Method for removing gallium nitride residue and mass transfer method

Abstract

The application relates to a method for removing gallium nitride residues and a mass transfer method. The method for removing gallium nitride residues comprises the following steps: providing a circuit backboard; bonding a plurality of light emitting chips on the circuit backboard; forming a protective layer on the circuit backboard; the height of the protective layer relative to the circuit backboard is lower than the height of the surface of the light emitting chip away from the circuit backboard; and cleaning each light emitting chip through an acid solution to remove the gallium nitride residues on the surface of each light emitting chip. By forming the protective layer, the gallium nitride residues on the light emitting chip can be exposed, so that the gallium nitride residues can be in contact with the acid solution and corroded to be removed, the light emitting effect of the light emitting chip is improved, the visual correction is optimized, meanwhile, the protective layer can block the acid solution from contacting the circuit backboard, so that the circuit backboard is protected by the protective layer and is prevented from being corroded and damaged, the yield and product reliability are improved.

Description

Technical Field

[0001] This application relates to the field of semiconductor process technology, and in particular to a method for removing gallium nitride residue and a mass transfer method. Background Technology

[0002] Micro LED chips are grown on sapphire substrates by depositing gallium nitride (GaN) and gallium arsenide (GaAs) epitaxial structures. Since sapphire itself is relatively thick and has slow thermal conductivity, the GaN layer needs to be removed by laser and then bonded to the circuit backplane through mass transfer process to realize the product application of Micro LED.

[0003] Lasers can decompose the surface GaN, but GaN remains on the chip surface. Currently, Micro LED products generally use bottom-emitting structures, and the residual GaN will seriously affect the light-emitting effect of Micro LEDs, leading to reduced visibility.

[0004] However, existing acid pickling methods risk damaging the pads (UBM) and drive circuits on the circuit backplane, leading to reduced yield and decreased product reliability.

[0005] Therefore, how to remove gallium nitride residue without damaging the pads and drive circuits on the circuit backplane is an urgent problem to be solved. Summary of the Invention

[0006] In view of the shortcomings of the prior art, the purpose of this application is to provide a method for removing gallium nitride residue and a mass transfer method, which aims to solve the problem of removing gallium nitride residue without damaging the pads and drive circuits on the circuit backplane.

[0007] A method for removing gallium nitride residue includes:

[0008] A circuit backplane is provided; wherein a plurality of light-emitting chips are bonded on the circuit backplane; a protective layer is formed on the circuit backplane; wherein the height of the protective layer relative to the circuit backplane is lower than the height of the surface of the light-emitting chips away from the circuit backplane; and each of the light-emitting chips is cleaned with an acidic solution to remove gallium nitride residue from the surface of each of the light-emitting chips.

[0009] By forming a protective layer on the circuit backplane and setting the height of the protective layer to be lower than the height of the light-emitting chip, gallium nitride residue on the light-emitting chip can be exposed. This allows the gallium nitride residue to come into contact with the acidic solution and undergo a corrosion reaction to be removed, improving the light-emitting effect of the light-emitting chip and optimizing visual calibration. At the same time, the protective layer can prevent the acidic solution from contacting the circuit backplane, thus protecting the circuit backplane from corrosion and damage, which can improve yield and product reliability.

[0010] Optionally, the electrodes of the light-emitting chip are bonded to the pads of the circuit backplane; the height of the protective layer relative to the circuit backplane is not less than the total height of the pads and the electrodes. Providing such a protective layer allows for the exposure of gallium nitride residue on the surface of the light-emitting chip while simultaneously covering the circuit backplane.

[0011] Optionally, the electrodes of the light-emitting chip are bonded to the pads of the circuit backplane; the height of the protective layer relative to the circuit backplane is between the height of the pads and the total height of the electrodes plus the pad height. This protective layer, on the one hand, exposes gallium nitride residue on the surface of the light-emitting chip; on the other hand, it covers the circuit backplane, encapsulates the first and second pads, and can encapsulate part of the first and second electrodes, preventing the first and second pads, and part of the first and second electrodes from reacting with the acidic solution. This protects the driving circuit of the circuit backplane, as well as the first and second pads, and part of the first and second electrodes, further improving yield and product reliability.

[0012] Optionally, the protective layer is formed using inkjet printing. Inkjet printing can form the desired structure at various sizes. Since Micro LEDs and Mini LEDs are at the micrometer level, inkjet printing can meet the processing needs of micro-scale applications. Furthermore, inkjet printing is a relatively mature technology with low processing difficulty and is easy to implement.

[0013] Optionally, the step of forming the protective layer includes: providing an inkjet printing device, the inkjet printing device including a plurality of printheads; inserting each of the printheads between two adjacent light-emitting chips, and spraying a protective layer of a predetermined thickness onto the circuit backplane through each of the printheads; and baking and curing the protective layer. Setting multiple printheads extending into the gaps between the multiple light-emitting chips allows for a more uniform formation of the protective layer, ensuring that the circuit backplane is evenly covered and each light-emitting chip is evenly wrapped, avoiding localized failure of the protective effect due to uneven coverage or wrapping. Simultaneously, using multiple printheads to spray ink and print the protective layer improves the efficiency of the protective layer formation.

[0014] Optionally, the predetermined thickness of the sprayed protective layer is between 4μm and 6μm. This allows the protective layer to cover the circuit backplane and encapsulate the electrodes of each pad and the light-emitting chip, providing excellent protection.

[0015] Optionally, the acidic solution is hydrochloric acid with a concentration between 20% and 30%. Hydrochloric acid is a commonly used chemical raw material, readily available, and inexpensive. Furthermore, pre-concentrated hydrochloric acid, such as 25% concentration, is readily available on the market, eliminating the need for self-preparation and saving on processing costs.

[0016] Optionally, the process also includes removing the protective layer after the light-emitting chip has been cleaned. Removing the protective layer allows the circuit backplane and the light-emitting chip to be fully exposed, avoiding any impact of the protective layer on the light-emitting effect. Furthermore, if any light-emitting chip is damaged, the absence of a protective layer makes repair easier.

[0017] Based on the same inventive concept, this application also provides a mass transfer method, comprising: providing a substrate on which a plurality of light-emitting chips are formed; bonding the side of the substrate having the light-emitting chips to a circuit backplane; peeling off the substrate with a laser; and processing the light-emitting chips by any of the foregoing embodiments for removing gallium nitride residue.

[0018] By employing the gallium nitride (GaN) residue removal method of this application, a protective layer is formed on the circuit backplane, and the height of the protective layer is set lower than the height of the light-emitting chip. This exposes the GaN residue on the light-emitting chip, allowing it to come into contact with the acidic solution and undergo a corrosion reaction to be removed. This improves the light-emitting effect of the light-emitting chip and optimizes visual calibration. At the same time, the protective layer can prevent the acidic solution from contacting the circuit backplane, thus protecting the circuit backplane from corrosion and damage, thereby improving yield and product reliability.

[0019] Optionally, the substrate includes any one of a growth substrate, a transient substrate, or a temporary substrate. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of a step in a mass transfer method according to one embodiment.

[0021] Figure 2 This is a schematic diagram of a step in a mass transfer method according to one embodiment.

[0022] Figure 3 This is a schematic diagram of a step in a mass transfer method according to one embodiment.

[0023] Figure 4 This is a schematic diagram of a step in a mass transfer method according to one embodiment.

[0024] Figure 5 This is a flowchart illustrating a method for removing gallium nitride residue according to one embodiment.

[0025] Figure 6 This is a schematic diagram of a step in a method for removing gallium nitride residue according to an embodiment.

[0026] Figure 7 This is a schematic diagram of a step in a method for removing gallium nitride residue according to an embodiment.

[0027] Figure 8 This is a schematic diagram of a step in a method for removing gallium nitride residue according to an embodiment.

[0028] Figure 9 This is a schematic diagram of a step in a method for removing gallium nitride residue according to an embodiment.

[0029] Figure 10 This is a schematic diagram of a step in a method for removing gallium nitride residue according to an embodiment.

[0030] Explanation of reference numerals in the attached figures:

[0031] 10 - Growth substrate, 11 - Gallium nitride layer, 12 - Gallium nitride residue;

[0032] 20 - Light-emitting chip, 21 - Epitaxial structure, 22 - First electrode, 23 - Second electrode;

[0033] 30 - Circuit backplane;

[0034] 40 - Inkjet printing unit; 41 - Main body; 42 - Printhead;

[0035] 50 - Protective layer. Detailed Implementation

[0036] To facilitate understanding of this application, a more complete description will be provided below with reference to the accompanying drawings. Preferred embodiments of this application are shown in the drawings. However, this application can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a more thorough and complete understanding of the disclosure of this application.

[0037] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein in the specification of this application is for the purpose of describing particular embodiments only and is not intended to be limiting of this application.

[0038] Micro LED chips are grown on sapphire substrates by depositing gallium nitride (GaN) and gallium arsenide (GaAs) epitaxial structures. Since sapphire itself is relatively thick and has slow thermal conductivity, the GaN layer needs to be removed by laser and then bonded to the circuit backplane through mass transfer process to realize the product application of Micro LED.

[0039] Lasers can decompose the surface GaN, but GaN remains on the chip surface. Currently, Micro LED products generally use bottom-emitting structures, and the residual GaN will seriously affect the light-emitting effect of Micro LEDs, leading to reduced visibility.

[0040] However, existing acid pickling methods risk damaging the pads (UBM) and drive circuits on the circuit backplane, leading to reduced yield and decreased product reliability.

[0041] Therefore, how to remove gallium nitride residue without damaging the pads and drive circuits on the circuit backplane is an urgent problem to be solved.

[0042] Therefore, this application aims to provide a solution that can solve the above-mentioned technical problems, the details of which will be described in subsequent embodiments.

[0043] This application provides a mass transfer method, including steps one to five, which are described in detail below.

[0044] Please refer to Figure 1 Step 1: Grow a light-emitting chip 20 on the growth substrate 10.

[0045] The growth substrate 10 can be sapphire, and the light-emitting chip 20 can be a micro LED chip, a mini LED chip, or a conventional LED chip. Multiple light-emitting chips 20 can be distributed at intervals on the growth substrate 10.

[0046] A gallium nitride (GaN) layer 11 is formed on the growth substrate 10, and a light-emitting chip 20 is grown on the GaN layer 11. The light-emitting chip 20 includes an epitaxial structure 21, a first electrode 22, and a second electrode 23. The epitaxial structure 21 is grown on the GaN layer 11, and the first electrode 22 and the second electrode 23 are formed alternately on the surface of the epitaxial structure 21 facing away from the GaN layer 11. The first electrode 22 can be a P-electrode, and the second electrode 23 can be an N-electrode. For the specific internal structure of the light-emitting chip 20, as well as the specific structures of the epitaxial structure 21, the first electrode 22, and the second electrode 23, please refer to the prior art, which will not be elaborated in detail here. It should be understood that the structures of the epitaxial structure 21, the first electrode 22, and the second electrode 23 may be different depending on the type of light-emitting chip 20.

[0047] Please refer to Figure 2 Step 2: Bond the light-emitting chip 20 to the circuit backplate 30.

[0048] Specifically, step two involves bonding the electrodes of the light-emitting chip 20 to the pads of the circuit backplane 30. Further, the circuit backplane 30 has a first pad (not shown in the figure) and a second pad (not shown in the figure), as well as a driving circuit (not shown in the figure) connected to the first and second pads. During bonding, the first electrode 22 is soldered to the first pad, and the second electrode 23 is soldered to the second pad.

[0049] In step two, several light-emitting chips 20 are formed on a substrate, which can be any one of a growth substrate 10, a transient substrate, or a temporary substrate. Depending on the type of substrate, various technical routes are possible, such as: 1) bonding the light-emitting chips 20 on the growth substrate 10 to a circuit backplane 30; 2) transferring the light-emitting chips 20 on the growth substrate 10 to a transient substrate, and then bonding the light-emitting chips 20 on the transient substrate to the circuit backplane 30; 3) transferring the light-emitting chips 20 on the growth substrate 10 to a temporary substrate, transferring the light-emitting chips 20 on the temporary substrate to a transient substrate, and then bonding the light-emitting chips 20 on the transient substrate to the circuit backplane 30. The growth substrate 10, transient substrate, and temporary substrate can be made of the same material, such as sapphire. The choice of substrate type mainly depends on which steps in the mass transfer process the substrate is used for or which scheme is adopted. For example, the growth substrate 10 is used to grow the light-emitting chips 20, and then, depending on the scheme adopted in the mass transfer process, any one of technical routes 1), 2), or 3) can be selected.

[0050] When the number of light-emitting chips 20 grown on the growth substrate 10 is a plurality of spaced-apart chips, the number of light-emitting chips 20 on the bonded current backplane is also a plurality of spaced-apart chips. The types of light-emitting chips 20 may include red light-emitting chips, green light-emitting chips, blue light-emitting chips, etc. One red light-emitting chip, one green light-emitting chip, and one blue light-emitting chip can constitute one pixel, and multiple pixels can display a color image.

[0051] Please refer to Figure 3 Step 3: Remove the growth substrate 10 by laser stripping process.

[0052] When the growth substrate 10 is irradiated with a laser, the gallium nitride layer 11 decomposes under the action of the laser, generating nitrogen gas and liquid gallium metal, thereby allowing the growth substrate 10 and the light-emitting chip 20 to be separated.

[0053] Please refer to Figure 4 After the growth substrate 10 is removed, there is still gallium nitride residue 12 on the surface of the light-emitting chip 20. Gallium nitride residue 12 will affect the light-emitting effect and needs to be removed. Gallium nitride residue 12 can be distributed arbitrarily on the surface of the light-emitting chip 20 facing away from the circuit backplate 30, such as covering the entire surface or being divided into multiple pieces arranged in multiple positions on the surface.

[0054] Please refer to Figure 5 Step 4: Remove gallium nitride residue 12.

[0055] When removing gallium nitride residue 12, the light-emitting chip 20 is processed using a method for removing gallium nitride residue 12 provided in the embodiments of this application, specifically including steps S1 and S2.

[0056] Please refer to Figures 5 to 7 Step S1: A protective layer 50 is formed on the circuit backplate 30. The height of the protective layer 50 relative to the circuit backplate 30 (i.e., the thickness of the protective layer 50) is lower than the height of the surface of the light-emitting chip 20 away from the circuit backplate 30.

[0057] The method for forming the protective layer 50 on the circuit backplane 30 can be any feasible method, and some embodiments are provided later in this application, but are not limited to the embodiments provided in this application. The material of the protective layer 50 is an acid-resistant material, such as tetrafluoroethylene, epoxy resin, phenolic resin, polyimide, etc., and is not specifically limited. By setting such a height for the protective layer 50, the gallium nitride residue 12 on the light-emitting chip 20 can be exposed, while covering the circuit backplane 30 to provide protection.

[0058] Please refer to Figure 5 , Figure 8 and Figure 9 Step S2: Clean each light-emitting chip 20 with an acidic solution to remove gallium nitride residue 12 from the surface of each light-emitting chip 20.

[0059] Gallium nitride residue 12 can be removed by chemical reaction with acidic solution, and the acidic solution will not come into contact with circuit backplane 30 due to the barrier of protective layer 50.

[0060] Optionally, the acidic solution is hydrochloric acid. Specifically, hydrochloric acid with a concentration between 20% and 30% is used. Optionally, the concentration of hydrochloric acid can be 20%, 21%, 22%, 23%, 24%, 25%, 26%, 27%, 28%, 29%, 30%, etc., with a preferred concentration of 25%. Hydrochloric acid is a commonly used chemical raw material, readily available, and inexpensive. Furthermore, pre-concentrated hydrochloric acid, such as 25% concentration, is readily available on the market and can be purchased directly, eliminating the need for self-preparation and saving on processing costs.

[0061] Therefore, by forming a protective layer 50 on the circuit backplane 30 and setting the height of the protective layer 50 to be lower than the height of the light-emitting chip 20, the gallium nitride residue 12 on the light-emitting chip 20 can be exposed, allowing the gallium nitride residue 12 to come into contact with the acidic solution and undergo a corrosion reaction to be removed, thereby improving the light-emitting effect of the light-emitting chip 20 and optimizing visual calibration. At the same time, the protective layer 50 can prevent the acidic solution from contacting the circuit backplane 30, so that the circuit backplane 30 is protected by the protective layer 50, avoiding corrosion and damage to the circuit backplane 30, thereby improving yield and product reliability.

[0062] Optional, please refer to Figure 7 The height of the protective layer 50 relative to the circuit backplane 30 is not less than the total height of the first pad and the first electrode 22, and not less than the total height of the second pad and the second electrode 23. In other words, the height of the protective layer 50 relative to the circuit backplane 30 is not less than the higher of the first electrode 22 and the second electrode 23.

[0063] The protective layer 50 serves two purposes: firstly, it exposes the gallium nitride residue 12 on the surface of the light-emitting chip 20; secondly, it covers the circuit backplane 30 and encapsulates the first pad, the second pad, the first electrode 22, and the second electrode 23, preventing them from reacting with the acidic solution. This protects the driving circuit of the circuit backplane 30, as well as the first pad, the second pad, the first electrode 22, and the second electrode 23, further improving yield and product reliability.

[0064] Optionally, when the light-emitting chip 20 is a Micro LED, the height of the protective layer 50 relative to the circuit backplate 30 can be 5μm±1μm, so that the protective layer 50 can cover the circuit backplate 30 and cover each pad and the electrode of the light-emitting chip 20, providing excellent protection.

[0065] Optional, please refer to Figure 7 The height of the protective layer 50 relative to the circuit backplane 30 is between the height of the pad and the total height of the electrode plus the pad height. Specifically, the height of the protective layer 50 relative to the circuit backplane 30 is between the height of the first pad and the total height of the first pad plus the first electrode 22, and also between the height of the second pad and the total height of the second pad plus the second electrode 23. In other words, the protective layer 50 covers the first and second pads, but does not completely cover the first electrode 22 and the second electrode 23.

[0066] The protective layer 50 serves two purposes: firstly, it exposes the gallium nitride residue 12 on the surface of the light-emitting chip 20; secondly, it covers the circuit backplane 30 and encapsulates the first pad, the second pad, a portion of the first electrode 22, and the second electrode 23. This prevents the first pad, the second pad, a portion of the first electrode 22, and the second electrode 23 from reacting with the acidic solution, thus protecting the driving circuit of the circuit backplane 30, as well as the first pad, the second pad, a portion of the first electrode 22, and the second electrode 23, further improving yield and product reliability.

[0067] Optionally, the protective layer 50 is formed using inkjet printing. Alternatively, piezoelectric ceramic inkjet printing technology can be used to form the protective layer 50. Piezoelectric ceramic inkjet printing technology: Many tiny piezoelectric ceramics are placed near the printhead 42. These piezoelectric ceramics exhibit bending deformation under varying voltage. When an image information voltage is applied to the piezoelectric ceramics, their expansion, contraction, vibration, and deformation change with the image information voltage, ensuring that the ink in the printhead is ejected uniformly and accurately under stable conditions at room temperature and pressure. Piezoelectric ceramic inkjet printing systems can print almost any type of ink, including water-soluble and solvent-based inks.

[0068] The protective layer 50 formed by inkjet printing can form the required structure at various sizes. Since the size of MicroLED and Mini LED is at the micron level, inkjet printing can meet the processing needs of micro-sizes. Moreover, inkjet printing is a relatively mature technology with low process difficulty and is easy to implement.

[0069] Optional, please refer to Figure 6 The steps for forming the protective layer 50 include:

[0070] An inkjet printing apparatus 40 is provided, which includes a main body 41 and a plurality of printheads 42. The plurality of printheads 42 are spaced apart on the main body 41 and are used to eject ink to print a protective layer 50.

[0071] The inkjet printing device 40 is moved toward the circuit backplate 30, and a plurality of printheads 42 are inserted one by one into the gaps between a plurality of light-emitting chips 20. Each printhead 42 is inserted between two adjacent light-emitting chips 20, and a protective layer 50 of a predetermined thickness is sprayed onto the circuit backplate 30 through each printhead 42.

[0072] The inkjet printing device 40 and the circuit backplate 30 can be moved towards each other, either one can move while the other remains stationary, or both can move. The main body 41 and the printhead 42 may be provided with flow channels for the material of the protective layer 50 to flow through. The material storage tank of the protective layer 50 and the main body 41 can also be connected by pipes. The material of the protective layer 50 is evenly distributed to multiple printheads 42 for spraying through the main body 41.

[0073] By inserting multiple printheads 42 into the gaps between multiple light-emitting chips 20, the protective layer 50 can be formed more uniformly, ensuring that the circuit backplate 30 is evenly covered and each light-emitting chip 20 is evenly wrapped, thus avoiding the failure of local protection caused by uneven coverage or wrapping. At the same time, the multiple printheads 42 eject ink to print the protective layer 50, which can improve the efficiency of forming the protective layer 50.

[0074] After the protective layer 50 is sprayed, it is baked and cured to form a stable structure, thereby providing protection.

[0075] Please refer to Figure 9 and Figure 10 The mass transfer method in this application embodiment also includes step five: after the light-emitting chip 20 is cleaned, the protective layer 50 is removed.

[0076] Various feasible processes can be used to remove the protective layer 50, and no specific process is limited. Removing the protective layer 50 allows the circuit backplane 30 and the light-emitting chip 20 to be fully exposed, avoiding the influence of the protective layer 50 on the light-emitting effect. At the same time, if the light-emitting chip 20 is damaged, it is easier to repair it because there is no obstruction from the protective layer 50.

[0077] The mass transfer method of this application embodiment removes gallium nitride residue 12 by forming a protective layer 50 on the circuit backplane 30. The height of the protective layer 50 is set lower than the height of the light-emitting chip 20, exposing the gallium nitride residue 12 on the light-emitting chip 20. This allows the gallium nitride residue 12 to contact with the acidic solution and undergo a corrosion reaction to be removed, improving the light-emitting effect of the light-emitting chip 20 and optimizing visual calibration. Simultaneously, the protective layer 50 prevents the acidic solution from contacting the circuit backplane 30, protecting the circuit backplane 30 from corrosion and damage, thus improving yield and product reliability.

[0078] It should be understood that the application of this application is not limited to the examples above. Those skilled in the art can make improvements or modifications based on the above description, and all such improvements and modifications should fall within the protection scope of the appended claims.

Claims

1. A method for removing gallium nitride residue, characterized in that, include: A circuit backplane is provided; wherein, a plurality of light-emitting chips are bonded on the circuit backplane; A protective layer is formed on a circuit backplane; wherein the height of the protective layer relative to the circuit backplane is lower than the height of the surface of the light-emitting chip away from the circuit backplane; and Each of the light-emitting chips is cleaned with an acidic solution to remove gallium nitride residue from the surface of each of the light-emitting chips; The protective layer is made of an acid-resistant material, and the height of the protective layer relative to the circuit backplane is greater than or equal to the height of the solder pads on the circuit backplane.

2. The method for removing gallium nitride residue as described in claim 1, characterized in that, The electrodes of the light-emitting chip are bonded to the pads of the circuit backplane; The height of the protective layer relative to the circuit backplane is not less than the total height of the pads and the electrodes.

3. The method for removing gallium nitride residue as described in claim 1, characterized in that, The electrodes of the light-emitting chip are bonded to the pads of the circuit backplane; The height of the protective layer relative to the circuit backplane is between the height of the pad and the total height of the electrode plus the height of the pad.

4. The method for removing gallium nitride residue as described in claim 1, characterized in that, The protective layer is formed using an inkjet printing process.

5. The method for removing gallium nitride residue as described in claim 4, characterized in that, The step of forming the protective layer includes: An inkjet printing apparatus is provided, the inkjet printing apparatus comprising a plurality of printheads; Each of the nozzles is inserted between two adjacent light-emitting chips, and a protective layer of a predetermined thickness is sprayed onto the circuit backplane through each nozzle. The protective layer is then baked and cured.

6. The method for removing gallium nitride residue as described in claim 5, characterized in that, The predetermined thickness of the sprayed protective layer is between 4 μm and 6 μm.

7. The method for removing gallium nitride residue as described in claim 1, characterized in that, The acidic solution is hydrochloric acid with a concentration between 20% and 30%.

8. The method for removing gallium nitride residue as described in claim 1, characterized in that, Also includes: After the light-emitting chip has been cleaned, the protective layer is removed.

9. A mass transfer method, characterized in that, include: A substrate is provided on which a plurality of light-emitting chips are formed; The side of the substrate with the light-emitting chip is bonded to the circuit backplane; The substrate is stripped by a laser, and the light-emitting chip is processed by the method for removing gallium nitride residue as described in any one of claims 1 to 6.

10. The mass transfer method as described in claim 9, characterized in that, The substrate includes any one of a growth substrate, a transient substrate, or a temporary substrate.

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