CN113921556A - Micro LED device and manufacturing method thereof - Google Patents

Micro LED device and manufacturing method thereof Download PDF

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CN113921556A
CN113921556A CN202111182861.2A CN202111182861A CN113921556A CN 113921556 A CN113921556 A CN 113921556A CN 202111182861 A CN202111182861 A CN 202111182861A CN 113921556 A CN113921556 A CN 113921556A
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anode
type semiconductor
epitaxial
micro led
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王仕伟
任清江
张金金
王赛文
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Semiconductor Integrated Display Technology Co Ltd
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Semiconductor Integrated Display Technology Co Ltd
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    • 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
    • H01L33/02—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 bodies
    • H01L33/04—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 bodies with a quantum effect structure or superlattice, e.g. tunnel junction
    • H01L33/06—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 bodies with a quantum effect structure or superlattice, e.g. tunnel junction within the light emitting region, e.g. quantum confinement structure or tunnel barrier
    • H—ELECTRICITY
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    • 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
    • H01L27/153—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 in a repetitive configuration, e.g. LED bars
    • H01L27/156—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 in a repetitive configuration, e.g. LED bars two-dimensional arrays
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
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    • 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
    • H01L33/02—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 bodies
    • H01L33/10—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 bodies with a light reflecting structure, e.g. semiconductor Bragg reflector
    • 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
    • H01L33/02—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 bodies
    • H01L33/20—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 bodies with a particular shape, e.g. curved or truncated substrate
    • 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
    • H01L33/36—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 electrodes
    • H01L33/38—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 electrodes with a particular shape
    • 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
    • H01L33/44—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 coatings, e.g. passivation layer or anti-reflective coating
    • H01L33/46—Reflective coating, e.g. dielectric Bragg reflector
    • H—ELECTRICITY
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    • 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
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Abstract

The invention provides a micro LED device applied to the technical field of display, and also relates to a manufacturing method of the micro LED device, wherein the micro LED device comprises a wafer (8), the wafer (8) comprises a CMOS driving circuit and a through hole (9), a first anode layer (10) is arranged on the surface of the wafer (8), a light-emitting unit (11) is arranged on the upper surface of the first anode layer (10), the light-emitting unit (11) is formed by LED light-emitting units, the light-emitting unit (11) is sequentially provided with a substrate (1), an N-type semiconductor layer (201), an MQW layer (202) and a P-type semiconductor layer (203) from bottom to top, the N-type semiconductor layer (201), the MQW layer (202) and the P-type semiconductor layer (203) are arranged to form a structure with a narrow top layer and a wide bottom layer, and the micro LED device (micro LED) is provided by the invention and the manufacturing method thereof, the external quantum efficiency of the micro LED display device can be effectively improved, the high pixel density is met, the pixels are improved, and therefore the product performance is comprehensively improved.

Description

Micro LED device and manufacturing method thereof
Technical Field
The invention belongs to the technical field of display, and particularly relates to a micro LED device and a manufacturing method thereof.
Background
Micro Light emitting diodes (Micro LEDs) are a new generation of display technology, have self-luminous display characteristics, and compared with Organic Light-emitting diode (OLED) technology in the prior art, the Micro LED display device has the advantages of higher brightness, better Light-emitting efficiency and lower power consumption. The display principle of the Micro LED display device is that the LED structure is designed to be thinned, miniaturized and arrayed, and the size of the Micro LED display device is only about 1-10 um grade; the display is then formed by methods such as monolithic integration or bulk transfer. However, since the refractive index of GaN, which is a material forming the LED device, is high, it is difficult to emit photons generated in the quantum well into the air, and thus the external quantum efficiency of the LED device is low, so the technical problem of how to improve the external quantum efficiency of the micro LED display device becomes a technical problem to be solved in the art: meanwhile, with the development of technologies for micro-display, AR, VR, etc., smaller-sized pixels of display devices are required to increase pixel density. However, the flip-chip LED device structure P, N electrodes are on the same side of the quantum well and occupy a larger area. Therefore, it is difficult to satisfy the requirement of high pixel density.
Because the upper side and the lower side of the vertical LED device structure chip need to be provided with a P electrode and an N electrode which respectively provide driving current for a P-type semiconductor and an N-type semiconductor, and the conductivity of DBR mirror layer materials adopted for improving the external quantum efficiency in the forward-mounted and inverted LED structures is poor, the external quantum efficiency cannot be improved by directly adopting the DBR mirror layer structure on one side of the chip; in addition, the technical solution proposed in chinese patent CN 101937967B: providing a reflecting substrate, and a light-emitting diode core positioned on the reflecting substrate, wherein one side of the reflecting substrate facing the light-emitting diode core is provided with more than one truncated cone-shaped reflecting pit, light emitted by the light-emitting diode can be reflected on the side wall of the truncated cone-shaped reflecting pit, and the reflected light can reach the light-emitting surface of the light-emitting diode, so that the light-emitting rate of the light-emitting diode is improved; in chinese patent CN 110462833B, a passive collimating optical device is added to collimate light in different directions. However, in the above structure: because the gap exists between the light emitting diode and the pit, the occupied area of the active area of the light emitting diode in the unit area in the pit is lower, and when the pixel size is smaller (such as 0.5um), the area of the active area of the light emitting diode is smaller, and the occupied area of the light emitting diode cannot be fully utilized in a limited space to improve the display brightness.
Disclosure of Invention
The technical problem to be solved by the invention is as follows: the micro LED display device is simple in structure, can effectively improve the external quantum efficiency of the micro LED display device, meets high pixel density, improves pixels and accordingly comprehensively improves product performance.
To solve the technical problems, the invention adopts the technical scheme that:
the invention relates to a micro LED device, which comprises a CMOS wafer substrate 8, wherein the CMOS wafer substrate 8 comprises a CMOS driving circuit and a through hole 9, a second anode layer 10 is arranged on the surface of the CMOS wafer substrate 8, a light-emitting unit is arranged on the upper surface of the second anode layer 10, the light-emitting unit is an LED epitaxial functional layer 2, the epitaxial functional layer 2 is sequentially provided with a P-type semiconductor layer 203, an MQW layer 202 and an N-type semiconductor layer 201 from bottom to top, and the N-type semiconductor layer 201, the MQW layer 202 and the P-type semiconductor layer 203 are set to be capable of forming a structure with a narrow top layer and a wide bottom layer.
The shape of the N-type semiconductor layer 201, the MQW layer 202 and the P-type semiconductor layer 203 is a paraboloid structure or an inverted trapezoid structure, when the epitaxial functional layer 2 forms the paraboloid structure, the MQW layer 202 of the composite light emitting region is located on the plane where the focus of the paraboloid is located, and the insulating passivation layer 5 and the reflecting layer 6 are sequentially formed on the outer side of the light emitting unit.
The second anode layer 10 is a structure formed by depositing metal Au on the surface of the CMOS wafer substrate 8, a second anode 1001 is formed at the position of the second anode layer 10, and the second anode 1001 is a structure formed at the position of the through hole 9 on the second anode layer 10 through a photoetching process.
The upper surface of the epitaxial functional layer 2 is also provided with a first anode layer 4, and the first anode layer 4 is arranged on the upper surface of the epitaxial functional layer 2 and is a structure formed by depositing metal Cr/Al/Cr/Pt/Au.
When the first anode layer 4 forms the first anode 401, the first anode 401 is configured to make the first anode layer 4 and the epitaxial functional layer 2 form an inverted trapezoid structure or a parabolic structure together through a photolithography and etching process, wherein the first anode 401 is formed after the first anode layer 4 is isolated.
The invention also relates to a manufacturing method of the micro LED device, which comprises the following manufacturing steps:
s1, providing a CMOS wafer substrate 8 comprising a CMOS driving circuit, wherein the CMOS wafer substrate 8 comprises a through hole 9;
s2, after the surface of the CMOS wafer substrate 8 is cleaned, depositing metal Au to form a second anode layer 10; forming a second anode 1001 at the position of the through hole 9 by a photolithography process;
s3, providing an LED epitaxial wafer, wherein the LED epitaxial wafer sequentially comprises a substrate 1, an N-type semiconductor layer 201, an MQW layer 202 and a P-type semiconductor layer 203 from bottom to top;
s4, when the epitaxial functional layer 2 is of an inverted trapezoidal structure, after the surface of the epitaxial functional layer 2 is cleaned, depositing metal SiO on the surface2/TiO2Forming a DBR reflector layer 3, forming reflectors 301 through photoetching, etching and other processes, and depositing a first anode 401 in a groove between the reflectors 301; and then the reflector 301 and the epitaxial functional layer 2 form a trapezoidal structure by adopting a photoetching and etching process.
S5, when the epitaxial functional layer 2 is set to be a paraboloid structure, after the surface of the epitaxial functional layer 2 is cleaned, depositing metal Cr/Al/Cr/Pt/Au on the surface to form a first anode layer 4; the first anode layer 4 and the epitaxial functional layer 2 together form a parabolic structure by adopting a photoetching and etching process, wherein the first anode layer 4 forms a first anode 401 after being isolated.
After the first anode layer 401 is formed, depositing SiO2 on the surface of the light-emitting unit by CVD, photoetching and etching processes to form an insulating passivation layer 5, wherein the insulating passivation layer 5 is positioned on the side surfaces of the epitaxial functional layer 2 and the first anode 401 or the side surfaces of the epitaxial functional layer 2 and the reflector 301; and depositing a reflecting layer 6 on the surface of the epitaxial functional layer 2 by adopting optical coating, photoetching and etching processes, wherein the reflecting layer 6 is positioned on the outer side of the insulating passivation layer 5.
After the reflecting layers 6 are formed, filling and flattening the light resistance between the reflecting layers 6 by adopting a spin coating process, and then curing; and then the first anode on the CMOS wafer substrate 8 is butted and aligned with the second anode on the epitaxial functional layer 2.
Applying pressure at 300 ℃ to enable the electrode of the first anode and the electrode of the second anode to generate bonding reaction; stripping and removing the substrate 1 by adopting a process of acting laser on the N-type semiconductor layer 201, a CMP process or a chemical etching process; and forming transparent conductive common cathode ITO11 on the surfaces of the N-type semiconductor layer 201 and the planarized photoresist of all the epitaxial functional layers 2 by adopting a sputtering process.
By adopting the technical scheme of the invention, the following beneficial effects can be obtained:
according to the micro LED device and the manufacturing method thereof, the external quantum efficiency is improved by adopting the epitaxial layer bottom layer structure which is formed by the inverted trapezoid of the epitaxial structure and the reflecting anode + mirror layer structure; the P-type semiconductor, the MQW and the N-type semiconductor in the LED structure are utilized to form a shape with a narrow top layer and a wide bottom layer, and a reflector layer is arranged on the outer side of the LED structure to improve the external quantum efficiency of the device; thus, the proposed external quantum efficiency for MQW-generated photons is further improved by the first anode structure with ITO + Al layer, which together with the epitaxial layer constitutes the finished parabolic structure. The micro LED device and the manufacturing method thereof have simple structure, can effectively improve the external quantum efficiency of the micro LED display device, meet high pixel density and improve pixels, thereby comprehensively improving the product performance.
Drawings
The contents of the description and the references in the drawings are briefly described as follows:
FIG. 1 is a cross-sectional view of an epitaxial wafer with a deposited mirror layer;
FIG. 2 is a schematic cross-sectional view of an epitaxial wafer after patterning a mirror layer;
FIG. 3 is a schematic cross-sectional view of an epitaxial wafer after forming a first anode;
FIG. 4 is a schematic cross-sectional view of an epitaxial wafer after deposition of a passivation layer;
FIG. 5 is a schematic cross-sectional view of an epitaxial wafer after deposition of a reflective layer;
FIG. 6 is a schematic cross-sectional view of an epitaxial wafer after being filled with a fill layer;
FIG. 7 is a chart of prescription A of FIG. 5;
FIG. 8 is an enlarged view of FIG. 6 at B;
FIG. 9 is a cross-sectional view of a wafer including CMOS driver circuits;
FIG. 10 is a cross-sectional view of a driver circuit wafer after deposition of a first anode layer;
FIG. 11 is a cross-sectional view of the driving circuit wafer after the first anode is patterned and filled with the filling layer;
FIG. 12 is a cross-sectional view of an epitaxial wafer bonded to a driver circuit wafer;
FIG. 13 is a cross-sectional view after the substrate has been stripped;
FIG. 14 is a schematic cross-sectional view after deposition of a common cathode;
FIG. 15 is a cross-sectional view of a detailed structure of an epitaxial wafer;
FIG. 16 is a cross-sectional view of an epitaxial wafer after deposition of a first anode layer;
FIG. 17 is a cross-sectional view of an epitaxial wafer with a paraboloid formed;
FIG. 18 is an epitaxial wafer after deposition of a passivation layer and a reflective layer, respectively;
FIG. 19 is a cross-sectional view of the fill layer after filling;
FIG. 20 is a cross-sectional view of an epitaxial wafer bonded to a driver circuit wafer;
FIG. 21 is a schematic cross-sectional view of the substrate after it has been stripped;
FIG. 22 is a schematic cross-sectional view of a co-cathode deposition;
FIG. 23 is a rear cross-sectional view of the prescription C of FIG. 22;
in the drawings, the reference numbers are respectively: 1. an epitaxial substrate (substrate); 2. an epitaxial functional layer; 201. an N-type semiconductor layer; 202. a MQW layer; 203. a P-type semiconductor layer; 3. a mirror layer; 301. a mirror; 4. a first anode layer; 401. a first anode; 5. a passivation layer; 6. a reflective layer; (ii) a 601. An insulating passivation layer; 7. a filling layer; 701. a DBR mirror layer; 8. a CMOS wafer substrate (wafer); 9. a through hole; 10. a second electrode layer; 1001. a second electrode; 11. and (4) a common cathode.
Detailed Description
The following detailed description of the embodiments of the present invention, such as the shapes and structures of the components, the mutual positions and connection relations among the components, the functions and operation principles of the components, will be made by referring to the accompanying drawings and the description of the embodiments:
as shown in fig. 1 to 23, the micro LED device of the present invention includes a CMOS wafer substrate 8, the CMOS wafer substrate 8 includes a CMOS driving circuit and a through hole 9, a second anode layer 10 is disposed on a surface of the CMOS wafer substrate 8, a light emitting unit is disposed on an upper surface of the second anode layer 10, the light emitting unit is an LED epitaxial functional layer 2, the epitaxial functional layer 2 is a P-type semiconductor layer 203, an MQW layer 202, and an N-type semiconductor layer 201 sequentially from bottom to top, and the N-type semiconductor layer 201, the MQW layer 202, and the P-type semiconductor layer 203 are configured to form a structure with a narrow top layer and a wide bottom layer. In the prior art, the external quantum efficiency of a micro LED display device cannot be improved by adopting a DBR mirror layer structure of a traditional forward-mounted or inverted light-emitting diode; the mode of improving the external quantum efficiency by utilizing the conical reflection pits sacrifices the effective light-emitting area of part of light-emitting diodes, so that the technical problem that the brightness cannot be effectively improved when the pixels of the micro LED display device are small is solved. To the technical problem among the prior art, propose brand-new technical scheme to solve the problem among the prior art, promote product property ability: the invention adopts the inverted trapezoid epitaxial structure and the epitaxial layer bottom structure consisting of the reflecting anode and the mirror layer structure to improve the external quantum efficiency; the P-type semiconductor, the MQW and the N-type semiconductor in the LED structure are utilized to form a shape with a narrow top layer and a wide bottom layer, and a reflector layer is arranged on the outer side of the LED structure to improve the external quantum efficiency of the device; thus, the proposed external quantum efficiency for MQW-generated photons is further improved by the first anode structure with ITO + Al layer, which together with the epitaxial layer constitutes the finished parabolic structure. The micro LED device disclosed by the invention is simple in structure, can effectively improve the external quantum efficiency of the micro LED display device, meets the requirement of high pixel density, improves the pixels, and thus comprehensively improves the product performance.
The shape of the N-type semiconductor layer 201, the MQW layer 202 and the P-type semiconductor layer 203 is a paraboloid structure or an inverted trapezoid structure, when the epitaxial functional layer 2 forms the paraboloid structure, the MQW layer 202 of the composite light emitting region is located on the plane where the focus of the paraboloid is located, and the insulating passivation layer 5 and the reflecting layer 6 are sequentially formed on the outer side of the light emitting unit.
The second anode layer 10 is a structure formed by depositing metal Au on the surface of the CMOS wafer substrate 8, a second anode 1001 is formed at the position of the second anode layer 10, and the second anode 1001 is a structure formed at the position of the through hole 9 on the second anode layer 10 through a photoetching process.
The upper surface of the epitaxial functional layer 2 is also provided with a first anode layer 4, and the first anode layer 4 is arranged on the upper surface of the epitaxial functional layer 2 and is a structure formed by depositing metal Cr/Al/Cr/Pt/Au.
When the first anode layer 4 forms the first anode 401, the first anode 401 is configured to make the first anode layer 4 and the epitaxial functional layer 2 form an inverted trapezoid structure or a parabolic structure together through a photolithography and etching process, wherein the first anode 401 is formed after the first anode layer 4 is isolated.
The invention also relates to a manufacturing method of the micro LED device, which comprises the following manufacturing steps:
s1, providing a CMOS wafer substrate 8 comprising a CMOS driving circuit, wherein the CMOS wafer substrate 8 comprises a through hole 9;
s2, after the surface of the CMOS wafer substrate 8 is cleaned, depositing metal Au to form a second anode layer 10; forming a second anode 1001 at the position of the through hole 9 by a photolithography process;
s3, providing an LED epitaxial wafer, wherein the LED epitaxial wafer sequentially comprises a substrate 1, an N-type semiconductor layer 201, an MQW layer 202 and a P-type semiconductor layer 203 from bottom to top;
s4, when the epitaxial functional layer 2 is of an inverted trapezoidal structure, after the surface of the epitaxial functional layer 2 is cleaned, depositing metal SiO on the surface2/TiO2Forming a DBR reflector layer 3, forming reflectors 301 through photoetching, etching and other processes, and depositing a first anode 401 in a groove between the reflectors 301; and then the reflector 301 and the epitaxial functional layer 2 form a trapezoidal structure by adopting a photoetching and etching process.
S5, when the epitaxial functional layer 2 is set to be a paraboloid structure, after the surface of the epitaxial functional layer 2 is cleaned, depositing metal Cr/Al/Cr/Pt/Au on the surface to form a first anode layer 4; the first anode layer 4 and the epitaxial functional layer 2 together form a parabolic structure by adopting a photoetching and etching process, wherein the first anode layer 4 forms a first anode 401 after being isolated.
After the first anode layer 401 is formed, depositing SiO2 on the surface of the light-emitting unit by CVD, photoetching and etching processes to form an insulating passivation layer 5, wherein the insulating passivation layer 5 is positioned on the side surfaces of the epitaxial functional layer 2 and the first anode 401 or the side surfaces of the epitaxial functional layer 2 and the reflector 301; and depositing a reflecting layer 6 on the surface of the epitaxial functional layer 2 by adopting optical coating, photoetching and etching processes, wherein the reflecting layer 6 is positioned on the outer side of the insulating passivation layer 5.
After the reflecting layers 6 are formed, filling and flattening the light resistance between the reflecting layers 6 by adopting a spin coating process, and then curing; and then the first anode on the CMOS wafer substrate 8 is butted and aligned with the second anode on the epitaxial functional layer 2.
Applying pressure at 300 ℃ to enable the electrode of the first anode and the electrode of the second anode to generate bonding reaction; stripping and removing the substrate 1 by adopting a process of acting laser on the N-type semiconductor layer 201, a CMP process or a chemical etching process; and forming transparent conductive common cathode ITO11 on the surfaces of the N-type semiconductor layer 201 and the planarized photoresist of all the epitaxial functional layers 2 by adopting a sputtering process.
The micro LED device disclosed by the invention is prepared in the following steps:
as shown in fig. 22, a high-brightness micro LED micro-display light emitting device. The LED wafer comprises a wafer 8 comprising a CMOS drive connection electrode, a pixel anode on the surface of the wafer, and a light-emitting unit positioned on the upper surface of the pixel anode, wherein the light-emitting unit is an LED, and sequentially comprises a substrate 1, an N-type semiconductor layer 201, an MQW layer 202 and a P-type semiconductor layer 203 from bottom to top, and the N-type semiconductor layer 201, the MQW layer 202 and the P-type semiconductor layer 203 are arranged to form a structure with a narrow top layer and a wide bottom layer, in particular to an inverted trapezoid structure or a paraboloid structure. If the periphery of the light-emitting unit forms a paraboloid structure, the MQW layer of the composite light-emitting area is positioned on the plane where the focus of the paraboloid is positioned, and an insulating passivation layer and a reflector layer are sequentially formed on the outer side of the light-emitting unit.
Further, the first anode layer is composed of the following materials: one or more of metals such as ITO, Cr, Al, Ni, Pt, Au, Cu, etc., or a multilayer structure composed of various materials; furthermore, the first anode layer is ITO/Cr/Al/Cr/Pt/Au; ITO/Cr/Pt/Au; ITO/Al; further, the insulating passivation layer is made of transparent and non-conductive material, such as SiO, SiN or their combination; further, the DBR mirror layer (mirror layer) is formed of a metal having high reflectivity, such as Al, Ag, or DBR, ODR, and DBR/ODR; further, if the material of the reflector layer is a nature material, depositing an insulating passivation layer between the reflector layer and the pixel anode; furthermore, an insulating passivation layer is filled between the two light emitting units, the height of the insulating passivation layer is flush with that of the light emitting units, then transparent conductive common cathodes are formed on the surfaces of the N-type semiconductor layers of all the light emitting units and the surface of the insulating passivation layer, and cathode connecting electrodes are formed in the areas among the light emitting units.
A manufacturing method of a high-brightness micro LED device comprises the following steps:
s1, providing a wafer 8 including CMOS driving circuits, which includes through holes 9;
s2, after the surface of the wafer 8 is cleaned, depositing 600nm metal Au to form a first anode layer;
s3, forming a first anode at the position of the through hole 9 through a photoetching process;
s4, providing a light emitting unit (LED epitaxial wafer), wherein the LED epitaxial wafer sequentially comprises a substrate, an N-type semiconductor layer, an MQW layer and a P-type semiconductor layer from bottom to top;
s5, after the surface of the LED epitaxial wafer is cleaned, depositing metal Cr/Al/Cr/Pt/Au on the surface, wherein the thickness is respectively 5nm/100nm/5nm/20nm/500nm, and forming a second anode layer;
s6, adopting photoetching and etching process to make the second anode layer and the epitaxial layer form a paraboloid structure together, wherein the second anode layer forms a second anode after being isolated;
s7, depositing SiO with thickness of 300nm on the surface of the epitaxial wafer after the step S6 by adopting the processes of CVD, photoetching, etching and the like2An insulating passivation layer 601, which is located on the epitaxial layer and the second anode side;
s8, depositing a 900nm DBR mirror layer 701 on the surface of the epitaxial wafer after the step S7 by adopting optical coating, photoetching and etching processes, wherein the DBR mirror layer is positioned on the outer side of the insulating passivation layer 601;
s9, filling and flattening the DBR mirror layers 701 by using a photoresist through a spin coating process, and then curing;
s10, butting and aligning the first anode on the silicon wafer 8 and the second anode on the LED epitaxial wafer;
s11, applying 250KN pressure at 300 ℃ to enable the first anode electrode and the second anode electrode to generate bonding reaction;
s12, stripping and removing the substrate 1 by adopting a method of acting laser on the N-type semiconductor or a CMP process or a chemical etching method;
and S13, forming 1000nm transparent conductive common cathode ITO on the surfaces of the N-type semiconductor layers of all the light-emitting units and the surface of the planarized photoresist by adopting a sputtering process.
The micro LED device disclosed by the invention, in the embodiment 2:
as shown in fig. 22, a high-brightness micro LED micro-display light emitting device. The LED wafer comprises a wafer 8 comprising a CMOS drive connection electrode, a pixel anode on the surface of the wafer, and a light-emitting unit positioned on the upper surface of the pixel anode, wherein the light-emitting unit is an LED, and sequentially comprises a substrate 1, an N-type semiconductor layer 201, an MQW layer 202 and a P-type semiconductor layer 203 from bottom to top, and the N-type semiconductor layer 201, the MQW layer 202 and the P-type semiconductor layer 203 are arranged to form a structure with a narrow top layer and a wide bottom layer, in particular to an inverted trapezoid structure or a paraboloid structure. If the periphery of the LED light-emitting unit forms a paraboloid structure, the MQW layer of the composite light-emitting area is positioned on the plane where the focus of the paraboloid is positioned, and an insulating passivation layer and a reflector layer are sequentially formed on the outer side of the light-emitting unit.
Furthermore, the anode structure is a multilayer structure which is composed of one or more of the following materials such as ITO, Cr, Al, Ni, Pt, Au, Cu and the like, and can also be composed of various materials; furthermore, the first anode layer is ITO/Cr/Al/Cr/Pt/Au; ITO/Cr/Pt/Au; ITO/Al; ITO/Al/Au and other structures; further, the insulating passivation layer is made of transparent and non-conductive material, such as SiO, SiN or a combination thereof; further, the mirror layer is formed of a metal having high reflectivity, such as Al, Ag or DBR, ODR and DBR/ODR; further, if the material of the reflector layer is a nature material, depositing an insulating passivation layer between the reflector layer and the pixel anode; furthermore, an insulating passivation layer is filled between the two light emitting units, the height of the insulating passivation layer is flush with that of the light emitting units, then transparent conductive common cathodes are formed on the surfaces of the N-type semiconductor layers of all the light emitting units in the AA area and the surface of the insulating passivation layer, and cathode connecting electrodes are formed in the area between the light emitting units.
A manufacturing method of a high-brightness micro LED device comprises the following steps:
s1, providing a silicon wafer 8 containing CMOS driving circuit, which contains through holes 9;
s2, cleaning the surface of the silicon wafer 8, and depositing 600nm metal Au to form a first anode layer;
s3, forming a first anode at the position of the through hole 9 through a photoetching process;
s4, providing an LED epitaxial wafer, wherein the LED epitaxial wafer sequentially comprises a substrate 1, an N-type semiconductor layer, an MQW layer and a P-type semiconductor layer from bottom to top;
s5, cleaning the surface of the LED epitaxial wafer, and depositing metal ITO with the thickness of 300nm on the surface;
s6, forming a paraboloid structure by the ITO and the epitaxial layer together by adopting a photoetching and etching process;
s7, depositing a 1000nmAl layer on the surface of the ITO layer;
s8, thinning the Al layer by 300nm by adopting a CMP process to form a first anode (adopting a first anode structure of the ITO + Al layer, on one hand, the first anode structure and the epitaxial layer jointly form a finished paraboloid structure to further improve the external quantum efficiency of photon generation of the MQW, and on the other hand, the side, far away from the epitaxial layer, of the Al layer is bonded with the silicon wafer in more follow-up mode after the CMP process);
s9, depositing SiO with thickness of 300nm on the surface of the epitaxial wafer after the step S6 by adopting the processes of CVD, photoetching, etching and the like2An insulating passivation layer 601, which is located on the epitaxial layer and the second anode side;
s10, depositing a 900nm DBR mirror layer 701 on the surface of the epitaxial wafer after the step S7 by adopting optical coating, photoetching and etching processes, wherein the DBR mirror layer is positioned on the outer side of the insulating passivation layer 601;
s11, filling and flattening the DBR mirror layers 701 by using a photoresist through a spin coating process, and then curing;
s12, butting and aligning the first anode on the silicon wafer 8 and the second anode on the LED epitaxial wafer;
s13, applying 250KN pressure at 300 ℃ to enable the first anode electrode and the second anode electrode to generate bonding reaction;
s14, stripping and removing the substrate 1 by adopting a method of acting laser on the N-type semiconductor or a CMP process or a chemical etching method;
s15, forming 1000nm transparent conductive common cathode ITO on the N-type semiconductor layer surfaces of all the light-emitting units in the AA area and the surface of the planarized photoresist by adopting a sputtering process.
The micro LED device disclosed by the invention, in the embodiment 3:
as shown in fig. 22, a high-brightness micro LED micro-display light emitting device. The LED light-emitting device comprises a wafer 8 comprising a CMOS drive connection electrode, a pixel anode on the surface of the wafer, DBR mirror layers on two sides of the anode, and a light-emitting unit located on the upper surface of the pixel anode, wherein the light-emitting unit is an LED, the specific structure of the light-emitting unit LED is sequentially a substrate 1, an N-type semiconductor layer 201, an MQW layer 202 and a P-type semiconductor layer 203 from bottom to top, and the N-type semiconductor layer 201, the MQW layer 202 and the P-type semiconductor layer 203 are set to be of a structure which can form a top layer with a narrow width and a bottom layer with a wide width, particularly an inverted trapezoidal structure or a paraboloid structure. Further, the first anode layer is composed of the following materials: one or more of ITO, Cr, Al, Ni, Pt, Au and Cu metals, and a multilayer structure consisting of various materials; furthermore, the first anode layer is ITO/Cr/Al/Cr/Pt/Au; ITO/Cr/Pt/Au; ITO/Al; ITO/Al/Au and other structures; further, the insulating passivation layer is made of transparent and non-conductive material, such as SiO, SiN or a combination thereof; further, the mirror layer is formed of a metal having high reflectivity, such as Al, Ag or DBR, ODR and DBR/ODR; further, if the material of the reflector layer is a nature material, depositing an insulating passivation layer between the reflector layer and the pixel anode;
furthermore, an insulating passivation layer is filled between the two light emitting units, the height of the insulating passivation layer is flush with that of the light emitting units, then transparent conductive common cathodes are formed on the surfaces of the N-type semiconductor layers of all the light emitting units and the surface of the insulating passivation layer, and cathode connecting electrodes are formed in the areas among the light emitting units.
A manufacturing method of a high-brightness micro LED device comprises the following steps:
s1, a silicon wafer 8 including CMOS driving circuits is provided, which includes vias 9.
S2, cleaning the surface of the silicon wafer 8, and depositing 700nm metal Cu to form a first anode layer;
s3, forming a first anode at the position of the through hole 9 through a photoetching process;
s4, providing an LED epitaxial wafer, wherein the LED epitaxial wafer sequentially comprises a substrate 1, an N-type semiconductor layer, an MQW layer and a P-type semiconductor layer from bottom to top;
s5, cleaning the surface of the LED epitaxial wafer, and depositing a 1100nm metal DBR mirror layer on the surface;
s6, etching holes at the through holes of the LED epitaxial wafer corresponding to the silicon wafer by photoetching and etching methods;
s7, depositing Cr/Al/Cr/Pt/Au at the position of the opening hole in sequence, wherein the thicknesses are respectively 5nm/100nm/5nm/20nm/500nm, and forming a second anode layer;
s8, etching the middle position of DBR at two sides of the second anode layer into V-shaped isolation channel by adopting photoetching and etching process;
s9, depositing SiO with thickness of 450nm on the surface of the isolation channel after the step S6 by adopting the processes of CVD, photoetching, etching and the like2An insulating passivation layer 601;
s10, depositing a 280nm Al layer on the surface of the insulating passivation layer 601 to be used as a reflector layer;
s11, adopting a spin coating process to fill and flatten the isolation channels between the mirror layers 701 by using a light resistance and then curing the isolation channels;
s12, butting and aligning the first anode on the silicon wafer 8 and the second anode on the LED epitaxial wafer;
s13, applying 230KN pressure at the high temperature of 350 ℃ to enable the first anode electrode and the second anode electrode to generate bonding reaction;
s14, stripping and removing the substrate 1 by adopting a method of acting laser on the N-type semiconductor or a CMP process or a chemical etching method;
s15, forming 1000nm transparent conductive common cathode ITO on the N-type semiconductor layer surfaces of all the light-emitting units in the AA area and the surface of the planarized photoresist by adopting a sputtering process.
According to the micro LED device (micro LED micro display light-emitting device) and the manufacturing method thereof, the external quantum efficiency is improved by adopting the inverted trapezoid epitaxial structure and the epitaxial layer bottom structure formed by the reflecting anode and the mirror layer structure; the P-type semiconductor, the MQW and the N-type semiconductor in the LED structure are utilized to form a shape with a narrow top layer and a wide bottom layer, and a reflector layer is arranged on the outer side of the LED structure to improve the external quantum efficiency of the device; thus, the proposed external quantum efficiency for MQW-generated photons is further improved by the first anode structure with ITO + Al layer, which together with the epitaxial layer constitutes the finished parabolic structure. The micro LED device (micro LED micro display luminescent device) and the manufacturing method thereof have the advantages that the structure is simple, the external quantum efficiency of the micro LED display device can be effectively improved, the high pixel density is met, the pixels are improved, and the product performance is comprehensively improved.
The present invention has been described in connection with the accompanying drawings, and it is to be understood that the invention is not limited to the specific embodiments disclosed, but is intended to cover various modifications, changes and equivalents of the embodiments of the invention, and its application to other applications without departing from the spirit and scope of the invention.

Claims (9)

1. A micro LED device, its characterized in that: the micro LED device comprises a CMOS wafer substrate (8), wherein the CMOS wafer substrate (8) comprises a CMOS driving circuit and a through hole (9), a second anode layer (10) is arranged on the surface of the CMOS wafer substrate (8), a light-emitting unit is arranged on the upper surface of the second anode layer (10), the light-emitting unit is an LED epitaxial functional layer (2), the epitaxial functional layer (2) is a P-type semiconductor layer (203), an MQW layer (202) and an N-type semiconductor layer (201) from bottom to top in sequence, and the N-type semiconductor layer (201), the MQW layer (202) and the P-type semiconductor layer (203) are set to be capable of forming a structure with a narrow top layer and a wide bottom layer.
2. The micro LED device according to claim 1, characterized in that: the shape of the N-type semiconductor layer (201), the MQW layer (202) and the P-type semiconductor layer (203) is a paraboloid structure or an inverted trapezoid structure, when the epitaxial functional layer (2) forms the paraboloid structure, the MQW layer (202) of the composite light-emitting region is located on the plane where the focus of the paraboloid is located, and the insulating passivation layer (5) and the reflecting layer (6) are sequentially formed on the outer side of the light-emitting unit.
3. Micro LED device according to claim 1 or 2, characterized in that: the second anode layer (10) is a structure formed by depositing metal Au on the surface of the CMOS wafer substrate (8), a second anode (1001) is formed at the position of the second anode layer (10), and the second anode (1001) is a structure formed at the position of a through hole (9) in the second anode layer (10) through a photoetching process.
4. Micro LED device according to claim 1 or 2, characterized in that: the upper surface of the epitaxial functional layer (2) is also provided with a first anode layer (4), and the first anode layer (4) is arranged on the upper surface of the epitaxial functional layer (2) and is a structure formed by depositing metal Cr/Al/Cr/Pt/Au.
5. The micro LED device according to claim 4, wherein: when the first anode layer (4) forms the first anode (401), the first anode (401) is arranged to enable the first anode layer (4) and the epitaxial function layer (2) to jointly form an inverted trapezoid structure or a paraboloid structure through a photoetching and etching process, wherein the first anode layer (4) forms the first anode (401) after being isolated.
6. A manufacturing method of a micro LED device is characterized in that: the manufacturing method of the micro LED device comprises the following manufacturing steps:
s1, providing a CMOS wafer substrate (8) comprising a CMOS driving circuit, wherein the CMOS wafer substrate (8) comprises a through hole (9);
s2, cleaning the surface of the CMOS wafer substrate (8), and depositing metal Au to form a second anode layer (10); forming a second anode (1001) at the position of the through hole (9) through a photoetching process;
s3, providing an LED epitaxial wafer, wherein the LED epitaxial wafer sequentially comprises a substrate (1), an N-type semiconductor layer (201), an MQW layer (202) and a P-type semiconductor layer (203) from bottom to top;
s4, when the epitaxial functional layer (2) is of an inverted trapezoidal structure, after the surface of the epitaxial functional layer (2) is cleaned, depositing metal SiO on the surface2/TiO2Forming a DBR reflector layer (3), forming reflectors (301) through photoetching, etching and other processes, and depositing and forming first anodes (401) in grooves between the reflectors (301); and then, a trapezoidal structure is formed by the reflector (301) and the epitaxial functional layer (2) by adopting a photoetching and etching process.
S5, when the epitaxial functional layer (2) is set to be a paraboloid structure, cleaning the surface of the epitaxial functional layer (2), and depositing metal Cr/Al/Cr/Pt/Au on the surface to form a first anode layer (4); and adopting a photoetching and etching process to enable the first anode layer (4) and the epitaxial functional layer (2) to jointly form a parabolic structure, wherein the first anode layer (4) is separated to form a first anode (401).
7. The manufacturing method of micro LED device according to claim 6, characterized in that: after a first anode layer (401) is formed, depositing SiO2 on the surface of a light-emitting unit by adopting CVD, photoetching and etching processes to form an insulating passivation layer (5), wherein the insulating passivation layer (5) is positioned on the side surfaces of an epitaxial functional layer (2) and the first anode (401) or an epitaxial functional layer (2) and a reflector (301); and depositing a reflecting layer (6) on the surface of the epitaxial functional layer (2) by adopting optical coating, photoetching and etching processes, wherein the reflecting layer (6) is positioned on the outer side of the insulating passivation layer (5).
8. The manufacturing method of micro LED device according to claim 7, characterized in that: after the reflecting layers (6) are formed, filling and flattening the photoresistors among the reflecting layers (6) by adopting a spin coating process, and then curing; and then, butting and aligning the first anode on the CMOS wafer substrate (8) and the second anode on the epitaxial functional layer (2).
9. The manufacturing method of micro LED device according to claim 8, characterized in that: applying pressure at 300 ℃ to enable the electrode of the first anode and the electrode of the second anode to generate bonding reaction; stripping and removing the substrate (1) by adopting a process of acting laser on the N-type semiconductor layer (201) or a CMP (chemical mechanical polishing) process or a chemical etching process; and forming transparent conductive common cathode ITO (11) on the surfaces of the N-type semiconductor layer (201) and the planarized photoresist of all the epitaxial functional layers (2) by adopting a sputtering process.
CN202111182861.2A 2021-10-11 2021-10-11 Micro LED device and manufacturing method thereof Pending CN113921556A (en)

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CN114649322A (en) * 2022-05-21 2022-06-21 镭昱光电科技(苏州)有限公司 Micro LED display device and preparation method
CN116544262A (en) * 2023-06-09 2023-08-04 盐城鸿石智能科技有限公司 Micro LED display panel with high light emitting utilization rate and preparation method thereof
CN116885084A (en) * 2023-09-07 2023-10-13 元旭半导体科技(无锡)有限公司 LED chip with package substrate and preparation method thereof

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114649322A (en) * 2022-05-21 2022-06-21 镭昱光电科技(苏州)有限公司 Micro LED display device and preparation method
CN116544262A (en) * 2023-06-09 2023-08-04 盐城鸿石智能科技有限公司 Micro LED display panel with high light emitting utilization rate and preparation method thereof
CN116544262B (en) * 2023-06-09 2023-10-20 盐城鸿石智能科技有限公司 Micro LED display panel with high light emitting utilization rate and preparation method thereof
CN116885084A (en) * 2023-09-07 2023-10-13 元旭半导体科技(无锡)有限公司 LED chip with package substrate and preparation method thereof
CN116885084B (en) * 2023-09-07 2023-12-15 元旭半导体科技(无锡)有限公司 LED chip with package substrate and preparation method thereof

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