CN114093905A - Laminated Micro LED full-color display device and preparation method thereof - Google Patents

Laminated Micro LED full-color display device and preparation method thereof Download PDF

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CN114093905A
CN114093905A CN202111368449.XA CN202111368449A CN114093905A CN 114093905 A CN114093905 A CN 114093905A CN 202111368449 A CN202111368449 A CN 202111368449A CN 114093905 A CN114093905 A CN 114093905A
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light
emitting unit
iii
layer
anode
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王仕伟
任清江
张金金
李蕊
赵铮涛
刘胜芳
倪俊
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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
    • 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
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L23/00—Details of semiconductor or other solid state devices
    • H01L23/52—Arrangements for conducting electric current within the device in operation from one component to another, i.e. interconnections, e.g. wires, lead frames
    • H01L23/538—Arrangements for conducting electric current within the device in operation from one component to another, i.e. interconnections, e.g. wires, lead frames the interconnection structure between a plurality of semiconductor chips being formed on, or in, insulating substrates
    • H01L23/5386—Geometry or layout of the interconnection structure
    • 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
    • H01L33/385—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 the electrode extending at least partially onto a side surface of the semiconductor body
    • 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
    • H01L33/40—Materials therefor
    • H01L33/42—Transparent materials

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Abstract

The invention discloses a laminated Micro LED full-color display device and a preparation method thereof, belonging to the technical field of preparation of Micro LED display devices.

Description

Laminated Micro LED full-color display device and preparation method thereof
Technical Field
The invention relates to the technical field of Micro LED display device preparation, in particular to a laminated Micro LED full-color display device and a preparation method thereof.
Background
With the rise of emerging technologies such as intelligent wearable devices, augmented reality, virtual reality and the like, high-end display technology has become an urgent need in the market. Micro Light emitting diodes (Micro LEDs) are a new generation of display technology, and have self-luminous display characteristics, and compared with the existing Organic Light-emitting diode (OLED) technology, the Micro LED display device has a series of advantages of higher brightness and stability, better Light emitting efficiency, lower power consumption, faster response time, and the like.
The display principle of the Micro LED display device is that the LED structure is designed to be thinned, miniaturized and arrayed, the size of the LED structure is only about 1-10 um, and then a display is formed through methods such as monolithic integration or mass transfer. However, the Micro LED display technology still faces many key technical difficulties including huge device integration, and the reduction of the size of the Micro LED also causes problems of device performance deterioration and increased manufacturing difficulty. Therefore, there are technical difficulties in forming a full color display using Micro LEDs.
Disclosure of Invention
In order to solve the technical problems, the invention provides a laminated Micro LED full-color display device and a preparation method thereof.
In order to achieve the purpose, the technical scheme adopted by the invention for solving the technical problems is as follows: the laminated Micro LED full-color display device comprises a wafer substrate, wherein a plurality of laminated RGB units are arranged on the wafer substrate in an array mode, each laminated RGB unit comprises a plurality of pixel light-emitting units which are arranged in a laminated mode and can independently drive to emit light, and the cathode and the anode of each pixel light-emitting unit are respectively located on two sides of the corresponding pixel light-emitting unit.
The pixel light-emitting units comprise a light-emitting unit I, a light-emitting unit II and a light-emitting unit III which are sequentially arranged from bottom to top along the surface of the wafer substrate, and a transparent return layer is arranged between the light-emitting unit I and the light-emitting unit II and/or between the light-emitting unit II and the light-emitting unit III.
The plurality of pixel light-emitting units are arranged and combined of a red light-emitting unit, a blue light-emitting unit and a green light-emitting unit.
An anode through hole I, an anode through hole II and an anode through hole III which penetrate through the upper surface of the wafer substrate are arranged in the wafer substrate, the anode of the light-emitting unit I is connected with the anode through hole I, the anode of the light-emitting unit II is connected with the anode through hole II, and the anode of the light-emitting unit III is connected with the anode through hole III; and cathode pad connecting wires are arranged on two sides of each row of pixel light-emitting units on the surface of the wafer substrate, and cathodes of the light-emitting units I, the light-emitting units II and the light-emitting units III are connected with the cathode pad connecting wires.
The light-emitting unit I comprises an anode I and a light-emitting layer I which are sequentially arranged on the surface of a wafer substrate from bottom to top, a passivation layer I is deposited on the peripheries of the anode I and the light-emitting layer I, and a transparent cathode I is deposited on the surfaces of the passivation layer I and the light-emitting layer I; the positive pole I with I bonding of positive pole via hole links to each other, the periphery of transparent negative pole I pass through negative pole connecting electrode I with the negative pole pad connecting wire links to each other.
The light emitting unit II comprises a transparent anode II and a light emitting layer II which are sequentially arranged from bottom to top, a passivation layer II is deposited on the periphery of the light emitting layer II, and a transparent cathode II is deposited on the surfaces of the passivation layer II and the light emitting layer II; the transparent anode II is connected with the anode via hole II through an anode connecting electrode II, and the periphery of the transparent cathode II is connected with the cathode bonding pad connecting wire through a cathode connecting electrode II; and a filling layer III is arranged on the surfaces of the transparent cathode II and the cathode connecting electrode II.
The light-emitting unit III comprises a transparent anode III and a light-emitting layer III which are sequentially arranged from bottom to top, a passivation layer III is deposited on the periphery of the light-emitting layer III, and a transparent cathode III is deposited on the surfaces of the passivation layer III and the light-emitting layer III; transparent positive pole III pass through positive pole connecting electrode III with positive pole via hole III links to each other, transparent negative pole III's periphery pass through negative pole connecting electrode III with the negative pole pad connecting wire links to each other.
The surface of the filling layer I is connected with the filling layer II through the penetration return layer, and/or the surface of the filling layer III is connected with the filling layer V through the penetration return layer.
The upper surfaces of the plurality of laminated RGB units and the wafer substrate are covered with a filling layer IV, and cover plate glass is fixedly attached to the upper surface of the filling layer IV in an attached mode.
The preparation method of the laminated Micro LED full-color display device comprises the following steps:
step 1: providing a wafer substrate and red, blue and green LED epitaxial wafers;
step 2: preparing a light-emitting unit I on a wafer substrate by using an LED epitaxial wafer with a corresponding color;
and step 3: preparing a light-emitting unit II on the light-emitting unit I by using the LED epitaxial wafer with the corresponding color;
and 4, step 4: preparing a light-emitting unit III on the light-emitting unit II by using the LED epitaxial wafer with the corresponding color;
and 5: preparing a plurality of laminated RGB units according to the method in the step 2-step 5;
step 6: and packaging the device.
Preparing a filling layer on the surfaces of the light-emitting unit I and the light-emitting unit II; and preparing a penetration layer on the surface of the filling layer of the light-emitting unit I and/or the light-emitting unit II, and then preparing a filling layer.
The beneficial effects of the invention are:
1. according to the invention, the plurality of laminated RGB units are arranged on the wafer substrate in an array manner, and the plurality of pixel light-emitting units in the laminated RGB units are arranged in a laminated manner, so that the utilization rate of the active region of the wafer substrate is improved, and each pixel light-emitting unit can be driven to emit light independently, thereby realizing full-color display; and the anode and the cathode of the pixel light-emitting unit are respectively positioned at two sides, so that the shielding of the electrode connecting part on the light-emitting layer is reduced relative to the electrodes positioned at the same side, the pixel density of the display device is improved, and the brightness of the display device is improved.
2. The cathode of the light-emitting unit is set as the transparent cathode, the anodes of the light-emitting unit II and the light-emitting unit III are set as the transparent anodes, the light-emitting of the light-emitting layer is not influenced, and the transmission and reflection layer is arranged between the adjacent light-emitting units, so that the transmission and reflection effect is achieved, and the light-emitting efficiency of the device is improved.
3. The invention has the advantages that the plurality of anode through holes are dispersedly arranged on the wafer substrate, the periphery of the anode of each light-emitting unit is connected with the corresponding anode through hole through the anode connecting electrode, the blocking area of the light-emitting layer is reduced, the pixel density of the display device is improved, the driving current signal can be provided for the corresponding light-emitting unit through the anode through hole to drive the corresponding light-emitting unit to emit light, the plurality of anode through holes realize the independent control of the light-emitting unit to emit light while dispersing the current, and the full-color display is realized.
4. According to the invention, the cathode pad connecting line is arranged on the wafer substrate, so that the periphery of the cathode of each light-emitting unit is connected with the corresponding cathode pad connecting line through the cathode connecting electrode, the blocking area of the light-emitting layer is reduced, and the pixel density of the display device is further improved.
5. The laminated Micro LED full-color display device designed by the invention is prepared by adopting a semiconductor process, realizes high precision and microminiaturization, and realizes full-color display under a small size.
In summary, the invention is prepared by adopting a semiconductor process, improves the structure of the vertically arranged pixel light-emitting unit, improves the utilization rate of an active region, improves the pixel density of a display device, realizes the independent control of the pixel light-emitting unit, and realizes the full-color display under high precision and microminiaturization.
Drawings
The contents of the expressions in the various figures of the present specification and the labels in the figures are briefly described as follows:
FIG. 1 is a top view of an array arrangement of a display device according to the present invention;
FIG. 2 is a sectional view taken along line A-A of FIG. 1;
FIG. 3 is an enlarged view of FIG. 2 at A;
FIG. 4 is an enlarged view of FIG. 3 at B;
FIG. 5 is a sectional view taken along line B-B of FIG. 1;
FIG. 6 is an enlarged view at C of FIG. 5;
FIG. 7 is an enlarged view of FIG. 6 at D;
the labels in the above figures are: 1. the light emitting diode comprises a wafer substrate, 2 a laminated RGB unit, 3 a light emitting unit I, 31 an anode I, 32 a light emitting layer I, 33 a passivation layer I, 34 a transparent cathode I, 35 a cathode connecting electrode I, 4 a light emitting unit II, 41 a transparent anode II, 42 a light emitting layer II, 43 a passivation layer II, 44 a transparent cathode II, 45 an anode connecting electrode II, 46 a cathode connecting electrode II, 5 a light emitting unit III, 51 a transparent anode III, 52 a light emitting layer III, 53 a passivation layer III, 54 a transparent cathode III, 55 an anode connecting electrode III, 56 a cathode connecting electrode III, 6 a transmissive return layer, 7 an anode through hole I, 8 an anode through hole II, 9 an anode through hole III, 10 a cathode pad connecting line, 11 a filling layer I, 12 a filling layer II, 13 a filling layer III, 14 a filling layer IV and 15 cover glass.
Detailed Description
In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and the following embodiments are used for illustrating the present invention and are not intended to limit the scope of the present invention.
In the description of the present invention, it should be noted that the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "inner", "outer", and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience of description and simplicity of description, but do not indicate or imply that the device or element being referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus, should not be construed as limiting the present invention.
In the description of the present invention, it should be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; can be mechanically or electrically connected; may be directly connected or indirectly connected through an intermediate. The specific meanings of the above terms in the present invention can be understood in a specific case to those of ordinary skill in the art.
The specific implementation scheme of the invention is as follows: as shown in fig. 1, fig. 2 and fig. 5, a stacked Micro LED full color display device includes a wafer substrate 1, a plurality of stacked RGB units 2 arranged in an array on the wafer substrate 1, each stacked RGB unit 2 includes a plurality of pixel light emitting units arranged in a stacked manner, so that the utilization rate of an active region of the wafer substrate 1 is improved, and each pixel light emitting unit can independently drive to emit light, so as to realize full color display.
Specifically, as shown in fig. 3 and 6, the plurality of pixel light emitting units include a light emitting unit i 3, a light emitting unit ii 4, and a light emitting unit iii 5 sequentially arranged from bottom to top along the surface of the wafer substrate 1; a transmission and return layer 6 is arranged between the light-emitting unit I3 and the light-emitting unit II 4, the light emitted by the light-emitting unit I3 can be transmitted through the transmission and return layer 6, and the light emitted by the light-emitting unit II 4 and the light-emitting unit III 5 can be reflected; or a transmission return layer 6 is arranged between the light-emitting unit II 4 and the light-emitting unit III 5, and the light emitted by the light-emitting unit I3 and the light-emitting unit II 4 can be transmitted through the transmission return layer 6 and reflected by the light-emitting unit III 5; or a transparent return layer 6 is arranged between the light emitting unit I3 and the light emitting unit II 4 and between the light emitting unit II 4 and the light emitting unit III 5, the transparent return layer 6 between the light emitting unit I3 and the light emitting unit II 4 transmits light emitted by the light emitting unit I3, reflects light emitted by the light emitting unit II 4 and the light emitting unit III 5, and the transparent return layer 6 between the light emitting unit II 4 and the light emitting unit III 5 reflects light emitted by the light emitting unit III 5 and transmits light emitted by the light emitting unit I3 and the light emitting unit II 4. The arrangement of the transmission/return layer 6 between the light-emitting units can increase the light-emitting efficiency of the light-emitting units on the transmission/return layer 6, and of course, the transmission/return layer 6 may not be arranged between the light-emitting units, and full-color display can be realized. And the size of the retro-reflection layer 6 is larger than that of the luminescent layer in the luminescent unit above the retro-reflection layer, so that the luminescent reflection efficiency of the luminescent layer above the retro-reflection layer can be improved.
The plurality of pixel light-emitting units are any arrangement combination of a red light-emitting unit, a blue light-emitting unit and a green light-emitting unit, and the arrangement combination comprises the following conditions: the light-emitting unit I3 is a red light-emitting unit, the light-emitting unit II 4 is a blue light-emitting unit, and the light-emitting unit III 5 is a green light-emitting unit; the light-emitting unit I3 is a red light-emitting unit, the light-emitting unit II 4 is a green light-emitting unit, and the light-emitting unit III 5 is a blue light-emitting unit; the light-emitting unit I3 is a blue light-emitting unit, the light-emitting unit II 4 is a red light-emitting unit, and the light-emitting unit III 5 is a green light-emitting unit; the light-emitting unit I3 is a blue light-emitting unit, the light-emitting unit II 4 is a green light-emitting unit, and the light-emitting unit III 5 is a red light-emitting unit; the light-emitting unit I3 is a green light-emitting unit, the light-emitting unit II 4 is a blue light-emitting unit, and the light-emitting unit III 5 is a red light-emitting unit; the light-emitting unit I3 is a green light-emitting unit, the light-emitting unit II 4 is a red light-emitting unit, and the light-emitting unit III 5 is a blue light-emitting unit. Preferably, a transparent return layer 6 is arranged between the light emitting unit I3 and the light emitting unit II 4, the light emitting unit III 5 is arranged as a red light emitting unit, the red light emitting unit is arranged at the topmost layer due to low light emitting efficiency of the red light emitting unit, and the transparent return layer 6 is arranged between the adjacent light emitting units at the bottom layer, so that the absorption of the blue light emitting unit, the green light emitting unit and the transparent return layer 6 to red light can be reduced.
Specifically, as shown in fig. 3 and fig. 6, an anode via hole i 7, an anode via hole ii 8, and an anode via hole iii 9 penetrating through the upper surface of the wafer substrate 1 are provided in the wafer substrate 1, the anode via hole i 7 is provided in the middle, the anode via hole ii 8 and the anode via hole iii 9 are both provided with two anode via holes and are respectively provided on two opposite sides of the anode via hole i 7, the anode of the light-emitting unit i 3 is connected to the anode via hole i 7, the anode of the light-emitting unit ii 4 is connected to the anode via hole ii 8, the anode of the light-emitting unit iii 5 is connected to the anode via hole iii 9, a driving current signal can be provided to the corresponding light-emitting unit through the anode via hole to drive the corresponding light-emitting unit to emit light, the plurality of anode via holes realize independent control of the light-emitting unit corresponding to emit light while dispersing the current, and realize full-color display. Cathode pad connecting wires 10 are arranged on two sides of each row of pixel light-emitting units on the surface of the wafer substrate 1, cathodes of the light-emitting units I3, the light-emitting units II 4 and the light-emitting units III 5 are connected with the cathode pad connecting wires 10, and cathode connecting parts are led out of the light-emitting units, so that the blocking area of light-emitting layers in the light-emitting units is reduced, and the pixel density of a display device is further improved.
Specifically, as shown in fig. 4 and 7, the light emitting unit i 3 includes an anode i 31 and a light emitting layer i 32 sequentially disposed from bottom to top on the surface of the wafer substrate 1, a passivation layer i 33 is deposited on the peripheries of the anode i 31 and the light emitting layer i 32, a transparent cathode i 34 is deposited on the surfaces of the passivation layer i 33 and the light emitting layer i 32, and the transparent cathode i 34 does not affect the transmission luminescence of the entire light emitting layer i 32; the positive pole I31 links to each other with the bonding of positive pole via hole I7, can drive positive pole I31 through positive pole via hole I7 and get electric to make emitting layer I32 luminous, the periphery of transparent negative pole I34 is connected with negative pole pad connecting wire 10 through negative pole connecting electrode I35, has reduced the regional of blockking to emitting layer I32, has further improved display device's pixel density. Thereby passivation layer I33 wherein has realized restoreing the epitaxial layer lateral wall etching damage of luminescence unit I3 and has accomplished the technological effect that improves LED's quantum efficiency, simultaneously, makes I35 contact luminescence unit I3's epitaxial layer lateral wall of negative pole connecting electrode when avoiding forming I35 of negative pole connecting electrode to form the electric leakage, whole device is invalid even.
Specifically, a filling layer I11 is arranged on the surfaces of the transparent cathode I34 and the cathode connecting electrode I35, the size of the filling layer I11 is larger than that of the luminescent layer I32, the filling layer I11 is used for covering and filling the transparent cathode I34 and the cathode connecting electrode I35, when the penetration and return layer 6 is arranged between the luminescent unit I3 and the luminescent unit II 4, the penetration and return layer 6 with the same size as the filling layer I11 is arranged on the surface of the filling layer I11, and a filling layer II 12 with the same size as the penetration and return layer 6 is arranged on the surface of the penetration and return layer 6 for covering and filling, so that the luminescent unit II 4 is arranged on the filling layer II 12.
Specifically, the light emitting unit II 4 comprises a transparent anode II 41 and a light emitting layer II 42 which are sequentially arranged from bottom to top, the transparent anode II 41 does not influence the transmission luminescence of the lower light emitting layer I32, a passivation layer II 43 is deposited on the periphery of the light emitting layer II 42, a transparent cathode II 44 is deposited on the surfaces of the passivation layer II 43 and the light emitting layer II 42, and the transparent cathode II 44 does not influence the transmission luminescence of the whole light emitting layer II 42; the periphery of the transparent anode II 41 is connected with the anode via hole II 8 through an anode connecting electrode II 45, and the periphery of the transparent cathode II 44 is connected with the cathode pad connecting wire 10 through a cathode connecting electrode II 46, so that the blocking area of the light emitting layer II 42 is reduced, and the pixel density of the display device is further improved. The passivation layer II 43 realizes the technical effect of repairing the etching damage of the epitaxial layer side wall of the light-emitting unit II 4 to improve the LED quantum efficiency, and meanwhile, the cathode connecting electrode II 46 is prevented from contacting the epitaxial layer side wall of the light-emitting unit II 4 when the cathode connecting electrode II 46 is formed, so that electric leakage is formed, and even the whole device is invalid.
Wherein, the surfaces of the transparent cathode II 44 and the cathode connecting electrode II 46 are provided with a filling layer III 13 for covering and filling, when the penetration and return layer 6 is arranged between the light-emitting unit II 4 and the light-emitting unit III 5, the surface of the filling layer III 13 is provided with the penetration and return layer 6, and the surface of the penetration and return layer 6 is additionally provided with a filling layer V for covering and filling so as to arrange the light-emitting unit III 5; of course, the light-emitting unit ii 4 may be directly provided on the filling layer ii 12 without providing the reverse-transmitting layer 6, so that the light-emitting unit iii 5 may be provided on the filling layer iii 13.
Specifically, the light-emitting unit III 5 comprises a transparent anode III 51 and a light-emitting layer III 52 which are sequentially arranged from bottom to top, the transparent anode III 51 does not influence the transmission luminescence of the lower light-emitting layer II 42, a passivation layer III 53 is deposited on the periphery of the light-emitting layer III 52, a transparent cathode III 54 is deposited on the surfaces of the passivation layer III 53 and the light-emitting layer III 52, and the transparent cathode III 54 does not influence the transmission luminescence of the whole light-emitting layer III 52; transparent positive pole III 51 is connected with positive pole via hole III 9 through positive pole connecting electrode III 55, and transparent negative pole III 54's periphery is connected with negative pole pad connecting wire 10 through negative pole connecting electrode III 56, has reduced the block region to luminescent layer III 52, has further improved display device's pixel density.
Specifically, the upper surfaces of the plurality of laminated RGB units 2 and the wafer substrate 1 are covered with a filling layer IV 14 for covering and filling, and the upper surface of the filling layer IV 14 is fixedly attached with a cover plate glass 15 for packaging, so that the full-color Micro LED display device is realized.
The preparation method of the laminated Micro LED full-color display device comprises the following steps:
step 1: a wafer substrate 1 and red, blue, and green LED epitaxial wafers (hereinafter referred to as epitaxial wafer i, epitaxial wafer ii, and epitaxial wafer iii) are provided. Specifically, an anode through hole I7, an anode through hole II 8, an anode through hole III 9 and deposited metal are prepared on the wafer substrate 1 to form a cathode pad connecting line 10.
Step 2: and preparing the light-emitting unit I on the wafer substrate by using the LED epitaxial wafer with the corresponding color. Specifically, 1) conducting materials are respectively deposited on the surfaces of the anode via hole I7 of the wafer substrate 1 and the epitaxial structure of the epitaxial wafer I, and then an anode I31 is formed through para-bonding; 2) after the substrate of the epitaxial wafer I is stripped, pixel patterning is carried out on the surface of the epitaxial wafer I to form a light-emitting layer I32, and after oxides are deposited on the peripheries of the light-emitting layer I32 and the anode I31, a passivation layer I33 is formed through photoetching and dry etching processes; 3) depositing metal on the surfaces of the passivation layer I33 and the luminescent layer I32, forming a transparent cathode I34 by utilizing photoetching, etching and stripping processes, and forming a cathode connecting electrode I35 by photoetching and etching processes after depositing the metal on the periphery of the transparent cathode I34; 4) epoxy resin is coated on the surfaces of the transparent cathode I34 and the cathode connecting electrode I35 in a spinning mode, and then photoetching and developing processes are carried out to form a filling layer I11. When the transparent and returning layer 6 is required to be prepared between the light-emitting unit I3 and the light-emitting unit II 4, the transparent and returning layer 6 is transferred to the surface of the filling layer I11 after the transparent and returning layer 6 is prepared, and then photoetching and developing processes are carried out after epoxy resin is coated on the surface of the transparent and returning layer 6 to form a filling layer II 12.
And step 3: and preparing a light-emitting unit II on the light-emitting unit I by using the LED epitaxial wafer with the corresponding color. Specifically, 1) depositing a transparent conductive material on an epitaxial structure of an epitaxial wafer II, annealing, then patterning to form a transparent anode II 41 containing a light emitting layer II 42, etching a groove at the periphery of the transparent anode II 41, then depositing the conductive material in the groove, depositing the conductive material on the surface of the filling layer formed in the step 5, and performing counterpoint bonding on the epitaxial wafer II and the filling layer formed in the step 5 through the deposited conductive material to form an anode connecting electrode II 45; 2) after the substrate of the epitaxial wafer II is stripped, pixel patterning is carried out on the surface of the epitaxial wafer II to form a light-emitting layer II 42, and after oxides are deposited on the peripheries of the light-emitting layer II 42 and the transparent anode II 41, a passivation layer II 43 is formed through photoetching and dry etching processes; 3) depositing metal on the surfaces of the passivation layer II 43 and the luminescent layer II 42, forming a transparent cathode II 44 by utilizing photoetching, etching and stripping processes, and forming a cathode connecting electrode II 46 by photoetching and etching processes after depositing the metal on the periphery of the transparent cathode II 44; 4) and (3) carrying out photoetching and developing processes after epoxy resin is coated on the surfaces of the transparent cathode II 44 and the cathode connecting electrode II 46 in a spinning mode to form a filling layer III 13. When the transparent and reflective layer 6 is required to be prepared between the light-emitting unit II 4 and the light-emitting unit III 5, the transparent and reflective layer 6 is transferred to the surface of the filling layer III 13 after the transparent and reflective layer 6 is prepared, and then the filling layer V is formed by photoetching and developing processes after epoxy resin is coated on the surface of the transparent and reflective layer 6 in a spinning mode.
And 4, step 4: and preparing a light-emitting unit III on the light-emitting unit II by using the LED epitaxial wafer with the corresponding color. The light-emitting unit III 5 was prepared according to the method of step 3. Specifically, 1) depositing a transparent conductive material on an epitaxial structure of an epitaxial wafer III, annealing, then patterning to form a transparent anode III 51 containing a light-emitting layer III 52, etching a groove at the periphery of the transparent anode III 51, then depositing the conductive material in the groove, depositing the conductive material on the surface of the filling layer formed in the step 9, and performing para-bonding on the epitaxial wafer III and the filling layer formed in the step 9 through the deposited conductive material to form an anode connecting electrode III 55; 2) after the substrate of the epitaxial wafer III is stripped, pixel patterning is carried out on the surface of the epitaxial wafer III to form a light-emitting layer III 52, and a passivation layer III 53 is formed by photoetching and dry etching processes after oxides are deposited on the peripheries of the light-emitting layer III 52 and the transparent anode III 51; 3) and depositing metal on the surfaces of the passivation layer III 53 and the light-emitting layer III 52, forming a transparent cathode III 54 by utilizing photoetching, etching and stripping processes, and forming a cathode connecting electrode III 56 by photoetching and etching processes after depositing the metal on the periphery of the transparent cathode III 54.
And 5: preparing a plurality of laminated RGB units according to the method of the step 2 to the step 4.
Step 6: and packaging the device. Specifically, epoxy resin is coated on the surfaces of the multiple laminated RGB units 2 and the wafer substrate 1 in a spin coating mode, photoetching and developing processes are carried out to form a filling layer IV 14, and the glass cover plate is attached to the filling layer IV 14 and then solidified.
Examples
The following embodiment is a specific preparation method of a stacked Micro LED full-color display device, in which a transmission/return layer 6 is disposed between a light emitting unit i 3 and a light emitting unit ii 4, the light emitting unit i 3 is set as a red light emitting unit, the light emitting unit ii 4 is set as a green light emitting unit, and the light emitting unit iii 5 is set as a blue light emitting unit.
Step 1: a substrate and an epitaxial wafer are provided.
Providing a CMOS wafer substrate 1, forming an anode through hole I7, an anode through hole II 8 and an anode through hole III 9 in the CMOS wafer substrate 1, enabling the anode through hole to penetrate through the surface of the CMOS wafer substrate 1, and providing a driving current signal for a corresponding light-emitting unit through the anode through hole, wherein the anode through hole is a tungsten hole generally. A metal is deposited on the CMOS wafer substrate 1 to form cathode pad connection lines 10. And respectively providing a sapphire substrate blue light LED epitaxial wafer, a sapphire substrate green light LED epitaxial wafer and a gallium arsenide substrate red light LED epitaxial wafer. A gallium arsenide substrate for preparing a transmission-return layer is provided.
Step 2: a luminescent unit I3 was prepared.
1) Depositing metal Cr (with the thickness of 10-30 nm), Pt (with the thickness of 40-60 nm) or Au (with the thickness of 900-1100 nm) on the surface of an anode through hole I7 of a wafer substrate 1, depositing conductive materials ITO (with the thickness of 40-60 nm), Cr (with the thickness of 10-30 nm), Al (with the thickness of 190-210 nm), Pt (with the thickness of 40-60 nm) or Au (with the thickness of 900-1100 nm) on the surface of an epitaxial structure of a red light LED epitaxial wafer, and bonding a CMOS wafer and the red light LED epitaxial wafer in an opposite position, so that the metal on the surface of the CMOS wafer and the conductive materials deposited on the surface of the red light LED epitaxial wafer form an anode I31 with a reflection characteristic together.
2) Removing the gallium arsenide substrate, and performing photoetching and etching processes on the epitaxial structure of the red light LED epitaxial wafer to form a pixel pattern to form a light emitting layer I32; SiO with the thickness of 490-510 nm is deposited on the peripheries of the luminescent layer I32 and the anode I312And then forming a passivation layer I33 by photoetching and dry etching processes.
3) Depositing a layer of Ag with the thickness of 90-110 nm on the surfaces of the passivation layer I33 and the luminescent layer I32 by adopting an electron beam evaporation process, and forming a transparent cathode I34 by utilizing photoetching, etching and stripping processes; a layer of Cr (with the thickness of 10-30 nm), Pt (with the thickness of 40-60 nm) or Au (with the thickness of 900-1100 nm) is deposited on the periphery of the transparent cathode I34, and a cathode connecting electrode I35 is formed through photoetching and etching processes.
4) SU-8 epoxy resin is coated on the surfaces of the transparent cathode I34 and the cathode connecting electrode I35 in a spin coating mode, photoetching, developing and other processes are carried out to form a filling layer I11, and the transparent cathode I34 and the cathode connecting electrode I35 are covered and filled.
And step 3: preparing a permeable layer 6 and a filling layer II 12.
Deposition of SiO on GaAs substrate2Or TiO2DBR structure, and transferring to Carrier wafer, and stripping off GaAs substrate by wet etching to form transparent back layer. The transflective layer is transferred to the surface of the filling layer I11 through a mass transfer process, and the filling layer II 12 is formed on the surface of the transflective layer through processes of spin coating, photoetching, developing and the like of SU-8 epoxy resin.
And 4, step 4: preparing a luminescent unit II 4.
1) Depositing ITO (790-810 nm) on a green LED epitaxial wafer, annealing, and patterning by photoetching and dry etching to form a transparent anode II 41 containing a light-emitting layer II 42; after a groove with the depth of 290-310 nm is etched on the periphery of the transparent anode II 41, depositing a metal layer Cr (with the thickness of 10-30 nm), Pt (with the thickness of 40-60 nm) or Au (with the thickness of 290-310 nm) in the groove by adopting an electron beam evaporation process; depositing a metal layer Cr (with the thickness of 10-30 nm), Pt (with the thickness of 40-60 nm) or Au (with the thickness of 290-310 nm) on the periphery of the filling layer II 12 by utilizing photoetching, etching and stripping processes; and aligning the green light LED epitaxial wafer with the wafer containing the filling layer II 12, and bonding the two metal layers in an aligned mode, wherein the two metal layers jointly form an anode connecting electrode II 45.
2) Stripping a sapphire substrate of the green LED epitaxial wafer by using laser, forming a pixel pattern on an epitaxial structure of the green LED epitaxial wafer through photoetching and etching processes to form a light-emitting layer II 42, and depositing SiO with the thickness of 490-510 nm on the peripheries of the light-emitting layer II 42 and the transparent anode II 412And then forming a passivation layer II 43 by photoetching and dry etching processes.
3) Depositing a layer of Ag with the thickness of 90-110 nm on the surfaces of the passivation layer II 43 and the luminescent layer II 42 by adopting an electron beam evaporation process, and forming a transparent cathode II 44 by utilizing photoetching, etching and stripping processes; and depositing a layer of Cr (with the thickness of 10-30 nm), Pt (with the thickness of 40-60 nm) or Au (with the thickness of 900-1100 nm) on the periphery of the transparent cathode II 44, and forming a cathode connecting electrode II 46 through photoetching and etching processes.
4) SU-8 epoxy resin is coated on the surfaces of the transparent cathode II 44 and the cathode connecting electrode II 46 in a spin coating mode, photoetching, development and other processes are carried out to form a filling layer III 13, and the transparent cathode II 44 and the cathode connecting electrode II 46 are covered and filled.
And 5: a light-emitting unit iii 5 was prepared.
1) Depositing ITO (790-810 nm) on a blue light LED epitaxial wafer, annealing, and patterning through photoetching and dry etching to form a transparent anode III 51 containing a light-emitting layer III 52; after a groove with the depth of 290-310 nm is etched on the periphery of the transparent anode III 51, depositing a metal layer Cr (with the thickness of 10-30 nm), Pt (with the thickness of 40-60 nm) or Au (with the thickness of 290-310 nm) in the groove by adopting an electron beam evaporation process; depositing a metal layer Cr (with the thickness of 10-30 nm), Pt (with the thickness of 40-60 nm) or Au (with the thickness of 290-310 nm) on the periphery of the filling layer III 13 by utilizing photoetching, etching and stripping processes; and aligning the blue LED epitaxial wafer with the wafer containing the filling layer III 13, and aligning and bonding two metal layers which together form an anode connecting electrode III 55.
2) Stripping a sapphire substrate of a blue LED epitaxial wafer by using laser, forming pixel patterning on an epitaxial structure of the blue LED epitaxial wafer through photoetching and etching processes to form a light-emitting layer III 52, and depositing SiO with the thickness of 490-510 nm on the peripheries of the light-emitting layer III 52 and a transparent anode III 512And then forming a passivation layer III 53 by photoetching and dry etching processes.
3) Depositing a layer of Ag with the thickness of 90-110 nm on the surfaces of the passivation layer III 53 and the light-emitting layer III 52 by adopting an electron beam evaporation process, and forming a transparent cathode III 54 by utilizing photoetching, etching and stripping processes; a layer of Cr (with the thickness of 10-30 nm), Pt (with the thickness of 40-60 nm) or Au (with the thickness of 900-1100 nm) is deposited on the periphery of the transparent cathode III 54, and a cathode connecting electrode III 56 is formed through photoetching and etching processes.
Step 6: preparing a plurality of laminated RGB units 2 according to the method of the step 2 to the step 5.
And 7: and packaging the device.
And spin-coating epoxy resin on the surfaces of the multiple laminated RGB units 2 and the wafer substrate 1, then carrying out photoetching and developing processes to form a filling layer IV 14, attaching the glass cover plate to the filling layer IV 14, and then curing to form the laminated Micro LED full-color display device.
In summary, the invention is prepared by adopting a semiconductor process, improves the structure of the vertically arranged pixel light-emitting unit, improves the utilization rate of an active region, improves the pixel density of a display device, realizes the independent control of the pixel light-emitting unit, and realizes the full-color display under high precision and microminiaturization.
While the foregoing is directed to the principles of the present invention, other and further embodiments of the invention may be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims that follow.

Claims (10)

1. The utility model provides a stromatolite Micro LED full-color display device which characterized in that: the LED light-emitting device comprises a wafer substrate, wherein a plurality of laminated RGB units are arranged on the wafer substrate in an array mode, each laminated RGB unit comprises a plurality of pixel light-emitting units which are arranged in a laminated mode and can independently drive to emit light, and a cathode and an anode of each pixel light-emitting unit are respectively located on two sides of the corresponding pixel light-emitting unit.
2. The stacked Micro LED full-color display device according to claim 1, wherein: the pixel light-emitting units comprise a light-emitting unit I, a light-emitting unit II and a light-emitting unit III which are sequentially arranged from bottom to top along the surface of the wafer substrate, and a transparent return layer is arranged between the light-emitting unit I and the light-emitting unit II and/or between the light-emitting unit II and the light-emitting unit III.
3. The stacked Micro LED full-color display device according to claim 1, wherein: the plurality of pixel light-emitting units are arranged and combined of a red light-emitting unit, a blue light-emitting unit and a green light-emitting unit.
4. The stacked Micro LED full-color display device according to claim 2, wherein: an anode through hole I, an anode through hole II and an anode through hole III which penetrate through the upper surface of the wafer substrate are arranged in the wafer substrate, the anode of the light-emitting unit I is connected with the anode through hole I, the anode of the light-emitting unit II is connected with the anode through hole II, and the anode of the light-emitting unit III is connected with the anode through hole III; and cathode pad connecting wires are arranged on two sides of each row of pixel light-emitting units on the surface of the wafer substrate, and cathodes of the light-emitting units I, the light-emitting units II and the light-emitting units III are connected with the cathode pad connecting wires.
5. The stacked Micro LED full-color display device according to claim 4, wherein: the light-emitting unit I comprises an anode I and a light-emitting layer I which are sequentially arranged on the surface of a wafer substrate from bottom to top, a passivation layer I is deposited on the peripheries of the anode I and the light-emitting layer I, and a transparent cathode I is deposited on the surfaces of the passivation layer I and the light-emitting layer I; the anode I is connected with the anode through hole I in a bonding mode, and the periphery of the transparent cathode I is connected with the cathode bonding pad connecting line through a cathode connecting electrode I; and a filling layer I is arranged on the surfaces of the transparent cathode I and the cathode connecting electrode I.
6. The stacked Micro LED full-color display device according to claim 4, wherein: the light emitting unit II comprises a transparent anode II and a light emitting layer II which are sequentially arranged from bottom to top, a passivation layer II is deposited on the periphery of the light emitting layer II, and a transparent cathode II is deposited on the surfaces of the passivation layer II and the light emitting layer II; the transparent anode II is connected with the anode through hole II through an anode connecting electrode II, and the periphery of the transparent cathode II is connected with the cathode bonding pad connecting wire through a cathode connecting electrode II; and a filling layer III is arranged on the surfaces of the transparent cathode II and the cathode connecting electrode II.
7. The stacked Micro LED full-color display device according to claim 4, wherein: the light-emitting unit III comprises a transparent anode III and a light-emitting layer III which are sequentially arranged from bottom to top, a passivation layer III is deposited on the periphery of the light-emitting layer III, and a transparent cathode III is deposited on the surfaces of the passivation layer III and the light-emitting layer III; transparent positive pole III pass through positive pole connecting electrode III with positive pole via hole III links to each other, transparent negative pole III's periphery pass through negative pole connecting electrode III with negative pole pad connecting wire links to each other.
8. The laminated Micro LED full-color display device according to claim 1, characterized in that: and the upper surfaces of the plurality of laminated RGB units and the wafer substrate are covered with a filling layer IV, and cover plate glass is fixedly attached to the upper surface of the filling layer IV.
9. The preparation method of the laminated Micro LED full-color display device as claimed in any one of claims 1 to 8, characterized by comprising the following steps:
step 1: providing a wafer substrate and red, blue and green LED epitaxial wafers;
step 2: preparing a light-emitting unit I on a wafer substrate by using an LED epitaxial wafer with a corresponding color;
and step 3: preparing a light-emitting unit II on the light-emitting unit I by using the LED epitaxial wafer with the corresponding color;
and 4, step 4: preparing a light-emitting unit III on the light-emitting unit II by using the LED epitaxial wafer with the corresponding color;
and 5: preparing a plurality of laminated RGB units according to the method of the step 2 to the step 4;
step 6: and packaging the device.
10. The method for preparing the laminated Micro LED full-color display device according to claim 9, wherein the method comprises the following steps: preparing a filling layer on the surfaces of the light-emitting unit I and the light-emitting unit II; and preparing a penetration layer on the surface of the filling layer of the light-emitting unit I and/or the light-emitting unit II, and then preparing a filling layer.
CN202111368449.XA 2021-11-18 2021-11-18 Laminated Micro LED full-color display device and preparation method thereof Pending CN114093905A (en)

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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2023207692A1 (en) * 2022-04-28 2023-11-02 京东方科技集团股份有限公司 Display substrate, packaging substrate, and display device
WO2024012271A1 (en) * 2022-07-12 2024-01-18 诺视科技(苏州)有限公司 Pixel unit as well as manufacturing method therefor, micro-display screen, and discrete device

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2023207692A1 (en) * 2022-04-28 2023-11-02 京东方科技集团股份有限公司 Display substrate, packaging substrate, and display device
WO2024012271A1 (en) * 2022-07-12 2024-01-18 诺视科技(苏州)有限公司 Pixel unit as well as manufacturing method therefor, micro-display screen, and discrete device

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