WO2020223481A1 - Integration and mass transfer of micro-leds - Google Patents

Integration and mass transfer of micro-leds Download PDF

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Publication number
WO2020223481A1
WO2020223481A1 PCT/US2020/030708 US2020030708W WO2020223481A1 WO 2020223481 A1 WO2020223481 A1 WO 2020223481A1 US 2020030708 W US2020030708 W US 2020030708W WO 2020223481 A1 WO2020223481 A1 WO 2020223481A1
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leds
micro
substrate
light emitting
tiles
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PCT/US2020/030708
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French (fr)
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Matthew S. WONG
Steven P. Denbaars
James S. Speck
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The Regents Of The University Of California
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Publication of WO2020223481A1 publication Critical patent/WO2020223481A1/en

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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
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L29/00—Semiconductor devices specially adapted for rectifying, amplifying, oscillating or switching and having potential barriers; Capacitors or resistors having potential barriers, e.g. a PN-junction depletion layer or carrier concentration layer; Details of semiconductor bodies or of electrodes thereof ; Multistep manufacturing processes therefor
    • H01L29/66—Types of semiconductor device ; Multistep manufacturing processes therefor
    • H01L29/68—Types of semiconductor device ; Multistep manufacturing processes therefor controllable by only the electric current supplied, or only the electric potential applied, to an electrode which does not carry the current to be rectified, amplified or switched
    • H01L29/76—Unipolar devices, e.g. field effect transistors
    • H01L29/772—Field effect transistors
    • H01L29/78—Field effect transistors with field effect produced by an insulated gate
    • H01L29/786—Thin film transistors, i.e. transistors with a channel being at least partly a thin film
    • H01L29/78642—Vertical transistors
    • 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
    • H01L33/08—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 plurality of light emitting regions, e.g. laterally discontinuous light emitting layer or photoluminescent region integrated within the semiconductor body

Definitions

  • One embodiment of the present invention discloses the use of tiles comprised of an array of integrated micro-LEDs on a substrate, wherein the array of micro-LEDs comprises an n x m array of red, green and/or blue light emitting devices, and each of the tiles is sized similarly to a conventional LED for mass transfer of the micro-LEDs using a pick-and-place technique. Blue and/or green light emitting micro-LEDs are fabricated on the substrate, while red light emitting micro-LEDs are transferred to the substrate.
  • One or more integrated circuits (ICs) may also be fabricated on the substrate with the micro-LEDs.
  • the tiles are diced from the substrate, and may be dimensioned as necessary for a display application, which is accomplished by assembling the tiles using the pick-and-place technique.
  • the micro-LEDs comprise pixels of the display application.
  • the tiles with the red, green and/or blue light emitting micro-LEDs may be stacked due to the use of the transparent sapphire substrate, and mechanical supports may be used to separate the tiles, wherein the mechanical supports are selected according to their optical transparency, mechanical stiffness, thermal conductivity and electrical properties for specific applications.
  • FIGS.9A, 9B, 9C and 9D are schematics that illustrate a process flow of the transfer of micro-LEDs from a GaAs substrate to a sapphire substrate.
  • FIG.11 is a schematic of stacked tiles with mechanical support for protecting the micro-LEDs.
  • this embodiment integrates red emitting III-V micro-LEDs with blue and/or green emitting InGaN micro-LEDs by wafer or flip-chip bonding onto a substrate.
  • this embodiment dices the substrate into tiles having dimensions similar to conventional LEDs for the mass transfer of arrays of the red, green and blue emitting micro- LEDs.
  • This embodiment offers advantages in rapid fabrication and integration times to reduce manufacturing time, eliminate the possibility of dead pixels by examining the micro- LED arrays on the diced substrates after bonding, and transfer of the diced substrates using the pick-and-place technique.
  • micro-LEDs are a relatively new technology considered a candidate for next- generation displays.
  • new manufacturing processes have been developed for micro- LEDs, it is difficult to predict if these new processes are applicable to mass production, in terms of being be cost- and time-effective. Therefore, instead of inventing new manufacturing processes for micro-LEDs, it is beneficial to employ the manufacturing processes for conventional LEDs. This applies specifically to the integration and the mass transfer of red, green, and blue micro-LEDs for display applications. This leads to real benefits for companies by eliminating the need to purchase and/or develop new manufacturing processes for micro-LEDs.
  • FIGS.3A and 3B show examples of possible III-nitride micro-LED structures 300A, 300B fabricated on growth substrates 301A, 301B, respectively, wherein FIG.3A comprises a blue or green emitting micro-LED 300A comprised of an n-GaN layer 302, active region 303, p-GaN layer 304, p-contact 305 and n-contact 306, and FIG.3B comprises a blue and green emitting micro-LED 300B comprised of an n-GaN layer 307, blue active region 308, p- GaN layer 309, n-GaN layer 310, green active region 311, p-GaN layer 312, p-contact 313 and n-contact 314.
  • the micro-LED structures 300A, 300B can have one or more active regions 303, 308, 311, and electrical contacts 305, 306, 313, 314, 315 can be made separately to inject current to individual active regions 303, 308, 311. For those tiles that pass the yield and quality control requirements, integration of the III-V micro-LEDs can proceed. For example, III-V micro-LEDs, which have been fabricated and tested on another substrate, may be bonded on the tiles and then removed from their original substrate.
  • this embodiment takes advantage of the well-developed liftoff and transfer processes used with AlGaInP material systems. Due to a lack of mature liftoff and transfer techniques, InGaN devices might be damaged during the liftoff or transfer processes, wherein the damage can be more pronounced when the device dimensions are small. On the other hand, InGaN materials can be grown on optically transparent sapphire substrates, unlike AlGaInP materials.
  • FIG.8 is a schematic illustrating a method of fabricating full-color transparent displays using red, green, and blue light emitting micro-LEDs, where the displays can achieve high pixel density (more than 100 pixels per inch) by proper design.
  • the P x Q tiles 801 are diced from the substrate 800 using a method such as dicing, diamond scribing, laser cutting, or other techniques.
  • Each of the tiles 802 contains one or more n x m arrays of one or more micro-LEDs 802, as well as ICs, wherein each of the micro-LEDs 802 comprises a pixel.
  • a high pixel density e.g., more than 100 pixels per inch
  • This method of tile 801 formation can be employed to create arrays of InGaN-based green and/or blue light emitting micro-LEDS 801 grown on the substrate 801.
  • AlGaInP-based red light emitting micro-LEDs cannot be grown on sapphire substrates while maintaining high crystal quality, so further transfer steps are required for arrays of AlGaInP-based red light emitting micro-LEDs.
  • AlGaInP materials have mature liftoff processes, unlike InGaN materials, such that AlGaInP- based red light emitting micro-LEDs can be removed from their growth substrates and transferred to sapphire substrates.
  • This embodiment describes a method of integrating inorganic LEDs and micro-LEDs with different emission wavelengths onto a substrate to form an assembly of the LEDs with arrays of the micro-LEDs.
  • This embodiment takes advantage of compositions such as transparent-and-conductive oxides (TCOs), differences in refractive indexes, and light extraction methodologies, to reveal full-color displays combining LED and micro-LED arrays with different emission wavelengths.
  • TCOs transparent-and-conductive oxides
  • differences in refractive indexes differences in refractive indexes
  • light extraction methodologies to reveal full-color displays combining LED and micro-LED arrays with different emission wavelengths.
  • InGaN micro-LEDs with AlGaInP LEDs, where the InGaN micro-LEDs have smaller dimensions than the AlGaInP LEDs, which have standard LED dimensions.
  • the AlGaInP LEDs are covered with reflective materials such that light only emits at desire positions, and the openings of the light, which is the actual light-emitting dimensions of AlGaInP materials, can be modulated in a variety of methods during the fabrication steps.
  • the issue of sidewall damage and surface recombination of AlGaInP micro-LEDs can be avoid and InGaN micro-LEDs can be integrated onto AlGaInP LEDs.

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  • General Physics & Mathematics (AREA)
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Abstract

A device comprised of one or more tiles, wherein each of the tiles is comprised of a plurality of light emitting diodes (LEDs) on a substrate, and the plurality of LEDs is comprised of red, green and blue light emitting LEDs and includes at least one array of integrated micro-sized LEDs (micro-LEDs). The green or blue light emitting LEDs comprise one or more InGaN-based LEDs and the red light emitting LEDs comprise one or more AlGaInP-based LEDs. The blue and green light emitting LEDs may be fabricated on the substrate and the red light emitting LEDs transferred to the substrate, or the red light emitting LEDs may be fabricated on the substrate and the blue and green light emitting LEDs transferred to the substrate. The micro-LEDs have mesa dimensions less than 100 x 100 µm2 and the tiles are sized for the mass transfer of the LEDs.

Description

INTEGRATION AND MASS TRANSFER OF MICRO-LEDS CROSS REFERENCE TO RELATED APPLICATIONS
This application claims the benefit under 35 U.S.C. Section 119(e) of the following co-pending and commonly-assigned applications:
U.S. Provisional Application Serial No.62/840,502, filed on April 30, 2019, by Matthew S. Wong and James S. Speck, entitled“INTEGRATION AND MASS TRANSFER OF MICRO-LEDS,” attorneys’ docket number G&C 30794.0726USP1 (UC 2019-420-1);
U.S. Provisional Application Serial No.62/866,138, filed on June 25, 2019, by Matthew S. Wong, Steven P. DenBaars and James S. Speck, entitled“FORMATION OF TRANSPARENT INTEGRATED MICRO-LED DISPLAYS,” attorneys’ docket number G&C 30794.0727USP1 (UC 2019-430-1); and
U.S. Provisional Application Serial No.62/888,148, filed on August 16, 2019, by Steven P. DenBaars, Matthew S. Wong and James S. Speck, entitled“INTEGRATION OF GALLIUM-CONTAINING MICRO-LEDS FOR DISPLAYS,” attorneys’ docket number G&C 30794.0738USP1 (UC 2019-979-1);
all of which applications are incorporated by reference herein. BACKGROUND OF THE INVENTION
1. Field of the Invention.
This invention relates generally to micro-sized light emitting diodes (micro-LEDs), and specifically, the integration of micro-LEDs for displays. 2. Description of the Related Art.
Currently, liquid-crystal displays (LCDs) and organic LEDs (OLEDs) are the most common display technologies, because of their mature time-effective and cost-effective manufacturing processes. LCDs employ LEDs as the backlighting source, and the LEDs are transferred and assembled onto circuit boards so that they can be addressed individually.
LEDs that are used for LCD backlighting are usually grown on foreign substrates, such as sapphire substrates, and fabricated into device sizes greater than 100 x 100 mm2 (01. x 0.1 mm2). The LEDs are then transferred from the growth substrate to a circuit board or other substrate individually by a pick-and-place technique. Because the LED size is large, and the required number of LEDs for LCD backlighting is relatively small, a pick-and-place technique has been applied extensively for the mass transfer of conventional LEDs.
Micro-LEDs (also referred to as PLEDs) are a promising candidate for a variety of next-generation display applications. Micro-LEDs are defined as LEDs with mesa dimensions less than 100 x 100 mm2.
Inorganic micro-LEDs are considered to be the most promising candidate for a variety of conventional screen displays, as well as future display applications. Compared to LCDs and OLEDs, inorganic micro-LEDs can achieve better performances in brightness and operating lifespan, while having lower power consumption than LCDs and OLEDs.
Generally, three types of micro-LEDs are needed for full-color displays, namely, red, green and blue light emitting micro-LEDs. It has been demonstrated that InGaN based micro- LEDs have high performance in terms of energy efficiency and brightness in blue and green, and III-V based micro-LEDs, such as AlInGaP based micro-LEDs, have been employed for red light emission.
Additionally, for micro-LED displays, each device represents a pixel of the display, which means relatively large numbers of devices may be needed for any specific display application. As a result, having dead pixels (devices with defects) is detrimental to the displays.
However, unlike conventional LEDs, new integration techniques have to be developed for combining both InGaN based micro-LEDs and III-V based micro-LEDs.
Thus, there is a need in the art for improved methods for integrating micro-LEDs for displays. The present invention satisfies this need. SUMMARY OF THE INVENTION
One embodiment of the present invention discloses the use of tiles comprised of an array of integrated micro-LEDs on a substrate, wherein the array of micro-LEDs comprises an n x m array of red, green and/or blue light emitting devices, and each of the tiles is sized similarly to a conventional LED for mass transfer of the micro-LEDs using a pick-and-place technique. Blue and/or green light emitting micro-LEDs are fabricated on the substrate, while red light emitting micro-LEDs are transferred to the substrate. One or more integrated circuits (ICs) may also be fabricated on the substrate with the micro-LEDs. The tiles are diced from the substrate, and may be dimensioned as necessary for a display application, which is accomplished by assembling the tiles using the pick-and-place technique. The micro-LEDs comprise pixels of the display application.
Another embodiment of the present invention discloses the formation of transparent integrated micro-LEDs displays from tiles comprised of arrays of red, green or blue light emitting micro-LEDs. A substrate is divided into P x Q tiles, and each of the tiles is comprised of n x m red, green and/or blue light emitting micro-LEDs formed on the substrate. The substrate is a transparent sapphire substrate, and the green and/or blue light emitting micro-LEDs comprise InGaN-based micro-LEDs grown on the sapphire substrate. The red light emitting micro-LEDs comprise AlGaInP-based micro-LEDs grown on a GaAs substrate, which are subsequently transferred and bonded onto the transparent sapphire substrate. The tiles with the red, green and/or blue light emitting micro-LEDs may be stacked due to the use of the transparent sapphire substrate, and mechanical supports may be used to separate the tiles, wherein the mechanical supports are selected according to their optical transparency, mechanical stiffness, thermal conductivity and electrical properties for specific applications.
Yet another embodiment of the present invention discloses InGaN micro-LEDs bonded to an AlGaInP LED, with the InGaN micro-LEDs emitting light at blue and green wavelengths, and the AlGaInP LED emitting light at red wavelengths. Reflective materials are deposited on a surface of the AlGaInP LED between the AlGaInP LED and the InGaN micro-LEDs, wherein the reflective materials provide for optical confinement of the light emitted from the InGaN micro-LEDs and AlGaInP LEDs, to control interference between light emitted from the InGaN micro-LEDs and AlGaInP LEDs. One or more openings exist on the surface of the AlGaInP LED where no reflective material is deposited, in order to extract the light from the AlGaInP LED, and one or more optical elements are positioned at the openings to enhance extraction of the light from the AlGaInP LED. Moreover, one or more arrays of the InGaN micro-LEDs may be bonded to the AlGaInP LED, with one or more arrays of the optical elements positioned between the arrays of the InGaN micro-LEDs. In addition, the AlGaInP LED may be assembled into an array of AlGaInP LEDs, each with their bonded arrays of InGaN micro-LEDs. BRIEF DESCRIPTION OF THE DRAWINGS
FIG.1 is a schematic of a III-nitride epitaxial structure comprising an LED that is formed on a substrate.
FIGS.2A and 2B illustrate a tile fabricated on a growth substrate, wherein the tile comprises an n x m array of micro-LEDs.
FIGS.3A and 3B show examples of possible micro-LED structures fabricated on a growth substrate, wherein FIG.3A comprises a blue or green emitting III-nitride micro-LED and FIG.3B comprises a blue and green emitting III-nitride micro-LED.
FIG.4 illustrates a tile after red emitting III-V micro-LEDs have been bonded onto the tile in gaps between the blue-green emitting III-nitride micro-LEDs.
FIGS.5A and 5B illustrate how the red emitting III-V micro-LEDs may be bonded onto the substrate with the blue-green emitting III-nitride micro-LEDs.
FIG.6 shows an example of 2×2 tiles with each tile has an array of 4×6 red, green and blue emitting micro-LEDs.
FIG.7 is a process flow describing a method of fabricating micro-LEDs.
FIG.8 is a schematic of tile formation from a sapphire substrate.
FIGS.9A, 9B, 9C and 9D are schematics that illustrate a process flow of the transfer of micro-LEDs from a GaAs substrate to a sapphire substrate.
FIG.10 is a schematic of stacked tiles defining a pitch for the micro-LEDs from different tiles.
FIG.11 is a schematic of stacked tiles with mechanical support for protecting the micro-LEDs.
FIG.12 is a schematic of an AlGaInP light-emitting structure grown on a substrate. FIG.13 is a schematic of an array of AlGaInP light-emitting devices fabricated on substrate.
FIG.14 is a schematic of InGaN micro-LEDs bonded onto an AlGaInP LED.
FIG.15 is a schematic of the use of two InGaN micro-LEDs and a light-enhancing optical element on top of an AlGaInP LED.
FIG.16 is a schematic of a completed cell that comprises an AlGaInP LED InGaN and arrays of InGaN micro-LEDs, optical elements and openings. FIG.17 is a schematic of an assembly of a 2x2 array of AlGaInP LEDs and arrays of InGaN micro-LEDs, optical elements and openings that form a full-color display. DETAILED DESCRIPTION OF THE INVENTION
In the following description of the preferred embodiment, reference is made to the accompanying drawings which form a part hereof, and in which is shown by way of illustration a specific embodiment in which the invention may be practiced. It is to be understood that other embodiments may be utilized and structural changes may be made without departing from the scope of the present invention. INTEGRATION AND MASS TRANSFER OF MICRO-LEDS
Overview
This embodiment describes a method of integrating micro-LEDs with different emission wavelengths onto a substrate to form arrays of red, green and blue light emitting micro-LEDs. Thereafter, the arrays of micro-LEDs are mass transferred using conventional pick-and-place techniques.
Specifically, this embodiment integrates red emitting III-V micro-LEDs with blue and/or green emitting InGaN micro-LEDs by wafer or flip-chip bonding onto a substrate. In addition, this embodiment dices the substrate into tiles having dimensions similar to conventional LEDs for the mass transfer of arrays of the red, green and blue emitting micro- LEDs.
This embodiment offers advantages in rapid fabrication and integration times to reduce manufacturing time, eliminate the possibility of dead pixels by examining the micro- LED arrays on the diced substrates after bonding, and transfer of the diced substrates using the pick-and-place technique.
The manufacturing processes for conventional LEDs, including tools and packaging techniques, and for LCD backlighting, are well-developed to be cost- and time-effective. On the other hand, micro-LEDs are a relatively new technology considered a candidate for next- generation displays. Although new manufacturing processes have been developed for micro- LEDs, it is difficult to predict if these new processes are applicable to mass production, in terms of being be cost- and time-effective. Therefore, instead of inventing new manufacturing processes for micro-LEDs, it is beneficial to employ the manufacturing processes for conventional LEDs. This applies specifically to the integration and the mass transfer of red, green, and blue micro-LEDs for display applications. This leads to real benefits for companies by eliminating the need to purchase and/or develop new manufacturing processes for micro-LEDs. Technical Description
FIG.1 is a schematic of a III-nitride epitaxial structure 100 comprising an LED 101 that is formed on a substrate 102, where the substrate 102 could be a growth substrate, such as gallium nitride (GaN), sapphire (Al2O3) or silicon (Si). The LED 101 can have one or more active regions with tunnel junctions. Electrical contact layers can be formed in the LED 101. During or after the fabrication of the LED 101, one or more ICs (not shown) can also be formed on the substrate 102. Parallel processing with ICs can be used to speed up the manufacturing time and obtain a cost-effective processing.
FIGS.2A and 2B illustrate a tile 200 fabricated on a growth substrate 201, wherein the tile 200 comprises an n x m array 202 of micro-LEDs 203, as well as other components (not shown). A P x Q array (not shown) of tiles 200 may be fabricated on the growth substrate 201, wherein each tile 200 is then diced from the substrate 201. Preferably, the tile 201 is sized similarly to a conventional LED (not shown), e.g., having an area greater than 100 x 100 mm2. The micro-LEDs 203 in each tile 200 can be examined individually or as arrays for yield and quality control requirements.
FIGS.3A and 3B show examples of possible III-nitride micro-LED structures 300A, 300B fabricated on growth substrates 301A, 301B, respectively, wherein FIG.3A comprises a blue or green emitting micro-LED 300A comprised of an n-GaN layer 302, active region 303, p-GaN layer 304, p-contact 305 and n-contact 306, and FIG.3B comprises a blue and green emitting micro-LED 300B comprised of an n-GaN layer 307, blue active region 308, p- GaN layer 309, n-GaN layer 310, green active region 311, p-GaN layer 312, p-contact 313 and n-contact 314. Other device structures may be used as well. The micro-LED structures 300A, 300B can have one or more active regions 303, 308, 311, and electrical contacts 305, 306, 313, 314, 315 can be made separately to inject current to individual active regions 303, 308, 311. For those tiles that pass the yield and quality control requirements, integration of the III-V micro-LEDs can proceed. For example, III-V micro-LEDs, which have been fabricated and tested on another substrate, may be bonded on the tiles and then removed from their original substrate.
The liftoff processes used with III-V semiconductors have been well-developed by using chemical etching. This minimizes the possibility of damaging the III-V micro-LEDs during transfer, bonding and liftoff steps.
FIG.4 illustrates a tile 400 comprised of a substrate 401 and an n x m array 402 of blue and/or green emitting III-nitride micro-LEDs 403 after red emitting III-V micro-LEDs 404 have been bonded onto the tile 400 in gaps between the blue and/or green emitting III- nitride micro-LEDs 403. After the integration of III-V micro-LEDs 404 onto the tile 400, further yield and quality control testing can be performed.
Finally, the tile is used as a holder for a conventional pick-and-place technique that assembles the tiles to form displays. The dimensions of the tiles are important for the pick- and-place technique.
The place-and-place technique typically uses mechanical forces to transfer LEDs, and the LEDs must be greater than some specific dimensions to transfer. In this embodiment, the tiles comprised of diced substrates having arrays of micro-LEDs can be used as a mechanical handle during the pick-and-place technique. Moreover, each of the tiles is sized to have the same dimensions as conventional LEDs, which depends on the specific display resolution and applications.
FIGS.5A and 5B illustrate how the red emitting III-V micro-LEDs 500A may be bonded onto a substrate 501 with blue and/or green emitting III-nitride micro-LEDs 500B, wherein the red emitting micro-LED 500A is comprised of a p-AlGaInP layer 502, active region 503, n-AlGaInP layer 504, n-contact 505 and n-contact 506, and the blue or green emitting III-nitride micro-LED 500B is comprised of an n-GaN layer 507, active region 508, p-GaN layer 509, p-contact 510 and n-contact 511.
In FIG.5A, a metal contact 506 for the red emitting III-V micro-LED 500A can be deposited either on an insulating substrate 501 (for example, Al2O3 for sapphire substrates) or a semi-insulating substrate 501 (such as AlN for Si substrates). In FIG.5B, a metal contact 506 for the red emitting III-V micro-LED 500A can be deposited on an n-GaN layer 512 deposited on the substrate 501. In the case of an n-contact 506, metal deposition on the n- GaN layer 512 might be preferable; otherwise, metal deposition on the insulating substrate 501 serves as an alternative processing route. Both paths are possible, and it is dependent on different factors of the fabrication process, for instance, the choice of metal contacts and the adhesive property of metal contacts.
FIG.6 shows an example of a structure 600 formed on a substrate 601 comprised of a 2 x 2 array 602 of tiles 603, wherein each tile 603 is a 4ൈ6 array 604 of red and green and/or blue emitting micro-LEDs 605.
FIG.7 presents a basic process flow 700 of this embodiment, which includes the steps of growth of the LED’s epitaxy structure 701; blue and/or green emitting micro-LED and IC fabrication on a substrate 702; dice the substrate into tiles 703; micro-LED testing 704; flip- chip bonding of red emitting micro-LEDs onto the tiles 705; micro-LED testing 706; and transfer by pick-and-place 707. FORMATION OF TRANSPARENT INTEGRATED MICRO-LED DISPLAYS Overview
This embodiment describes a method for the integration of inorganic micro-LEDs to form full-color and transparent displays, without employing any advanced techniques for the mass-transfer of individual devices. Specifically, arrays of red, green and blue light emitting micro-LEDs are transferred onto tiles, which provides a better fabrication method for full- color and transparent displays, in terms of manufacturing cost and time.
Mass transfer of micro-LED arrays using tiles ensures perfect yield on the device level, for example, as described above in the section entitled“INTEGRATION AND MASS TRANSFER OF MICRO-LEDS.” The tile transfer technique utilizes a mature pick-and- place transfer technique for transferring micro-LED arrays, which speeds up the
manufacturing time.
This embodiment extends the tile transfer technique to include stacking tiles for full- color and optically transparent displays, wherein each tile contains one or more monolithic micro-LED arrays, and each of the arrays is comprised of one or more red, green, or blue light emitting micro-LEDs. Preferably, the substrates for the tiles are double-side polished sapphire substrates, which are optically transparent. With the proper design and alignment of the tiles and micro-LEDs, the pitch (i.e., the spacing between micro-LEDs) and the positions of the micro-LEDs can be accurately controlled.
In terms of manufacturing, this embodiment takes advantage of the well-developed liftoff and transfer processes used with AlGaInP material systems. Due to a lack of mature liftoff and transfer techniques, InGaN devices might be damaged during the liftoff or transfer processes, wherein the damage can be more pronounced when the device dimensions are small. On the other hand, InGaN materials can be grown on optically transparent sapphire substrates, unlike AlGaInP materials.
By stacking tiles formed from optically transparent substrates with red, green, and blue light emitting micro-LED arrays, this embodiment can obtain perfect yields employing the tile transfer technique. Because this embodiment does not require the transfer of individual devices, the positions of devices are defined during wafer fabrication, and integrated circuits and other displays components can be added to the substrate by parallel processing during device fabrication. Using this embodiment, full color and optically transparent micro-LED displays can be manufactured with conventional semiconductor manufacturing equipment. Technical Description
FIG.8 is a schematic illustrating a method of fabricating full-color transparent displays using red, green, and blue light emitting micro-LEDs, where the displays can achieve high pixel density (more than 100 pixels per inch) by proper design.
Gallium nitride-based light-emitting structures are grown on a flat or patterned sapphire substrate 800, wherein the substrate 800 can be optically transparent or opaque, depending on the specific display applications. The substrate 800 is sub-divided into P x Q tiles 801, and semiconductor device processing is then performed to fabricate the micro- LEDs 802 (e.g., with a device area less than 100 x 100 mm2) within the tiles 801 on the substrate 800, as well as ICs (not shown). Other than the standard materials for conventional device design, semi-transparent or transparent materials, including thin metals and transparent-and-conductive oxides, can be used. The substrate 800 can be polished, or its thickness can be reduced, before or after device fabrication. The P x Q tiles 801 are diced from the substrate 800 using a method such as dicing, diamond scribing, laser cutting, or other techniques. Each of the tiles 802 contains one or more n x m arrays of one or more micro-LEDs 802, as well as ICs, wherein each of the micro-LEDs 802 comprises a pixel. A high pixel density (e.g., more than 100 pixels per inch) can be achieved by proper design. This method of tile 801 formation can be employed to create arrays of InGaN-based green and/or blue light emitting micro-LEDS 801 grown on the substrate 801.
On the other hand, arrays of AlGaInP-based red light emitting micro-LEDs can also be transferred onto the tiles 802 with a different strategy. AlGaInP-based red light emitting micro-LEDs are commonly grown on native substrates, such as GaAs substrates, which are not transparent and are mechanically fragile. Compared to GaAs substrates, sapphire substrates can be optically transparent, and can provide mechanical and thermal support, because they have excellent mechanical stiffness and thermal conductivity. As a result, besides serving as a growth substrate, sapphire substrates have additional advantages as support substrates for the design of display applications.
However, AlGaInP-based red light emitting micro-LEDs cannot be grown on sapphire substrates while maintaining high crystal quality, so further transfer steps are required for arrays of AlGaInP-based red light emitting micro-LEDs. On the other hand, AlGaInP materials have mature liftoff processes, unlike InGaN materials, such that AlGaInP- based red light emitting micro-LEDs can be removed from their growth substrates and transferred to sapphire substrates.
FIGS.9A, 9B, 9C and 9D are schematics that illustrate a process flow for the transfer of AlGaInP-based red light emitting micro-LEDs. In FIG.9A, a GaAs substrate 900 provides the growth substrate for one or more AlGaInP-based red light emitting micro-LEDs 901. In FIG.9B, a sapphire substrate 902 is bonded to the top surfaces of the AlGaInP-based red light emitting micro-LEDs 901 using one or more metal layers 903. In FIG.9C, the AlGaInP-based red light emitting micro-LEDs 901 are lifted off 904 of the GaAs substrate 900, while remaining bonded to the sapphire substrate 902. In FIG.9D, the end result (which is flipped from FIG.9C) is one or more AlGaInP-based red light emitting micro-LEDs 901 bonded to the sapphire substrate 902. In this embodiment, all of the AlGaInP-based red light emitting micro-LEDs 901 are transferred to the sapphire substrate 902. In other embodiments, fewer than all the micro- LEDs 901 may be transferred at one time and/or one or more transfers from the GaAs substrate 900 may be performed. Each transfer may comprise one or more than one of the micro-LEDs 901, including arrays of micro-LEDs 901, depending on the position of the metal layers 903. The purpose of the metal layers 903 is to serve as a bonding layer between the micro-LEDs 901 and the sapphire substrate 902, as well as to act as an electrical contact for the micro-LEDs 901 after the transfer.
FIG.10 is a schematic of stacked tiles 1000A, 1000B, 1000C, each comprising one or more micro-LEDs 1001A, 1001B, 1001C, also labeled as PLED 1, PLED 2 and PLED 3, respectively, in the figure. In this embodiment, the tiles 1000A, 1000B, 1000C are stacked on each other to form displays.
In one embodiment, each of tiles 1000A, 1000B, 1000C contains only red, green or blue light emitting micro-LEDs 1001A, 1001B, 1001C. For example, each micro-LED 1001A may comprise an AlGaInP-based red light emitting micro-LED, each micro-LED 1001B may comprise an InGaN-based green light emitting micro-LED, and each micro-LED 1001C may comprise an InGaN-based blue light emitting micro-LED. However, other embodiments may stack the tiles 1000A, 1000B, 1000C in a different order, or may mix the red, green and/or blue light emitting micro-LEDs 1001A, 1001B, 1001C on one or more of the tiles 1000A, 1000B, 1000C, or may use only two tiles 1000A, 1000B comprised of red light emitting micro-LEDs 1001A and green and blue light emitting micro-LEDs 1001B.
The alignment of the tiles 1000A, 1000B, 1000C, and micro-LEDs 1001A, 1001B, 1001C, define a pitch d1, d2, d3 for the micro-LEDs 1001A, 1001B, 1001C from different tiles 1000A, 1000B, 1000C, wherein the pitch d1, d2, d3 comprises the distance between any two of the micro-LEDs 1001A, 1001B, 1001C. The pitch d1, d2, d3 can be defined during fabrication steps or during post-fabrication alignment steps, wherein the pitch d1, d2, d3 may be different between different micro-LEDs 1001A, 1001B, 1001C and/or between different tiles 1000A, 1000B, 1000C. Moreover, after the tiles 1000A, 1000B, 1000C are formed, the thickness of the tiles 1000A, 1000B, 1000C can be further reduced to decrease the optical absorption from the tiles 1000A, 1000B, 1000C. FIG.11 is a schematic of stacked tiles 1100A, 1100B, 1100C, each comprising one or more micro-LEDs 1101A, 1101B, 1101C, also labeled as PLED 1, PLED 2 and PLED 3, respectively, in the figure, where mechanical supports 1102A, 1102B, 1103C protect the micro-LEDs 1101A, 1101B, 1101C. In this embodiment, the mechanical supports 1102A, 1102B, 1103C prevent touching between the tiles 1100A, 1100B, 1100C and the micro- LEDs 1101A, 1101B, 1101C. The mechanical supports 1102A, 1102B, 1103C may be selected according to their optical transparency, mechanical stiffness, thermal conductivity and electrical properties for specific applications, which includes but is not limited to dielectric materials, adhesives, and polymers. The mechanical supports 1102A, 1102B, 1103C may also serve as an adhesive medium between the tiles 1100A, 1100B, 1100C. INTEGRATION OF GALLIUM-CONTAINING MICRO-LEDS FOR DISPLAYS Overview
This embodiment describes a method of integrating inorganic LEDs and micro-LEDs with different emission wavelengths onto a substrate to form an assembly of the LEDs with arrays of the micro-LEDs. This embodiment takes advantage of compositions such as transparent-and-conductive oxides (TCOs), differences in refractive indexes, and light extraction methodologies, to reveal full-color displays combining LED and micro-LED arrays with different emission wavelengths.
Because AlGaInP materials have been utilized for conventional LED applications, surface recombination and sidewall damage are not critical in standard LED dimensions. However, problems arise as the device sizes decrease below 100 x 100 mm2 for micro-LEDs. For InGaN materials, since the minority carrier diffusion length is shorter and InGaN is more chemical robust, there are techniques to lessen or minimize the effects of sidewall damage and surface recombination, which the device dimensions can shrink down to sub-micron without detrimental issues.
One promising solution is to integrate InGaN micro-LEDs with AlGaInP LEDs, where the InGaN micro-LEDs have smaller dimensions than the AlGaInP LEDs, which have standard LED dimensions. Moreover, the AlGaInP LEDs are covered with reflective materials such that light only emits at desire positions, and the openings of the light, which is the actual light-emitting dimensions of AlGaInP materials, can be modulated in a variety of methods during the fabrication steps. As a result, the issue of sidewall damage and surface recombination of AlGaInP micro-LEDs can be avoid and InGaN micro-LEDs can be integrated onto AlGaInP LEDs.
The integration of InGaN micro-LEDs onto AlGaInP LEDs can also provide advantages in the transfer process. The methods where the InGaN micro-LEDs are transferred and integrated onto AlGaInP LEDs do not need to be specified, since various of approaches can be applied, including traditional bonding, transfer using stamp, or fluidic assembly.
For display applications, millions of devices are needed to transfer to display panels, because each device represents a pixel on the display. The main problem with current LED transfer technology is that the process is limited by the transfer speed and the device dimensions. The desired transfer method should have high transfer rate, such that millions of devices can be transferred in short time period.
This embodiment describes micro-LED arrays with different emission wavelengths can be formed in this design. After the formation of micro-LED arrays, the arrays can be transferred using the original transfer approach, namely pick-and-place, to deliver onto display panels. After the transfer, the LEDs can be arranged such that the packing density of the micro-LED arrays can be adjusted. Technical Description
FIG.12 is a cross-sectional side view of a structure 1200 comprised of a substrate 1201 and an AlGaInP light-emitting device 1202 grown on the substrate 1201, where the substrate 1201 can be removed in later fabrication steps, if desired, for a specific application.
Conventional device fabrication can be applied on a wafer to form AlGaInP LEDs, as shown in FIG.13, which is a cross-sectional side view of a structure 1300 comprised of a substrate 1301 and an array 1302 of AlGaInP LEDs 1303 fabricated on the substrate 1301. This implies that the AlGaInP LEDs 1303 are defined and other materials, such as metals and dielectric materials, can be deposited onto the substrate 1301 for electrical and/or optical purposes.
Moreover, in the fabrication process, patterns can be identified on any layer above the substrate for the transfer of the InGaN micro-LEDs onto the AlGaInP LEDs. The patterns can be defined by using bonding materials, including metals and adhesive materials, or any other methods that can secure micro-LEDs in position.
FIG.14 is a cross-sectional side view of a structure 1400 fabricated on a substrate 1401 comprised of two InGaN micro-LEDs 1402A, 1402B, also labeled as InGan PLED 1 and PLED 2, respectively, in the figure, wherein the InGaN micro-LEDs 1402A, 1402B are bonded using bonding materials 1403 onto an AlGaInP LED 1404. The two InGaN mLEDs 1402A, 1402B may emit light at different wavelengths, for example, blue and green wavelengths, respectively, while the AlGaInP LED 1404 emits at still another wavelength, for example, a red wavelength, with the combination of red, green and blue light resulting in a white light emitting device.
Reflective materials 1405 are deposited on a surface of the AlGaInP LED 1404, and the two InGaN micro-LEDs 1402A, 1402B are secured on or above the reflective materials 1405 by the bonding materials 1403. The reflective materials 1405 can be metals or dielectric materials that can form reflectors (for example, either omnidirectional reflectors or distributed Bragg reflectors), while the bonding materials 1403 can be specified for thermal, electrical, optical, and/or other purposes.
The reflective materials 1405 provide for optical confinement of the light emitted from the InGaN micro-LEDs 1402A, 1402B and AlGaInP LED 1404, as well as electrical isolation between contacts of the InGaN micro-LEDs 1402A, 1402B and AlGaInP LED 1404. The aim of the optical confinement is to control interference between light emitted from the InGaN micro-LEDs 1402A, 1402B and AlGaInP LED 1404. In one example, the light emitted from the InGaN micro-LEDs 1402A, 1402B is reflected by the reflective materials 1405, as is the light emitted from the AlGaInP LED 1404. The aim of the electrical isolation is to separate the electrical contacts of the InGaN micro-LEDs 1402A, 1402B from the electrical contacts of AlGaInP LED 1404, wherein each device 1042A, 1042B, 1404 can be individually addressed to form an active matrix display.
With the use of the reflective materials 1405 for optical confinement, it is crucial to have one or more openings for extraction of the light emitted from AlGaInP LED 1404. Because the difference in refractive index between air (n=1) and AlGaInP (n=3.5) is high, only a small portion of the light emitted from AlGaInP LED 1404 can be extracted through the AlGaInP material and most of the light is trapped within the device. As a result, an optical element that has a refractive index between the air and AlGaInP can be utilized to enhance light extraction from the AlGaInP LED 1404. This element may be comprised of any optically transparent materials that is either electrically conductive or insulative, which includes TCOs and dielectric materials. By employing TCOs, a limited area of the AlGaInP LED 1404 can emit light. Moreover, the shape of the optical element can be designed such for further enhancement of light extraction.
FIG.15 is a cross-sectional side view of a structure 1500 fabricated on a substrate 1501 comprised of two InGaN micro-LEDs 1502A, 1502B, also labeled as InGan PLED 1 and PLED 2, respectively, in the figure, wherein the InGaN micro-LEDs 1502A, 1502B are bonded using bonding materials 1503 onto an AlGaInP LED 1504. The two InGaN micro- LEDs 1502A, 1502B may emit light at different wavelengths, for example, blue and green wavelengths, respectively, while the AlGaInP LED 1504 emits at still another wavelength, for example, a red wavelength, with the combination of red, green and blue light resulting in a white light emitting device.
In this example, the InGaN micro-LEDs 1502A, 1502B are bonded to reflective materials 1505 deposited on the AlGaInP LED 1504, wherein the reflective materials 1505 cover most of the surface of the AlGaInP LED 1504, except for an area where an optical element 1506 is positioned. Moreover, the geometry of the optical element 1506 has significant effects on the light extraction from the AlGaInP LED 1504, wherein a top surface of the optical element 1506 provides an opening 1507 for extraction of the light emitted from AlGaInP LED 1504. Sidewall emission from the AlGaInP LED 1504 can be reduced or minimized by modulating the sidewall geometry or by employing reflective materials to cover the sidewall.
FIG.16 is a top view of a completed assembly 1600 comprised of an AlGaInP LED 1601, wherein three 2x4 arrays 1602 of InGaN micro-LEDs 1603A, 1603B, also labeled as InGan PLED 1 and PLED 2, respectively, in the figure, wherein the InGaN micro-LEDs 1603A, 1603B are bonded to the AlGaInP LED 1601 with two 1x4 arrays 1604 of optical elements 1605 positioned between the 2x4 arrays 1602 of InGaN micro-LEDs 1603A, 1603B to provide openings 1606 for the extraction of light from the AlGaInP LED 16-1. Electrical contacts 1607 for the AlGaInP LED 1601 are shown near the top and bottom edges of the AlGaInP LED 1601, while electrical contacts (not shown) for the InGaN micro-LEDs 1603A, 1603B are on the InGaN micro-LEDs 1603A, 1603B. Electrical conductors, contacts, ICs and other features, may be fabricated on the AlGaInP LED 1601 or the InGaN micro-LEDs 1603A, 1603B.
Using this approach, the AlGaInP LED 1601 with its arrays 1602 of the InGaN micro-LEDs 1603A, 1603B and arrays 1604 of optical elements 1605 can be transferred using a conventional pick-and-place method due to its larger standard LED dimensions. By placing AlGaInP LEDs 1601, each with their arrays 1602 of InGaN micro-LEDs 1603A, 1603B, next to each other, displays with a larger number of pixels can be manufactured.
FIG.17 is a top view of a full-color display 1700 comprised of a 2x2 array of AlGaInP LEDs 1701, wherein each of the AlGaInP LEDs 1701 includes two 2x5 arrays 1702 of InGaN micro-LEDs 1703A, 1703B, also labeled as PLED 1 and PLED 2, respectively, in the figure, and a 1x5 array 1704 of optical elements 1705 positioned between the two 2x5 arrays 1702 of InGaN micro-LEDs 1703A, 1703B to provide openings 1706 for the extraction of light from the AlGaInP LED 1701. Electrical contacts 1707 for the AlGaInP LED 1701 are shown near the top and bottom edges of the AlGaInP LED 1701, while electrical contacts (not shown) for the InGaN micro-LEDs 1703A, 1703B are on the InGaN micro-LEDs 1703A, 1703B. Electrical conductors, contacts, ICs and other features, may be fabricated on the AlGaInP LED 1701 or the InGaN micro-LEDs 1703A, 1703B. Benefits and Advantages
The present invention provides a number of benefits and advantages. As the development of smart portable devices becomes more advanced, the commercial desire of better and novel displays, including foldable displays and displays with ultra-high resolution, has been increasing. For current display technologies, namely LCDs and OLED displays, are unable to achieve the standards for next-generation displays due to their inherent limitations. Moreover, micro-LEDs have been considered as the most promising candidate for future display candidate, which have the benefits, such as extremely high resolution, excellent energy efficiency, and long operating lifespan. However, the key barriers of micro-LED displays are in the manufacturing processes, especially in the device and yield steps.
This invention reports a method that can resolve the device and yield issues with simple and industrial-available techniques. In additional to this advantage, this invention also describes solution for red light-emitter of displays and strategy to sustain high efficiency for micro-LED displays. AlGaInP materials have been used for conventional red-light emitter due to its high efficiency in standard LED dimensions, but this feature vanishes as the size decreases. On the other hand, InGaN can cover the entire visible spectrum by varying the alloy composition, yet the efficiency of InGaN red emitter is low due to high lattice mismatch in the light-emitting region. Therefore, the red emitter of micro-LED displays is unclear. In this invention, the property of high efficiency of AlGaInP LEDs is maintained while efficient blue and green InGaN micro-LEDs are used. This invention solves some important challenges in micro-LED displays and traditional LED manufacturers will be interested in this invention. Conclusion
This concludes the description of the present invention. The foregoing description of one or more embodiments of the invention has been presented for the purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed. Many modifications and variations are possible in light of the above teaching. It is intended that the scope of the invention be limited not by this detailed description, but rather by the claims appended hereto.

Claims

WHAT IS CLAIMED IS: 1. A device, comprising:
one or more tiles comprised of a plurality of light emitting diodes (LEDs) on a substrate, wherein the plurality of LEDs is comprised of red, green and blue light emitting LEDs and includes at least one array of integrated micro-sized LEDs (micro-LEDs).
2. The device of claim 1, wherein the green or blue light emitting LEDs comprise one or more InGaN-based LEDs and the red light emitting LEDs comprise one or more AlGaInP-based LEDs.
3. The device of claim 1, wherein the micro-LEDs have mesa dimensions less than 100 x 100 mm2.
4. The device of claim 1, wherein the array of micro-LEDs is an n x m array of the micro-LEDs.
5. The device of claim 1, wherein the tiles comprise a P x Q array of the tiles.
6. The device of claim 1, wherein the blue and green light emitting LEDs are fabricated on the substrate, and the red light emitting LEDs are transferred to the substrate.
7. The device of claim 1, wherein the red light emitting LEDs are fabricated on the substrate, and the blue and green light emitting LEDs are transferred to the substrate.
8. The device of claim 1, wherein the tiles are sized for mass transfer of the micro-LEDs.
9. The device of claim 1, wherein the tiles are diced from the substrate.
10. The device of claim 1, further comprising a display comprised of the tiles.
11. The device of claim 10, wherein the display is formed by assembling the tiles using a pick-and-place technique.
12. The device of claim 10, wherein the substrate is transparent and the display is formed by stacking the tiles.
13. The device of claim 12, wherein one or more mechanical supports separate the tiles, and the mechanical supports are selected according to their optical transparency, mechanical stiffness, thermal conductivity and electrical properties for specific applications.
14. The device of claim 1, wherein a reflective material is deposited on a surface of the substrate between at least some of the LEDs, one or more openings exist on the surface of the substrate where no reflective material is deposited, in order to extract the light from the surface of the substrate, and one or more optical elements are positioned at the openings to enhance the light extracted from the surface of the substrate.
15. The device of claim 14, wherein the reflective material provides for optical confinement of the light emitted from the LEDs, to prevent interference between light emitted from the LEDs.
16. The device of claim 14, wherein the reflective material provides for electrical isolation between contacts of the LEDs, to separate electrical contacts of the LEDs.
17. A method, comprising:
fabricating one or more tiles comprised of a plurality of light emitting diodes (LEDs) on a substrate, wherein the plurality of LEDs is comprised of red, green and blue light emitting devices and includes at least one array of integrated micro-sized LEDs (micro- LEDs).
18. A method, comprising:
generating a display using one or more tiles comprised of a plurality of light emitting diodes (LEDs) on a substrate, wherein the plurality of LEDs is comprised of red, green and blue light emitting devices and includes at least one array of integrated micro-sized LEDs (micro-LEDs).
PCT/US2020/030708 2019-04-30 2020-04-30 Integration and mass transfer of micro-leds WO2020223481A1 (en)

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Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP4687109B2 (en) * 2005-01-07 2011-05-25 ソニー株式会社 Manufacturing method of integrated light emitting diode
US20140226329A1 (en) * 2013-02-11 2014-08-14 Nthdegree Technologies Worldwide Inc. Interlocking light sheet tiles
US20150372053A1 (en) * 2014-06-18 2015-12-24 X-Celeprint Limited Micro assembled led displays and lighting elements
US9653642B1 (en) * 2014-12-23 2017-05-16 Soraa Laser Diode, Inc. Manufacturable RGB display based on thin film gallium and nitrogen containing light emitting diodes
CN107331680A (en) * 2017-07-05 2017-11-07 上海天马微电子有限公司 A kind of display panel and its manufacture method, display device

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP4687109B2 (en) * 2005-01-07 2011-05-25 ソニー株式会社 Manufacturing method of integrated light emitting diode
US20140226329A1 (en) * 2013-02-11 2014-08-14 Nthdegree Technologies Worldwide Inc. Interlocking light sheet tiles
US20150372053A1 (en) * 2014-06-18 2015-12-24 X-Celeprint Limited Micro assembled led displays and lighting elements
US9653642B1 (en) * 2014-12-23 2017-05-16 Soraa Laser Diode, Inc. Manufacturable RGB display based on thin film gallium and nitrogen containing light emitting diodes
CN107331680A (en) * 2017-07-05 2017-11-07 上海天马微电子有限公司 A kind of display panel and its manufacture method, display device

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