Gallium oxide removing method, chip manufacturing method and display device manufacturing method

Abstract

The invention relates to a gallium oxide removing method, a chip manufacturing method and a display device manufacturing method. The gallium oxide removal method comprises the following steps: providing a gallium nitride epitaxial wafer stripped from a growth substrate, wherein the gallium nitride epitaxial wafer comprises a substrate and a gallium nitride epitaxial layer laminated on the substrate; and inductively coupled plasma etching processing is carried out on the surface of the gallium nitride epitaxial layer to remove gallium oxide on the surface, and the gallium oxide at least covers part of the surface of the gallium nitride epitaxial layer. The gallium oxide removing method can effectively remove the gallium oxide remained on the surface of the gallium nitride.

Description

Technical Field

[0001] The present invention relates to the technical field of LED chips, and in particular to a gallium oxide removal method, a chip manufacturing method and a display device manufacturing method. Background Art

[0002] Micro LED inherits the high efficiency, high brightness, high reliability and fast response time of inorganic LED, and has the characteristics of self-luminescence without backlight. It has the advantages of energy saving, simple structure, small size and thinness. Its micron-level pixel pitch enables each pixel to be controlled and driven individually. Its brightness can be 3 to 4 orders of magnitude higher than OLED. OLED can provide about 1000 nits (cd / m 2 ), while Micro LED provides hundreds of thousands of nits at the same power consumption. Therefore, its resolution, brightness, contrast and power consumption are no less than OLED.

[0003] When manufacturing GaN-based Micro LED chips, it is usually necessary to perform laser stripping on the growth substrate. During laser stripping, the GaN on the upper layer of U-GaN generates instantaneous high temperature when the high-energy pulsed laser beam penetrates the sapphire substrate, decomposing the GaN into Ga and N2, separating the sapphire from the epitaxial layer. After separation, part of the Ga on the surface is oxidized to form Ga2O3, and Ga2O3 is difficult to remove. If not processed, the manufacturing yield and reliability of the Micro LED chip will be greatly reduced. Summary of the invention

[0004] In view of the above-mentioned deficiencies in the prior art, the purpose of the present application is to provide a gallium oxide removal method, aiming to solve the problem of how to remove gallium oxide on the surface of the gallium nitride epitaxial layer after laser stripping, so as to improve the manufacturing yield and reliability of Micro LED chips.

[0005] In a first aspect, the present application provides a method for removing gallium oxide, comprising:

[0006] A gallium nitride epitaxial wafer peeled from a growth substrate is provided, wherein the gallium nitride epitaxial wafer comprises a substrate and a gallium nitride epitaxial layer stacked on the substrate; an inductively coupled plasma etch (ICP etching) process is performed on a surface of the gallium nitride epitaxial layer to remove gallium oxide on the surface, wherein the gallium oxide at least covers a portion of the surface of the gallium nitride epitaxial layer.

[0007] In some optional embodiments, the etching gas used in the inductively coupled plasma etching process is argon.

[0008] In some optional embodiments, during the inductively coupled plasma etching process, the argon gas flow rate is 55-65 sccm.

[0009] In some optional embodiments, an etching selectivity ratio between gallium oxide and gallium nitride during the inductively coupled plasma etching process is greater than 6:1.

[0010] In some optional embodiments, during the inductively coupled plasma etching process, the upper etching power is 240-2600W, and the lower etching power is 290-310W.

[0011] In some optional embodiments, before performing the inductively coupled plasma etching process on the surface of the gallium nitride epitaxial layer, the method further comprises: soaking the gallium nitride epitaxial wafer in an acidic solution for 5-10 minutes.

[0012] In the embodiment of the present application, after the gallium nitride epitaxial layer is peeled off from the growth substrate, argon ions are used to physically bombard the peeled surface of the gallium nitride epitaxial layer, and the peeled surface of the gallium nitride epitaxial layer is subjected to ICP physical etching. In this process, when the argon ions physically bombard the peeled surface of the gallium nitride epitaxial layer, gallium oxide and gallium nitride have a high selective etching ratio, so this process can effectively remove the gallium oxide remaining on the surface of gallium nitride.

[0013] In a second aspect, based on the same inventive concept, the present application also provides a chip manufacturing method, comprising: providing a gallium nitride epitaxial wafer treated by the gallium oxide removal method described in the first aspect; wherein the gallium nitride epitaxial layer comprises a first type gallium nitride layer, a light-emitting layer and a second type gallium nitride layer stacked in sequence; patterning the first type gallium nitride layer, the light-emitting layer and the second type gallium nitride layer to form a plurality of independent LED epitaxies; evaporating a first electrode and a second electrode, the first electrode being connected to the first type gallium nitride layer of the LED epitaxy, and the second electrode being connected to the second type gallium nitride layer of the LED epitaxy.

[0014] In the embodiment of the present application, the gallium oxide removal method described in the first aspect is used to remove gallium oxide from the gallium nitride epitaxial wafer, which effectively removes gallium oxide remaining on the surface of the gallium nitride, thereby improving the reliability of the LED chip during the subsequent manufacture of the LED chip.

[0015] In a third aspect, based on the same inventive concept, the present application also provides a method for manufacturing a display device, comprising: providing a gallium nitride epitaxial wafer processed by the gallium oxide removal method described in the first aspect; wherein the substrate is a driving substrate, the driving substrate includes a plurality of connection contacts, the gallium nitride epitaxial layer is bonded to the driving substrate via a metal bonding layer, the gallium nitride epitaxial layer includes a first type gallium nitride layer, a light emitting layer and a second type gallium nitride layer stacked in sequence; patterning the first type gallium nitride layer, the light emitting layer and the second type gallium nitride layer to form a plurality of independent LED epitaxies; removing the metal bonding layer between adjacent LED epitaxies so that adjacent LED epitaxies cannot be electrically connected via the metal bonding layer; and forming an electrode on the second type gallium nitride layer of the LED epitaxy.

[0016] In some optional embodiments, before forming the electrode on the second type gallium nitride layer of the LED epitaxy, the method further includes: forming a passivation layer on the LED epitaxy; patterning the passivation layer to form an opening on the second type gallium nitride layer of the LED epitaxy; and forming the electrode on the second type gallium nitride layer of the LED epitaxy includes: forming the electrode in the opening.

[0017] In some optional embodiments, the method further comprises: forming a light reflecting layer or a light blocking layer on a side wall of the LED epitaxial portion.

[0018] In the embodiment of the present application, the gallium oxide removal method described in the first aspect is used to remove gallium oxide remaining on the surface of the gallium nitride epitaxial wafer, thereby improving the reliability of the display device when the display device is subsequently manufactured. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 A schematic flow chart of a gallium oxide removal method provided in an embodiment of the present application;

[0020] Figure 2 A schematic diagram of the structure of a gallium nitride epitaxial wafer after being peeled off from a growth substrate provided in an embodiment of the present application;

[0021] Figure 3 A schematic diagram of peeling off a gallium nitride epitaxial layer from a growth substrate to form a gallium nitride epitaxial wafer provided in an embodiment of the present application;

[0022] Figure 4 A schematic diagram of the changes before and after etching of the surface of a gallium nitride epitaxial layer provided in an embodiment of the present application;

[0023] Figure 5 A schematic diagram of a chip manufacturing method provided in an embodiment of the present application;

[0024] Figure 6 A schematic flow chart of a method for manufacturing a display device provided in an embodiment of the present application.

[0025] Reference numerals: 10 - substrate; 20 - gallium nitride epitaxial layer; 21 - functional layer; 22 - buffer layer / U-shaped gallium nitride layer; 30 - gallium oxide; 40 - growth substrate. DETAILED DESCRIPTION

[0026] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention.

[0027] The disclosure of the present invention provides many different embodiments or examples to realize different structures of the present invention. In order to simplify the disclosure of the present invention, the components and settings of specific examples are described in the present invention. Of course, they are only examples, and the purpose is not to limit the present invention. In addition, the present invention can repeat reference numbers and / or reference letters in different examples, and this repetition is for the purpose of simplicity and clarity, which itself does not indicate the relationship between the various embodiments and / or settings discussed. In addition, the present invention provides various specific examples of processes and materials, but those of ordinary skill in the art can be aware of the application of other processes and / or the use of other materials.

[0028] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those generally understood by those skilled in the art to which the present application belongs. The terms used herein in the specification of the present application are only for the purpose of describing specific embodiments and are not intended to limit the present application. Generally, the terms can be understood at least in part according to the usage of the present invention. For example, the term "one or more" used in the present invention depends at least in part on the present invention and can be used to describe any component, structure or feature in a singular form, or can be used to describe a combination of components, structures or features in a plural form. Similarly, terms such as "one", "an" or "the" can also be understood at least in part to convey singular usage or convey plural usage depending on the present invention. In addition, the term "based on..." can be understood as not necessarily intended to convey a set of exclusive factors, but at least in part depending on the present invention can instead allow the presence of additional factors that do not necessarily have to be explicitly described.

[0029] It should be easily understood that the meanings of “on,” “over,” and “on…” in the present invention should be interpreted in the broadest manner, so that “on…” means not only “directly on something,” but also means “on something” including the presence of intermediate components or layers therebetween, and “on something” or “on something” means not only “on something” or “on something,” but also includes the meaning of “on something” or “on something” without any intermediate components or layers therebetween.

[0030] Additionally, for ease of description, spatially relative terms such as "below," "beneath," "lower," "above," "upper," etc. may be used herein to describe the relationship of one element or component to another element or component as shown in the drawings. The spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientations depicted in the drawings. The device may be otherwise oriented, rotated 90 degrees or at other orientations, and the spatially relative descriptors used herein may likewise be interpreted accordingly.

[0031] The term "layer" used in the present invention refers to a material portion including an area with a certain thickness. The layer can extend over the entire lower or upper structure, or can have a degree less than the scope of the lower or upper structure. In addition, the layer can be a region of a homogeneous or inhomogeneous continuous structure, and its thickness is less than the thickness of the continuous structure. For example, the layer can be located between the top surface and the bottom surface of the continuous structure or between any pair of horizontal planes therebetween. The layer can extend horizontally, vertically and / or along a tapered surface. The substrate can be a layer, one or more layers can be included therein, and / or one or more layers can be provided thereon, above and / or below. A layer can include multiple layers. For example, the semiconductor layer can include one or more doped or undoped semiconductor layers, and can have the same or different materials.

[0032] When making gallium nitride-based Micro LED chips, it is usually necessary to perform laser stripping on the growth substrate. After the gallium nitride epitaxial layer is stripped from the growth substrate, the buffer layer is generally removed by chemical etching, and the functional layer is retained to make LED devices. However, when the gallium nitride epitaxial layer is stripped from the growth substrate by the laser stripping process, the high-energy pulsed laser beam generates instantaneous high temperature when penetrating the sapphire substrate, decomposing the gallium nitride into metallic gallium and nitrogen, separating the sapphire from the epitaxial layer. After separation, part of the metallic gallium on the surface is oxidized to form gallium oxide. If the gallium oxide is not removed and chemical etching is used directly to remove the buffer layer, the gallium oxide remaining on the surface of the buffer layer will form an etching mask, resulting in the formation of some micrometer-sized columnar buffer layer residues on the functional layer when the buffer layer is removed. This will greatly reduce the yield and reliability of the LED chip process.

[0033] Based on this, the present application hopes to provide a solution that can solve the above-mentioned technical problems, the details of which will be described in the subsequent embodiments.

[0034] refer to Figure 1 , is a schematic flow chart of a gallium oxide removal method provided in an embodiment of the present application, the method comprising:

[0035] 101: Provide a gallium nitride epitaxial wafer peeled from a growth substrate, wherein the gallium nitride epitaxial wafer comprises a substrate and a gallium nitride epitaxial layer stacked on the substrate.

[0036] refer to Figure 2 The gallium nitride epitaxial wafer provided in the embodiment of the present application may include a substrate 10, a gallium nitride epitaxial layer 20, and gallium oxide 30 remaining on the surface of the gallium nitride epitaxial layer 20.

[0037] The gallium nitride epitaxial layer 20 may include a functional layer 21 and a buffer layer 22 (or a U-shaped gallium nitride layer 22), and the functional layer 21 at least includes an N-type gallium nitride layer, a light-emitting layer and a P-type gallium nitride layer constituting an LED epitaxial structure. The substrate may be a driving substrate, such as a CMOS driving substrate; or a temporary substrate, such as a sapphire substrate, a silicon substrate or a gallium nitride substrate.

[0038] In the embodiment of the present application, the gallium nitride epitaxial wafer provided above after being peeled off from the growth substrate can be specifically referred to Figure 3 .

[0039] like Figure 3 As shown in (a), a gallium nitride epitaxial layer 20 having a growth substrate 40 and a base plate 10 are provided.

[0040] like Figure 3 As shown in (b), the gallium nitride epitaxial layer 20 is bonded to the substrate 10. Specifically, a bonding layer (not shown in the figure) can be provided on the functional layer 21 and the substrate 10. The material of the bonding layer can be selected according to the substrate. For example, when the substrate is a COMS driving substrate, a metal bonding layer can be provided on the functional layer 21 and the substrate 10, respectively, and then the gallium nitride epitaxial layer 20 is bonded to the substrate 10 by metal bonding. In the subsequent LED device manufacturing process, the metal bonding layer can be patterned and used as a component for electrical connection between the LED device and the COMS driving substrate. For another example, when the substrate 10 is a temporary substrate, an adhesive can be selected as a bonding layer for bonding to facilitate the transfer of the LED device after the LED device is manufactured in the later stage.

[0041] like Figure 3 (c) and Figure 3As shown in (d), the growth substrate 40 is peeled off from the above-mentioned gallium nitride epitaxial layer 20 using a laser lift-off process. During the lift-off, the high-energy pulsed laser beam generates an instantaneous high temperature when passing through the growth substrate 40, decomposing the gallium nitride into metal gallium and nitrogen, so that the growth substrate 40 is separated from the gallium nitride epitaxial layer 20. After the separation, part of the metal gallium on the surface is oxidized to generate gallium oxide 30.

[0042] 102: Performing an inductively coupled plasma etching process on the surface of the gallium nitride epitaxial layer to remove gallium oxide on the surface, wherein the gallium oxide at least covers a portion of the surface of the gallium nitride epitaxial layer.

[0043] In the embodiment of the present application, the etching gas in the above-mentioned inductively coupled plasma etching process is pure argon gas, without other gases. That is, in the present embodiment, the etching process performed on the surface of the gallium nitride epitaxial layer is pure physical etching, and the etching process is to bombard the surface of the gallium nitride epitaxial layer with argon ions. Since the Ga-N bond energy of gallium nitride (about 876.9 kJ / mol) is greater than the Ga-O bond energy of gallium oxide (about 363.6 kJ / mol), gallium oxide and gallium nitride can be selectively etched by controlling the energy of the argon ions.

[0044] In some optional embodiments, the etching selectivity ratio between gallium oxide and gallium nitride during the above-mentioned inductively coupled plasma etching process is greater than 6:1.

[0045] In the embodiment of the present application, the changes before and after the etching treatment on the surface of the gallium nitride epitaxial layer can be referred to Figure 4 After etching, there will be a gallium nitride protrusion on the surface of the gallium nitride epitaxial layer where the gallium oxide was originally located; when the height of the gallium nitride protrusion is greater than a certain threshold, it will affect the subsequent process of the LED device. In the embodiment of the present application, in order to ensure the yield and reliability of the LED device, the height of the gallium nitride protrusion needs to be kept less than 0.1um. However, after measurement, the maximum thickness of gallium oxide remaining on the surface of the gallium nitride epitaxial layer is approximately 0.6um. Therefore, when etching the surface of the gallium nitride epitaxial layer, it is only necessary to ensure that the selectivity ratio of gallium oxide and gallium nitride etching is greater than 6:1 to ensure that the height of the gallium nitride protrusion is less than 0.1um.

[0046] In some optional embodiments, during the inductively coupled plasma etching process, the argon gas flow rate is 55-65 sccm. For example, the argon gas flow rate may be 55 sccm, 57 sccm, 58 sccm, 60 sccm, 63 sccm or 65 sccm.

[0047] In some optional embodiments, during the above-mentioned inductively coupled plasma etching process, the upper etching power is 240-2600W, and the lower etching power is 290-310W.

[0048] In some optional embodiments, before the inductively coupled plasma etching is performed on the surface of the gallium nitride epitaxial layer, the method further comprises: soaking the gallium nitride epitaxial wafer in an acidic solution for 5-10 minutes.

[0049] refer to Figure 5 , is a schematic flow chart of a chip manufacturing method provided in this application, including:

[0050] 201: Providing a gallium nitride epitaxial wafer, wherein the gallium nitride epitaxial layer comprises a first type gallium nitride layer, a light emitting layer, and a second type gallium nitride layer sequentially stacked on the metal bonding layer.

[0051] In the embodiment of the present application, the gallium nitride epitaxial wafer is as follows Figure 1 Gallium nitride epitaxial wafer after being processed by the gallium oxide removal method shown.

[0052] In the embodiment of the present application, the first type of gallium nitride layer and the second type of gallium nitride layer are gallium nitride layers of different doping types; the first type of gallium nitride layer may be an N-type gallium nitride layer or a P-type gallium nitride layer; the second type of gallium nitride layer may be a P-type gallium nitride layer or an N-type gallium nitride layer; the light-emitting layer may be a multiple quantum well structure (Multiple Quantum Well, MQW). Specifically, the quantum well or quantum layer may be InGaN, AlGaN, InN, InAlN, AlInGaN, etc., and the quantum barrier alternately stacked with the quantum well layer may be GaN, AlN, AlGaN, AlInGaN, InAlN, etc.; the multiple quantum well structure may include one or two or three or four or five or six or six or seven or eight quantum wells (or at least one quantum hole); the wavelength emitted by the active layer may be a wavelength in the blue light band, a wavelength in the green light band, or a wavelength in the red light band, which is not specifically limited in the embodiment of the present application.

[0053] 202: Patterning the first type gallium nitride layer, the light emitting layer, and the second type gallium nitride layer to form a plurality of independent LED epitaxy.

[0054] The above patterning refers to forming a layer structure into a predetermined pattern shape through multiple processes such as photolithography and etching. After the above patterning of the first type gallium nitride layer, the light-emitting layer and the second type gallium nitride layer, multiple independent LED epitaxies are formed, each LED epitaxy is separated from each other, and channels are formed between adjacent LED epitaxies.

[0055] 203 : Vapor-depositing a first electrode and a second electrode, wherein the first electrode is connected to the first type gallium nitride layer of the LED epitaxy, and the second electrode is connected to the second type gallium nitride layer of the LED epitaxy.

[0056] In the embodiment of the present application, the first electrode is one or more metals that can form an ohmic contact with the first type gallium nitride layer for current conduction, for example, the first electrode can be formed by a combination of one or more of Cr, Pt, Ti, Ni, Au, and Sn. The second electrode is one or more metals that can form an ohmic contact with the second type gallium nitride layer for current conduction, for example, the second electrode can be formed by a combination of one or more of Cr, Pt, Ti, Ni, Au, Sn, Ag, Cu, Cu, and Al.

[0057] In the present application examples, the Figure 1 The gallium oxide removal method shown in the figure effectively removes the gallium oxide remaining on the surface of the gallium nitride epitaxial wafer, thereby improving the reliability of the LED chip during the subsequent production of the LED chip.

[0058] refer to Figure 6 Based on the same inventive concept, the present application also provides a method for manufacturing a display device, comprising:

[0059] 301: Provide a gallium nitride epitaxial wafer processed by the gallium oxide removal method described above.

[0060] In an embodiment of the present application, the substrate is a driving substrate, for example, the driving substrate may be a CMOS substrate, the driving substrate includes a plurality of connection contacts, the gallium nitride epitaxial layer is bonded to the driving substrate via a metal bonding layer, and the gallium nitride epitaxial layer includes a first type gallium nitride layer, a light emitting layer, and a second type gallium nitride layer sequentially stacked on the metal bonding layer.

[0061] 302: Patterning the first type gallium nitride layer, the light emitting layer, and the second type gallium nitride layer to form a plurality of independent LED epitaxies, each LED epitaxy being disposed corresponding to a connection contact.

[0062] 303: removing the metal bonding layer between the adjacent LED epitaxies so that the adjacent LED epitaxies cannot be electrically connected through the metal bonding layer.

[0063] 304: Forming an electrode on the second-type gallium nitride layer of the LED epitaxy.

[0064] In some optional embodiments, before forming the electrode on the second type gallium nitride layer of the LED epitaxy, the method further includes: forming a passivation layer on the LED epitaxy; patterning the passivation layer to form an opening on the second type gallium nitride layer of the LED epitaxy; forming the electrode on the second type gallium nitride layer of the LED epitaxy includes: forming the electrode in the opening.

[0065] In some optional embodiments, the method further comprises: forming a light reflecting layer or a light blocking layer on the side wall of the LED epitaxial layer.

[0066] In the present application examples, the Figure 1 The gallium oxide removal method shown in the figure effectively removes the gallium oxide remaining on the surface of the gallium nitride epitaxial wafer, thereby improving the reliability of the display device during the subsequent manufacture of the display device.

[0067] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0068] The present invention has been introduced in detail above. Specific examples have been applied in the present invention to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the technical solutions and core ideas of the present invention. Ordinary technicians in this field should understand that they can still modify the technical solutions recorded in the aforementioned embodiments, or replace some of the technical features therein with equivalents. However, these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for removing gallium oxide, characterized in that: include: Providing a gallium nitride epitaxial wafer peeled from a growth substrate, the gallium nitride epitaxial wafer comprising a substrate and a gallium nitride epitaxial layer stacked on the substrate; The surface of the gallium nitride epitaxial layer is subjected to an inductively coupled plasma etching process to remove gallium oxide on the surface, wherein the gallium oxide at least covers a portion of the surface of the gallium nitride epitaxial layer.

2. The gallium oxide removal method according to claim 1, characterized in that: The etching gas during the inductively coupled plasma etching process is argon.

3. The gallium oxide removal method according to claim 2, wherein during the inductively coupled plasma etching process, the argon gas flow rate is 55-65 sccm.

4. The gallium oxide removal method according to claim 2, characterized in that: The etching selectivity ratio between gallium oxide and gallium nitride during the inductively coupled plasma etching process is greater than 6:

1.

5. The gallium oxide removal method according to claim 2, characterized in that: During the inductively coupled plasma etching process, the upper etching power is 240-2600W, and the lower etching power is 290-310W.

6. The gallium oxide removal method according to any one of claims 1 to 5, characterized in that: Before performing the inductively coupled plasma etching process on the surface of the gallium nitride epitaxial layer, the method further comprises: soaking the gallium nitride epitaxial wafer in an acidic solution for 5-10 minutes.

7. A chip manufacturing method, characterized in that: include: Providing a gallium nitride epitaxial wafer treated by the gallium oxide removal method according to any one of claims 1 to 6; The gallium nitride epitaxial layer includes a first type gallium nitride layer, a light emitting layer and a second type gallium nitride layer stacked in sequence; Patterning the first type gallium nitride layer, the light emitting layer and the second type gallium nitride layer to form a plurality of independent LED epitaxies; A first electrode and a second electrode are evaporated, wherein the first electrode is connected to the first type gallium nitride layer of the LED epitaxy, and the second electrode is connected to the second type gallium nitride layer of the LED epitaxy.

8. A method for manufacturing a display device, characterized in that: include: Providing a gallium nitride epitaxial wafer treated by the gallium oxide removal method according to any one of claims 1 to 6; The substrate is a driving substrate, the driving substrate includes a plurality of connection contacts, the gallium nitride epitaxial layer is bonded to the driving substrate via a metal bonding layer, and the gallium nitride epitaxial layer includes a first type gallium nitride layer, a light emitting layer, and a second type gallium nitride layer stacked in sequence; Patterning the first type gallium nitride layer, the light emitting layer and the second type gallium nitride layer to form a plurality of independent LED epitaxies; Removing the metal bonding layer between adjacent LED epitaxies so that adjacent LED epitaxies cannot be electrically connected through the metal bonding layer; An electrode is formed on the second type gallium nitride layer epitaxially grown on the LED.

9. The method for manufacturing a display device according to claim 8, wherein: Before forming an electrode on the second type gallium nitride layer of the LED epitaxy, the method further includes: forming a passivation layer on the LED epitaxy; Patterning the passivation layer to form openings on the second type gallium nitride layer of the LED epitaxy; The forming of an electrode on the second type gallium nitride layer of the LED epitaxy comprises: The electrode is formed in the opening.

10. The method for manufacturing a display device according to claim 9, wherein: The method further comprises: A light reflecting layer or a light blocking layer is formed on the side wall of the LED epitaxial layer.

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