Light-emitting chip and preparation method thereof

Abstract

The embodiment of the invention discloses a light-emitting chip and a preparation method thereof, and the method comprises the steps: arranging a stripping function layer which is made of the same material as an intrinsic semiconductor layer corresponding to a first semiconductor layer at the bottom of an isolation channel of adjacent light-emitting units; in this way, the materials of the contact interfaces of the light-emitting units and the substrate and the materials of the isolation channels between the adjacent light-emitting units and the contact interfaces of the substrate are close, so that when the substrate is stripped, the connection between the stripping function layer and the light-emitting units on the two sides is tighter; the overall structure of the light-emitting units and the stripping function layer on the substrate can be stripped from the substrate conveniently, the structural integrity of the obtained light-emitting chip is ensured, breakage at the position of an isolation channel of the adjacent light-emitting units is avoided, and the yield and reliability of the light-emitting chip are improved.

Description

Technical Field

[0001] This invention relates to the field of display technology, and in particular to a light-emitting chip and its fabrication method. Background Technology

[0002] Micro LEDs, with their small size, high integration, and self-emissive characteristics, are widely used in display devices.

[0003] In existing technologies, some light-emitting chips include at least two light-emitting units, with a spacing between adjacent units. During the fabrication of these chips, maintaining chip integrity is difficult when peeling them from the substrate, affecting chip yield. Summary of the Invention

[0004] This invention provides a light-emitting chip and its fabrication method to improve the yield and ensure the reliability of the light-emitting chip.

[0005] According to one aspect of the present invention, a light-emitting chip is provided, comprising:

[0006] At least two light-emitting units are arranged in a flat arrangement. Each light-emitting unit includes a first semiconductor layer, a light-emitting layer, and a second semiconductor layer that are stacked together. An isolation channel is provided between adjacent light-emitting units.

[0007] The functional layer is stripped, and the functional layer is located at least at the bottom of the isolation channel. The material of the functional layer is the same as that of the intrinsic semiconductor layer corresponding to the first semiconductor layer.

[0008] Optionally, the bottom surface of the stripping functional layer in the isolation channel is flush with the bottom surface of the first semiconductor layer, and the bottom surface of the first semiconductor layer is the surface of the first semiconductor layer away from the light-emitting layer.

[0009] Optionally, the stripping functional layer is also disposed on the sidewall of the light-emitting unit near the isolation channel.

[0010] Optionally, the thickness of the stripped functional layer is less than the thickness of the first semiconductor layer.

[0011] Optionally, the thickness of the stripped functional layer is greater than or equal to 50 nanometers and less than or equal to 500 nanometers.

[0012] Optionally, the light-emitting chip further includes a reflective layer located on the side of the second semiconductor layer away from the first semiconductor layer, and / or at least a portion of the side surface of the light-emitting unit;

[0013] The stripped functional layer is also partially located on the side of the reflective layer away from the light-emitting unit.

[0014] Optionally, the light-emitting chip also includes a bridging electrode, one end of which is electrically connected to the first semiconductor layer of the light-emitting unit on one side of the isolation channel, and the other end of which is electrically connected to the second semiconductor layer of the light-emitting unit on the other side of the isolation channel.

[0015] Optionally, the light-emitting chip also includes a filling layer, which is at least partially disposed in the isolation channel and at least partially located between the stripped functional layer and the bridging electrode.

[0016] Optionally, at least two tiled light-emitting units include a first light-emitting unit and a second light-emitting unit, with the first light-emitting unit and the second light-emitting unit located on both sides of the isolation trench;

[0017] The surface of the filling layer away from the second light-emitting unit includes a recessed portion, which is recessed towards the side closer to the second light-emitting unit to form a receiving space; the bridging electrode is electrically connected to the first semiconductor layer of the first light-emitting unit in the receiving space.

[0018] According to another aspect of the present invention, a method for fabricating a light-emitting chip is provided, comprising:

[0019] The epitaxial layer on the substrate is patterned to form at least two light-emitting units, and an isolation channel is formed between adjacent light-emitting units, with the isolation channel exposing the substrate; the epitaxial layer includes a first semiconductor layer, a light-emitting layer and a second semiconductor layer stacked together.

[0020] A release functional layer is formed at least at the bottom of the isolation channel on the substrate, and the release functional layer is made of the same material as the intrinsic semiconductor layer corresponding to the first semiconductor layer.

[0021] Remove the substrate.

[0022] Optionally, after forming the release functional layer and before stripping the substrate, the process further includes:

[0023] A bridging electrode is formed, with one end of the bridging electrode electrically connected to the first semiconductor layer of the light-emitting unit on one side of the isolation channel, and the other end of the bridging electrode electrically connected to the second semiconductor layer of the light-emitting unit on the other side of the isolation channel.

[0024] Optionally, after forming the stripping functional layer and before forming the bridging electrode, the process further includes:

[0025] The isolation trench is filled to form a filling layer.

[0026] The light-emitting chip and its fabrication method of this invention provide a release functional layer with the same intrinsic semiconductor material as the first semiconductor layer at the bottom of the isolation channel between adjacent light-emitting units. This makes the materials of the contact interface between the light-emitting unit and the substrate, as well as the contact interface between the isolation channel between adjacent light-emitting units and the substrate, similar. This results in a tighter connection between the release functional layer and the light-emitting units on both sides when the substrate is peeled off. This facilitates the peeling of the light-emitting units and the overall structure of the release functional layer from the substrate, ensuring the structural integrity of the resulting light-emitting chip. This avoids breakage at the location of the isolation channel between adjacent light-emitting units, improving the yield and reliability of the light-emitting chip.

[0027] It should be understood that the description in this section is not intended to identify key or essential features of the embodiments of the present invention, nor is it intended to limit the scope of the invention. Other features of the invention will become readily apparent from the following description. Attached Figure Description

[0028] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0029] Figure 1 This is a schematic diagram of the structure of a light-emitting chip provided in an embodiment of the present invention;

[0030] Figure 2 This is a schematic diagram of another light-emitting chip provided in an embodiment of the present invention;

[0031] Figure 3 This is a schematic diagram of another light-emitting chip provided in an embodiment of the present invention;

[0032] Figure 4 This is a schematic diagram of another light-emitting chip provided in an embodiment of the present invention;

[0033] Figure 5 This is a top view of a light-emitting chip provided in an embodiment of the present invention;

[0034] Figure 6 This is a flowchart of a method for fabricating a light-emitting chip according to an embodiment of the present invention;

[0035] Figure 7 This is a schematic diagram of the epitaxial layer structure;

[0036] Figure 8 This is a schematic diagram of the structure after an ohmic contact layer is formed on the epitaxial layer;

[0037] Figure 9 This is a schematic diagram of the structure after the hole is opened;

[0038] Figure 10 This is a schematic diagram of the structure after the bridging electrode, the first electrode, and the second electrode are formed. Detailed Implementation

[0039] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0040] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0041] Figure 1 This is a schematic diagram of the structure of a light-emitting chip provided in an embodiment of the present invention, for reference. Figure 1 The light-emitting chip includes: at least two flatly arranged light-emitting units 10, each light-emitting unit 10 including a first semiconductor layer 11, a light-emitting layer 12 and a second semiconductor layer 13 stacked together; an isolation channel 20 is provided between adjacent light-emitting units 10; and a stripped functional layer 30, which is located at least at the bottom of the isolation channel 20, and the stripped functional layer 30 is made of the same material as the intrinsic semiconductor layer corresponding to the first semiconductor layer 11.

[0042] In the light-emitting unit 10, the first semiconductor layer 11 is an N-type semiconductor layer, and the second semiconductor layer 13 is a P-type semiconductor layer; or the first semiconductor layer 11 is a P-type semiconductor layer, and the second semiconductor layer 13 is an N-type semiconductor layer. The N-type semiconductor layer may include n-GaN, and the P-type semiconductor layer may include p-GaN. The light-emitting layer 12 may be a quantum well layer, optionally a multi-quantum well layer, such as an InGaN / GaN multi-quantum well layer. Optionally, the light-emitting unit 10 further includes an ohmic contact layer 14, which is disposed on the side of the P-type semiconductor layer away from the N-type semiconductor layer. In some embodiments, the ohmic contact layer 14 is also disposed on the side of the N-type semiconductor layer away from the P-type semiconductor layer. The ohmic contact layer 14 is a transparent conductive layer, and the material may be indium tin oxide.

[0043] An isolation channel 20 is provided between adjacent light-emitting units 10 to achieve electrical isolation between different light-emitting units 10. No structural layer of light-emitting unit 10 is provided at the location of the isolation channel 20. Optionally, the isolation channel 20 between adjacent light-emitting units 10 is formed by patterning an epitaxial layer. When patterning the epitaxial layer, the epitaxial layer at the corresponding position of the isolation channel 20 can be removed to form the isolation channel 20, and light-emitting units 10 are formed on both sides of the isolation channel 20. In the light-emitting chip, different light-emitting units 10 can be electrically connected to each other, for example, in series or in parallel; different light-emitting units 10 can also be insulated from each other, for example, the electrodes of different light-emitting units 10 are independently set, and each light-emitting unit 10 emits light independently.

[0044] In this embodiment of the invention, the light-emitting chip further includes a release functional layer 30, which is located at least at the bottom of the isolation channel 20. The bottom of the isolation channel 20 is between the first semiconductor layers 11 of adjacent light-emitting units 10. The release functional layer 30 is made of the same material as the first semiconductor layer 11; for example, if the first semiconductor layer 11 is made of gallium nitride, then the release functional layer 30 is also made of gallium nitride. Specifically, during the fabrication of the light-emitting chip, a plurality of light-emitting units 10 and an isolation channel 20 can first be formed by patterning an epitaxial layer on a substrate. The epitaxial layer includes a first semiconductor layer 11, a light-emitting layer 12, and a second semiconductor layer 13 stacked together. At the location of the isolation channel 20, the substrate is exposed. Then, the release functional layer 30 is formed at least at the exposed substrate location. The release functional layer 30 is made of an insulating material to prevent adjacent light-emitting units 10 from forming unnecessary connections through the release functional layer 30, thus avoiding short circuits, or short circuits formed between the first semiconductor layer 11, the light-emitting layer 12, and the second semiconductor layer 13 of the same light-emitting unit 10 on the sidewalls through the release functional layer 30.

[0045] In this embodiment of the invention, the stripping functional layer 30 is made of the same intrinsic semiconductor layer material as the first semiconductor layer 11; that is, the stripping functional layer 30 is the intrinsic semiconductor layer corresponding to the first semiconductor layer 11. The semiconductor layer of the first semiconductor layer 11 before doping is the intrinsic semiconductor layer corresponding to the first semiconductor layer, meaning the first semiconductor layer 11 can be obtained by doping the corresponding intrinsic semiconductor layer. For example, if the first semiconductor layer 11 is N-type gallium nitride, then the intrinsic semiconductor layer corresponding to the first semiconductor layer 11 is pure gallium nitride, meaning the material of the stripping functional layer 30 is pure gallium nitride. In summary, the intrinsic semiconductor layer is a pure material with high resistance or insulating properties, ensuring that adjacent light-emitting units 10 will not form an electrical connection through the stripping functional layer 30. The first semiconductor layer 11, being a doped material, can provide electrical connection. Making the stripping functional layer 30 and the intrinsic semiconductor layer corresponding to the first semiconductor layer 11 the same material ensures that the materials of the stripping functional layer 30 and the first semiconductor layer 11 are similar.

[0046] The light-emitting chip of this invention provides a release functional layer with the same intrinsic semiconductor material as the first semiconductor layer at the bottom of the isolation channel between adjacent light-emitting units. This makes the materials at the contact interface between the light-emitting unit and the substrate, as well as at the contact interface between the isolation channel between adjacent light-emitting units and the substrate, similar. This results in a tighter connection between the release functional layer and the light-emitting units on both sides when the substrate is peeled off. This facilitates the peeling of the light-emitting units and the overall structure of the release functional layer from the substrate, ensuring the structural integrity of the resulting light-emitting chip. This avoids breakage at the location of the isolation channel between adjacent light-emitting units, improving the yield and reliability of the light-emitting chip.

[0047] Optionally, the bottom surface of the stripping functional layer 30 in the isolation channel 20 is flush with the bottom surface of the first semiconductor layer 11, and the bottom surface of the first semiconductor layer 11 is the surface of the first semiconductor layer 11 away from the light-emitting layer 12.

[0048] The bottom surface of the release functional layer 30 in the isolation channel 20 is the surface on which the release functional layer 30 contacts the substrate during the fabrication of the light-emitting chip. By setting the bottom surface of the release functional layer 30 in the isolation channel 20 to be flush with the bottom surface of the first semiconductor layer 11, the overall structure of the release functional layer 30 and the light-emitting unit 10 has a smoother contact surface with the substrate. This avoids uneven surfaces between the release functional layer 30 and the first semiconductor layer 11 and the substrate, which could lead to differences in the bonding force between the release functional layer 30 and the first semiconductor layer 11 and the substrate, ultimately affecting the integrity of the light-emitting chip obtained by release. That is, in this embodiment, by setting the bottom surface of the release functional layer 30 in the isolation channel 20 to be flush with the bottom surface of the first semiconductor layer 11, the integrity of the light-emitting chip during the release from the substrate is further ensured.

[0049] Figure 2 This is a schematic diagram of another light-emitting chip provided in an embodiment of the present invention, for reference. Figure 2 Optionally, the release layer 30 is also disposed on the sidewall of the light-emitting unit 10 near the isolation channel 20. This ensures that the contact surface between the release layer 30 and the light-emitting unit 10 is larger at the location of the isolation channel 20, making the release layer 30 and the light-emitting unit 10 more tightly bonded to each other. This makes it easier for the release layer 30 and the light-emitting unit 10 to detach from the substrate together when the substrate is peeled off, further ensuring the integrity of the light-emitting chip.

[0050] Combination Figure 1 and Figure 2 In some embodiments, the thickness d1 of the stripped functional layer 30 is less than the thickness d2 of the first semiconductor layer 11.

[0051] Specifically, since the stripped functional layer 30 needs to be fabricated as a whole layer, and then a portion of the film layer is retained to obtain the stripped functional layer 30, by setting the thickness d1 of the stripped functional layer 30 to be less than the thickness d2 of the first semiconductor layer 11, the thickness d1 of the stripped functional layer 30 is made smaller. Therefore, the setting of the stripped functional layer 30 will not have an excessive impact on the thickness of the light-emitting chip, ensuring that the overall thickness of the light-emitting chip is small.

[0052] For example, the thickness d1 of the stripped functional layer 30 is greater than or equal to 50 nanometers and less than or equal to 500 nanometers.

[0053] Specifically, if the thickness d1 of the stripped functional layer 30 is too small, for example, less than 50 nanometers, the interfacial bonding force between the stripped functional layer 30 and the light-emitting unit 10 will be weak. During substrate stripping, the stripped functional layer 30 will be more likely to adhere to the substrate, causing the light-emitting chip to break at the isolation channel 20, affecting the integrity of the light-emitting chip. If the thickness d1 of the stripped functional layer 30 is too large, for example, greater than 500 nanometers, the light-emitting chip will be too thick, failing to meet the miniaturization requirements of the light-emitting chip. In this embodiment, the thickness d1 of the stripping functional layer 30 is set to be greater than or equal to 50 nanometers and less than or equal to 500 nanometers. For example, the thickness d1 of the stripping functional layer 30 is 50 nanometers, 85 nanometers, 100 nanometers, 126 nanometers, 150 nanometers, 200 nanometers, 280 nanometers, 300 nanometers, 360 nanometers, 400 nanometers, 450 nanometers, or 500 nanometers. This ensures that the thickness d1 of the stripping functional layer 30 is neither too thin nor too thick, and that the interfacial bonding force between the stripping functional layer 30 and the light-emitting unit 10 is relatively large. When the substrate is stripped, the overall structure of the stripping functional layer 30 and the light-emitting unit 10 is more likely to detach from the substrate together. At the same time, it ensures that the thickness d1 of the stripping functional layer 30 is not too thick, thereby meeting the miniaturization requirements of the light-emitting chip.

[0054] Figure 3 This is a schematic diagram of another light-emitting chip provided in an embodiment of the present invention, for reference. Figure 3 Optionally, the light-emitting chip also includes a reflective layer 40, which is located on the side of the second semiconductor layer 13 away from the first semiconductor layer 11, and / or at least a portion of the side of the light-emitting unit 10; a portion of the stripping functional layer 30 is located on the side of the reflective layer 40 away from the light-emitting unit 10.

[0055] In this embodiment, by providing a reflective layer 40 on the side of the second semiconductor layer 13 away from the first semiconductor layer 11, light incident on the bottom surface of the light-emitting chip can be reflected by the reflective layer 40 to the light-emitting side, thereby improving the light extraction efficiency of the light-emitting chip. By providing a reflective layer 40 on at least a portion of the sides of the light-emitting unit 10, light incident on the sides of the light-emitting chip can be reflected to the light-emitting side, improving the light extraction efficiency of the light-emitting chip. In some embodiments, the reflective layer 40 may not be provided, and a passivation layer may be provided at the location of the reflective layer 40, that is, the reflective layer 40 is replaced by a passivation layer. Optionally, the reflective layer 40 may be a distributed Bragg reflective layer 40. The distributed Bragg reflective layer 40 may include an optical structure formed by alternating stacks of two materials with different refractive indices to improve reflectivity. For example, the distributed Bragg reflective layer 40 may be an alternating stacked combination of SiO2 and TiO2. In this embodiment, the stripping functional layer 30 is also partially located on the side of the reflective layer 40 away from the light-emitting unit 10, which can play a protective and insulating role.

[0056] Figure 4 This is a schematic diagram of another light-emitting chip provided in an embodiment of the present invention, for reference. Figure 4 The light-emitting chip also includes a bridging electrode 50, one end of which is electrically connected to the first semiconductor layer 11 of the light-emitting unit 10 on one side of the isolation channel 20, and the other end of which is electrically connected to the second semiconductor layer 13 of the light-emitting unit 10 on the other side of the isolation channel 20.

[0057] The bridging electrode 50 is made of a conductive material, such as a metallic material. Optionally, the material of the bridging electrode 50 includes at least one of Ni, Al, Ti, Pt, and Au. In some embodiments, the bridging electrode 50 includes a multilayer metal composed of Ni, Al, Ti, Pt, and Au. Optionally, the thickness of the bridging electrode 50 is 0.5 micrometers to 2 micrometers. One end of the bridging electrode 50 is electrically connected to the first semiconductor layer 11 of the light-emitting unit 10 on one side of the isolation channel 20, and the other end is electrically connected to the second semiconductor layer 13 of the light-emitting unit 10 on the other side of the isolation channel 20, thereby connecting the light-emitting units 10 on both sides of the isolation channel 20 in series. This achieves a high-voltage, low-current, high-power MicroLED chip.

[0058] Continue to refer to Figure 4 Optionally, the light-emitting chip further includes a first electrode 70 and a second electrode 80. The first electrode 70 is electrically connected to the first semiconductor layer 11 of one light-emitting unit 10, and the second electrode 80 is electrically connected to the second semiconductor layer 13 of another light-emitting unit 10. The first electrode 70 serves as the first electrode 70 of the entire light-emitting chip, the second electrode 80 serves as the second electrode 80 of the entire light-emitting chip, and the bridging electrode 50 serves as an internal electrode that connects different light-emitting units 10 in series in the light-emitting chip.

[0059] Continue to refer to Figure 4 Optionally, the light-emitting chip also includes a filling layer 60, which is at least partially disposed in the isolation channel 20 and is at least partially located between the stripping functional layer 30 and the bridging electrode 50.

[0060] At least a portion of the filler layer 60 is disposed within the isolation channel 20, resulting in a filler layer 60 having a certain height within the isolation channel 20. The filler layer 60 is made of an insulating material. Since the bridging electrode 50 needs to cross the isolation channel 20, the presence of the filler layer 60 ensures that the bridging electrode 50 is above the filler layer 60 and does not reach the bottom of the isolation channel 20. This reduces the height difference traversed by the bridging electrode 50, mitigating breakage caused by excessive height differences that would occur if the isolation channel 20 were too deep.

[0061] Figure 5 This is a top view of a light-emitting chip provided in an embodiment of the present invention. Figure 4 Can correspond Figure 5 Obtained by cutting along AA', see reference. Figure 4 and Figure 5 Optionally, at least two flatly arranged light-emitting units 10 include a first light-emitting unit 101 and a second light-emitting unit 102, with the first light-emitting unit 101 and the second light-emitting unit 102 located on both sides of the isolation channel 20; the surface of the filling layer 60 away from the second light-emitting unit 102 includes a recess 61, which is recessed towards the side closer to the second light-emitting unit 102 to form a receiving space 62; the bridging electrode 50 is electrically connected to the first semiconductor layer 11 of the first light-emitting unit 101 in the receiving space 62.

[0062] Taking the stacking direction of the first semiconductor layer 11, the light-emitting layer 12, and the second semiconductor layer 13 in the light-emitting unit 10 as defined as the thickness direction of the light-emitting chip, the direction in which the recessed portion 61 in the filling layer 60 is recessed toward the second light-emitting unit 102 is perpendicular to the thickness direction, for example, the direction of the recess is horizontal. That is, there is a recess in the vertical projection of the filling layer 60 along the thickness direction of the light-emitting chip, which is also the vertical projection of the recessed portion 61. The surface of the filling layer 60 away from the second light-emitting unit 102 is recessed toward the second light-emitting unit 102 along the thickness direction of the light-emitting chip. When the light-emitting chip includes a substrate, the light-emitting unit 10 and the filling layer 60 are located on the same side of the substrate. The vertical projection of the surface of the filling layer 60 away from the second light-emitting unit 102 onto the substrate is recessed toward the second light-emitting unit 102, that is, recessed toward the interior of the filling layer 60.

[0063] The recessed portion 61 on the side of the filling layer 60 away from the second light-emitting unit 102 can form a receiving space 62. The bridging electrode 50 is electrically connected to the first semiconductor layer 11 of the first light-emitting unit 101 in this receiving space 62. This ensures a reliable connection between the bridging electrode 50 and the first semiconductor layer 11, and also makes it less likely for both the bridging electrode 50 and the filling layer 60 to loosen. This makes the structure formed between the bridging electrode 50 and the filling layer 60 more stable and reliable, which is beneficial to improving the performance of the light-emitting chip. Figure 5 The stripping functional layer 30 is not shown in the diagram.

[0064] This invention also provides a method for fabricating a light-emitting chip, which is used to fabricate the light-emitting chip of any of the above embodiments of this invention. Figure 6 This is a flowchart of a method for fabricating a light-emitting chip according to an embodiment of the present invention, see reference. Figure 6 Optionally, the method for fabricating the light-emitting chip includes:

[0065] S210. Pattern the epitaxial layer on the substrate to form at least two light-emitting units, and form an isolation channel between adjacent light-emitting units, with the isolation channel exposing the substrate.

[0066] The epitaxial layer includes a first semiconductor layer, a light-emitting layer, and a second semiconductor layer stacked together. Figure 7 This is a schematic diagram of the epitaxial layer structure, for reference. Figure 7 Optionally, the epitaxial layer 100 is disposed on one side of the substrate 200, and a first semiconductor layer 11, a light-emitting layer 12, and a second semiconductor layer 13 can be sequentially grown on one side of the substrate 200 to form the epitaxial layer 40. Subsequently, an ohmic contact layer can be formed on the side of the second semiconductor layer 13 away from the light-emitting layer 12. Figure 8 This is a schematic diagram of the structure after an ohmic contact layer is formed on the epitaxial layer. (Refer to...) Figure 8The ohmic contact layer 14 can be prepared by vapor deposition, such as by magnetron sputtering or electron beam vapor deposition.

[0067] S220. At least a release functional layer is formed on the substrate at the bottom of the isolation channel, and the release functional layer is made of the same material as the intrinsic semiconductor layer corresponding to the first semiconductor layer.

[0068] The release functional layer can be deposited by sputtering. For example, a whole layer of release functional layer can be formed first, and then the whole layer of release functional layer can be patterned to retain the release functional layer at the required position. The retained release functional layer is at least located at the bottom of the isolation channel.

[0069] S230, substrate stripping.

[0070] The substrate can be removed by any of the following methods: laser peeling, chemical etching peeling, mechanical grinding and chemical polishing peeling. The embodiments of the present invention do not specifically limit the method.

[0071] The method for fabricating a light-emitting chip according to embodiments of the present invention involves forming a release functional layer at the bottom of an isolation channel. The release functional layer is made of the same material as the intrinsic semiconductor layer corresponding to the first semiconductor layer. This makes the materials of the contact interface between the light-emitting unit and the substrate, as well as the contact interface between the isolation channel and the substrate between adjacent light-emitting units, similar. This allows for a tighter connection between the release functional layer and the light-emitting units on both sides when the substrate is peeled off. This facilitates the peeling of the light-emitting units and the overall structure of the release functional layer from the substrate, ensuring the structural integrity of the resulting light-emitting chip. This avoids breakage at the location of the isolation channel between adjacent light-emitting units, thereby improving the yield and reliability of the light-emitting chip.

[0072] Optionally, after S220 and before S230, the method for fabricating the light-emitting chip further includes: forming a bridging electrode, one end of which is electrically connected to a first semiconductor layer of a light-emitting unit on one side of an isolation channel, and the other end of which is electrically connected to a second semiconductor layer of a light-emitting unit on the other side of an isolation channel.

[0073] The bridging electrode can be fabricated using a metal evaporation process. For example, a full-layer metal layer for the bridging electrode can be fabricated first, followed by a metal lift-off process to form the bridging electrode. The light-emitting chip may also include a reflective layer, which is fabricated before the functional layer is lifted off. After the reflective layer and the functional layer are formed, openings are made in both the reflective layer and the functional layer. Figure 9 This is a schematic diagram of the structure after the hole is opened, for reference. Figure 9 The openings on the reflective layer 40 and the stripping functional layer 30 can be used to bridge the electrical connection between the electrode and the light-emitting unit, the first electrode and the light-emitting unit, and the second electrode and the light-emitting unit. Figure 10This is a schematic diagram of the structure after the bridging electrode, the first electrode, and the second electrode are formed, as shown below. Figure 10 As shown, the bridging electrode 50 connects the two light-emitting units 10 in series, the first electrode 70 is electrically connected to the first semiconductor layer 11 of one of the light-emitting units, and the second electrode 80 is electrically connected to the second semiconductor layer 13 of the other light-emitting unit. Then, the substrate 200 is peeled off.

[0074] Combination Figure 9 and Figure 10 In some embodiments, after forming the stripping functional layer and before forming the bridging electrode, the method further includes filling the isolation channel to form a filling layer.

[0075] Specifically, in this step, a full-layer filler 60 can be prepared on one side of the patterned epitaxial layer, and then the full-layer filler 60 is patterned, retaining at least the filler 60 in the isolation channel 20. After forming the filler 60, the bridging electrode 50 is prepared, so that at the location of the isolation channel 20, the bridging electrode 50 is located above the filler 60, reducing the height difference traversed by the bridging electrode 50, thereby reducing the possibility of breakage of the bridging electrode 50.

[0076] It should be understood that the various forms of processes shown above can be used, with steps reordered, added, or deleted. For example, the steps described in this invention can be executed in parallel, sequentially, or in different orders, as long as the desired result of the technical solution of this invention can be achieved, and this is not limited herein.

[0077] The specific embodiments described above do not constitute a limitation on the scope of protection of this invention. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this invention should be included within the scope of protection of this invention.

Claims

1. A light-emitting chip, characterized in that, include: At least two light-emitting units are arranged in a flat arrangement, wherein the light-emitting unit includes a first semiconductor layer, a light-emitting layer and a second semiconductor layer stacked together; An isolation channel is provided between adjacent light-emitting units; A stripped functional layer is formed, which is located at least at the bottom of the isolation channel, and the stripped functional layer is made of the same material as the intrinsic semiconductor layer corresponding to the first semiconductor layer.

2. The light-emitting chip according to claim 1, characterized in that, The bottom surface of the stripping functional layer in the isolation channel is flush with the bottom surface of the first semiconductor layer, and the bottom surface of the first semiconductor layer is the surface of the first semiconductor layer away from the light-emitting layer.

3. The light-emitting chip according to claim 1, characterized in that, The stripping functional layer is also disposed on the side wall of the light-emitting unit near the isolation channel.

4. The light-emitting chip according to claim 1, characterized in that, The thickness of the stripped functional layer is less than the thickness of the first semiconductor layer.

5. The light-emitting chip according to any one of claims 1-4, characterized in that, The thickness of the stripped functional layer is greater than or equal to 50 nanometers and less than or equal to 500 nanometers.

6. The light-emitting chip according to claim 1, characterized in that, It also includes a reflective layer located on the side of the second semiconductor layer away from the first semiconductor layer, and / or at least a portion of the side surface of the light-emitting unit; The stripping functional layer is also partially located on the side of the reflective layer away from the light-emitting unit.

7. The light-emitting chip according to claim 1, characterized in that, It also includes a bridging electrode, one end of which is electrically connected to the first semiconductor layer of the light-emitting unit on one side of the isolation channel, and the other end of which is electrically connected to the second semiconductor layer of the light-emitting unit on the other side of the isolation channel.

8. The light-emitting chip according to claim 7, characterized in that, It also includes a filler layer, which is at least partially disposed in the isolation channel and is at least partially located between the stripping functional layer and the bridging electrode.

9. The light-emitting chip according to claim 8, characterized in that, At least two flatly arranged light-emitting units include a first light-emitting unit and a second light-emitting unit, with the first light-emitting unit and the second light-emitting unit located on both sides of the isolation trench; The surface of the filling layer away from the second light-emitting unit includes a recessed portion, which is recessed towards the side closer to the second light-emitting unit to form a receiving space; the bridging electrode is electrically connected to the first semiconductor layer of the first light-emitting unit in the receiving space.

10. A method for fabricating a light-emitting chip, characterized in that, include: An epitaxial layer on a substrate is patterned to form at least two light-emitting units, and an isolation channel is formed between adjacent light-emitting units, the isolation channel exposing the substrate; the epitaxial layer includes a first semiconductor layer, a light-emitting layer and a second semiconductor layer stacked together. A release functional layer is formed at least at the bottom of the isolation channel on the substrate, and the release functional layer is made of the same material as the intrinsic semiconductor layer corresponding to the first semiconductor layer. The substrate is peeled off.

11. The method for preparing a light-emitting chip according to claim 10, characterized in that, After forming the release functional layer and before peeling off the substrate, the method further includes: A bridging electrode is formed, one end of which is electrically connected to the first semiconductor layer of the light-emitting unit on one side of the isolation channel, and the other end of which is electrically connected to the second semiconductor layer of the light-emitting unit on the other side of the isolation channel.

12. The method for preparing a light-emitting chip according to claim 11, characterized in that, After forming the stripping functional layer and before forming the bridging electrode, the method further includes: The isolation channel is filled to form a filling layer.

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