred to the transient substrate 30 according to requirements, and finally transferred to the display substrate 50, or the micro-LEDs 100 on the substrate 10 are directly transferred to the display substrate 50 according to requirements to form a micro-LED display. The micro-LEDs 100 are small in size; for example, on a 4-inch chip, the number of micro-LEDs 100 is 14 × 10⁻⁶. 6Furthermore, the number of micro-diodes required to form a micro-diode display is also enormous. Specifically, the micro-light-emitting diodes 100 can be efficiently transferred onto the display substrate 50 via mass transfer.

[0087] Please see Figures 21 to 22 As shown, mass transfer specifically includes electrostatic transfer, van der Waals force transfer, magnetic transfer, laser selective transfer, fluid transfer, and direct transfer. In one embodiment of the present invention, the mass transfer method may include electrostatic transfer, van der Waals force transfer, magnetic transfer, etc. During mass transfer, a transfer structure 40 is needed to pick up the micro-LEDs 100 and transfer them onto the display substrate 50. However, the micro-LEDs 100 are bonded to the transient substrate 30 or the substrate 10 via adhesive. Before picking up the micro-LEDs 100, the transfer structure 40 needs to etch away part of the adhesive, leaving only a portion to support the micro-LEDs 100. However, the width of the retained adhesive is difficult to control. If the width is too small, the micro-LEDs 100 may fall and be damaged. If the width is too large, the adhesion between the micro-LEDs 10 and the adhesive is too strong, and the transfer structure cannot pick up all the selected micro-LEDs 100, resulting in poor yield.

[0088] Based on this, this application aims to provide a method for fabricating a weakened structure and a method for fabricating a micro-light-emitting diode (LED) display. The method involves doping a material with a substance that does not react with etching gases into a binder, and after etching the organic matter in the binder, forming a mesh-like first support structure. The formed first support structure can support the micro-light-emitting diode, and the etching process of the binder is easily controlled, which can improve the yield of mass transfer.

[0089] Please see Figure 1 As shown, the method for manufacturing a micro-light-emitting diode display provided by the present invention includes the following steps:

[0090] S1. Provide a substrate.

[0091] S2. Multiple micro-light-emitting diodes are formed on the substrate.

[0092] S3. Transfer the micro-LED to the transient substrate, and bond the micro-LED to the transient substrate with adhesive.

[0093] S4. Etch the adhesive material to form the first support structure.

[0094] S5. Transfer the micro-light-emitting diodes onto the display substrate.

[0095] Please see Figures 1 to 2As shown, in one embodiment of the present invention, the substrate 10 is made of a semiconductor structure formed from silicon, silicon germanium, silicon carbide, sapphire, indium phosphide, gallium arsenide, indium arsenide, or other III / V compounds, and also includes a stacked structure composed of these semiconductors, or silicon-on-insulator, silicon-on-insulator stacked, silicon-on-insulator stacked, silicon-on-insulator, and germanium-on-insulator. The material of the substrate 10 can be determined according to the type of micro-light-emitting diode 100 formed and the semiconductor epitaxial layer 11 on the substrate 10. In some embodiments, the micro-light-emitting diode 100 is a micro-light-emitting diode 100 that emits blue or green light, and the material of the semiconductor epitaxial layer 11 is, for example, gallium nitride (GaN) or indium gallium nitride (InGaN). The material of the substrate 10 can be, for example, sapphire (Al2O3), silicon carbide (SiC), zinc oxide (ZnO), gallium nitride (GaN), aluminum nitride (AlN), and silicon (Si). In other embodiments, the micro-light-emitting diode 100 is a micro-light-emitting diode 100 that emits red or yellow light, and the material of the semiconductor epitaxial layer 11 is one or more of materials such as gallium phosphide (GaP), aluminum gallium arsenide (AlGaAs), and aluminum gallium indium phosphide (AlGaInP), and the material of the substrate 10 can be, for example, gallium phosphide (GaP) or gallium arsenide (GaAs).

[0096] Please see Figure 2 As shown, multiple micro-light-emitting diodes of the same type can be formed simultaneously on the substrate 10. This invention uses a single micro-light-emitting diode as an example to illustrate the formation steps of the micro-light-emitting diode. In one embodiment of this invention, the step of forming a micro-light-emitting diode includes growing a semiconductor epitaxial layer 11 on the substrate 10. The semiconductor epitaxial layer 11 may include a first semiconductor layer 111, a light-emitting layer 112, and a second semiconductor layer 113 grown sequentially, i.e., the light-emitting layer 112 is located on the first semiconductor layer 111, and the second semiconductor layer 113 is located on the light-emitting layer 112. In this embodiment, the first semiconductor layer 111 may be an N-type semiconductor layer doped with a first impurity or a P-type semiconductor layer doped with a second impurity. Correspondingly, the second semiconductor layer 113 may be a P-type semiconductor layer doped with a second impurity or an N-type semiconductor layer doped with a first impurity. The first impurity is, for example, a donor impurity, and the second impurity is, for example, an acceptor impurity. Depending on the semiconductor material used, the first impurity and the second impurity may be different elements. In this embodiment, the first semiconductor layer 111 and the second semiconductor layer 113 can be gallium nitride, that is, the first semiconductor layer 111 is an N-type gallium nitride layer and the second semiconductor layer 113 is a P-type gallium nitride layer, and the first impurity can be silicon (Si) or tellurium (Te), and the second impurity can be magnesium (Mg) or zinc (Zn). In other embodiments, the first semiconductor layer 111 and the second semiconductor layer 113 can also be formed of other suitable materials.

[0097] Please refer to the following: Figure 2 In one embodiment of the present invention, the light-emitting layer 112 is an intrinsic semiconductor layer or a lightly doped semiconductor layer. The doping concentration of the light-emitting layer 112 is lower than that of adjacent semiconductor layers of the same doping type. The light-emitting layer 112 can also be a quantum well light-emitting layer. In this embodiment, the semiconductor epitaxial layer 11 emits blue or green light, for example, and the material of the light-emitting layer 112 is indium gallium nitride (InGaN). In other embodiments, the light-emitting layer 112 can be, for example, a quantum well emitting different light color bands. The material of the light-emitting layer 112 can be one or more of the following: zinc selenide (ZnSe), indium gallium nitride / gallium nitride (InGaN / GaN), indium gallium nitride / gallium nitride (InGaN / GaN), gallium phosphide (GaP), aluminum gallium phosphide (AlGaP), or aluminum gallium arsenide (AlGaAs).

[0098] Please refer to the following: Figures 2 to 4 As shown, in one embodiment of the present invention, after forming the semiconductor epitaxial layer 11, the semiconductor epitaxial layer 11 is etched to form a mesa (MESA) structure. Specifically, for example, a recess 114 is formed on the semiconductor epitaxial layer 11, the bottom of the recess 114 is in contact with the first semiconductor layer 111, and has a predetermined distance from the substrate 10. In this embodiment, a patterned first photoresist layer 21 can be formed on the second semiconductor layer 113. The first photoresist layer 21 in this step covers the second semiconductor layer 113, and a first opening 201 is provided on the first photoresist layer 21 to define the position of the recess 114. In this embodiment, the first opening 201 is circular. In other embodiments, the first opening 201 can be rectangular, polygonal, or other shapes. After forming the first photoresist layer 21, the second semiconductor layer 113, the light-emitting layer 112, and part of the first semiconductor layer 111 are dry-etched using the first photoresist layer 21 as a mask to form the recess 114, and the etching gas is, for example, boron trioxide (BCl3) or chlorine (Cl2). After the recess 114 is formed, the first photoresist layer 21 is removed.

[0099] Please see Figure 6 As shown, in one embodiment of the present invention, after forming the recess 114 and removing the first photoresist layer 21, a trench 115 is formed on the outside of the micro-light-emitting diode. The trench 115 contacts the substrate 10 and surrounds each micro-light-emitting diode to isolate adjacent micro-light-emitting diodes. For details, please refer to... Figures 5 to 7As shown, a patterned second photoresist layer 22 can be formed on the second semiconductor layer 113, and a plurality of second openings 202 are provided on the second photoresist layer 22 to define the position of the trench 115. The second openings 202 are arranged around the micro light-emitting diode 100, and the second openings 202 are, for example, rectangular rings. After the second photoresist layer 22 is formed, the semiconductor epitaxial layer 11 is dry-etched to the substrate 10 using the second photoresist layer 22 as a mask to form the trench 115, and the specific etching depth is, for example, 4 to 8 μm. After the trench 115 is formed, the second photoresist layer 22 is removed.

[0100] Please see Figure 9 As shown, in one embodiment of the present invention, after forming the trench 115 and removing the second photoresist layer 22, a transparent conductive layer 116 is formed on the second semiconductor layer 113, and the transparent conductive layer 116 is located on one side of the recess 114. For details, please refer to... Figures 8 to 10 As shown, an indium tin oxide (ITO) layer can be sputtered onto the second semiconductor layer 113, and the thickness of the ITO layer is, for example, 200 to 2000 angstroms. A patterned third photoresist layer 23 is then formed on the ITO layer, and a third opening 203 is provided on the third photoresist layer 23 to define the position of the transparent conductive layer 116. In this embodiment, the third opening 203 is located on one side of the protrusion and is rectangular in shape. After forming the third photoresist layer 23, the ITO layer is wet-etched using the third photoresist layer 23 as a mask to form the transparent conductive layer 116, and then the third photoresist layer 23 is removed.

[0101] Please refer to Figure 12. In one embodiment of the present invention, after removing the third photoresist layer 23, a reflective layer 117 is formed on the transparent conductive layer 116. The reflective layer 117 covers the transparent conductive layer 116, the second semiconductor layer 113, and the recesses 114 and trenches 115. A first conductive channel 118 and a second conductive channel 119 are provided on the reflective layer 117. The first conductive channel 118 communicates with the first semiconductor layer 111, and the second conductive channel 119 communicates with the transparent conductive layer 116. The reflective layer 117 includes, for example, a silicon oxide layer and a silicon nitride layer. For details, please refer to... Figures 11 to 13As shown, for example, silicon oxide and silicon nitride stacks are deposited in the recess 114 and trench 115 on the transparent conductive layer 116 and the second semiconductor layer 113 to form a reflective layer 117, and the thickness of the reflective layer 117 is, for example, 1 to 4 μm. The reflective layer 117 reflects the light emitted from the light-emitting layer 112, so that the light of the micro light-emitting diode 100 is emitted from one side of the first semiconductor layer 111. After the reflective layer 117 is formed, a patterned fourth photoresist layer 24 is formed on the reflective layer 117. The fourth photoresist layer 24 is provided with a fourth opening 204 and a fifth opening 205. The fourth opening 204 is located above the recess 114 and is used to define the position of the first conductive channel 118. The fifth opening is located above the transparent conductive layer 116 and is used to define the position of the second conductive channel 119. After forming the fourth photoresist layer 24, the reflective layer 117 is etched using the fourth photoresist layer 24 as a mask. A first conductive channel 118 communicating with the first semiconductor layer 111 is formed on the recess 114, and a second conductive channel 119 communicating with the transparent conductive layer 116 is formed on the transparent conductive layer 116. The first conductive channel 118 and the second conductive channel 119 can be of any shape, such as cylindrical, quadrangular prism, or other columnar shapes. In this embodiment, dry etching can be used, for example, and the etching gas can be one or more of tetrafluoromethane (CF4), oxygen (O2), or argon (Ar). After forming the first conductive channel 118 and the second conductive channel 119, the fourth photoresist layer 24 can be removed.

[0102] Please see Figure 15 As shown, in one embodiment of the present invention, after the reflective layer 117 is formed, a first electrode 121 is formed in the first conductive channel 118, and a second electrode 122 is formed in the second conductive channel 119. For details, please refer to [link to relevant documentation]. Figures 14 to 16As shown, in this embodiment, a patterned fifth photoresist layer 25 is first formed on the reflective layer 117. The fifth photoresist layer 25 has a sixth opening 206 and a seventh opening 207. The sixth opening 206 defines the position of the first electrode 121, and the seventh opening 207 defines the position of the second electrode 122. In some embodiments, the fourth photoresist layer 24 may not be removed before forming the electrode 120; the first electrode 121 and the second electrode 122 are formed using the fourth photoresist layer 24 as a mask. In this embodiment, the first electrode 121 and the second electrode 122 are formed using the fifth photoresist layer 25 as a mask. The sixth opening 206 exposes the first conductive channel 118, and the diameter of the sixth opening 206 is larger than the diameter of the first conductive channel 118. The seventh opening 207 exposes the second conductive channel 119, and the diameter of the seventh opening 207 is larger than the diameter of the second conductive channel 119, thus forming an electrode 120 with a larger area. After forming a patterned photoresist layer, metal is vapor-deposited into the first conductive channel 118 and the sixth opening 206 to form a first electrode 121. Metal is vapor-deposited into the second conductive channel 119 and the seventh opening 207 to form a second electrode 122. The thickness of the first electrode 121 and the second electrode 122 is 1 to 4 μm, and the materials of the first electrode 121 and the second electrode 122 are, for example, an alloy of gold (Au). The first electrode 121 is, for example, an N-type electrode 120, and the material is, for example, Ni / Au. The second electrode 122 is, for example, a P-type electrode 120, and the material is, for example, Ni / Al / Ni / Au.

[0103] Please see Figures 2 to 14 As shown, in this embodiment, the method for forming the patterned photoresist layer involves first coating photoresist, and then removing the photoresist above the openings using either an alkaline solution wet process or a dry ashing process, thereby patterning the coated photoresist to form a patterned photoresist layer. The photoresist layer material can be either positive or negative photoresist. Specifically, the fifth photoresist layer 25 is a negative photoresist. When the photoresist in the non-exposed area of ​​the fifth photoresist layer 25 dissolves in the developer, the angle between the sidewall of the patterned photoresist layer and the reflective layer 117 is less than 90 degrees, ensuring that the fifth photoresist layer 25 does not affect the deposition of the electrode 120. That is, the angle between the sidewalls of the sixth opening 206 and the seventh opening 207 and the reflective layer 117 is greater than 90 degrees.

[0104] Please see Figures 17 to 19As shown, in one embodiment of the present invention, after forming the micro-light-emitting diode (LED), the micro-LED 100 is transferred onto the transient substrate 30. Specifically, an adhesive layer 31 can be coated onto the micro-LED 100 and / or the transient substrate 30 first, and then the micro-LED 100 and the transient substrate 30 are bonded together using a bonding machine, with the micro-LED 100 and the transient substrate 30 adhered together by the adhesive layer 31. The transient substrate 30 is, for example, a sapphire substrate. Figure 20 As shown, after the micro-LED 100 is transferred onto the transient substrate 30, the substrate 10 is removed. For example, the substrate 10 can be removed using laser lift-off (LLO) technology.

[0105] Please see Figures 17 to 19 As shown, in this embodiment, the adhesive layer 31 includes a first adhesive layer 311 and a second adhesive layer 312. The first adhesive layer 311 is located on the micro-light-emitting diode 100 and covers the first electrode 121, the second electrode 122, and the gap between adjacent micro-light-emitting diodes 100. The second adhesive layer 312 is located on the transient substrate 30. When the micro-light-emitting diode 100 and the transient substrate 30 are bonded by a bonding machine, the first adhesive layer 311 and the second adhesive layer 312 fuse to form the adhesive layer 31. During bonding, the adhesive can be heated to fuse the first adhesive layer 311 and the second adhesive layer 312.

[0106] Please see Figures 17 to 19 As shown, in this embodiment, the material of the adhesive layer 31 is, for example, an organosilicon compound, and the silicon content in the adhesive layer 31 is, for example, 20% to 85%, to ensure that the adhesive layer 31 can form a mesh-like support after etching, which is the first support structure 313 of the weakened structure. Furthermore, the 20% to 85% silicon content in the adhesive layer 31 ensures that the formed first support structure 313 has a suitable mesh density, avoiding the situation where the first support structure 313 is insufficient to support the micro-LED 100 when the silicon content is too low, and where the adhesion between the first support structure 313 and the micro-LED 100 is too strong when the silicon content is too high, preventing the transfer structure from picking up the micro-LED 100. The adhesive layer 31 also includes groups containing carbon, hydrogen, and nitrogen, which can react with the etching gas during the etching process to generate easily removable substances.

[0107] Please see Figures 19 to 22As shown, in one embodiment of the present invention, after removing the substrate 10, the adhesive layer 31 is etched. After etching, the carbon, hydrogen, and nitrogen-containing groups in the adhesive layer 31 are removed, leaving only the mesh-like first support structure 313. Specifically, the adhesive layer can be dry-etched, and the etching gas is, for example, oxygen or chlorine. During etching, oxygen (or chlorine) reacts with the carbon, hydrogen, and oxygen-containing groups in the adhesive layer 31, causing the carbon, hydrogen, and nitrogen in the adhesive layer 31 to form compounds with oxygen. When the etching gas is oxygen, for example, the substances generated by the carbon, hydrogen, and oxygen groups are carbon dioxide, water, and nitrogen dioxide, wherein carbon dioxide and nitrogen dioxide are gases, and water is a liquid, which can be directly removed. The silicon in the adhesive layer 31 reacts with oxygen to generate silicon oxide, forming the mesh-like first support structure 313. The formed first support structure 313 surrounds the micro-light-emitting diode 100, which not only supports the micro-light-emitting diode 100, but also ensures that the micro-light-emitting diode 100 does not shake.

[0108] Please see Figure 22 and Figure 30 As shown, in one embodiment of the present invention, after the first support structure 313 is formed, the micro light-emitting diode 100 is transferred to the display substrate 50 using the transfer structure 40 to form a micro light-emitting diode display.

[0109] Please see Figure 28 As shown, in another embodiment of the present invention, the weakening structure further includes a second support structure 314, which is disposed on the transient substrate 30. For details, please refer to... Figures 23 to 28 As shown, a silicon oxide layer can be deposited on the transient substrate 20 to form a support layer 315. A patterned photoresist layer is formed on the support layer, and openings are provided on the photoresist layer to define the position of the second support structure 314. After the patterned photoresist layer is formed, the support layer 315 is etched using the patterned photoresist layer as a mask to form the second support structure 314. Specifically, for example, a wet etching method can be used to etch the support layer 315.

[0110] Please see Figures 28 to 29 As shown, in this embodiment, a plurality of second support structures 314 may be disposed on the transient substrate. The position of each second support structure 314 corresponds to the position of each micro-light-emitting diode 100, and the radial dimension of the second support structure 314 is smaller than the distance between the first electrode 121 and the second electrode 122. When the micro-light-emitting diode 100 is bonded to the transient substrate 30, the second support structure 314 is located between the first electrode 121 and the second electrode 122 of the micro-light-emitting diode.

[0111] Please see Figure 17 and Figure 25As shown, in another embodiment of the present invention, after forming the second support structure 314, a first adhesive layer 311 is formed on the micro-light-emitting diode, and the first adhesive layer 311 covers the first electrode 121, the second electrode 122, and the gap between adjacent micro-light-emitting diodes 100. A second adhesive layer 312 is formed on the transient substrate 30, and the second adhesive layer 312 covers the second support structure 314 and the gap between adjacent second support structures 314. Figure 26 As shown, when the micro light-emitting diode 100 and the transient substrate 30 are bonded by a bonding machine, the first adhesive layer 311 and the second adhesive layer 312 are fused to form the adhesive layer 31.

[0112] Please see Figures 26 to 27 As shown, in another embodiment of the present invention, after the micro-LED 100 is transferred to the transient substrate 30, the substrate 10 can be peeled off, for example, by laser lift-off (LLO) technology. After removing the substrate 10, the adhesive layer 31 is etched, and the carbon, hydrogen, and nitrogen-containing groups in the adhesive layer 31 are etched away, leaving only the mesh-like first support structure 313 and the second support structure 314. Specifically, the adhesive layer can be dry-etched, and the etching gas is, for example, oxygen or chlorine. During etching, oxygen (or chlorine) reacts with the carbon, hydrogen, and oxygen-containing groups in the adhesive layer 31, causing the carbon, hydrogen, and nitrogen in the adhesive layer 31 to form compounds with oxygen. When the etching gas is oxygen, for example, the substances generated by the carbon, hydrogen, and oxygen groups are carbon dioxide, water, and nitrogen dioxide, wherein carbon dioxide and nitrogen dioxide are gases, and water is a liquid, which can be directly removed. The silicon in the adhesive layer 31 reacts with oxygen to generate silicon oxide, forming the mesh-like first support structure 313. The first support structure 313 surrounds the micro-LED 100, not only supporting the micro-LED 100 but also ensuring that the micro-LED 100 does not wobble. The second support structure 314 is located between the first electrode 121 and the second electrode 122, and the height of the second support structure 314 is greater than the height of the electrodes. When the first adhesive layer 311 and the second adhesive layer 312 are fused, the second support structure 314 and the micro-LED 100 have a preset distance, ensuring that there is no adhesive force between the second support structure 314 and the micro-LED 100 during mass transfer.

[0113] Please see 29 and Figure 30 As shown, in one embodiment of the present invention, after the first support structure 313 and the second support structure 314 are formed, the micro light-emitting diode 100 is transferred to the display substrate 50 by the transfer structure 40 to form a micro light-emitting diode display.

[0114] Please see Figure 22 and Figure 29As shown, there are various methods for transferring the micro-LED 100. Depending on the force applied during the transfer process or the specific transfer method, these methods may include van der Waals force transfer, electrostatic transfer, magnetic transfer, laser transfer, fluid self-assembly transfer, and roll-to-roll transfer. In this embodiment, van der Waals force is used to transfer the micro-LED 100. The transfer structure 40 is, for example, an elastic stamp, and the material of the elastic stamp is, for example, polydimethylsiloxane (PDMS). The elastic stamp can pick up the micro-LED 100 and transfer it onto the display substrate 50. During the picking up of the micro-LED 100, the elastic stamp maintains a relatively high speed, at which point the adsorption force between the elastic stamp and the device is relatively large. During the placement of the micro-LED 100 onto the display substrate 50, the elastic stamp maintains a relatively low transfer speed, at which point the adsorption force between the elastic stamp and the device is relatively small. Furthermore, when using the flexible stamp to transfer the micro LED 100, the temperature of the flexible stamp can be adjusted to ensure the transfer effect. For example, a lower temperature is used during the picking up and transferring of the micro LED 100 to ensure a larger adsorption force between the flexible stamp and the device, while a higher temperature is used during the placement of the micro LED 100 to ensure a smaller adsorption force between the flexible stamp and the device.

[0115] Please see Figure 22 and Figure 29 As shown, in other embodiments, the micro-LED 100 can be transferred using electrostatic or magnetic force. When electrostatic transfer is used, the transfer structure 40 is, for example, an electrostatic transfer head with two separate electrodes at its tip. These electrodes are led out by a metal conductor, and an insulating material is deposited on top of the metal electrodes. When an alternating current is applied to the two electrodes, the micro-LED 100 is attracted to the electrostatic transfer head due to Coulomb force, thus transferring the micro-LED 100 onto the display substrate 50. When magnetic transfer is used, the transfer structure 40 is, for example, a micro-magnetic transfer head. The micro-magnetic transfer head uses a magnetic material as its core, such as an iron-silicon alloy (FeSi), and then uses gold wire to create coils in a plane or multiple planes. When current passes through, a strong magnetic field is generated in the coil to pick up the micro-LED 100.

[0116] Please refer to Figure 30. In one embodiment of the present invention, the micro-light-emitting diode display includes a display substrate 50 and a plurality of micro-light-emitting diodes 100 disposed on the display substrate 50. The display substrate 50 is, for example, a thin-film transistor array substrate, including a substrate and a circuit layer 501 disposed on the substrate 500. The circuit layer 501 has a plurality of thin-film transistors for driving the micro-light-emitting diodes 100. In this embodiment, the display substrate 50 is provided with, for example, a plurality of red micro-light-emitting diodes 100a, green micro-light-emitting diodes 100b, and blue micro-light-emitting diodes 100c. Each micro-light-emitting diode 100 is a sub-pixel. The red micro-light-emitting diode 100a can form a red sub-pixel, the green micro-light-emitting diode 100b can form a green sub-pixel, and the blue micro-light-emitting diode 100c can form a blue sub-pixel. The red micro-light-emitting diodes 100a, green micro-light-emitting diodes 100b, and blue micro-light-emitting diodes 100c arranged in sequence form a pixel.

[0117] Please see Figure 30 As shown, in one embodiment of the present invention, a planarization layer 503 can be formed within a pixel, on the micro-light-emitting diode 100 and between adjacent micro-light-emitting diodes 100, through an exposure and development process. A protective layer 504 can also be disposed on the planarization layer 503, between adjacent pixels and above the pixel. A protective substrate 505 can also be disposed on the protective layer 504, and the protective substrate 505 is bonded to the protective layer 504 to form a sealed cavity to protect the internal micro-light-emitting diodes 100.

[0118] In summary, the present invention provides a method for fabricating a weakened structure and a micro-LED display. The method involves forming micro-LEDs on a substrate, bonding the micro-LEDs to a transient substrate using an adhesive layer, and etching the adhesive layer to form a mesh-like first support structure that supports the micro-LEDs and prevents them from shifting. The micro-LEDs are then transferred to a display substrate using a transfer structure to form the micro-LED display. The method for fabricating the weakened structure and the micro-LED display provided by the present invention, by etching the adhesive layer into a mesh-like first support structure, is simple and easy to operate, and can improve the yield of mass transfer.

[0119] It should be understood that the application of the present invention is not limited to the examples above. Those skilled in the art can make improvements or modifications based on the above description, and all such improvements and modifications should fall within the protection scope of the appended claims.

Claims

1. A method for manufacturing a weakened structure, characterized in that, The weakening structure includes a first support structure, and the method for manufacturing the first support structure includes the following steps: A binder layer is formed on the micro light-emitting diode and / or transient substrate; The micro-light-emitting diode is transferred to a transient substrate, and the micro-light-emitting diode is bonded to the transient substrate through the adhesive layer; and The adhesive layer is etched to form a first support structure, which is mesh-like and surrounds the micro-light-emitting diode.

2. The method for manufacturing the weakened structure as described in claim 1, characterized in that, The adhesive layer is made of organosilicon compounds.

3. The method for fabricating the weakened structure as described in claim 1, characterized in that, The silicon content in the adhesive layer is 20% to 85%, and the material of the adhesive layer includes groups containing carbon, hydrogen, and nitrogen.

4. The method for fabricating the weakened structure as described in claim 1, characterized in that, The steps for forming the first support structure include: dry etching the adhesive layer, wherein the etching gas is oxygen or chlorine.

5. The method for fabricating the weakened structure as described in claim 1, characterized in that, The material of the first support structure is silicon oxide.

6. The method for fabricating the weakened structure as described in claim 1, characterized in that, The weakening structure also includes a second support structure, and when the micro-light-emitting diode is bonded to the transient substrate, the second support structure is located between the two electrodes of the micro-light-emitting diode.

7. The method for manufacturing the weakened structure as described in claim 6, characterized in that, The steps for forming the second support structure include: An oxide layer is formed on the transient substrate; and The oxide layer is etched to form the second support structure; The radial dimension of the second support structure is smaller than the distance between the two electrodes of the micro-LED.

8. The method for manufacturing the weakened structure as described in claim 6, characterized in that, The material of the second support structure is silicon oxide.

9. The method for manufacturing the weakened structure as described in claim 6, characterized in that, The second support structure is located on the transient substrate. When the micro light-emitting diode is bonded to the transient substrate, the second support structure and the micro light-emitting diode are at a predetermined distance in the direction perpendicular to the transient substrate.

10. A method for manufacturing a micro-light-emitting diode display, characterized in that, Includes the following steps: Provide a substrate; Multiple micro light-emitting diodes are formed on the substrate; The micro-light-emitting diode is transferred to the transient substrate, and the micro-light-emitting diode is bonded to the transient substrate through an adhesive layer; The adhesive layer is etched to form a first support structure, which is mesh-like and surrounds the micro-light-emitting diode. as well as The micro light-emitting diodes are transferred onto the display substrate.

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