WO2023070445A1 - 弱化结构的制作方法、微发光二极管显示器的制作方法 - Google Patents

弱化结构的制作方法、微发光二极管显示器的制作方法 Download PDF

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Publication number
WO2023070445A1
WO2023070445A1 PCT/CN2021/127067 CN2021127067W WO2023070445A1 WO 2023070445 A1 WO2023070445 A1 WO 2023070445A1 CN 2021127067 W CN2021127067 W CN 2021127067W WO 2023070445 A1 WO2023070445 A1 WO 2023070445A1
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layer
light emitting
micro light
micro
emitting diode
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PCT/CN2021/127067
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English (en)
French (fr)
Inventor
戴广超
马非凡
曹进
张雪梅
王子川
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重庆康佳光电技术研究院有限公司
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Priority to PCT/CN2021/127067 priority Critical patent/WO2023070445A1/zh
Publication of WO2023070445A1 publication Critical patent/WO2023070445A1/zh

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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
    • H01L21/67—Apparatus specially adapted for handling semiconductor or electric solid state devices during manufacture or treatment thereof; Apparatus specially adapted for handling wafers during manufacture or treatment of semiconductor or electric solid state devices or components ; Apparatus not specifically provided for elsewhere
    • H01L21/683—Apparatus specially adapted for handling semiconductor or electric solid state devices during manufacture or treatment thereof; Apparatus specially adapted for handling wafers during manufacture or treatment of semiconductor or electric solid state devices or components ; Apparatus not specifically provided for elsewhere for supporting or gripping
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L27/00—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate
    • H01L27/15—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate including semiconductor components having potential barriers, specially adapted for light emission
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L33/00—Semiconductor devices having potential barriers specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
    • H01L33/48—Semiconductor devices having potential barriers specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof characterised by the semiconductor body packages

Definitions

  • the invention belongs to the technical field of semiconductor manufacturing, and in particular relates to a method for manufacturing a weakened structure and a method for manufacturing a micro-light-emitting diode display.
  • Micro LED display is a new generation of display technology. Compared with liquid crystal display, it has the advantages of higher brightness, better luminous efficiency and lower power consumption.
  • micro-light-emitting diodes can be transferred to the display substrate by methods such as electrostatic force, van der Waals force, magnetic force, laser selective transfer, fluid transfer, and direct transfer.
  • electrostatic force van der Waals force
  • magnetic force magnetic force
  • laser selective transfer fluid transfer
  • direct transfer direct transfer
  • the micro-light-emitting diodes are bonded to the substrate through an adhesive material.
  • the etching width cannot be precisely controlled, which may easily cause damage to the micro-LEDs and affect the yield of mass transfer.
  • the purpose of this application is to provide a method for fabricating a weakened structure and a micro-LED display, aiming at solving the problem that the etching of the glue between the substrate and the micro-LED cannot be precisely controlled.
  • the present invention provides a method for manufacturing a weakened structure, the weakened structure includes a first support structure, and the method for manufacturing the first support structure includes the following steps:
  • the first support structure is in the shape of a net and surrounds the micro light emitting diodes.
  • the micro light-emitting diodes can be supported, and the etching process of the adhesive material is easy to control, which can improve the yield of mass transfer.
  • the material of the glue layer is organosilicon compound.
  • the silicon content in the glue layer is 20%-85%. It can ensure that the first support structure formed after etching is a network structure, and ensure that the formed first support structure has a suitable mesh density, so as to avoid that when the silicon content is too low, the first support structure is not enough to support the micro light emitting diodes, and when the silicon content is too high, the adhesion force between the first supporting structure and the micro light emitting diodes is too large, and the transfer structure cannot pick up the micro light emitting diodes.
  • the material of the glue layer includes groups containing carbon, hydrogen, and nitrogen.
  • the step of forming the first support structure includes: dry etching the adhesive material layer, and the etching gas is oxygen or chlorine.
  • the material of the first support structure is silicon oxide.
  • the material setting of the above-mentioned adhesive material layer and the first support structure can ensure that the substances in the adhesive material layer that form the first support structure react with the etching gas to form easily removable substances, which can be easily removed during etching. When complete, only the solid and mesh-like first support structure exists.
  • 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 two electrodes of the micro light emitting diode .
  • the above-mentioned second support structure further supports the micro light emitting diodes to ensure the stability of the micro light emitting diodes.
  • the step of forming the second support structure includes:
  • the radial dimension of the second supporting structure is smaller than the distance between the two electrodes of the micro light emitting diode.
  • the material of the second supporting structure is silicon oxide.
  • the second supporting structure has a preset distance from the micro light emitting diode. In order to ensure that there is no adhesion between the second support structure and the micro-light emitting diodes, and ensure the yield rate in the mass transfer.
  • the present application also provides a method for making a micro-light-emitting diode display, including:
  • the first support structure is in the form of a mesh and surrounds the micro light emitting diodes
  • the micro light emitting diodes are transferred to a display substrate.
  • the micro-light-emitting diode can be supported by etching the adhesive material layer into a mesh shape, and the etching process of the adhesive material is easy to control, which can improve the yield rate of mass transfer.
  • the transfer structure is an elastic stamp
  • the material of the elastic stamp is polydimethylsiloxane.
  • the step of forming the micro light emitting diodes includes:
  • a second electrode is deposited on the second semiconductor layer.
  • the step of forming the micro light emitting diode further includes: depositing a reflective layer on the second semiconductor layer and on the transparent conductive layer.
  • 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, and the first conductive channel is in contact with the first semiconductor layer, the The second conductive channel is in contact with the transparent conductive layer.
  • the step of forming the first conductive channel and the second conductive channel includes:
  • the angle between the sidewall of the opening and the reflective layer is greater than 90 degrees.
  • the formed electrode has a larger radial dimension, which is convenient for welding.
  • Fig. 1 is a flow chart of a manufacturing method of a micro light-emitting diode display in the present invention.
  • FIG. 2 is a structural diagram of forming a first photoresist layer on a semiconductor epitaxial layer in the present invention.
  • FIG. 3 is a structural diagram of forming a concave portion on a semiconductor epitaxial layer in the present invention.
  • FIG. 4 is a top view of FIG. 3 .
  • FIG. 5 is a structural diagram of forming a second photoresist layer on the semiconductor epitaxial layer in the present invention.
  • FIG. 6 is a structural diagram of trenches formed on the semiconductor epitaxial layer in the present invention.
  • FIG. 7 is a top view of FIG. 6 .
  • FIG. 8 is a schematic diagram of the structure of the third photoresist layer in the present invention.
  • FIG. 9 is a schematic structural diagram of a transparent conductive layer in the present invention.
  • FIG. 10 is a top view of FIG. 9 .
  • FIG. 11 is a schematic diagram of the structure of the fourth photoresist layer in the present invention.
  • Fig. 12 is a schematic diagram of the structure of the reflective layer in the present invention.
  • FIG. 13 is a top view of FIG. 12 .
  • FIG. 14 is a schematic diagram of the structure of the fifth photoresist layer in the present invention.
  • Fig. 15 is a schematic diagram of the structure of the electrode in the present invention.
  • FIG. 16 is a top view of FIG. 15 .
  • Fig. 17 is a schematic structural view of the first adhesive material layer in the present invention.
  • Fig. 18 is a schematic structural view of the second adhesive material layer in the present invention.
  • FIG. 19 is a schematic diagram of the structure of micro light emitting diodes transferred to a transient substrate in the present invention.
  • Fig. 20 is a schematic diagram of the micro light emitting diode structure after the substrate is peeled off in the present invention.
  • Fig. 21 is a schematic structural diagram of the first supporting structure in the present invention.
  • Fig. 22 is a schematic diagram of mass transfer in the present invention.
  • Fig. 23 is a schematic structural view of the supporting layer in the present invention.
  • Fig. 24 is a schematic structural diagram of the second supporting structure in the present invention.
  • Fig. 25 is a structural schematic diagram of forming a second adhesive material layer on the second supporting structure in the present invention.
  • FIG. 26 is a schematic diagram of the structure of micro light emitting diodes transferred to a transient substrate in another embodiment of the present invention.
  • Fig. 27 is a schematic diagram of the micro light emitting diode structure after the substrate is peeled off in another embodiment of the present invention.
  • Fig. 28 is a structural schematic diagram of the first support structure and the second support structure of the present invention.
  • FIG. 29 is a schematic diagram of a mass transfer in another embodiment of the present invention.
  • FIG. 30 is a schematic structural view of a micro-LED display in the present invention.
  • the micro-LED display may include a display substrate 50 and a plurality of micro-light-emitting diodes 100 disposed on the display substrate 50 .
  • the display substrate 50 is provided with a driving circuit for driving the micro-light-emitting diodes 100 to work.
  • a 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 matrix on the display substrate 50 to form a display area of the micro light emitting diode display.
  • Micro-LED displays have the advantages of long life, high contrast, high resolution, fast response, wide viewing angle, rich colors, ultra-high brightness and low power consumption, for example, they can be used in TVs, laptops, monitors, mobile phones, watches , wearable displays, vehicle-mounted devices, virtual reality (VR) devices, augmented reality (AR) devices, portable electronic devices, game consoles or other electronic devices.
  • VR virtual reality
  • AR augmented reality
  • a plurality of micro-light-emitting diodes 100 can be formed on the substrate 10, for example, a semiconductor epitaxial layer 11 is deposited on the substrate 10, and exposed The steps of developing, etching and depositing metal form the micro light emitting diode 100 .
  • the micro light emitting diode 100 emitting ultraviolet light can be made of gallium nitride (GaN) material
  • the substrate 10 of the micro light emitting diode 100 is usually Heteroepitaxial on sapphire, free-standing GaN substrates using hydride vapor phase epitaxy or ammonothermal methods.
  • gallium arsenide (GaAs), gallium phosphide (GaP) substrates or substrates of other materials may be used.
  • a plurality of micro light emitting diodes 100 are arranged on the same substrate 10 to form an array of micro light emitting diodes 100 .
  • the micro light emitting diodes 100 are transferred to the transient substrate 30 as required, and finally the micro light emitting diodes 100 are transferred to the display substrate 50, or the micro light emitting diodes 100 on the substrate 10 are directly transferred to the On the display substrate 50, a micro light emitting diode display is formed.
  • Micro LEDs 100 are small in size, for example, the number of micro LEDs 100 on a 4-inch wafer is, for example, 14 ⁇ 10 6 , and the number of micro diodes required to form a micro diode display is also very large. Specifically, the micro light emitting diode 100 can be efficiently transferred to the display substrate 50 through mass transfer.
  • the mass transfer specifically includes electrostatic force transfer, van der Waals force transfer, magnetic force transfer, laser selective transfer, fluid transfer, direct transfer and other transfer methods.
  • the mass transfer method may include, for example, electrostatic force transfer, van der Waals force transfer, magnetic force transfer, and other transfer methods.
  • part of the glue Before picking up the micro-LED 100 in the structure 40, part of the glue needs to be etched away, and only part of the glue is kept to support the micro-light-emitting diode 100, but the width of the reserved glue is not easy to control, and the width of the reserved glue is too small, and the micro-luminescence If the diode 10 falls, it is easy to cause damage to the micro-LEDs 100.
  • the width of the remaining adhesive material is too large, the adhesion between the micro-light-emitting diodes 10 and the adhesive material is relatively large, and the transfer structure cannot pick up all the selected micro-light-emitting diodes 100. Unable to perform yield.
  • the glue is doped with a substance that does not react with the etching gas, and the organic substances in the glue are etched to form a mesh-like first.
  • a support structure The formed first supporting structure can support micro-light emitting diodes, and the etching process of the adhesive material is easy to control, which can improve the yield rate of mass transfer.
  • the manufacturing method of the micro-light-emitting diode display comprises the following steps:
  • the material of the substrate 10 includes silicon, silicon germanium, silicon carbide, sapphire, indium phosphide, gallium arsenide, indium arsenide or other III/V
  • the semiconductor structure formed by the compound also includes the stacked structure of these semiconductors, or silicon-on-insulator, silicon-on-insulator, silicon-germanium-on-insulator, silicon-germanium-on-insulator, and germanium-on-insulator.
  • the material of the substrate 10 can be determined according to the type of the micro light emitting diode 100 to be formed and the semiconductor epitaxial layer 11 on the substrate 10 .
  • the micro light emitting diode 100 is a micro light emitting diode 100 that emits blue light or green light
  • 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 is Examples include sapphire (Al 2 O 3 ), silicon carbide (SiC), zinc oxide (ZnO), gallium nitride (GaN), aluminum nitride (AlN), and silicon (Si).
  • the micro light emitting diode 100 is a micro light emitting diode 100 that emits red light or yellow light
  • the material of the semiconductor epitaxial layer 11 is, for example, gallium phosphide (GaP), aluminum gallium arsenide (AlGaAs), aluminum gallium indium phosphide (AlGaInP) and other materials
  • the material of the substrate 10 may be, for example, gallium phosphide (GaP) or gallium arsenide (GaAs).
  • the step of forming a micro light emitting diode includes growing a semiconductor epitaxial layer 11 on the substrate 10, wherein the semiconductor epitaxial layer 11 may include a first semiconductor layer 111, a light emitting layer 112 and a second semiconductor layer grown sequentially.
  • the layer 113 ie, the light emitting layer 112 is located on the first semiconductor layer 111
  • the second semiconductor layer 113 is located on the light emitting layer 112 .
  • 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, and the corresponding second semiconductor layer 113 may be an N-type semiconductor layer doped with a second impurity.
  • the first impurity is, for example, a donor impurity
  • the second impurity is, for example, an acceptor impurity.
  • the first impurity and the second impurity may be different elements.
  • the first semiconductor layer 111 and the second semiconductor layer 113 may 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,
  • the first impurity may be silicon (Si) or tellurium (Te) element
  • the second impurity may be magnesium (Mg) or zinc (Zn) element.
  • the first semiconductor layer 111 and the second semiconductor layer 113 may also be formed of other suitable materials.
  • the light-emitting layer 112 is an intrinsic semiconductor layer or a low-doped semiconductor layer, and the doping concentration of the light-emitting layer 112 is lower than that of adjacent semiconductor layers of the same doping type. , while the light emitting layer 112 may be a quantum well light emitting layer.
  • the semiconductor epitaxial layer 11 emits blue light or green light, for example, and the material of the light emitting layer 112 is indium gallium nitride (InGaN).
  • the light-emitting layer 112 can be, for example, a quantum well that emits different light color bands, and the material of the light-emitting layer 112 can be selected from zinc selenide (ZnSe), indium gallium nitride/gallium nitride (InGaN/GaN), indium One or more of materials such as gallium nitride/gallium nitride (InGaN/GaN), gallium phosphide (GaP), aluminum gallium phosphide (AlGaP) or aluminum gallium arsenide (AlGaAs).
  • ZnSe zinc selenide
  • InGaN/GaN indium gallium nitride/gallium nitride
  • InGaN/GaN gallium phosphide
  • AlGaP aluminum gallium phosphide
  • AlGaAs aluminum gallium arsenide
  • the semiconductor epitaxial layer 11 is etched to form a mesa (MESA) structure.
  • a concave portion 114 is formed on the semiconductor epitaxial layer 11 , the bottom of the concave portion 114 is in contact with the first semiconductor layer 111 and has a predetermined distance from the substrate 10 .
  • 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 the first photoresist layer 21
  • a first opening 201 is provided for defining the position of the recess 114 .
  • the first opening 201 is circular. In other embodiments, the first opening 201 may be in other shapes such as rectangle and polygon.
  • the etching gas is, for example, Boron trichloride (BCl 3 ) or chlorine gas (Cl 2 ).
  • the concave portion 114 is formed, the first photoresist layer 21 is removed.
  • a groove 115 is formed outside the micro light emitting diode, and the groove 115 is in contact with the substrate 10, And the trench 115 is disposed around each micro-LED to isolate adjacent micro-LEDs.
  • 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 for use in at the location defining the trench 115 .
  • the second opening 202 is disposed around the micro LED 100 , and the second opening 202 is, for example, in the shape of a rectangular ring.
  • the semiconductor epitaxial layer 11 is dry-etched to the substrate 10 by using the second photoresist layer 22 as a mask to form a trench 115 , and the specific etching depth is, for example, 4-8 um.
  • the trench 115 is formed, the second photoresist layer 22 is removed.
  • a transparent conductive layer 116 is formed on the second semiconductor layer 113, and the transparent conductive layer 116 is located in the concave portion 114. side.
  • a layer of indium tin oxide (ITO) can be sputtered on the second semiconductor layer 113 , and the thickness of the indium tin oxide is, for example, 200 ⁇ 2000 angstroms.
  • a patterned third photoresist layer 23 is formed on the ITO, and the third photoresist layer 23 is provided with a third opening 203 for defining the position of the transparent conductive layer 116 .
  • the third opening 203 is located on one side of the protrusion and is arranged in a rectangular shape. After forming the third photoresist layer 23 , using the third photoresist layer 23 as a mask, wet-etch ITO to form the transparent conductive layer 116 , and then remove 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 concave portion 114 and the groove 115.
  • the reflective layer 117 is provided with a first conductive channel 118 and a second conductive channel 119.
  • the first conductive channel 118 and the The first semiconductor layer 111 communicates
  • 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. Specifically, as shown in FIGS.
  • a stack of silicon oxide and silicon nitride is vapor-deposited in the recess 114 and the trench 115 to form a reflective layer.
  • 117, and the thickness of the reflective layer 117 is, for example, 1-4 um.
  • the reflection layer 117 can reflect the light emitted by 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 .
  • 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 for defining the position of the first conductive channel 118, the fifth opening is located above the transparent conductive layer 116, Used to define the position of the second conductive channel 119 .
  • the reflective layer 117 is etched with the fourth photoresist layer 24 as a mask, and the first conductive channel 118 communicating with the first semiconductor layer 111 is formed on the concave portion 114, and the transparent conductive layer 116 A second conductive channel 119 communicating with the transparent conductive layer 116 is formed on it.
  • first conductive channel 118 and the second conductive channel 119 can be in any shape, such as columnar, quadrangular prism or columnar in other shapes.
  • dry etching can be used, and the etching gas is, for example, one or more of tetrafluoromethane (CF 4 ), oxygen (O 2 ) or argon (Ar).
  • the fourth photoresist layer 24 can be removed.
  • the first electrode 121 is formed in the first conductive channel 118
  • the second electrode 122 is formed in the second conductive channel 119 .
  • a patterned fifth photoresist layer 25 is first formed on the reflective layer 117, and the fifth photoresist layer 25 is provided with sixth openings 206 and The seventh opening 207 and the sixth opening 206 are used to define the position of the first electrode 121 , and the seventh opening 207 is used to define the position of the second electrode 122 .
  • the fourth photoresist layer 24 may not be removed before forming the electrode 120 , and the first electrode 121 and the second electrode 122 are formed by using the fourth photoresist layer 24 as a mask.
  • the first electrode 121 and the second electrode 122 are formed by 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 that of the first conductive channel 118, and the seventh opening 207 exposes the second conductive channel 119, and the diameter of the seventh opening 207 is larger than that of the first conductive channel 118.
  • the aperture of the second conductive channel 119 is used to form an electrode 120 with a larger area.
  • first electrode 121 is an N-type electrode 120, for example, The material is, for example, Ni/Au.
  • the second electrode 122 is, for example, the P-type electrode 120 , and the material is, for example, Ni/Al/Ni/Au.
  • the patterned photoresist layer is formed by first coating the photoresist, and then removing it with an alkaline solution in a wet method or using a dry ashing process (ashing ) removing the photoresist above the desired opening, patterning the coated photoresist to form a patterned photoresist layer.
  • the material of the photoresist layer can be positive photoresist or negative photoresist.
  • the fifth photoresist layer 25 is a negative photoresist, when the photoresist in the non-exposed area of the fifth photoresist layer 25 is dissolved in the developing solution, the side faces of the patterned photoresist layer and the reflective layer formed
  • the angle formed by 117 is less than 90 degrees, so that the fifth photoresist layer 25 does not affect the deposition of the electrode 120 . That is, the angle formed between the sidewalls of the sixth opening 206 and the seventh opening 207 and the reflective layer 117 is greater than 90 degrees.
  • the micro light emitting diodes 100 are transferred onto the transient substrate 30 .
  • a layer of adhesive material layer 31 can be coated on the micro light emitting diode 100 and/or the transient substrate 30 first, and then the micro light emitting diode 100 and the transient substrate 30 are bonded through a bonding machine, and the micro light emitting diode 100 and the transient substrate 30 can be bonded together.
  • the transient substrate 30 is bonded together by an adhesive layer 31 .
  • the transient substrate 30 is, for example, a sapphire substrate.
  • the substrate 10 is removed.
  • the substrate 10 can be lifted off by a laser lift off (Laser Lift Off, LLO) technique.
  • the adhesive material layer 31 includes a first adhesive material layer 311 and a second adhesive material layer 312, the first adhesive material layer 311 is located on the micro light emitting diode 100, and the second adhesive material layer An adhesive material layer 311 covers the gap between the first electrode 121 , the second electrode 122 and adjacent micro-LEDs 100 , and the second adhesive material layer 312 is located on the transient substrate 30 .
  • the first adhesive material layer 311 and the second adhesive material layer 312 are fused to form the adhesive material layer 31, and the adhesive material can be heated during bonding , so that the first adhesive material layer 311 and the second adhesive material layer 312 are fused.
  • the material of the adhesive material layer 31 is, for example, an organic silicon compound, and the silicon content in the adhesive material layer 31 is, for example, 20% to 85%, so as to ensure that the adhesive material layer 31 can form a net-like support after etching, which is the first supporting structure 313 of the weakened structure.
  • the glue layer 31 also includes groups containing carbon, hydrogen, and nitrogen, which can react with the etching gas to form easily removable substances during the etching process.
  • the adhesive material layer 31 is etched, and the groups containing carbon, hydrogen, and nitrogen in the adhesive material layer 31 are etched. , only the first support structure 313 in the shape of a mesh remains.
  • the adhesive material layer can be dry etched, and the etching gas is, for example, oxygen or chlorine. During etching, oxygen gas (or chlorine gas) reacts with groups containing carbon, hydrogen, and oxygen in the adhesive material layer 31 to make carbon, hydrogen, and nitrogen in the adhesive material layer 31 form compounds with oxygen.
  • the etching gas is oxygen
  • substances such as carbon, hydrogen, and oxygen groups are generated as carbon dioxide, water, and nitrogen dioxide, wherein carbon dioxide and nitrogen dioxide are gases, and water is a liquid that can be removed directly.
  • the silicon in the adhesive material layer 31 reacts with oxygen to form silicon oxide, forming a network-like first support structure 313 .
  • the formed first support structure 313 surrounds the micro LED 100 , not only can support the micro LED 100 , but also the surrounding first support structure 313 can ensure that the micro LED 100 does not shake.
  • the transfer structure 40 is used to transfer the micro LED 100 to the display substrate 50 to form a micro LED display.
  • the weakened structure further includes a second support structure 314 , and the second support structure 314 is disposed on the transient substrate 30 .
  • a layer of silicon oxide may 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 arranged on the photoresist layer to define the position of the second support structure 314 .
  • the support layer 315 is etched using the patterned photoresist layer as a mask to form the second support structure 314 .
  • the support layer 315 may be etched by a wet etching method.
  • a plurality of second support structures 314 can be arranged on the transient substrate, and 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 from the first electrode 121 to the second electrode 122 .
  • the second supporting structure 314 is located between the first electrode 121 and the second electrode 122 of the micro light emitting diode.
  • a first adhesive material layer 311 is formed on the micro light emitting diode, and the first adhesive material layer 311 covers the second The gap between the first electrode 121 , the second electrode 122 and the adjacent micro LEDs 100 .
  • a second adhesive material layer 312 is formed on the transient substrate 30 , and the second adhesive material layer 312 covers the second supporting structures 314 and gaps between adjacent second supporting structures 314 .
  • FIG. 26 when the micro-LED 100 and the transient substrate 30 are bonded by a bonding machine, the first adhesive material layer 311 and the second adhesive material layer 312 are fused to form the adhesive material layer 31 .
  • the substrate 10 can be removed by laser lift off (Laser Lift Off, LLO) technology. peel off.
  • LLO Laser Lift Off
  • the adhesive material layer 31 is etched, and the groups containing carbon, hydrogen, and nitrogen in the adhesive material layer 31 are etched, and only the first support structure 313 and the second support structure in a network shape remain. 314.
  • the adhesive material layer can be dry etched, and the etching gas is, for example, oxygen or chlorine.
  • oxygen gas reacts with groups containing carbon, hydrogen, and oxygen in the adhesive material layer 31 to make carbon, hydrogen, and nitrogen in the adhesive material layer 31 form compounds with oxygen.
  • the etching gas is oxygen
  • substances such as carbon, hydrogen, and oxygen groups are generated as carbon dioxide, water, and nitrogen dioxide, wherein carbon dioxide and nitrogen dioxide are gases, and water is a liquid that can be removed directly.
  • the silicon in the adhesive material layer 31 reacts with oxygen to form silicon oxide, forming the first support structure 313 in a network shape.
  • the formed first support structure 313 surrounds the micro LED 100 , not only can support the micro LED 100 , but also the surrounding first support structure 313 can ensure that the micro LED 100 does not shake.
  • 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 that of the electrodes, and when the first adhesive material layer 311 and the second adhesive material layer 312 are fused, the second adhesive material layer 314 is fused.
  • the second support structure 314 has a preset distance from the micro LED 100 to ensure that there is no adhesion between the second support structure 314 and the micro LED 100 during mass transfer.
  • the micro light emitting diode 100 is transferred to the display substrate 50 through the transfer structure 40 , A micro light emitting diode display is formed.
  • Fig. 22 and Fig. 29 there are many ways to transfer the micro light emitting diode 100, according to the force in the transfer process or the specific transfer method, it can include van der Waals force, electrostatic force, magnetic force, Laser transfer pie, fluid self-assembly pie and roll-to-roll transfer pie.
  • van der Waals force is used to transfer the micro-LED 100
  • the transfer structure 40 is, for example, an elastic stamp
  • the material of the elastic stamp is, for example, polydimethylsiloxane (PDMS).
  • the micro light emitting diode 100 can be picked up by the elastic stamp and transferred to the display substrate 50, and in the process of picking up the micro light emitting diode 100, the elastic stamp maintains a relatively high speed, at this time, the adsorption between the elastic stamp and the device Stronger. During the process of placing the micro light emitting diode 100 on the display substrate 50, the elastic stamp maintains a relatively low transfer speed, and at this time, the adsorption force between the elastic stamp and the device is relatively small.
  • the temperature of the elastic stamp can be adjusted to ensure the transfer effect, for example, a lower temperature is used in the process of picking up and transferring the micro-light-emitting diode 100 to ensure that the elastic stamp and the device The adsorption force between them is relatively large. During the process of placing the micro-LED 100, a higher temperature is used to ensure that the adsorption force between the elastic seal and the device is relatively small.
  • the micro-light emitting diode 100 can be transferred by electrostatic force or magnetic force.
  • the transfer structure 40 is, for example, an electrostatic transfer head. There are two separate electrodes on the top of the electrostatic transfer head, the two electrodes are drawn out through the metal, and then an insulating material is deposited on the metal electrode, when an alternating current is applied to the two electrodes, due to the effect of the Coulomb force, the micro light emitting diode 100 will be adsorbed on the electrostatic transfer head to transfer the micro light emitting diode 100 to the display substrate 50 .
  • the transfer structure 40 is, for example, a micro-magnetic transfer head.
  • the micro-magnetic transfer head uses a magnetic material as an iron core, such as iron-silicon alloy (FeSi), and then uses gold wires in a plane or multilayer A coil is fabricated in a plane, and when a current passes through, a strong magnetic field will be generated in the coil to pick up the micro-LEDs 100 .
  • FeSi iron-silicon alloy
  • a 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, for example including a base and a circuit layer 501 disposed on the base 500 .
  • the circuit layer 501 has a plurality of thin film transistors for driving the micro light emitting diodes 100 .
  • a plurality of red micro-light emitting diodes 100a, green micro-light-emitting diodes 100b and blue micro-light-emitting diodes 100c are arranged on the display substrate 50, each micro-light-emitting diode 100 is a sub-pixel, and the red micro-light-emitting diode 100a A red sub-pixel can be formed, a green micro-light emitting diode 100b can form a green sub-pixel, and a blue micro-light-emitting diode 100c can form a blue sub-pixel, and the red micro-light-emitting diode 100a, the green micro-light-emitting diode 100b and the blue micro-light-emitting diode 100b arranged in sequence Color micro light emitting diodes 100 and 100c form a pixel.
  • a planarization layer 503 can be formed through exposure and development processes.
  • a protection layer 504 may also be disposed on the planarization layer 503, and the protection layer 504 is disposed between adjacent pixels and above the pixels.
  • a protective substrate 505 may also be provided on the protective layer 504 , and the protective substrate 505 is bonded with the protective layer 504 to form a closed cavity to protect the micro light emitting diodes 100 inside.
  • the present invention provides a method for fabricating a weakened structure and a micro-LED display, forming micro-LEDs on a substrate, bonding the micro-LEDs to a transient substrate through an adhesive layer, And etch the adhesive material layer to form a mesh-like first support structure to support the micro-light emitting diodes and ensure that the micro-light-emitting diodes do not shake. Then the micro light emitting diode is transferred to the display substrate through the transfer structure to form the micro light emitting diode display.
  • the manufacturing method of the weakened structure and the manufacturing method of the micro-light-emitting diode display provided by the present invention by etching the adhesive layer into a mesh-like first support structure, the manufacturing process is simple and easy to operate, and the yield rate of mass transfer can be improved.

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Abstract

本发明公开了一种弱化结构的制作方法、微发光二极管显示器的制作方法，且所述弱化结构包括第一支撑结构，且所述第一支撑结构的制作方法包括步骤：在微发光二极管和/或暂态基板上形成胶材层；将所述微发光二极管转移至暂态基板上，且所述微发光二极管转与所述暂态基板通过所述胶材层键合；以及蚀刻所述胶材层，形成第一支撑结构，所述第一支撑结构呈网状，且环绕所述微发光二极管。

Description

弱化结构的制作方法、微发光二极管显示器的制作方法 技术领域
本发明属于半导体制造技术领域，特别涉及一种弱化结构的制作方法、微发光二极管显示器的制作方法。
背景技术
微发光二极管(Micro LED)显示器是新一代显示技术，相较于液晶显示器而言，具有亮度更高、发光效率更好和功耗更低的优点。
在微发光二极管的转移过程中，可通过静电力、范德华力、磁力、激光选择性转移、流体转移以及直接转印等方法将微发光二极管转移至显示基板上。但是在选择性拾取微发光二极管时，微发光二极管是与基板之间通过胶材键合，在转移结构在拾取发光二极管前，需要将胶材蚀刻，便于拾取微发光二极管，但是在蚀刻胶材时，蚀刻的宽度无法精确控制，易造成微发光二极管损伤，影响巨量转移的良率。
发明内容
鉴于上述现有技术的不足，本申请的目的在于提供一种弱化结构的制作方法、微发光二极管显示器的制作方法，旨在解决基板与微发光二极管之间的胶材蚀刻无法精确控制的问题。
为解决上述技术问题，本发明是通过以下技术方案实现的：
本发明提供一种弱化结构的制作方法，所述弱化结构包括第一支撑结构，且所述第一支撑结构的制作方法包括以下步骤：
在微发光二极管和/或暂态基板上形成胶材层；
将所述微发光二极管转移至暂态基板上，且所述微发光二极管转与所述暂 态基板通过所述胶材层键合；以及
蚀刻所述胶材层，形成第一支撑结构，所述第一支撑结构呈网状，且环绕所述微发光二极管。
上述的弱化结构的制作方法的制作方法，通过将所述胶材层蚀刻成网状，即可支撑微发光二极管，且胶材的蚀刻过程易控制，可提高巨量转移的良率。
可选地，所述胶材层的材料为有机硅化物。
可选地，所述胶材层中的硅含量为20％～85％。可保证蚀刻后形成的第一支撑结构为网状结构，且保证形成的所述第一支撑结构具有合适的网孔密度，避免硅含量过低时，所述第一支撑结构不足以支撑所述微发光二极管，以及硅含量过高时，所述第一支撑结构与所述微发光二极管之间的粘附力过大，转移结构无法拾取微发光二极管。
可选地，所述胶材层的材料包括含有碳、氢、氮的基团。
可选地，形成所述第一支撑结构的步骤包括：干法蚀刻所述胶材层，且蚀刻气体为氧气或氯气。
可选地，所述第一支撑结构的材料为氧化硅。
上述所述胶材层以及所述第一支撑结构的材料设置，可保证将所述胶材层中除形成所述第一支撑结构的物质与蚀刻气体反应，生成易于移除的物质，在蚀刻完成后，只存在固态且呈网状的第一支撑结构。
可选地，所述弱化结构还包括第二支撑结构，且当所述微发光二极管与所述暂态基板键合时，所述第二支撑结构位于所述微发光二极管的两个电极之间。
上述所述第二支撑结构对所述微发光二极管进一步支撑，保证所述微发光二极管的稳定性。
可选地，形成所述第二支撑结构的步骤包括：
在所述暂态基板上形成氧化层；以及
蚀刻所述氧化层，形成所述第二支撑结构；
其中，所述第二支撑结构的径向尺寸小于所述微发光二极管两个电极之间的距离。
可选地，所述第二支撑结构的材料为氧化硅。
可选地，当所述微发光二极管与所述暂态基板键合时，所述第二支撑结构与所述微发光二极管具有预设距离。以保证所述第二支撑结构和所述微发光二极管之间无粘附力，保证在巨量转的良率。
基于同样的发明构思，本申请还提供微发光二极管显示器的制作方法，包括：
提供一衬底；
在所述衬底上形成多个微发光二极管；
将所述微发光二极管转移至暂态基板上，且所述微发光二极管转与所述暂态基板通过胶材层键合；
蚀刻所述胶材层，形成第一支撑结构，所述第一支撑结构呈网状，且环绕所述微发光二极管；以及
将所述微发光二极管转移至显示基板上。
上述的微发关二极管显示器的制作方法，通过将所述胶材层蚀刻成网状，即可支撑微发光二极管，且胶材的蚀刻过程易控制，可提高巨量转移的良率。
可选地，所述转移结构为弹性印章，且弹性印章的材料为聚二甲基硅氧烷。
可选地，形成所述微发光二极管的步骤包括：
在所述衬底上形成第一半导体层；
在所述第一半导体层上形成发光层；
在所述发光层上形成第二半导体层；
在所述第二半导体层上形成透明导电层；
在所述第一半导体层上沉积第一电极；以及
在所述第二半导体层上沉积第二电极。
可选地，形成所述微发光二极管的步骤还包括：在所述第二半导体层上和透明导电层上沉积反射层。
可选地，形成所述微发光二极管的步骤还包括：在所述反射层上形成第一导电通道和第二导电通道，且所述第一导电通道与所述第一半导体层接触，所述第二导电通道与所述透明导电层接触。
可选地，形成所述第一导电通道和第二导电通道的步骤包括：
在所述反射层上沉积光阻层；
在所述光阻层上形成开口；以及
以所述光阻层为掩膜蚀刻所述反射层，
其中，所述开口的侧壁与所述反射层的之间的角度大于90度。
上述过程中，可保证形成的电极径向尺寸较大，便于焊接。
当然，实施本发明的任一产品并不一定需要同时达到以上所述的所有优点。
附图说明
为了更清楚地说明本发明实施例的技术方案，下面将对实施例描述所需要使用的附图作简单地介绍，显而易见地，下面描述中的附图仅仅是本发明的一些实施例，对于本领域普通技术人员来讲，在不付出创造性劳动的前提下，还可以根据这些附图获得其他的附图。
图1为本发明中一种微发光二极管显示器的制作方法流程图。
图2为本发明中在半导体外延层上形成第一光阻层结构图。
图3为本发明中在半导体外延层上形成凹部的结构图。
图4为图3的俯视图。
图5为本发明中在半导体外延层上形成第二光阻层结构图。
图6为本发明中在半导体外延层上形成沟槽的结构图。
图7为图6的俯视图。
图8为本发明中第三光阻层的结构示意图。
图9为本发明中透明导电层的结构示意图。
图10为图9的俯视图。
图11为本发明中第四光阻层的结构示意图。
图12为本发明中反射层的结构示意图。
图13为图12的俯视图。
图14为本发明中第五光阻层的结构示意图。
图15为本发明中电极的结构示意图。
图16为图15的俯视图。
图17为本发明中第一胶材层的结构示意图。
图18为本发明中第二胶材层的结构示意图。
图19为本发明中微发光二极管转移至暂态基板的结构示意图。
图20为本发明中衬底剥离后的微发光二极管结构示意图。
图21为本发明中第一支撑结构的结构示意图。
图22为本发明中巨量转移示意图。
图23为本发明中支撑层的结构示意图。
图24为本发明中第二支撑结构的结构示意图。
图25为本发明中在第二支撑结构上形成第二胶材层的结构示意图。
图26为本发明另一实施例中微发光二极管转移至暂态基板的结构示意图。
图27为本发明另一实施例中衬底剥离后的微发光二极管结构示意图。
图28为本发明第一支撑结构和第二支撑结构的结构示意图。
图29为本发明另一实施例中巨量转移示意图。
图30为本发明中微发光二极管显示器的结构示意图。
附图标记说明：
10衬底；100微发光二极管；100a红色微发光二极管；100b绿色微发光二极管；100c蓝色微发光二极管；11半导体外延层；111第一半导体层；112发光层；113第二半导体层；114凹部；115沟槽；116透明导电层；117反射层；118第一导电通道；119第二导电通道；120电极；121第一电极；122第二电极；21第一光阻层；22第二光阻层；23第三光阻层；24第四光阻层；25第五光阻层；201第一开口；202第二开口；203第三开口；204第四开口；205第五开口；206第六开口；207第七开口；30暂态基板；31胶材层；311第一胶材层；312第二胶材层；313第一支撑结构；314第二支撑结构；315支撑层；40转移结构；50显示基板；501基底；502电路层，503平坦化层，504保护层，505保护基板。
具体实施方式
为了便于理解本申请，下面将参照相关附图对本申请进行更全面的描述。附图中给出了本申请的较佳实施方式。但是，本申请可以以许多不同的形式来实现，并不限于本文所描述的实施方式。相反地，提供这些实施方式的目的是使对本申请的公开内容理解的更加透彻全面。
除非另有定义，本文所使用的所有的技术和科学术语与属于本申请的技术领域的技术人员通常理解的含义相同。本文中在本申请的说明书中所使用的术 语只是为了描述具体的实施方式的目的，不是旨在于限制本申请。
在本发明的描述中，需要理解的是，术语中“中心”、“上”、“下”、“前”、“后”、“左”、“右”等指示的方位或位置关系为基于附图所示的方位或位置关系，仅是为了便于描述本发明和简化描述，而不是指示或暗示所指的装置或组件必须具有特定的方位、以特定的方位构造和操作，因此不能理解为对本发明的限制。此外，术语“第一”、“第二”仅用于描述目的，而不能理解为指示或暗示相对重要性。
请参阅图22所示，微发光二极管显示器可包括显示基板50以及设置在显示基板50上的多个微发光二极管100，显示基板50上设置有驱动电路，用驱动微发光二极管100工作。多个微发光二极管100电性连接于驱动电路，且多个微发光二极管100在显示基板50上呈矩阵排列，形成微发光二极管显示器的显示区域。微发光二极管显示器具有寿命长，对比度高，分辨率高，响应速度快，视角广阔，色彩丰富，超高亮度和低功耗等优点，例如可应用于电视机、笔记本电脑、显示器、手机、手表、可穿戴显示器、车载装置、虚拟现实(VR)装置、扩充现实(AR)装置、可携式电子装置、游戏机或其他电子装置中。
请参阅图2至图22所示，在微发光微二极管显示器的制造过程中，可在衬底10上形成多个微发光二极管100，例如在衬底10上沉积半导体外延层11，并经过曝光显影、蚀刻以及沉积金属等步骤形成微发光二极管100。且可根据形成的微发光二极管100的类型，使用不同的衬底材料，例如发射紫外线的微发光二极管100可由氮化镓(GaN)材料制成，则该微发光二极管100的衬底10通常是蓝宝石上的异质磊晶、使用氢化物气相磊晶或氨热方法制成的自支撑氮化镓衬底。对于其他颜色的微发光二极管100，可以使用砷化镓(GaAs)、磷化镓(GaP)衬底或其他材料的衬底。多个微发光二极管100设置在同一衬底 10上，形成微发光二极管100阵列。再经过分拣挑选，按照需求将微发光二极管100转移到暂态基板30上，最后将微发光二极管100转移到显示基板50上，或直接将衬底10上的微发光二极管100按照需求转移至显示基板50上，形成微发光二极管显示器。微发光二极管100的体积小，一个例如4寸的晶片上，微发光二极管100的数量例如为14×10 6个，且形成微型二极管显示器需要的微型二极管的数量也非常庞大。具体可通过巨量转移高效地将微发光二极管100转移至显示基板50上。
请参阅图21至图22所示，巨量转移具体包括静电力转移、范德华力转移、磁力转移、激光选择性转移、流体转移以及直接转印等转移方式。在本发明一实施例中，巨量转移的方式例如可包括静电力转移、范德华力转移、磁力转移等转移方式。在进行巨量转移时，需要采用转移结构40拾取微发光二极管100，并将发光二极管转移至显示基板50上，但是微发光二极管100与暂态基板30或衬底10通过胶材键合，转移结构40在拾取微发光二极管100前，需要将部分胶材蚀刻掉，只保留部分胶材以支撑微发光二极管100，但保留的胶材宽度不好控制，保留的胶材宽度过小时，微发光二极管10跌落，易造成微发光二极管100损伤，保留的胶材宽度过大时，微发光二极管10与胶材之间的粘附力较大，转移结构无法拾取所选的所有微发光二极管100，无法进行良率。
基于此，本申请希望提供一种弱化结构的制作方法、微发光二极管显示器的制作方法，在胶材中掺杂不与蚀刻气体反应的物质，蚀刻完胶材中有机物质，形成网状的第一支撑结构。形成的第一支撑结构可支撑微发光二极管，且胶材的蚀刻过程易控制，可提高巨量转移的良率。
请参阅图1所示，本发明提供的微发光二极管显示器的制作方法包括以下步骤：
S1、提供一衬底。
S2、在衬底上形成多个微发光二极管。
S3、将微发光二极管转移至暂态基板上，且微发光二极管转与暂态基板通过胶材键合。
S4、蚀刻所述胶材，形成第一支撑结构。
S5、将微发光二极管转移至显示基板上。
请参阅图1至图2所示，在本发明一实施例中，衬底10的材料包括硅、硅锗、碳化硅、蓝宝石、磷化铟、砷化镓、砷化铟或者其它III/V化合物形成的半导体结构，还包括这些半导体构成的叠层结构等，或者为绝缘体上硅，绝缘体上层叠硅、绝缘体上层叠锗化硅、绝缘体上锗化硅以及绝缘体上锗等。衬底10的材料可根据形成的微发光二极管100的种类以及衬底10上的半导体外延层11确定。在一些实施例中，微发光二极管100为发出蓝光或绿光的微发光二极管100，半导体外延层11的材料例如是氮化镓(GaN)、铟氮化镓(InGaN)，衬底10的材料例如可以为蓝宝石(Al 2O 3)、碳化硅(SiC)、氧化锌(ZnO)、氮化镓(GaN)、氮化铝(AlN)及硅(Si)。在其他实施例中，微发光二极管100为发出红光或黄光的微发光二极管100，半导体外延层11的材料例如是磷化镓(GaP)、铝砷化镓(AlGaAs)、铝镓铟磷(AlGaInP)等材料中的一种或多种，衬底10的材料例如可以为磷化镓(GaP)或砷化镓(GaAs)。
请参阅图2所示，可同时在衬底10上形成多个同一类型的微发光二极管，本发明以独立的一个微发光二极管为例，阐述微发光二极管的形成步骤。在本发明一实施例中，形成微发光二极管的步骤包括在衬底10上生长半导体外延层11，其中，半导体外延层11可以包括依次生长的第一半导体层111、发光层112和第二半导体层113，即发光层112位于第一半导体层111上，第二半导体层113 位于发光层112上。在本实施例中，第一半导体层111可以是掺有第一杂质的N型半导体层，或者是掺有第二杂质的P型半导体层，相对应的第二半导体层113可以是掺有第二杂质的P型半导体层，或者是掺有第一杂质的N型半导体层。第一杂质例如为施主杂质，第二杂质例如为受主杂质，根据所使用的半导体材料，第一杂质和第二杂质可以为不同的元素。在本实施例中，第一半导体层111和第二半导体层113可以为氮化镓，即第一半导体层111为N型氮化镓层，第二半导体层113为P型氮化镓层，且第一杂质可以为硅(Si)或碲(Te)元素，第二杂质可以为镁(Mg)或锌(Zn)元素。在其他实施例中，第一半导体层111和第二半导体层113还可以是其他合适的材料形成。
请再参阅图2，在本发明一实施例中，发光层112是本征半导体层或低掺杂半导体层，发光层112掺杂浓度较相邻的同种掺杂类型的半导体层的更低，同时发光层112可以是量子阱发光层。在本实施例中，半导体外延层11例如发出蓝光或绿光，发光层112的材料为铟氮化镓(InGaN)。在其他实施例中，发光层112可例如为发出不同光色波段的量子阱，发光层112的材料可选硒化锌(ZnSe)、铟氮化镓/氮化镓(InGaN/GaN)、铟氮化镓/氮化镓(InGaN/GaN)、磷化镓(GaP)、铝磷化镓(AlGaP)或铝砷化镓(AlGaAs)等材料中的一种或多种。
请再参阅图2至图4所示，在本发明一实施例中，形成所述半导体外延层11后，蚀刻半导体外延层11形成台面(MESA)结构。具体的，例如在所述半导体外延层11上形成凹部114，凹部114的底部与第一半导体层111接触，且与衬底10具有预设距离。在本实施例中，可在第二半导体层113上形成图案化的第一光阻层21，本步骤中的第一光阻层21覆盖第二半导体层113，且第一光阻层21上设置有第一开口201，用于定义凹部114的位置。在本实施例中，第一开口201呈圆形。在其他实施例中，第一开口201可呈矩形、多边形等其他 形状。在形成第一光阻层21后，以第一光阻层21为掩膜，干法蚀刻第二半导体层113、发光层112以及部分第一半导体层111，形成凹部114，且蚀刻气体例如为三化硼(BCl 3)或氯气(Cl 2)。在形成凹部114后，移除第一光阻层21。
请参阅图6所示，在本发明一实施例中，形成凹部114后并移除第一光阻层21后，在微发光二极管的外侧形成沟槽115，沟槽115于衬底10接触，且沟槽115环绕每个微发光二极管设置，以隔离相邻的微发光二极管。具体的，请参阅图5至图7所示，可在第二半导体层113上形成图案化的第二光阻层22，且第二光阻层22上设置有多个第二开口202，用于定义沟槽115的位置。第二开口202环绕微发光二极管100设置，且第二开口202例如呈矩形环状。在形成第二光阻层22后，以第二光阻层22为掩膜，干法蚀刻半导体外延层11至衬底10，形成沟槽115，且具体的蚀刻深度例如为4～8um。在形成沟槽115后，移除第二光阻层22。
请参阅图9所示，在本发明一实施例中，形成沟槽115并移除第二光阻层22后，在第二半导体层113上形成透明导电层116，透明导电层116位于凹部114的一侧。具体的，请参阅图8至图10所示，可在第二半导体层113上溅射一层氧化铟锡(Indium tin oxide，ITO)，且氧化铟锡的厚度例如为200～2000埃。并在氧化铟锡上形成图案化的第三光阻层23，第三光阻层23上设置有第三开口203，用于定义透明导电层116的位置。在本实施例中，第三开口203位于凸部的一侧，且呈矩形设置。在形成第三光阻层23后，以第三光阻层23为掩膜，湿法蚀刻氧化铟锡，形成透明导电层116，进而移除第三光阻层23。
请参阅12所示，在本发明一实施例中，移除第三光阻层23后，在透明导电层116上形成反射层117。反射层117覆盖在透明导电层116、第二半导体层113上，以及凹部114和沟槽115内，反射层117上设置有第一导电通道118和 第二导电通道119，第一导电通道118与第一半导体层111连通，第二导电通道119与透明导电层116连通，且反射层117例如包括氧化硅层和氮化硅层。具体的，请参阅图11至图13所示，例如在透明导电层116、第二半导体层113上，凹部114和沟槽115内蒸镀氧化硅和氮化硅的叠层，以形成反射层117，且反射层117的厚度例如为1～4um。反射层117可将发光层112发出的光反射，使微发光二极管100的光从第一半导体层111的一侧发射出。形成反射层117后，在反射层117上形成图案化的第四光阻层24。第四光阻层24上设置有第四开口204和第五开口205，第四开口204位于凹部114上方，用于定义第一导电通道118的位置，第五开口位于透明导电层116的上方，用于定义第二导电通道119的位置。在形成第四光阻层24后，以第四光阻层24为掩膜，蚀刻反射层117，在凹部114上形成与第一半导体层111连通的第一导电通道118，在透明导电层116上形成与透明导电层116连通的第二导电通道119。其中，第一导电通道118和第二导电通道119可呈任意形状，例如呈圆柱、四棱柱或其他形状的柱状设置。在本实施例中，例如可以采用干法蚀刻，且蚀刻气体例如为四氟甲烷(CF 4)、氧气(O 2)或氩气(Ar)的一种或几种。形成第一导电通道118和第二导电通道119后，可移除第四光阻层24。
请参阅图15所示，在本发明一实施例中，形成反射层117后，在第一导电通道118内形成第一电极121，在第二导电通道119内形成第二电极122。具体的，请参阅图14至图16所示，在本实施例中，先在反射层117上形成图案化的第五光阻层25，第五光阻层25上设置有第六开口206和第七开口207，第六开口206用于定义第一电极121的位置，第七开口207用于定义第二电极122的位置。在一些实施例中，在形成电极120前可不移除第四光阻层24，以第四光阻层24为掩膜，形成第一电极121和第二电极122。在本实施例中，以第五 光阻层25为掩膜，形成第一电极121和第二电极122。其中，第六开口206暴露出第一导电通道118，且第六开口206的口径大于第一导电通道118的口径，第七开口207暴露出第二导电通道119，且第七开口207的口径大于第二导电通道119的口径，以形成面积较大的电极120。在形成图案化的光阻层后，在第一导电通道118以及第六开口206内蒸镀金属，形成第一电极121。在第二导电通道119以及第七开口207于内蒸镀金属，形成第二电极122。第一电极121和第二电极122的厚度为1～4um，且第一电极121和第二电极122的材料例如为金(Au)的合金制成,第一电极121例如为N型电极120，且材料例如为Ni/Au，第二电极122例如为P型电极120，材料例如为Ni/Al/Ni/Au。
请参阅图2至图14所示，在本实施例中，图案化光阻层的形成方法为首先涂覆光刻胶，并采用碱性溶液湿法去除或采用干法的灰化工艺(ashing)去除需要开口上方的光刻胶，使涂覆的光刻胶图案化，形成图案化的光阻层。且光阻层的材料可以为正性光刻胶，也可以负性光刻胶。其中，第五光阻层25为负性光刻胶，当第五光阻层25的非曝光区的光刻胶在显影液中溶解后，形成的图案化的光阻层的侧面与反射层117所呈角度小于90度，可使第五光阻层25并不影响电极120的沉积。即第六开口206和第七开口207的侧壁与反射层117所呈角度大于90度。
请参阅图17至图19所示，在本发明一实施例中，在形成微发光二极管后，将微发光二极管100转移至暂态基板30上。具体可以先在微发光二极管100和/或暂态基板30上涂覆一层胶材层31，再通过绑定机台将微发光二极管100和暂态基板30键合，且微发光二极管100和暂态基板30通过胶材层31粘结在一起。其中，暂态基板30例如为蓝宝石基板。如图20所示，当微发光二极管100转移到暂态基板30上后，将衬底10移除。例如可以通过激光剥离(Laser Lift Off， LLO)技术将衬底10剥离。
请参阅图17至图19所示，在本实施例中，胶材层31包括第一胶材层311和第二胶材层312，第一胶材层311位于微发光二极管100上，且第一胶材层311覆盖第一电极121、第二电极122以及相邻微发光二极管100之间的间隙，第二胶材层312位于暂态基板30上。当微发光二极管100和暂态基板30通过绑定机台键合时，第一胶材层311和第二胶材层312融合形成胶材层31，且在键合时，可对胶材加热，以使第一胶材层311和第二胶材层312融合。
请参阅图17至图19所示，在本实施例中，胶材层31的材料例如为有机硅化合物，且胶材层31中的硅含量例如为20％～85％，以保证胶材层31在蚀刻后可形成网状的支架，即为弱化结构的第一支撑结构313。且胶材层31中20％～85％的硅可保证形成的第一支撑结构313具有合适的网孔密度，避免硅含量过低时，第一支撑结构313不足以支撑微发光二极管100，以及硅含量过高时，第一支撑结构313与微发光二极管100之间的粘附力过大，转移结构无法拾取微发光二极管100。胶材层31中还包括含有碳、氢、氮的基团，在蚀刻过程中可与蚀刻气体反应生成易移除的物质。
请参阅图19至图22所示，在本发明一实施例中，在将衬底10移除后，蚀刻胶材层31，蚀刻完胶材层31中的含有碳、氢、氮的基团，仅保留呈网状的第一支撑结构313。具体的，可干法蚀刻胶材层，且蚀刻的气体例如位氧气或氯气。在蚀刻时，氧气(或氯气)与胶材层31中的含有碳、氢、氧的基团反应，使胶材层31中的碳、氢、氮形成与氧的化合物。当蚀刻气体为氧气时，例如碳、氢、氧的基团生成的物质为二氧化碳、水以及二氧化氮，其中，二氧化碳和二氧化氮为气体，水为液体，可直接移除。胶材层31中的硅与氧气反应生成氧化硅，形成网状的第一支撑结构313。形成的第一支撑结构313环绕微发光二极管100， 不仅可支撑微发光二极管100，且环绕的第一支撑结构313可保证微发光二极管100不晃动。
请参阅图22与图30所示，在本发明一实施例中，在形成第一支撑结构313后，使用转移结构40将微发光二极管100转移至显示基板50上，形成微发光二极管显示器。
请参阅图28所示，在本发明另一实施例中，弱化结构还包括第二支撑结构314，第二支撑结构314设置在暂态基板30上。具体的，请参阅图23至图28所示，可在暂态基板20上沉积一层氧化硅，形成支撑层315。并在支撑层上形成图案化光阻层，光阻层上设置有开口，以定义第二支撑结构314的位置。在形成图案化光阻层厚，以图案化光阻层为掩膜，蚀刻支撑层315，形成第二支撑结构314。具体例如可采用湿法蚀刻的方法蚀刻支撑层315。
请参阅图28至图29所示，在本实施例中，暂态基板上可设置多个第二支撑结构314，每个第二支撑结构314的位置与每个微发光二极管100的位置对应，且第二支撑结构314的径向尺寸小于第一电极121至第二电极122的距离。当微发光二极管100与暂态基板30键合时，第二支撑结构314位于微发光二极管的第一电极121和第二电极122之间。
请参阅图17与图25所示，在本发明另一实施例中，在形成第二支撑结构314后，在微发光二极管上形成第一胶材层311，且第一胶材层311覆盖第一电极121、第二电极122以及相邻微发光二极管100之间的间隙。在暂态基板30上形成第二胶材层312，第二胶材层312覆盖第二支撑结构314以及相邻第二支撑结构314之间的间隙。如图26所示，当微发光二极管100和暂态基板30通过绑定机台键合时，第一胶材层311和第二胶材层312融合形成胶材层31。
请参阅图26至图27所示，在本发明另一实施例中，当微发光二极管100 转移到暂态基板30上后，例如可以通过激光剥离(Laser Lift Off，LLO)技术将衬底10剥离。在将衬底10移除后，蚀刻胶材层31，且蚀刻完胶材层31中的含有碳、氢、氮的基团，仅保留呈网状的第一支撑结构313以及第二支撑结构314。具体的，可干法蚀刻胶材层，且蚀刻的气体例如位氧气或氯气。在蚀刻时，氧气(或氯气)与胶材层31中的含有碳、氢、氧的基团反应，使胶材层31中的碳、氢、氮形成与氧的化合物。当蚀刻气体为氧气时，例如碳、氢、氧的基团生成的物质为二氧化碳、水以及二氧化氮，其中，二氧化碳和二氧化氮为气体，水为液体，可直接移除。胶材层31中的硅与氧气反应生成氧化硅，形成网状的第一支撑结构313。形成的第一支撑结构313环绕微发光二极管100，不仅可支撑微发光二极管100，且环绕的第一支撑结构313可保证微发光二极管100不晃动。第二支撑结构314位于第一电极121和第二电极122之间，且第二支撑结构314的高度大于电极的高度，且当第一胶材层311与第二胶材层312融合时，第二支撑结构314与微发光二极管100具有预设距离，保证巨量转移时，第二支撑结构314与微发光二极管100之间无粘附力。
请参阅29与图30所示所示，在本发明一实施例中，在形成第一支撑结构313和第二支撑结构314后，通过转移结构40将微发光二极管100转移至显示基板50上，形成微发光二极管显示器。
请参阅图22和图29所示所示，将微发光二极管100转移的方法有多种，根据转移过程中的作用力或具体的转移方式，可包括范德华力派，静电力派，磁力派，激光转印派，流体自组装派和卷对卷转印派。在本实施例中，使用范德华力转移微发光二极管100，转移结构40例如为弹性印章，且弹性印章的材料例如为聚二甲基硅氧烷(PDMS)。可通过弹性印章拾取微发光二极管100，并将其转移至显示基板50上，且在拾取微发光二极管100的过程中，弹性印章 保持一个较高的速度，此时弹性印章与器件之间的吸附力较大。将微发光二极管100放置到显示基板50的过程中，弹性印章保持一个较低的转移速度，此时弹性印章与器件之间的吸附力较小。且在使用弹性印章转移微发光二极管100时，可调节弹性印章的温度以确保转移的效果，例如在拾取以及转移微发光二极管100的过程中，采用一个较低的温度，以保证弹性印章与器件之间的吸附力较大，在放置微发光二极管100的过程中，采用一个较高的温度，以保证弹性印章与器件之间的吸附力较小。
请参阅图22和图29所示所示，在其他施例中，可使用静电力或磁力转移微发光二极管100，当使用静电力转移微发光二极管100时，转移结构40例如为静电转移头，在静电转移头的顶端有两个分离的电极，两个电极通过金属引出来，然后在金属电极的上面沉积绝缘材料，当给两个电极施加交流电，则由于库伦力的作用，微发光二极管100将被吸附到静电转移头上，以将微发光二极管100转移到显示基板50上。当使用磁力转移微发光二极管100时，转移结构40例如为微磁性转移头，微磁性转移头采用具有磁性的材料作为铁芯，例如硅铁合金(FeSi)，然后用金线在平面内或多层平面内制作线圈，当电流通过时，线圈中就会产生强大的磁场以拾取微发光二极管100。
请参阅30所示所示，在本发明一实施例中，微发光二极管显示器包括显示基板50以及设置在显示基板50上的多个微发光二极管100。显示基板50例如为薄膜晶体管阵列基板，例如包括基底以及设置在基底500上的电路层501，电路层501中具有多个薄膜晶体管，用于驱动微发光二极管100。在本实施例中，显示基板50上例如设置有多个红色微发光二极管100a、绿色微发光二极管100b以及蓝色微发光二极管100c，每个微发光二极管100为一个子像素，红色微发光二极管100a可形成一个红色子像素，绿色微发光二极管100b可形成一个绿 色子像素，蓝色微发光二极管100c可形成一个蓝色子像素，且依次排列的红色微发光二极管100a、绿色微发光二极管100b以及蓝色微发光二极管100电100c组成一个像素。
请参阅图30所示，在本发明一实施例中，在一个像素内，且在微发光二极管100上以及相邻的微发光二极管100之间，可通过曝光和显影工艺形成平坦化层503。在平坦化层503上还可以设置保护层504，保护层504设置在相邻像素之间以及像素上方。在保护层504上还可以设置保护基板505，保护基板505与保护层504键合形成密闭空腔，以保护内部的微发光二极管100。
综上所示，本发明提供的一种弱化结构的制作方法、微发光二极管显示器的制作方法，在衬底上形成微发光二极管，通过胶材层将微发光二极管键合在暂态基板上，并蚀刻胶材层，形成网状的第一支撑结构支撑微发光二极管，且保证微发光二极管不晃动。再通过转移结构将微发光二极管转移至显示基板上，形成微发光二极管显示器。本发明提供的弱化结构的制作方法、微发光二极管显示器的制作方法，通过将胶层蚀刻成网状的第一支撑结构，制成过程简单易操作，可提高巨量转移的良率。
应当理解的是，本发明的应用不限于上述的举例，对本领域普通技术人员来说，可以根据上述说明加以改进或变换，所有这些改进和变换都应属于本发明所附权利要求的保护范围。

Claims (16)

  1. 一种弱化结构的制作方法，其中，所述弱化结构包括第一支撑结构，且所述第一支撑结构的制作方法包括以下步骤：
    在微发光二极管和/或暂态基板上形成胶材层；
    将所述微发光二极管转移至暂态基板上，且所述微发光二极管转与所述暂态基板通过所述胶材层键合；以及
    蚀刻所述胶材层，形成第一支撑结构，所述第一支撑结构呈网状，且环绕所述微发光二极管。
  2. 如权利要求1所述的弱化结构的制作方法，其中，所述胶材层的材料为有机硅化物。
  3. 如权利要求1所述的弱化结构的制作方法，其中，所述胶材层中的硅含量为20％～85％。
  4. 如权利要求3所述的弱化结构的制作方法，其中，所述胶材层的材料包括含有碳、氢、氮的基团。
  5. 如权利要求1所述的弱化结构的制作方法，其中，形成所述第一支撑结构的步骤包括：干法蚀刻所述胶材层，且蚀刻气体为氧气或氯气。
  6. 如权利要求1所述的弱化结构的制作方法，其中，所述第一支撑结构的材料为氧化硅。
  7. 如权利要求1所述的弱化结构的制作方法，其中，所述弱化结构还包括第二支撑结构，且当所述微发光二极管与所述暂态基板键合时，所述第二支撑结构位于所述微发光二极管的两个电极之间。
  8. 如权利要求7所述的弱化结构的制作方法，其中，形成所述第二支撑结构的步骤包括：
    在所述暂态基板上形成氧化层；以及
    蚀刻所述氧化层，形成所述第二支撑结构；
    其中，所述第二支撑结构的径向尺寸小于所述微发光二极管两个电极之间的距离。
  9. 如权利要求7所述的弱化结构的制作方法，其中，所述第二支撑结构的材料为氧化硅。
  10. 如权利要求7所述的弱化结构的制作方法，其中，当所述微发光二极管与所述暂态基板键合时，所述第二支撑结构与所述微发光二极管具有预设距离。
  11. 一种微发光二极管显示器的制作方法，包括以下步骤：
    提供一衬底；
    在所述衬底上形成多个微发光二极管；
    将所述微发光二极管转移至暂态基板上，且所述微发光二极管转与所述暂态基板通过胶材层键合；
    蚀刻所述胶材层，形成第一支撑结构，所述第一支撑结构呈网状，且环绕所述微发光二极管；以及
    将所述微发光二极管转移至显示基板上。
  12. 如权利要求11所述的微发光二极管显示器的制作方法，其中，所述转移结构为弹性印章，且弹性印章的材料为聚二甲基硅氧烷。
  13. 如权利要求11所述的微发光二极管显示器的制作方法，其中，形成所述微发光二极管的步骤包括：
    在所述衬底上形成第一半导体层；
    在所述第一半导体层上形成发光层；
    在所述发光层上形成第二半导体层；
    在所述第二半导体层上形成透明导电层；
    在所述第一半导体层上沉积第一电极；以及
    在所述第二半导体层上沉积第二电极。
  14. 如权利要求13所述的微发光二极管显示器的制作方法，其中，形成所述微发光二极管的步骤还包括：在所述第二半导体层上和透明导电层上沉积反射层。
  15. 如权利要求14所述的微发光二极管显示器的制作方法，其中，形成所述微发光二极管的步骤还包括：在所述反射层上形成第一导电通道和第二导电通道，且所述第一导电通道与所述第一半导体层接触，所述第二导电通道与所述透明导电层接触。
  16. 如权利要求15所述的微发光二极管显示器的制作方法，其中，形成所述第一导电通道和第二导电通道的步骤包括：
    在所述反射层上沉积光阻层；
    在所述光阻层上形成开口；以及
    以所述光阻层为掩膜蚀刻所述反射层，
    其中，所述开口的侧壁与所述反射层的之间的角度大于90度。
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