Epitaxial layer transfer method and manufacturing method of light emitting chip

Abstract

The application relates to an epitaxial layer transfer method and manufacturing method of a light-emitting chip. The epitaxial layer transfer method of the light-emitting chip comprises the following steps: forming a semi-solid first etching type glue layer on a bearing substrate, and forming a semi-solid second etching type glue layer on an epitaxial layer borne by a substrate; thinning the thickness of at least one of the first etching type glue layer and the second etching type glue layer through etching; aligning and pressing the first etching type glue layer and the second etching type glue layer after the thinning treatment; and removing the substrate. The etching type glue layer can be etched to any required thickness through control of etching rate and etching time, so that a thin enough etching type glue layer can be manufactured. After the etching type glue layer is thinned and then bonded, the overall thickness of a bonding layer formed after the first etching type glue layer and the second etching type glue layer are pressed together can be reduced, laser ablation in a subsequent manufacturing process is facilitated, the residual glue layer on the light-emitting surface of the light-emitting chip can be reduced, and the light-emitting effect of the light-emitting chip is optimized.

Description

Technical Field

[0001] This application relates to the technical field of LED displays, and in particular to a method for transferring the epitaxial layer of a light-emitting chip and a method for fabricating it. Background Technology

[0002] Micro-LED (Micro Light Emitting Diode) has been sought after by various manufacturers due to its advantages of high brightness, wide color gamut coverage and high contrast, and is known as the next generation of display devices.

[0003] Currently, the fabrication process of some light-emitting chips requires the transfer of epitaxial layers. This transfer typically involves spin-coating a bonding adhesive layer onto the epitaxial layer. However, due to limitations in adhesive viscosity and the spin-coating process, the thinnest possible adhesive layer for spin-coating remains relatively thick. This thick adhesive layer results in significant residue on the light-emitting surface of the chip during subsequent fabrication processes, negatively impacting the light emission performance.

[0004] Therefore, how to reduce the thickness of the bonding adhesive layer is an urgent problem to be solved. Summary of the Invention

[0005] In view of the shortcomings of the above-mentioned related technologies, the purpose of this application is to provide an epitaxial layer transfer method and fabrication method for a light-emitting chip, which aims to solve the technical problem that a thick bonding adhesive layer affects the light emission effect of the light-emitting chip.

[0006] A method for transferring the epitaxial layer of a light-emitting chip includes:

[0007] A semi-solid first etchable adhesive layer is formed on the substrate, and a semi-solid second etchable adhesive layer is formed on the epitaxial layer supported by the substrate.

[0008] The thickness of at least one of the first etchable adhesive layer and the second etchable adhesive layer is reduced by etching;

[0009] The first etchable adhesive layer and the second etchable adhesive layer, after being thinned, are aligned and pressed together;

[0010] Remove the substrate.

[0011] In the aforementioned epitaxial layer transfer method for the light-emitting chip, after forming the first etchable adhesive layer and the second etchable adhesive layer, at least one of the first and second etchable adhesive layers is further etched to thin it. By controlling the etching rate and etching time, the etchable adhesive layer can be etched to any desired thickness, thereby producing a sufficiently thin etchable adhesive layer. Thinning the etchable adhesive layer before bonding reduces the overall thickness of the bonding layer formed after the first and second etchable adhesive layers are pressed together. A reduced bonding layer thickness facilitates laser lift-off in subsequent fabrication processes, reduces adhesive residue on the light-emitting surface of the light-emitting chip, and optimizes the light emission effect. Furthermore, etching the etchable adhesive layer increases its surface roughness, thereby increasing the contact area between the first and second etchable adhesive layers, improving their bonding strength, and increasing the bonding yield.

[0012] Optionally, after thinning the thickness of at least one of the first etched adhesive layer and the second etched adhesive layer by etching, before aligning and bonding the thinned first etched adhesive layer and the second etched adhesive layer, the method further includes: performing a surface roughening treatment on at least one of the first etched adhesive layer and the second etched adhesive layer. Surface roughening treatment on the etched adhesive layer can further improve the roughness of the etched adhesive layer, thereby further improving the bonding strength between the first etched adhesive layer and the second etched adhesive layer and improving the bonding yield.

[0013] Based on the same inventive concept, this application also provides a method for manufacturing a light-emitting chip, comprising:

[0014] The epitaxial layer transfer of the light-emitting chip is completed using the epitaxial layer transfer method described above.

[0015] Electrodes are fabricated on the epitaxial layer.

[0016] In the above-described method for fabricating a light-emitting chip, the epitaxial layer transfer method is used to complete the epitaxial layer transfer. This reduces the overall thickness of the bonding layer formed after the first and second etched adhesive layers are laminated. The reduced bonding layer thickness facilitates laser lift-off in subsequent fabrication processes, minimizing adhesive residue on the light-emitting surface of the chip and resulting in better light emission. Furthermore, etching the adhesive layer increases its surface roughness, thereby increasing the contact area between the first and second etched adhesive layers, improving their bonding strength, and ultimately increasing the bonding yield. Attached Figure Description

[0017] Figure 1A flowchart of an epitaxial layer transfer method for a light-emitting chip provided in an embodiment of this application;

[0018] Figure 2 This is a schematic diagram of the structure of forming a second etchable adhesive layer on the epitaxial layer provided in an embodiment of this application;

[0019] Figure 3 This is a schematic diagram of the structure for forming a first etchable adhesive layer on a carrier substrate, provided in an embodiment of this application.

[0020] Figure 4 This is a schematic diagram of the structure of the second etched adhesive layer after it has been etched and thinned according to an embodiment of this application.

[0021] Figure 5 This is a schematic diagram of the structure of the first etchable adhesive layer after it has been etched and thinned according to an embodiment of this application.

[0022] Figure 6 This is a schematic diagram of the structure after the first etched adhesive layer and the second etched adhesive layer are aligned and pressed together, as provided in the embodiments of this application.

[0023] Figure 7 Another flowchart of an epitaxial layer transfer method for a light-emitting chip provided in another optional embodiment of this application;

[0024] Figure 8 A schematic diagram of the structure of the second etched adhesive layer after surface roughening treatment, provided in another optional embodiment of this application;

[0025] Figure 9 A schematic diagram of the structure after roughening the surface of the first etchable adhesive layer provided in another optional embodiment of this application;

[0026] Explanation of reference numerals in the attached figures:

[0027] 1-Substrate; 2-Epipolar layer; 3-Second etchable adhesive layer; 4-Carrier substrate; 5-First etchable adhesive layer. Detailed Implementation

[0028] 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.

[0029] 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.

[0030] In the fabrication of some light-emitting chips, epitaxial layers need to be transferred. For example, in the fabrication of red light-emitting chips, epitaxial layers are typically grown on gallium arsenide (GaAs) substrates. After the epitaxial layer growth is complete, the light-absorbing GaAs substrate needs to be removed, and the epitaxial layer transferred to another transparent substrate for further fabrication. During the epitaxial layer transfer process, a bonding adhesive layer is usually spin-coated onto the epitaxial layer. However, due to limitations in adhesive viscosity and the spin-coating process, the thinnest possible adhesive layer is still relatively thick. This thick adhesive layer results in significant residue on the light-emitting surface of the chip during subsequent fabrication, affecting the light emission performance of the chip.

[0031] 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.

[0032] This embodiment provides a method for transferring the epitaxial layer of a light-emitting chip, such as... Figures 1-6 As shown, it includes the following steps:

[0033] S101: A semi-solid first etchable adhesive layer is formed on the substrate, and a semi-solid second etchable adhesive layer is formed on the epitaxial layer supported by the substrate.

[0034] The structure after the first etchable adhesive layer 5 is formed on the substrate 4 is as follows: Figure 3 As shown, the structure after forming the second etch-type adhesive layer 3 on the epitaxial layer 2 is as follows: Figure 2 As shown. In this embodiment, the first etchable adhesive layer 5 and the second etchable adhesive layer 3 are made of a transparent adhesive material that can be etched away, such as an organic material, including benzocyclobutene (BCB), but not limited to this. The material of the carrier substrate 4 in this embodiment may include glass, sapphire, plastic, or any other suitable material. If laser lift-off of the carrier substrate 4 is required in subsequent fabrication processes, the carrier substrate 4 may be made of a light-transmitting or transparent material. The substrate 1 in this embodiment may be a substrate used to support the epitaxial layer 2 during the transfer process, and its material may be glass, sapphire, plastic, ceramic, or any other suitable material; or it may be the growth substrate 1 of the epitaxial layer 2, for example, when fabricating a red light-emitting chip, the grown substrate 1 may be a gallium arsenide substrate 1. The epitaxial layer 2 in this embodiment includes an N semiconductor layer, a P semiconductor layer, and an active layer located between the N semiconductor layer and the P semiconductor layer. The active layer in this embodiment may include a quantum well layer, or may include other structures.

[0035] In some embodiments, an etchable adhesive layer can be spin-coated onto the substrate 4 and the epitaxial layer 2 respectively using a spin coater to form a first etchable adhesive layer 5 and a second etchable adhesive layer 3. The spin coater has a spin speed of ≥4500 rpm and a spin coat time of ≥30 s. Generally, the higher the spin coat speed, the thinner the spin-coated adhesive layer. However, at a spin coat speed of ≥4500 rpm, the thickness of the adhesive layer tends to stabilize due to the viscosity of the adhesive layer and will not decrease further with increasing spin coat speed. In this embodiment, a spin coat speed of ≥4500 rpm can produce the etchable adhesive layer to the thinnest thickness achievable by spin coating, thereby reducing the thickness of the adhesive layer that needs to be removed during subsequent etching, shortening the etching time, and improving processing efficiency. However, due to limitations in spin coat quality and equipment, the spin coat speed should not be too high. In this embodiment, a spin coat time of ≥30 s can improve the quality of spin coat coating. In some applications, depending on the different spin coating equipment and requirements, a spin coating speed of less than 4500 rpm and a spin coating time of less than 30 seconds can be selected.

[0036] In this embodiment, after spin coating is completed, a first curing temperature is applied to the etchable adhesive layer on the substrate 4 and the etchable adhesive layer on the epitaxial layer 2 to make them semi-solid, forming a semi-solid first etchable adhesive layer 5 and a semi-solid etchable adhesive layer 3. It is understood that the semi-solid state is between liquid and solid, and the hardness of the semi-solid state is less than that of the solid state. When the etchable adhesive layer includes benzocyclobutene, the first curing temperature in this embodiment can be 140℃-160℃, but it is not limited to this; other temperatures that semi-cur the etchable adhesive layer can also be used, depending on the material.

[0037] S102: Reduce the thickness of at least one of the first etchable adhesive layer and the second etchable adhesive layer by etching.

[0038] In some embodiments, this step may involve etching to thin the thickness of the first etchable adhesive layer 5 and the second etchable adhesive layer 3, respectively. After thinning the first etchable adhesive layer 5 and the second etchable adhesive layer 3, the structure of the first etchable adhesive layer 5 after thinning is as follows: Figure 5 As shown, the structure of the second etched adhesive layer 3 after thinning is as follows: Figure 4As shown. Thinning the bonding layer after subsequent lamination allows for a thinner layer, which is more beneficial in reducing adhesive residue on the light-emitting surface of the LED chip. To reduce adhesive residue and achieve optimal light emission from the LED chip, the first etchable adhesive layer 5 and the second etchable adhesive layer 3 can be etched separately to reduce their thickness to 1 micrometer or less. In some embodiments, this step can also involve thinning the first etchable adhesive layer 5 by etching, without thinning the second etchable adhesive layer 3; thinning only the first etchable adhesive layer 5 can also reduce the thickness of the bonding layer formed by subsequent lamination. In still other embodiments, this step can also involve thinning the second etchable adhesive layer 3 by etching, without thinning the first etchable adhesive layer 5; similarly, thinning only the second etchable adhesive layer 3 can also reduce the thickness of the bonding layer formed by subsequent lamination.

[0039] In some embodiments, the etching in this example can be dry etching, such as, but not limited to, ICP (Inductively Coupled Plasma) etching. By controlling the etching rate and etching time of the etching equipment, the thinning thickness of the first etchable adhesive layer 5 and the second etchable adhesive layer 3 can be controlled. In this example, etching gases of O2 and CF4 can be used to etch at least one of the first etchable adhesive layer 5 and the second etchable adhesive layer 3. In this example, the gas flow ratio of O2 to CF4 can be 1:1, as the etching gases of O2 and CF4 have a good thinning effect on the adhesive material. However, this is not the only possibility; other etching gases suitable for thinning adhesive layers can also be used in some applications.

[0040] S103: Align and press the thinned first etched adhesive layer with the second etched adhesive layer.

[0041] The structure after aligning and pressing the first etched adhesive layer 5 and the second etched adhesive layer 3 is as follows: Figure 6As shown. In this embodiment, pressure is applied to the carrier substrate 4 and the substrate 1, causing the side of the first etchable adhesive layer 5 away from the carrier substrate 4 to bond with the side of the second etchable adhesive layer 3 away from the substrate 1, forming a bonding layer composed of the first etchable adhesive layer 5 and the second etchable adhesive layer 3. This bonding layer can be cured during the pressing process, or it can be cured by placement or heating after pressing, depending on the material types of the first etchable adhesive layer 5 and the second etchable adhesive layer 3. For example, when the first etchable adhesive layer 5 and the second etchable adhesive layer 3 each comprise benzocyclobutene adhesive material, the pressing can be hot pressing. At a second curing temperature, the thinned first etchable adhesive layer 5 and the second etchable adhesive layer 3 are aligned and pressed together, so that the first etchable adhesive layer 5 and the second etchable adhesive layer 3 are bonded and then cured. In this embodiment, the second curing temperature is higher than the first curing temperature; for example, the second curing temperature can be, but is not limited to, 200°C to 250°C. After lamination, the thickness of the cured bonding layer formed by the first etched adhesive layer 5 and the second etched adhesive layer 3 together can be less than the sum of the thicknesses of the semi-solid first etched adhesive layer 5 and the second etched adhesive layer 3.

[0042] S104: Remove substrate.

[0043] This embodiment does not impose specific restrictions on the specific method for removing substrate 1; removing substrate 1 is sufficient.

[0044] In the aforementioned epitaxial layer transfer method for the light-emitting chip, after forming the first etchable adhesive layer 5 and the second etchable adhesive layer 3, at least one of the first etchable adhesive layer 5 and the second etchable adhesive layer 3 is further etched to thin it. By controlling the etching rate and etching time, the etchable adhesive layer can be etched to any desired thickness, thereby producing a sufficiently thin etchable adhesive layer. Thinning the etchable adhesive layer before bonding reduces the overall thickness of the bonding layer formed after the first etchable adhesive layer 5 and the second etchable adhesive layer 3 are pressed together. The reduced thickness of the bonding layer facilitates laser lift-off in subsequent fabrication processes, reduces adhesive layer residue on the light-emitting surface of the light-emitting chip, and optimizes the light emission effect of the light-emitting chip. Moreover, etching the etchable adhesive layer increases its surface roughness, thereby increasing the contact area between the first etchable adhesive layer 5 and the second etchable adhesive layer 3, improving the bonding strength between the first etchable adhesive layer 5 and the second etchable adhesive layer 3, and improving the bonding yield.

[0045] Another optional embodiment of this application:

[0046] This embodiment provides a method for transferring the epitaxial layer of a light-emitting chip, such as... Figure 7 As shown, it includes the following steps:

[0047] S201: A semi-solid first etchable adhesive layer is formed on a substrate by spin coating, and a semi-solid second etchable adhesive layer is formed on an epitaxial layer supported by a growth substrate by spin coating.

[0048] S202: The thickness of the first etchable adhesive layer and the second etchable adhesive layer are reduced by etching, respectively.

[0049] The first etchable adhesive layer 5 and the second etchable adhesive layer 3 are thinned respectively, so that the thickness of the bonding layer formed by subsequent lamination can be thinner, which is more conducive to reducing the residue of adhesive layer on the light-emitting surface of the light-emitting chip.

[0050] S203: Surface roughening treatment is performed on at least one of the first etchable adhesive layer and the second etchable adhesive layer.

[0051] In this embodiment, at least one of the sides of the first etched adhesive layer 5 away from the substrate 4 and the second etched adhesive layer 3 away from the substrate 1 is roughened. This can further improve the roughness of the etched adhesive layers, thereby further improving the bonding strength between the first etched adhesive layer 5 and the second etched adhesive layer 3 and improving the bonding yield.

[0052] In some embodiments, this step may involve etching to roughen the surfaces of the first etchable adhesive layer 5 and the second etchable adhesive layer 3, respectively. The structure of the first etchable adhesive layer 5 after surface roughening is as follows: Figure 9 As shown, the structure of the second etched adhesive layer 3 after surface roughening treatment is as follows: Figure 8 As shown. After roughening the first etched adhesive layer 5 and the second etched adhesive layer 3 respectively, because the adhesive material has a certain deformation capacity before curing, the contact area between the first etched adhesive layer 5 and the second etched adhesive layer 3 during pressing can be greatly increased, thereby improving the bonding strength between the first etched adhesive layer 5 and the second etched adhesive layer 3. In some embodiments, this step can also be to roughen only the surface of the first etched adhesive layer 5 by etching, without roughening the second etched adhesive layer 3. Roughening only the first etched adhesive layer 5 can also increase the contact area between the first etched adhesive layer 5 and the second etched adhesive layer 3. In still other embodiments, this step can also be to roughen the surface of the second etched adhesive layer 3 by etching, without roughening the first etched adhesive layer 5. Similarly, roughening only the second etched adhesive layer 3 can also increase the contact area between the first etched adhesive layer 5 and the second etched adhesive layer 3, thereby improving the bonding strength between the first etched adhesive layer 5 and the second etched adhesive layer 3.

[0053] In this embodiment, to achieve a good roughening effect, etching gases of Cl2 and BCl3 can be used to etch the surface of at least one of the first etchable adhesive layer 5 and the second etchable adhesive layer 3. In this embodiment, the gas flow ratio of Cl2 and BCl3 can be 1:4, and the etching gases of Cl2 and BCl3 have a good roughening effect on the adhesive material. However, this is not the only option; other etching gases suitable for surface roughening can also be used in some application scenarios.

[0054] In some embodiments, to increase bonding yield, grooves can be machined on the surfaces of the first etched adhesive layer 5 and the second etched adhesive layer 3 to form an uneven surface. During alignment and pressing, the protrusions on the first etched adhesive layer 5 correspond to the grooves on the second etched adhesive layer 3, and vice versa, to form a convex-concave fit. This further increases the contact area between the first etched adhesive layer 5 and the second etched adhesive layer 3 on top of the roughened surface, increasing bonding yield and preventing lateral slippage between them, resulting in better adhesion.

[0055] S204: Align and press the thinned first etched adhesive layer with the second etched adhesive layer at high temperature.

[0056] S205: Remove the growth substrate.

[0057] In the above-described method for transferring the epitaxial layer 2 of the light-emitting chip, after forming the first etchable adhesive layer 5 and the second etchable adhesive layer 3, at least one of the first etchable adhesive layer 5 and the second etchable adhesive layer 3 is further etched to thin it. By controlling the etching rate and etching time, the etchable adhesive layer can be etched to any desired thickness, thereby producing a sufficiently thin etchable adhesive layer. Thinning the etchable adhesive layer before bonding reduces the overall thickness of the bonding layer formed after the first etchable adhesive layer 5 and the second etchable adhesive layer 3 are pressed together. The reduced thickness of the bonding layer is more conducive to laser lift-off in subsequent fabrication processes, reducing adhesive layer residue on the light-emitting surface of the light-emitting chip and optimizing the light emission effect of the light-emitting chip. Moreover, etching the etchable adhesive layer increases its surface roughness, thereby increasing the contact area between the first etchable adhesive layer 5 and the second etchable adhesive layer 3, improving the bonding strength between the first etchable adhesive layer 5 and the second etchable adhesive layer 3, and improving the bonding yield.

[0058] Another optional embodiment of this application:

[0059] This embodiment provides a method for fabricating a light-emitting chip, which first uses the above-described epitaxial layer transfer method to complete the transfer of the epitaxial layer 2 of the light-emitting chip, and then fabricates electrodes on the epitaxial layer 2.

[0060] In this embodiment, electrodes can be formed on the epitaxial layer 2 using methods including, but not limited to, evaporation and deposition. After forming the electrodes, independent light-emitting chips can be formed by dicing. The light-emitting chips in this embodiment include, but are not limited to, at least one of Mini LED (Mini Light Emitting Diode), Micro LED (Micron-scale Light Emitting Diode), and nanoscale light-emitting diode. The light-emitting chips in this embodiment can be red, blue, or green light-emitting chips. The electrodes in this embodiment include positive and negative electrodes, and the material and shape of the electrodes are not limited. For example, in one example, the electrode material may include, but is not limited to, at least one of Cr, Ni, Al, Ti, Au, Pt, W, Pb, Rh, Sn, Cu, and Ag.

[0061] In the above-described method for fabricating a light-emitting chip, the epitaxial layer 2 of the light-emitting chip is transferred using the aforementioned epitaxial layer transfer method. This reduces the overall thickness of the bonding layer formed after the first etched adhesive layer 5 and the second etched adhesive layer 3 are laminated. The reduced thickness of the bonding layer facilitates laser stripping during subsequent fabrication processes, reduces adhesive residue on the light-emitting surface of the chip, and results in better light emission from the fabricated chip. Simultaneously, etching the etched adhesive layer increases its surface roughness, thereby increasing the contact area between the first etched adhesive layer 5 and the second etched adhesive layer 3, improving their bonding strength, and ultimately increasing the bonding yield.

[0062] 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 transferring the epitaxial layer of a light-emitting chip, characterized in that, Comprising: forming a semi-solid first etching-type glue layer on a carrier substrate, and forming a semi-solid second etching-type glue layer on an epitaxial layer of a substrate carrier; thinning the thickness of at least one of the first etching-type glue layer and the second etching-type glue layer by etching; aligning and pressing the thinned first etching-type glue layer and the second etching-type glue layer; removing the substrate.

2. The epitaxial layer transfer method for a light-emitting chip as described in claim 1, characterized in that, The forming a semi-solid first etching-type glue layer on a carrier substrate, and forming a semi-solid second etching-type glue layer on an epitaxial layer of a substrate carrier comprises: spinning an etching-type glue layer on the carrier substrate and the epitaxial layer respectively by a spin coating device; applying a first solidification temperature to the etching-type glue layer on the carrier substrate and the etching-type glue layer on the epitaxial layer to make them semi-solid; wherein the spin coating speed of the spin coating device is greater than or equal to 4500 rpm, and the spin coating time is greater than or equal to 30 s.

3. The method of claim 2, wherein the epitaxial layer of the light emitting chip is transferred by using a wafer bonding method. The first etching-type glue layer and the first etching-type glue layer respectively comprise a benzocyclobutene glue material, and the aligning and pressing the thinned first etching-type glue layer and the second etching-type glue layer comprises: aligning and pressing the first etching-type glue layer and the second etching-type glue layer at a second solidification temperature to make the first etching-type glue layer and the second etching-type glue layer bond and solidify; wherein the second solidification temperature is greater than the first solidification temperature.

4. The epitaxial layer transfer method for a light-emitting chip as described in claim 1, characterized in that, The thinning the thickness of at least one of the first etching-type glue layer and the second etching-type glue layer by etching comprises: thinning the thickness of the first etching-type glue layer and the second etching-type glue layer respectively by dry etching.

5. The epitaxial layer transfer method for a light-emitting chip as described in claim 4, characterized in that, The thinning the thickness of the first etching-type glue layer and the second etching-type glue layer respectively by dry etching comprises: etching the first etching-type glue layer and the second etching-type glue layer respectively to thin their thicknesses to 1 micrometer or below.

6. The method of claim 1-5, wherein the epitaxial layer of the light emitting chip is transferred by using a wafer bonding method. The thinning the thickness of at least one of the first etching-type glue layer and the second etching-type glue layer by etching comprises: etching at least one of the first etching-type glue layer and the second etching-type glue layer using etching gas of O2 and CF4.

7. The method of claim 1-5, wherein the epitaxial layer of the light emitting chip is transferred by using a wafer bonding method. After the thinning the thickness of at least one of the first etching-type glue layer and the second etching-type glue layer by etching, before the aligning and pressing the thinned first etching-type glue layer and the second etching-type glue layer, further comprising: performing surface roughening treatment on at least one of the first etching-type glue layer and the second etching-type glue layer.

8. The method of claim 7, wherein the epitaxial layer transfer is performed by a method comprising: The performing surface roughening treatment on at least one of the first etching-type glue layer and the second etching-type glue layer comprises: performing surface roughening treatment on the first etching-type glue layer and the second etching-type glue layer respectively.

9. The epitaxial layer transfer method for a light-emitting chip as described in claim 7, characterized in that, The performing surface roughening treatment on at least one of the first etching-type glue layer and the second etching-type glue layer comprises: etching the surface of at least one of the first etching-type glue layer and the second etching-type glue layer using etching gas of Cl2 and BCl3.

10. A method for manufacturing a light-emitting chip, characterized in that, Comprising: completing epitaxial layer transfer of a light emitting chip using the epitaxial layer transfer method of the light emitting chip according to any one of claims 1-9; making electrodes on the epitaxial layer.

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