Epitaxial wafer and manufacturing method thereof, and manufacturing method of light-emitting chip

Abstract

The invention relates to an epitaxial wafer and a manufacturing method thereof, and a manufacturing method of a light-emitting chip. The epitaxial wafer comprises a transparent substrate; the stripping layer is arranged on the transparent substrate; the epitaxial layer is arranged on the stripping layer and comprises an N-type semiconductor layer, an active layer and a P-type semiconductor layer which are stacked in sequence; and the thin film layer is arranged on one surface, far away from the stripping layer, of the transparent substrate, and the thin film layer is configured to reflect laser emitted into the epitaxial wafer from the thin film layer back to the stripping layer to be absorbed by the stripping layer again when the transparent substrate is stripped by the laser. Laser is emitted into the epitaxial wafer from the thin film layer, and part of the laser is reflected by the inner surface of the thin film layer and finally reflected back to the stripping layer to be absorbed by the stripping layer twice or multiple times. Therefore, the laser absorptivity of the stripping layer is improved, the laser energy penetrating into the epitaxial layer from the stripping layer is reduced, the influence of the laser on the P-type semiconductor layer in the epitaxial layer is reduced, and the conditions of film layer separation and falling off are avoided.

Description

Technical Field

[0001] The present application relates to the field of semiconductor technology, and particularly to an epitaxial wafer, a manufacturing method thereof, and a manufacturing method of a light-emitting chip. Background Art

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

[0003] Currently, in the process of manufacturing LEDs, an epitaxial layer needs to be grown on a growth substrate, and then the growth substrate is laser-lifted off to transfer the epitaxial layer onto a carrier substrate. During this process, the laser will partially irradiate the P-type semiconductor layer, causing GaN decomposition in the P-type semiconductor layer, resulting in separation between the P-type semiconductor layer and its adjacent film layers, and even film layer peeling off, reducing the product quality of the light-emitting chip.

[0004] Therefore, how to reduce the influence of the laser on the P-type semiconductor layer is an urgent problem to be solved. Summary of the Invention

[0005] In view of the deficiencies of the above-related technologies, the purpose of the present application is to provide an epitaxial wafer, a manufacturing method thereof, and a manufacturing method of a light-emitting chip, aiming to solve the problem of the influence of the laser on the P-type semiconductor layer.

[0006] An epitaxial wafer, comprising:

[0007] A transparent substrate;

[0008] A release layer provided on the transparent substrate;

[0009] An epitaxial layer provided on the release layer, the epitaxial layer comprising an N-type semiconductor layer, an active layer, and a P-type semiconductor layer stacked in sequence; and

[0010] A thin film layer provided on a surface of the transparent substrate away from the release layer, the thin film layer being configured to reflect the laser incident into the epitaxial wafer from the thin film layer back to the release layer for the release layer to absorb again when the transparent substrate is laser-lifted off.

[0011] The above-mentioned epitaxial wafer includes a thin film layer. When the transparent substrate is peeled off, laser light enters the epitaxial wafer from the thin film layer. A part of the laser light passes through the thin film layer and the transparent substrate and then enters the peeling layer and is directly absorbed by the peeling layer. A part of the laser light is reflected by the inner surface of the thin film layer and finally reflected back to the peeling layer for the peeling layer to absorb twice or more times. Thereby, the absorption rate of the laser light by the peeling layer is increased, the laser energy transmitted from the peeling layer to the epitaxial layer is reduced, the influence of the laser on the P-type semiconductor layer in the epitaxial layer is reduced, the situation of film layer separation and peeling off is avoided, and the quality of the light-emitting chip is improved. Moreover, the thin film layer is disposed on the side of the transparent substrate away from the peeling layer, and the thin film layer does not affect the growth of the epitaxial layer, and good growth quality of the epitaxial layer can be ensured.

[0012] Based on the same inventive concept, the present application further provides a method for manufacturing an epitaxial wafer as described above, including:

[0013] Disposing the peeling layer on the transparent substrate;

[0014] Disposing the epitaxial layer on the peeling layer;

[0015] Disposing the thin film layer on the side of the transparent substrate away from the epitaxial layer.

[0016] In the method for manufacturing the above-mentioned epitaxial wafer, a thin film layer is disposed on the side of the transparent substrate away from the epitaxial layer. When the transparent substrate is peeled off, laser light enters the epitaxial wafer from the thin film layer. A part of the laser light passes through the thin film layer and the transparent substrate and then enters the peeling layer and is directly absorbed by the peeling layer. A part of the laser light is reflected by the inner surface of the thin film layer and finally reflected back to the peeling layer for the peeling layer to absorb twice or more times. Thereby, the absorption rate of the laser light by the peeling layer is increased, the laser energy transmitted from the peeling layer to the epitaxial layer is reduced, the influence of the laser on the P-type semiconductor layer in the epitaxial layer is reduced, the situation of film layer separation and peeling off is avoided, and the quality of the light-emitting chip is improved. Moreover, the thin film layer is disposed on the side of the transparent substrate away from the peeling layer, and the thin film layer does not affect the growth of the epitaxial layer, and good growth quality of the epitaxial layer can be ensured.

[0017] Based on the same inventive concept, the present application further provides a method for manufacturing a light-emitting chip, including:

[0018] Providing an epitaxial wafer as described above;

[0019] Irradiating the epitaxial wafer from one side of the thin film layer with laser light, a part of the laser light entering the epitaxial wafer is directly absorbed by the peeling layer after passing through the thin film layer, and a part of the laser light is reflected by the thin film layer back to the peeling layer for the peeling layer to absorb again, so that the peeling layer decomposes and peels off the transparent substrate.

[0020] Disposing electrodes on the epitaxial layer.

[0021] In the method for fabricating the above light-emitting chip, laser light is incident from the thin film layer into the epitaxial wafer. A part of the laser light is directly absorbed by the stripping layer after passing through the thin film layer and the transparent substrate. Another part of the laser light is reflected by the inner surface of the thin film layer and finally reflected back to the stripping layer for the stripping layer to absorb two or more times. Thereby, the absorption rate of the laser light by the stripping layer is increased, the laser energy transmitted from the stripping layer to the epitaxial layer is reduced, the influence of the laser on the P-type semiconductor layer in the epitaxial layer is minimized, the situation of film layer separation and peeling off is avoided, and the quality of the light-emitting chip is improved. Moreover, the thin film layer is disposed on the side of the transparent substrate away from the stripping layer, and the thin film layer does not affect the growth of the epitaxial layer, ensuring good growth quality of the epitaxial layer. At the same time, during the stripping process, the thin film layer will be stripped together with the transparent substrate, eliminating the need for an additional step to remove the thin film layer and avoiding the influence of the thin film layer on subsequent fabrication. Description of the Drawings

[0022] Figure 1 Schematic structural diagram of an epitaxial wafer provided by an embodiment of the present application;

[0023] Figure 2 Another schematic structural diagram of the epitaxial wafer provided by an embodiment of the present application;

[0024] Figure 3 Schematic diagram of the thin film layer reflecting laser light inside the epitaxial wafer provided by an embodiment of the present application;

[0025] Figure 4 A graph showing the variation of the absorption rate with the increase of the laser wavelength when the stripping layer and the thin film layer act together provided by an embodiment of the present application;

[0026] Figure 5 Another graph showing the variation of the absorption rate with the increase of the laser wavelength when the stripping layer and the thin film layer act together provided by an embodiment of the present application;

[0027] Figure 6 Yet another graph showing the variation of the absorption rate with the increase of the laser wavelength when the stripping layer and the thin film layer act together provided by an embodiment of the present application;

[0028] Figure 7 Flowchart of a method for fabricating an epitaxial wafer provided by another alternative embodiment of the present application;

[0029] Figure 8 Schematic structural diagram of setting a thin film layer after bonding provided by another alternative embodiment of the present application;

[0030] Figure 9 Schematic structural diagram of setting a thin film layer before bonding provided by another alternative embodiment of the present application;

[0031] Figure 10Flow chart of a method for manufacturing a light-emitting chip provided by another optional embodiment of the present application;

[0032] Figure 11 Schematic structural diagram after peeling off the transparent substrate provided by another optional embodiment of the present application;

[0033] Description of reference numerals:

[0034] 1 - Transparent substrate; 2 - Peeling layer; 3 - N-type semiconductor layer; 4 - Active layer; 5 - P-type semiconductor layer; 6 - Thin film layer; 7 - ITO film layer; 8 - Bonding layer; 9 - Carrier substrate. Detailed implementation manners

[0035] To facilitate the understanding of the present application, the present application will be described more comprehensively below with reference to the relevant drawings. The preferred embodiments of the present application are shown in the drawings. However, the present application can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, these embodiments are provided to make the disclosure of the present application more thorough and comprehensive.

[0036] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the technical field to which the present application belongs. The terms used in the description of the present application herein are only for the purpose of describing specific embodiments and are not intended to limit the present application.

[0037] During the manufacturing process of an LED, an epitaxial layer needs to be grown on a growth substrate, and then the growth substrate is laser-peeled off to transfer the epitaxial layer onto a carrier substrate. During this process, the laser will partially irradiate the P-type semiconductor layer, causing GaN decomposition in the P-type semiconductor layer, resulting in separation between the P-type semiconductor layer and its adjacent film layer, and even film layer peeling off, reducing the product quality of the light-emitting chip. For example, during the manufacturing process of a vertical light-emitting chip, an epitaxial layer needs to be grown on a sapphire growth substrate, an ITO (indium tin oxide) film layer is formed on the epitaxial layer, a silicon substrate is bonded to the epitaxial layer through a bonding metal, and then the growth substrate is laser-peeled off to transfer the epitaxial layer onto the silicon substrate. During peeling, part of the laser will irradiate the P-type semiconductor layer in the epitaxial layer, causing GaN decomposition in the P-type semiconductor layer to generate N2, reducing the adhesion of the P-type semiconductor layer, resulting in separation between the P-type semiconductor layer and the ITO film layer, and even causing the ITO film layer to peel off.

[0038] Based on this, the present application hopes to provide a solution that can solve the above technical problems, and its detailed content will be elaborated in the subsequent embodiments.

[0039] This embodiment provides an epitaxial wafer, such as Figure 1 、 Figure 2, including a transparent substrate 1, a release layer 2, an epitaxial layer, and a thin film layer 6. It can be understood that the transparent substrate 1 in this embodiment can be a growth substrate for growing the epitaxial layer, and the material of the transparent substrate 1 is a transparent material, which allows the laser to pass through and irradiate the release layer 2. For example, the material of the transparent substrate 1 can be, but is not limited to, sapphire.

[0040] The release layer 2 in this embodiment is disposed on the transparent substrate 1. The material of the release layer 2 can be, but is not limited to, GaN. GaN can decompose under the irradiation of the laser to generate Ga and N2. After the release layer 2 decomposes, the transparent substrate 1 can be separated from the epitaxial layer to strip the transparent substrate 1.

[0041] The epitaxial layer in this embodiment is disposed on the release layer 2, and the epitaxial layer includes an N-type semiconductor layer 3, an active layer 4, and a P-type semiconductor layer 5 stacked in sequence. It can be understood that the active layer 4 in this embodiment can include a quantum well layer, a quantum barrier layer, and can also include other structures. The material of the N-type semiconductor layer 3 in this embodiment can be N-GaN, and the material of the P-type semiconductor layer 5 can be P-GaN. In some embodiments, the N-type semiconductor layer 3, the active layer 4, and the P-type semiconductor layer 5 can be stacked in sequence on the release layer 2 in a direction away from the transparent substrate 1.

[0042] The thin film layer 6 in this embodiment is disposed on a surface of the transparent substrate 1 away from the release layer 2. The thin film layer 6 is configured to reflect the laser incident into the epitaxial wafer back to the release layer 2 for the release layer 2 to absorb again when the transparent substrate 1 is laser-stripped. It can be understood that the laser can pass through the thin film layer 6 and irradiate the release layer 2, and the thin film layer 6 can reflect the laser incident into the epitaxial wafer, that is, the refractive index of the thin film layer 6 is different from that of the transparent substrate 1. As Figure 3 shown, through the difference in refractive index, the thin film layer 6 can reflect the laser in the epitaxial wafer twice or multiple times, making it more difficult for the laser to exit the epitaxial wafer. The laser is reflected back to the release layer 2 twice or multiple times, so that the release layer 2 can absorb the laser twice or multiple times, thereby increasing the absorption rate of the laser by the thin film layer 6, making the decomposition of the thin film layer 6 more complete, solving the problem of residue when the thin film layer 6 is not decomposed sufficiently, and ensuring a good light-emitting effect of the light-emitting chip.

[0043] In some embodiments, the thin film layer 6 can be disposed on the transparent substrate 1 before bonding. Then, the epitaxial wafer in this embodiment can be an epitaxial wafer including a carrier substrate 9 after bonding. The carrier substrate 9 is disposed on a side of the epitaxial layer away from the transparent substrate 1, and the carrier substrate 9 and the epitaxial layer are bonded through a bonding layer 8, as Figure 2 shown, that is, the epitaxial wafer includes the thin film layer 6, the transparent substrate 1, the release layer 2, the epitaxial layer, the bonding layer 8, and the carrier substrate 9 stacked in sequence; the epitaxial wafer in this embodiment can also be an epitaxial wafer that does not include the carrier substrate 9 before bonding, as Figure 1As shown, that is, the epitaxial wafer includes a thin film layer 6, a transparent substrate 1, a release layer 2, and an epitaxial layer that are stacked in sequence. In some other embodiments, after bonding, the thin film layer 6 may also be provided on the transparent substrate 1. Then, the epitaxial wafer in this embodiment is the epitaxial wafer including a carrier substrate 9 after bonding.

[0044] In this embodiment, the material of the thin film layer 6 includes any one of metals, metal oxides, and metal nitrides. For example, the thin film layer 6 can be a metal, a metal oxide, or a metal nitride, as long as it can reflect the laser in the epitaxial wafer back to the release layer 2. The laser incident into the epitaxial wafer in this embodiment, that is, the laser located in the thin film layer 6 and the transparent substrate 1 after entering from the thin film layer 6.

[0045] After the thin film layer 6 and the release layer 2 in this embodiment act together, the absorption rate of the laser can reach more than 90%. For example, in the following three embodiments, the absorption rate of the laser is more than 90%. When the thin film layer 6 is not provided, the absorption rate of the laser is less than 80%. The epitaxial wafer in this embodiment can significantly improve the absorption rate of the laser through the action of the thin film layer 6.

[0046] In one embodiment, the material of the thin film layer 6 includes Ag, and the thickness of the thin film layer 6 is 50 nm to 70 nm. For example, the material of the thin film layer 6 is Ag, and the thickness of Ag is 50 nm to 70 nm. Specifically, the thickness of Ag can be 50 nm, 55 nm, 60 nm, 65 nm, 70 nm or other values, which are not limited here. Exemplarily, when the thickness of Ag is 60 nm, the curve of the absorption rate changing with the increase of the laser wavelength when the release layer 2 and the thin film layer 6 act together is as Figure 4 shown. When the laser wavelength is 298 nm to 318 nm, the absorption rate is in the maximum value range. For example, when irradiated with a laser of 308 nm, the absorption rate of the laser can reach 95%, and the laser has basically no influence on the P-type semiconductor layer 5 of the epitaxial layer.

[0047] In another embodiment, the material of the thin film layer 6 includes MgO, and the thickness of the thin film layer 6 is 65 nm to 85 nm. For example, the material of the thin film layer 6 is MgO, and the thickness of MgO is 65 nm to 85 nm. Specifically, the thickness of MgO can be 65 nm, 70 nm, 75 nm, 80 nm, 85 nm or other values, which are not limited here. Exemplarily, when the thickness of MgO is 75 nm, the curve of the absorption rate changing with the increase of the laser wavelength when the release layer 2 and the thin film layer 6 act together is as Figure 5 shown. When the laser wavelength is 183 nm to 203 nm, the absorption rate is in the maximum value range. For example, when irradiated with a laser of 193 nm, the absorption rate of the laser can reach 99%, and the laser has basically no influence on the P-type semiconductor layer 5 of the epitaxial layer.

[0048] In another embodiment, the material of the thin film layer 6 includes AlN, and the thickness of the thin film layer 6 is 80 nm to 100 nm. For example, the material of the thin film layer 6 is AlN, and the thickness of the AlN is 80 nm to 100 nm. Specifically, the thickness of the AlN can be 80 nm, 85 nm, 90 nm, 95 nm, 100 nm or other values, which are not limited herein. Exemplarily, when the thickness of the AlN is 90 nm, the curve of the absorption rate of the peeling layer 2 and the thin film layer 6 changing with the increase of the laser wavelength is as Figure 6 shown. When the laser wavelength is 183 nm to 203 nm, the absorption rate is in the maximum value range. For example, when irradiated with a laser of 193 nm, the absorption rate of the laser can reach 93%, and the laser has basically no influence on the P-type semiconductor layer 5 of the epitaxial layer.

[0049] The above epitaxial wafer includes a thin film layer 6. When peeling the transparent substrate 1, the laser enters the epitaxial wafer from the thin film layer 6. Part of the laser is directly absorbed by the peeling layer 2 after passing through the thin film layer 6 and the transparent substrate 1, and part of the laser is reflected by the inner surface of the thin film layer 6 and finally reflected back to the peeling layer 2 for the peeling layer 2 to absorb twice or more times. Thereby, the absorption rate of the peeling layer 2 to the laser is increased, the laser energy transmitted to the epitaxial layer from the peeling layer 2 is reduced, the influence of the laser on the P-type semiconductor layer 5 in the epitaxial layer is reduced, the situation of film layer separation and shedding is avoided, and the quality of the light-emitting chip is improved. Moreover, the thin film layer 6 is disposed on the side of the transparent substrate 1 away from the peeling layer 2, and the thin film layer 6 does not affect the growth of the epitaxial layer, and good growth quality of the epitaxial layer can be ensured.

[0050] Another optional embodiment of the present application:

[0051] This embodiment provides a method for manufacturing the above-mentioned epitaxial wafer, as Figure 7 shown, including the following steps:

[0052] S11: Set a peeling layer on the transparent substrate.

[0053] S12: Set an epitaxial layer on the peeling layer.

[0054] S13: Set a thin film layer on the side of the transparent substrate away from the peeling layer.

[0055] It can be understood that the settings of the transparent substrate 1, the peeling layer 2, the epitaxial layer, and the thin film layer 6 in this embodiment are the same as those in the previous embodiment, and will not be described in detail herein. In this embodiment, the thin film layer 6 can be formed on the transparent substrate 1 by, but not limited to, evaporation coating or deposition.

[0056] In some embodiments, as Figure 8As shown, before the thin film layer 6 is disposed on one side of the transparent substrate 1 away from the release layer 2, the carrier substrate 9 can be bonded through the bonding layer 8 on the side of the epitaxial layer away from the transparent substrate 1. Exemplarily, a bonding metal layer can be respectively disposed on the epitaxial layer and the carrier substrate 9 first; then the two bonding metal layers are bonded to form the bonding layer 8 to complete the bonding between the epitaxial layer and the carrier substrate 9; then the thin film layer 6 is disposed on one side of the transparent substrate 1 away from the release layer 2. In some embodiments, as Figure 9 shown, after the thin film layer 6 is disposed on one side of the transparent substrate 1 away from the release layer 2, the carrier substrate 9 can be bonded through the bonding layer 8 on the side of the epitaxial layer away from the transparent substrate 1. Exemplarily, the thin film layer 6 can be disposed on one side of the transparent substrate 1 away from the release layer 2 first, and then a bonding metal layer can be respectively disposed on the epitaxial layer and the carrier substrate 9; then the two bonding metal layers are bonded to form the bonding layer 8 to complete the bonding between the epitaxial layer and the carrier substrate 9.

[0057] In this embodiment, an ITO film layer 7 can also be disposed on the epitaxial layer before bonding the carrier substrate 9 for the subsequent fabrication of the vertical light-emitting chip.

[0058] In the above method for fabricating the epitaxial wafer, the thin film layer 6 is disposed on one side of the transparent substrate 1 away from the epitaxial layer. When the transparent substrate 1 is peeled off, the laser is incident into the epitaxial wafer from the thin film layer 6. Part of the laser is directly absorbed by the release layer after passing through the thin film layer 6 and the transparent substrate 1, and part of the laser is reflected by the inner surface of the thin film layer 6 and finally reflected back to the release layer for the release layer to absorb twice or more times. Thereby, the absorption rate of the laser by the release layer 2 is increased, the laser energy transmitted from the release layer 2 to the epitaxial layer is reduced, the influence of the laser on the P-type semiconductor layer 5 in the epitaxial layer is reduced, the situation of film layer separation and peeling off is avoided, and the quality of the light-emitting chip is improved. Moreover, the thin film layer 6 is disposed on one side of the transparent substrate 1 away from the release layer 2, and the thin film layer 6 does not affect the growth of the epitaxial layer, and good growth quality of the epitaxial layer can be ensured.

[0059] Another alternative embodiment of the present application:

[0060] This embodiment provides a method for fabricating a light-emitting chip, as Figure 10 shown, including:

[0061] S21: Provide an epitaxial wafer.

[0062] The epitaxial wafer in this embodiment is the same as the epitaxial wafer in the above embodiment, and will not be described in detail herein.

[0063] S22: Use a laser to irradiate the epitaxial wafer from one side of the thin film layer. Part of the laser incident into the epitaxial wafer is directly absorbed by the release layer after passing through the thin film layer, and part of the laser is reflected back to the release layer by the thin film layer for the release layer to absorb again, so that the release layer decomposes and peels off the transparent substrate.

[0064] It is understandable that after the laser in this embodiment is directly absorbed and re - absorbed by the stripping layer 2, the stripping layer 2 can be decomposed more fully, avoiding the residue situation. The laser wavelength in this embodiment can be selected according to the material of the thin film layer 6. For example, when the material of the thin film layer 6 is Ag and the thickness of Ag is 50 nm - 70 nm, such as 60 nm, a laser with a wavelength of 298 nm - 318 nm, such as a 308 nm laser, can be used for irradiation; when the material of the thin film layer 6 is MgO and the thickness of MgO is 65 nm - 85 nm, such as 75 nm, a laser with a wavelength of 183 nm - 203 nm, such as a 193 nm laser, can be selected for irradiation; when the material of the thin film layer 6 is AlN and the thickness of AlN is 80 nm - 100 nm, such as 90 nm, a laser with a wavelength of 183 nm - 203 nm, such as a 193 nm laser, can be selected for irradiation. The above is only an example for explanation, and other materials, thicknesses of the thin film layer 6 and other wavelengths of lasers can also be used as long as the thin film layer 6 can achieve secondary or multiple reflections of the laser.

[0065] S23: Set an electrode on the epitaxial layer.

[0066] The electrode in this embodiment can be formed by, but not limited to, evaporation coating, deposition. The material and shape of the electrode are not specifically limited in this embodiment. For example, the material of the electrode can include at least one of, but not limited to, Cr, Ni, Al, Ti, Au, Pt, W, Pb, Rh, Sn, Cu, Ag. The light - emitting chip in this embodiment includes at least one of, but not limited to, high - brightness LED light - emitting chips, MiniLED (Mini Light Emitting Diode, sub - millimeter light - emitting diode), Micro LED (Micro Light Emitting Diode, micron - scale light - emitting diode), and nano - scale light - emitting diodes. The light - emitting chip in this embodiment can be, but not limited to, a vertical LED chip. When manufacturing a vertical light - emitting chip, such as Figure 8 、 Figure 9 , an ITO film layer 7 can be formed before bonding, and finally a top electrode is set on the side of the epitaxial layer away from the ITO film layer 7.

[0067] In the method for manufacturing the above light-emitting chip, the laser is incident on the epitaxial wafer from the thin film layer 6. A part of the laser is directly absorbed by the stripping layer 2 after passing through the thin film layer 6 and the transparent substrate 1, and a part of the laser is reflected by the inner surface of the thin film layer 6 and finally reflected back to the stripping layer 2 for the stripping layer 2 to absorb twice or more times. Thereby, the absorption rate of the laser by the stripping layer 2 is increased, the laser energy transmitted to the epitaxial layer from the stripping layer 2 is reduced, the influence of the laser on the P-type semiconductor layer 5 in the epitaxial layer is reduced, the situation of film layer separation and peeling off is avoided, and the quality of the light-emitting chip is improved. Moreover, the thin film layer 6 is disposed on the side of the transparent substrate 1 away from the stripping layer 2, and the thin film layer 6 does not affect the growth of the epitaxial layer, and good growth quality of the epitaxial layer can be ensured. At the same time, during the stripping process, the thin film layer 6 will be stripped together with the transparent substrate 1, without the need to additionally add a step for removing the thin film layer 6, and the influence of the thin film layer 6 on subsequent manufacturing is also avoided.

[0068] It should be understood that the application of the present application is not limited to the above examples. For those of ordinary skill in the art, improvements or transformations can be made according to the above description, and all such improvements and transformations should fall within the protection scope of the appended claims of the present application.

Claims

1. An epitaxial wafer, characterized in that, Comprising: A transparent substrate; A release layer provided on the transparent substrate; An epitaxial layer provided on the release layer, the epitaxial layer comprising an N-type semiconductor layer, an active layer, and a P-type semiconductor layer stacked in sequence; and A thin film layer provided on a side of the transparent substrate away from the release layer, the thin film layer being configured to reflect the laser light incident into the epitaxial wafer from the thin film layer back to the release layer for the release layer to absorb again when the transparent substrate is laser lifted off.

2. The epitaxial wafer according to claim 1, wherein The epitaxial wafer further includes a carrier substrate, the carrier substrate is provided on a side of the epitaxial layer away from the transparent substrate, and the carrier substrate and the epitaxial layer are bonded through a bonding layer.

3. The epitaxial wafer according to claim 1 or 2, characterized in that The material of the thin film layer includes any one of metal, metal oxide, and metal nitride.

4. The epitaxial wafer according to claim 3, wherein The material of the thin film layer includes Ag, and the thickness of the thin film layer is 50 nm to 70 nm.

5. The epitaxial wafer according to claim 3, wherein The material of the thin film layer includes MgO, and the thickness of the thin film layer is 65 nm to 85 nm.

6. The epitaxial wafer according to claim 3, wherein The material of the thin film layer includes AlN, and the thickness of the thin film layer is 80 nm to 100 nm.

7. The epitaxial wafer according to claim 1 or 2, characterized in that, The material of the transparent substrate includes sapphire, and the material of the release layer includes GaN.

8. A method for manufacturing an epitaxial wafer according to any one of claims 1-7, characterized in that, Comprising: Providing the release layer on the transparent substrate; Providing the epitaxial layer on the release layer; Providing the thin film layer on a side of the transparent substrate away from the release layer.

9. The manufacturing method of the epitaxial wafer according to claim 8, characterized in that, Before providing the thin film layer on a side of the transparent substrate away from the release layer, it includes: Bonding a carrier substrate on a side of the epitaxial layer away from the transparent substrate through a bonding layer.

10. A method for manufacturing a light-emitting chip, characterized in that, Comprising: Providing the epitaxial wafer according to any one of claims 1-7; Irradiating the epitaxial wafer from one side of the thin film layer with a laser, a part of the laser light incident into the epitaxial wafer is directly absorbed by the release layer after passing through the thin film layer, and a part of the laser light is reflected back to the release layer by the thin film layer for the release layer to absorb again, so that the release layer decomposes to lift off the transparent substrate; Providing electrodes on the epitaxial layer.

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