Light-emitting device with improved reliability, method of manufacturing the same, and display panel

Abstract

The present disclosure provides a light-emitting device with improved reliability, a preparation method thereof and a display panel, and belongs to the technical field of optoelectronic manufacturing. The light-emitting device comprises at least two light-emitting units and a bridging metal. The at least two light-emitting units are arranged at intervals along a first direction. The bridging metal is located at least in the gap between adjacent light-emitting units and connects the adjacent light-emitting units in series. The ratio of the width of the bridging metal in a second direction to the width of the light-emitting unit in the second direction is greater than or equal to 0.5, and the first direction is perpendicular to the second direction. The present disclosure can improve the problem of removing the substrate and improve the reliability of the light-emitting device.

Description

Technical Field

[0001] This disclosure relates to the field of optoelectronic manufacturing technology, and in particular to a light-emitting device with improved reliability, a method for fabricating the same, and a display panel. Background Technology

[0002] A high-voltage light-emitting diode (LED) is a light-emitting diode with a higher operating voltage than a traditional LED. The operating voltage of a high-voltage LED can reach tens of volts or even higher. High-voltage LEDs achieve their high-voltage operating characteristics by integrating multiple light-emitting units in series within the chip.

[0003] In related technologies, when fabricating high-voltage LED chips, an epitaxial layer is first grown on a substrate, and the epitaxial layer is divided into multiple independent light-emitting units by etching isolation trenches; then, different light-emitting units are connected in series and integrated using metal wires to form an internal high-voltage circuit; finally, the substrate is cut to obtain a high-voltage light-emitting device.

[0004] However, when applied to miniature light-emitting diodes (LED size <50μm), the light-emitting device needs to be removed from the substrate. During the fabrication of the light-emitting device using related technologies, the isolation trenches formed by deep etching weaken the mechanical strength of the light-emitting device, making it prone to breakage during substrate removal and resulting in a reduced fabrication yield. Summary of the Invention

[0005] This disclosure provides a light-emitting device with improved reliability, a method for fabricating the same, and a display panel, which can improve the problem of substrate fragmentation during removal and enhance the reliability of the light-emitting device. The technical solution is as follows: This disclosure provides a light-emitting device comprising: at least two light-emitting units and a bridging metal, wherein the at least two light-emitting units are arranged at intervals along a first direction, the bridging metal is located at least in the gap between adjacent light-emitting units and is connected in series with adjacent light-emitting units; the ratio of the width of the bridging metal in a second direction to the width of the light-emitting unit in the second direction is greater than or equal to 0.5, and the first direction is perpendicular to the second direction.

[0006] In another implementation of the present disclosure, the light-emitting device further includes a connecting layer located on the surface of the light-emitting unit and within the gap between adjacent light-emitting units. The connecting layer also has a first via exposing the light-emitting unit. The bridging metal is located on the surface of the connecting layer away from the light-emitting unit and is connected to the light-emitting unit through the first via.

[0007] In another implementation of the present disclosure, the ratio of the width of the connecting layer in the second direction to the width of the light-emitting unit in the second direction is greater than or equal to 0.5.

[0008] In another implementation of the present disclosure, the bottom surface of the connecting layer located in the gap between adjacent light-emitting units is coplanar with the bottom surface of the light-emitting unit that is away from the bridging metal.

[0009] In another implementation of the present disclosure, the light-emitting device further includes a carrier layer, wherein the bottom surface of the connecting layer and the bottom surface of the light-emitting unit within the gap between adjacent light-emitting units are both located on the same surface of the carrier layer.

[0010] In another implementation of the present disclosure, the light-emitting device further includes an insulating layer located on the surface of the connecting layer away from the light-emitting unit and covering the bridging metal.

[0011] In another implementation of the present disclosure, the light-emitting device further includes an electrode, and the surface of the insulating layer away from the light-emitting unit has a through hole that sequentially penetrates the insulating layer and the connecting layer. The electrode is located on the surface of the insulating layer away from the light-emitting unit and is connected to the light-emitting unit through the through hole; or, the connecting layer further has a second through hole exposing the light-emitting unit, and the electrode is located on the surface of the connecting layer away from the light-emitting unit and is connected to the light-emitting unit through the second through hole.

[0012] In another implementation of the embodiments of this disclosure, the thickness of the bridging metal is greater than or equal to 0.5 μm.

[0013] This disclosure provides a method for fabricating a light-emitting device, the method comprising: forming at least two light-emitting units spaced apart along a first direction on a substrate; forming a bridging metal in the gap between adjacent light-emitting units, such that the bridging metal connects adjacent light-emitting units in series, wherein the ratio of the width of the bridging metal in a second direction to the width of the light-emitting unit in the second direction is greater than or equal to 0.5, and the first direction is perpendicular to the second direction.

[0014] This disclosure provides a display panel including a driving backplate and a plurality of light-emitting devices as described above, wherein the plurality of light-emitting devices are located on the driving backplate and electrically connected to the driving backplate.

[0015] The beneficial effects of the technical solutions provided in this disclosure include at least the following: In the light-emitting device provided in this disclosure, the bridging metal serves as a support structure between adjacent light-emitting units, directly compensating for the mechanical strength degradation caused by deep isolation trenches. Furthermore, the ratio of the width of the bridging metal in the second direction to the width of the light-emitting unit is ≥0.5. This ratio ensures that the bridging metal has sufficient width to provide effective support and allows it to uniformly distribute stress, maintaining the structural integrity of the light-emitting device during transfer (such as laser transfer) or subsequent use, avoiding failure due to localized weaknesses, and enhancing the reliability of the light-emitting device. In other words, by filling the gaps between the light-emitting units with the bridging metal and designing its width to be sufficiently large, it is equivalent to adding a rigid connection between adjacent light-emitting units, structurally enhancing the overall fracture resistance of the light-emitting device, reducing the risk of breakage during substrate removal, and improving fabrication yield. Moreover, the improved reliability allows the light-emitting device to adapt to various transfer methods (such as laser transfer), broadening its application scenarios; simultaneously, the stable structure reduces luminous efficiency loss due to breakage or poor contact. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of this disclosure, 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 this disclosure. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of the structure of a light-emitting device provided in an embodiment of this disclosure; Figure 2 This is a top view of a light-emitting device provided in an embodiment of this disclosure; Figure 3 This is a schematic diagram of another light-emitting device provided in an embodiment of this disclosure; Figure 4 This is a flowchart of a method for fabricating a light-emitting device according to an embodiment of this disclosure; Figure 5 This is a fabrication state diagram of a light-emitting device provided in an embodiment of this disclosure; Figure 6 This is a fabrication state diagram of a light-emitting device provided in an embodiment of this disclosure.

[0018] The markings in the diagram are explained as follows: 1a. First direction; 1b. Second direction; 10. Light-emitting unit; 11. First semiconductor layer; 12. Multiple quantum well layer; 13. Second semiconductor layer; 20. Bridging metal; 30. Connecting layer; 31. First via; 32. Second via; 41. Bearing layer; 42. Insulating layer; 420. Through hole; 50. Electrode; 61. Transparent substrate; 62. Substrate; 63. Temporary substrate. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of this disclosure clearer, the embodiments of this disclosure will be described in further detail below with reference to the accompanying drawings.

[0020] Unless otherwise defined, the technical or scientific terms used herein shall have the ordinary meaning understood by one of ordinary skill in the art to which this disclosure pertains. The terms “first,” “second,” “third,” and similar terms used in this patent application specification and claims do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Similarly, the terms “an” or “a” and similar terms do not indicate a quantity limitation, but rather indicate the presence of at least one. The terms “comprising” or “including” and similar terms mean that the elements or objects preceding “comprising” or “including” encompass the elements or objects listed following “comprising” or “including” and their equivalents, and do not exclude other elements or objects. The terms “connected” or “linked” and similar terms are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. The terms “upper,” “lower,” “left,” “right,” “top,” and “bottom,” etc., are used only to indicate relative positional relationships, and these relative positional relationships may change accordingly when the absolute position of the described objects changes.

[0021] Figure 1 This is a schematic diagram of the structure of a light-emitting device provided in an embodiment of this disclosure. Figure 1 As shown, the light-emitting device includes at least two light-emitting units 10 and a bridging metal 20. The at least two light-emitting units 10 are arranged at intervals along a first direction 1a. The bridging metal 20 is located at least in the gap between adjacent light-emitting units 10, and the bridging metal 20 is connected in series with adjacent light-emitting units 10.

[0022] Figure 2 This is a top view of a light-emitting device provided in an embodiment of this disclosure. Figure 2 As shown, the ratio of the width of the bridging metal 20 in the second direction 1b to the width of the light-emitting unit 10 in the second direction 1b is greater than or equal to 0.5, and the first direction 1a is perpendicular to the second direction 1b.

[0023] In the light-emitting device provided in this embodiment, the bridging metal 20 serves as a support structure between adjacent light-emitting units 10, directly compensating for the mechanical strength degradation caused by deep isolation trenches. Furthermore, the ratio of the width of the bridging metal 20 in the second direction 1b to the width of the light-emitting unit 10 is ≥0.5. This ratio ensures that the bridging metal 20 has sufficient width to provide effective support and allows it to uniformly distribute stress, maintaining the structural integrity of the light-emitting device during transfer (such as laser transfer) or subsequent use, avoiding failure due to localized weaknesses, and enhancing the reliability of the light-emitting device. In other words, by filling the gaps between the light-emitting units 10 with the bridging metal 20 and designing its width to be sufficiently large, it is equivalent to adding a rigid connection between adjacent light-emitting units 10, structurally enhancing the overall fracture resistance of the light-emitting device, reducing the risk of breakage during substrate removal, and improving fabrication yield. Moreover, the improved reliability allows the light-emitting device to adapt to various transfer methods (such as laser transfer), broadening its application scenarios; simultaneously, the stable structure reduces luminous efficiency loss due to breakage or poor contact.

[0024] Optionally, such as Figure 1 As shown, the light-emitting device also includes a connecting layer 30, which is located on the surface of the light-emitting unit 10 and within the gap between adjacent light-emitting units 10. The connecting layer 30 also has a first through hole 31 that exposes the light-emitting unit 10.

[0025] like Figure 1 As shown, the bridging metal 20 is located on the surface of the connecting layer 30 away from the light-emitting unit 10, and the bridging metal 20 is connected to the light-emitting unit 10 through the first via 31.

[0026] In the above implementation, the connecting layer 30 fills the gap between adjacent light-emitting units 10, which not only continues the supporting role of the bridging metal 20 and forms a double-layer support structure of the connecting layer 30 and the bridging metal 20, but also more evenly disperses the mechanical stress during the substrate removal and transfer process, preventing the light-emitting units 10 from breaking due to isolation, and improving the overall mechanical strength of the light-emitting device; at the same time, the connecting layer 30 covers the surface of the light-emitting unit 10 and is provided with a first via 31, providing a stable attachment substrate for the bridging metal 20, so that the bridging metal 20 can be electrically connected to the light-emitting unit 10 through the first via 31, ensuring the conductivity stability of the series circuit.

[0027] Furthermore, the connecting layer 30 also serves as a protective layer covering the surface of the light-emitting unit 10, effectively isolating it from water and oxygen erosion and external physical damage, protecting key structures such as the epitaxial layer from environmental degradation, and extending the device's lifespan. The combination of double-layer support and surface protection makes the light-emitting device more impact-resistant and stable during transfer and application.

[0028] Optionally, the connecting layer 30 includes an inorganic material layer.

[0029] Because inorganic materials have high hardness, low coefficient of thermal expansion and excellent chemical stability, they can effectively support the light-emitting unit 10 and the bridging metal 20, resist mechanical stress and thermal stress, prevent breakage, and at the same time block water and oxygen penetration to protect the internal structure.

[0030] For example, the interconnect layer 30 includes at least one of a silicon oxide layer, a silicon nitride layer, an aluminum oxide layer, and a titanium oxide layer.

[0031] The silicon oxide layer has a moderate dielectric constant and a low coefficient of thermal expansion, and has good thermal matching with the epitaxial layer, which can effectively alleviate thermal stress. In addition, the silicon oxide layer has stable chemical properties, is resistant to acid and alkali corrosion, and can block water and oxygen penetration, thus protecting the light-emitting unit 10. At the same time, the silicon oxide layer also has a certain mechanical strength, providing basic support for the bridging metal 20.

[0032] Among them, the silicon nitride layer has high hardness, good wear resistance, and strong resistance to mechanical impact; and the silicon nitride layer has good ultraviolet light transmittance and does not affect the function of optoelectronic devices.

[0033] Among them, the aluminum oxide layer has a high thermal conductivity, which is better than most insulating materials, and can help dissipate heat and alleviate the local high temperature when the light-emitting unit 10 is working; and it has extremely strong chemical stability, which is not easy to decompose in high temperature and humid environment, and has high long-term reliability.

[0034] Among them, the titanium oxide layer has a high refractive index, which can optimize the optical reflection performance of the device and improve the light extraction efficiency.

[0035] For example, the thickness of the connecting layer 30 is 1 μm to 5 μm.

[0036] By controlling the thickness of the connecting layer 30 within the aforementioned range, sufficient mechanical strength can be provided to effectively disperse the vertical stress between the bridging metal 20 and the light-emitting unit 10, preventing breakage; while avoiding stress accumulation caused by excessive thickness, ensuring the structural stability of the light-emitting device.

[0037] Optionally, such as Figure 2 As shown, the ratio of the width of the connecting layer 30 in the second direction 1b to the width of the light-emitting unit 10 in the second direction 1b is greater than or equal to 0.5.

[0038] For example, the width of the connecting layer 30 in the second direction 1b is equal to the width of the light-emitting unit 10 in the second direction 1b by a ratio of 1. That is, the width of the connecting layer 30 is the same as the width of the light-emitting unit 10, so that the connecting layer 30 can completely cover the light-emitting unit 10.

[0039] In the above implementation, the sufficient width allows the connecting layer 30 to form a continuous and thick support band in the gap of the light-emitting unit 10, which together with the bridging metal 20 constitutes a wide double support structure. This can more efficiently disperse the local stress during substrate removal or transfer, avoid stress concentration caused by the connecting layer 30 being too narrow, enhance the anti-fracture ability of the light-emitting device, and improve the fabrication yield.

[0040] Furthermore, the wider connecting layer 30 can completely cover the sidewalls and bottom of the gaps of the light-emitting unit 10, forming a more complete and dense inorganic protective barrier, isolating external erosion such as water, oxygen, and particles, strengthening the protection of the epitaxial layer of the light-emitting unit 10, and delaying performance degradation.

[0041] Meanwhile, the wide connection layer 30 provides a more stable attachment interface for the bridging metal 20, ensuring the long-term electrical stability of the series circuit.

[0042] Optionally, such as Figure 1 As shown, the bottom surface of the connecting layer 30 located in the gap between adjacent light-emitting units 10 is coplanar with the bottom surface of the light-emitting unit 10 away from the bridging metal 20.

[0043] The bottom surface of the connecting layer 30 and the bottom surface of the light-emitting unit 10 are designed to be coplanar, so that the bottom surface of the light-emitting device is flat. The flat bottom surface allows the light-emitting device to fit more tightly with the substrate to be bonded later, reducing gaps and thermal resistance and improving heat dissipation.

[0044] Optionally, such as Figure 1 As shown, the light-emitting device also includes a carrier layer 41, and the bottom surface of the connecting layer 30 in the gap between adjacent light-emitting units 10 and the bottom surface of the light-emitting unit 10 are both located on the same surface of the carrier layer 41.

[0045] The carrier layer 41 provides a stable planar foundation, enhancing the double-layer support effect of the connecting layer 30 and the bridging metal 20. Furthermore, the bottom surface of the connecting layer 30 and the bottom surface of the light-emitting unit 10 are designed to be coplanar, ensuring that there is no height difference between the bottom surfaces of the light-emitting devices. Combined with the rigid support of the carrier layer 41, this significantly reduces the risk of breakage caused by local suspension, improving yield and reliability.

[0046] Optionally, the support layer 41 includes an organic material layer.

[0047] Because of their excellent flexibility and adhesion, organic materials can buffer external impacts and provide extra protection. Furthermore, organic materials are easy to process and mold, and have high compatibility with subsequent packaging processes.

[0048] For example, the carrier layer 41 may be a deep ultraviolet photoresist.

[0049] Among them, deep ultraviolet photoresist can be decomposed by high-energy laser irradiation, achieving selective removal.

[0050] Optionally, the thickness of the carrier layer 41 can be from 5 μm to 20 μm. For example, the thickness of the carrier layer 41 can be 10 μm.

[0051] Optionally, such as Figure 1 As shown, the light-emitting device also includes an insulating layer 42, which is located on the surface of the connecting layer 30 away from the light-emitting unit 10, and the insulating layer 42 covers the bridging metal 20.

[0052] The insulating layer 42 is located on the surface of the connecting layer 30 away from the light-emitting unit 10 and covers the bridging metal 20. It effectively isolates the bridging metal 20 from external conductive structures, preventing short circuits or leakage current and ensuring the normal operation of the series circuit. Simultaneously, the insulating layer 42 acts as an additional barrier, resisting damage to the bridging metal 20 from water, oxygen, dust, and mechanical scratches, thus extending the device's lifespan. For micro-LEDs, exposed metal in the delicate structure is prone to failure; the covering of the insulating layer 42 improves overall environmental tolerance.

[0053] Optionally, the insulating layer 42 includes at least one of a silicon oxide layer, a silicon nitride layer, and a titanium oxide layer.

[0054] For example, the insulating layer 42 may be a silicon oxide layer.

[0055] For example, the insulating layer 42 may include a plurality of alternating layers of first material and a plurality of alternating layers of second material, the first and second material layers having different refractive indices. By providing alternating layers of high and low refractive index material, a distributed Bragg reflector (DBR) can be formed.

[0056] As an example, the first material layer can be a silicon dioxide layer with a refractive index of 1.44 to 1.55, and the second material layer can be a titanium dioxide layer with a refractive index of 2.2 to 2.9. The significant difference in refractive indices between the two material layers allows for the achievement of high reflectivity and low absorption loss in the visible light region with only 10 to 20 cycles of material layers.

[0057] Optionally, such as Figure 1 As shown, the light-emitting unit 10 includes an epitaxial layer, which includes a first semiconductor layer 11, a multiple quantum well layer 12, and a second semiconductor layer 13 sequentially stacked on the surface of the carrier layer 41.

[0058] In this embodiment of the present disclosure, one of the first semiconductor layer 11 and the second semiconductor layer 13 is an n-type layer, and the other of the first semiconductor layer 11 and the second semiconductor layer 13 is a p-type layer.

[0059] For example, the first semiconductor layer 11 is an n-type layer and the second semiconductor layer 13 is a p-type layer.

[0060] Taking a blue light epitaxial structure as an example, the structure of each layer is illustrated. In the blue light epitaxial structure, the p-type layer includes a p-type GaN layer.

[0061] The multi-quantum-well layer 12 may include alternating InGaN quantum-well layers and GaN quantum-barrier layers. The third light-emitting layer may include alternating layers of 3 to 8 cycles of InGaN quantum-well layers and GaN quantum-barrier layers.

[0062] Among them, the n-type layer includes the n-type GaN layer.

[0063] Optionally, the thickness of the epitaxial layer is 2 μm to 10 μm.

[0064] For example, the thickness of the epitaxial layer is 6 μm.

[0065] like Figure 1 As shown, the surface of the second semiconductor layer 13 has a groove that exposes the first semiconductor layer 11. The interconnect layer 30 is located within the groove and on the surface of the second semiconductor layer 13.

[0066] In one implementation of this disclosure, such as Figure 1 As shown, the light-emitting device also includes an electrode 50. The surface of the insulating layer 42 away from the light-emitting unit 10 has a through hole 420 that passes through the insulating layer 42 and the connecting layer 30 in sequence. The electrode 50 is located on the surface of the insulating layer 42 away from the light-emitting unit 10, and the electrode 50 is connected to the light-emitting unit 10 through the through hole 420.

[0067] In the above implementation, the electrode 50 can be precisely connected to the light-emitting unit 10 through the through hole 420 and the connecting layer 30 to achieve stable electrical lead-out; the insulating layer 42 fully covers the surface of the light-emitting unit 10, which not only prevents metal migration and electrical interference, but also enhances the moisture resistance and corrosion resistance, further improving the reliability and environmental tolerance of the light-emitting device.

[0068] For example, such as Figure 1 As shown, the bridging metal 20 connects the different semiconductor layers of the two light-emitting units 10 in series. One end of the bridging metal 20 is connected to the second semiconductor layer 13 of one light-emitting unit 10, and the other end of the bridging metal 20 is connected to the first semiconductor layer 11 of the other light-emitting unit 10.

[0069] For example, such as Figure 1 As shown, a portion of the through-hole 420 of the insulating layer 42 exposes the bottom of the groove of the epitaxial layer of one light-emitting unit 10, and another portion of the through-hole 420 of the insulating layer 42 exposes the second semiconductor layer 13 of the epitaxial layer of another light-emitting unit 10.

[0070] For example, such as Figure 1As shown, the light-emitting device can be provided with two electrodes 50. One electrode 50 is connected to the first semiconductor layer 11 exposed in the groove through a through hole 420, and the other electrode 50 is connected to the second semiconductor layer 13 through a through hole 420.

[0071] In another implementation of this disclosure, such as Figure 3 As shown, the connecting layer 30 also has a second via 32 that exposes the light-emitting unit 10. The electrode 50 is located on the surface of the connecting layer 30 away from the light-emitting unit 10, and the electrode 50 is connected to the light-emitting unit 10 through the second via 32.

[0072] In the above implementation, the connecting layer 30 is provided with a second via 32 exposing the light-emitting unit 10, and the electrode 50 is located on the surface of the connecting layer 30 away from the light-emitting unit 10, and is connected to the light-emitting unit 10 through the second via 32. The advantage of this design is that it simplifies the electrical connection path between the electrode 50 and the light-emitting unit 10, avoids opening holes in the insulating layer 42, thereby reducing the process difficulty and manufacturing cost.

[0073] For example, such as Figure 3 As shown, the bridging metal 20 connects the different semiconductor layers of the two light-emitting units 10 in series. One end of the bridging metal 20 is connected to the second semiconductor layer 13 of one light-emitting unit 10, and the other end of the bridging metal 20 is connected to the first semiconductor layer 11 of the other light-emitting unit 10.

[0074] For example, such as Figure 3 As shown, a portion of the via 420 of the connecting layer 30 exposes the bottom of the groove of the epitaxial layer of one light-emitting unit 10, and another portion of the via 420 of the connecting layer 30 exposes the second semiconductor layer 13 of the epitaxial layer of another light-emitting unit 10.

[0075] For example, such as Figure 3 As shown, the light-emitting device can be provided with two electrodes 50. One electrode 50 is connected to the first semiconductor layer 11 exposed in the groove through a through hole 420, and the other electrode 50 is connected to the second semiconductor layer 13 through a through hole 420.

[0076] Optionally, the thickness of the bridging metal 20 is greater than or equal to 0.5 μm. A thickness of ≥0.5 μm for the bridging metal 20 improves its mechanical strength and conductivity. Sufficient thickness allows it to form a stable support between the light-emitting units 10, better dispersing stress and reducing the risk of breakage during substrate removal or transfer.

[0077] For example, the thickness of the bridging metal 20 can be 0.8 μm.

[0078] Figure 4 This is a flowchart illustrating a method for fabricating a light-emitting device according to an embodiment of this disclosure. For example... Figure 4As shown, the preparation method includes: Step S11: Form at least two light-emitting units 10 spaced apart along a first direction on the substrate.

[0079] Step S12: A bridging metal 20 is formed in the gap between adjacent light-emitting units 10, so that the bridging metal 20 is connected in series with the adjacent light-emitting units 10.

[0080] The ratio of the width of the bridging metal 20 in the second direction 1b to the width of the light-emitting unit 10 in the second direction 1b is greater than or equal to 0.5, and the first direction 1a is perpendicular to the second direction 1b.

[0081] The method for fabricating a light-emitting device provided in this disclosure directly compensates for the mechanical strength degradation caused by deep isolation trenches by using bridging metal 20 as a support structure between adjacent light-emitting units 10. Furthermore, the ratio of the width of the bridging metal 20 in the second direction 1b to the width of the light-emitting unit 10 is ≥0.5. This ratio ensures that the bridging metal 20 has sufficient width to provide effective support and allows it to uniformly distribute stress, maintaining the structural integrity of the light-emitting device during transfer (such as laser transfer) or subsequent use, avoiding failure due to localized weaknesses, and enhancing the reliability of the light-emitting device. In other words, by filling the gaps between the light-emitting units 10 with bridging metal 20 and designing its width to be sufficiently large, it is equivalent to adding a rigid connection between adjacent light-emitting units 10, structurally enhancing the overall fracture resistance of the light-emitting device, reducing the risk of breakage during substrate removal, and improving fabrication yield. Moreover, the improved reliability allows the light-emitting device to adapt to various transfer methods (such as laser transfer), broadening its application scenarios; simultaneously, the stable structure reduces luminous efficiency loss due to breakage or poor contact.

[0082] Step S11, in which the article is prepared, may specifically include the following steps: First, an epitaxial layer is formed on the surface of the substrate.

[0083] For example, the substrate may be a sapphire substrate, a GaAs substrate, a silicon substrate, or a silicon carbide substrate.

[0084] For example, such as Figure 5 As shown, the epitaxial layer includes a first semiconductor layer 11, a multiple quantum well layer 12, and a second semiconductor layer 13 stacked sequentially.

[0085] The epitaxial layer may include: a first semiconductor layer 11, a multiple quantum well layer 12, and a second semiconductor layer 13 sequentially formed on a substrate using MOCVD technology.

[0086] Among them, one of the first semiconductor layer 11 and the second semiconductor layer 13 is an n-type layer, and the other of the first semiconductor layer 11 and the second semiconductor layer 13 is a p-type layer.

[0087] For example, the epitaxial layer includes an n-type GaN layer, a multi-quantum well layer 12 and a p-type GaN layer stacked sequentially.

[0088] Optionally, the thickness of the n-type GaN layer can be from 0.5 μm to 3 μm.

[0089] The growth temperature of the n-type GaN layer can be from 1000℃ to 1100℃, and the growth pressure of the n-type GaN layer can be from 100 torr to 300 torr.

[0090] Optionally, the multi-quantum-well layer 12 includes alternating InGaN quantum well layers and GaN quantum barrier layers. Specifically, the multi-quantum-well layer 12 may include 3 to 8 alternating stacked InGaN quantum well layers and GaN quantum barrier layers.

[0091] When growing the multi-quantum-well layer 12, the MOCVD reaction chamber pressure was controlled at 200 torr. When growing the InGaN quantum well layer, the reaction chamber temperature was 760℃ to 780℃. When growing the GaN quantum barrier layer, the reaction chamber temperature was 860℃ to 890℃.

[0092] As an example, in an embodiment of this disclosure, the multi-quantum-well layer 12 includes five alternating stacked InGaN quantum-well layers and GaN quantum-barrier layers.

[0093] Optionally, the thickness of the multiple quantum well layer 12 can be from 150 nm to 200 nm.

[0094] Optionally, the thickness of the p-type GaN layer can be from 0.5 μm to 3 μm.

[0095] When growing p-type GaN layers, the growth pressure of p-type GaN layers can be from 200 Torr to 600 Torr, and the growth temperature of p-type GaN layers can be from 800℃ to 1000℃.

[0096] Then, as Figure 5 As shown, etching is performed on the surface of the second semiconductor layer 13 to form a groove that exposes at least the multiple quantum well layer 12; at the same time, an opening is etched at the corresponding bridging position of the epitaxial layer, and the opening does not penetrate to the substrate 62, retaining an epitaxial structure of 0.2μm to 1μm, that is, the distance from the opening to the substrate 62 is 0.2μm to 1μm.

[0097] Specifically, it may include: forming a mask on the surface of the second semiconductor layer 13 using photolithography, and then using plasma etching to form grooves and corresponding bridging positions on the surface of the second semiconductor layer 13 through the mask to form openings.

[0098] During the etching process, the power of the etching equipment is controlled at 300W to 600W, and the lower power is controlled at 100W to 300W.

[0099] For example, the groove depth is 1 μm to 2 μm.

[0100] Next, as Figure 5 As shown, a connecting layer 30 covering the epitaxial layer, grooves and openings is formed on the substrate 62.

[0101] Optionally, the interconnect layer 30 includes at least one of a silicon oxide layer, a silicon nitride layer, and a titanium oxide layer.

[0102] For example, the interconnect layer 30 may be a silicon oxide layer. The thickness of the silicon oxide layer may be 5000 angstroms.

[0103] Then, as Figure 5 As shown, the interconnect layer 30 is etched to form a first via 31 on the surface of the interconnect layer 30, exposing the second semiconductor layer 13 and the groove, respectively.

[0104] Etching can be achieved through dry etching, or by combining photolithography with wet etching, such as etching with a mixed solution of H3PO4 / H2SO4, or by using laser front scribing.

[0105] Step S12 may include: using photolithography and evaporation or sputtering to form a bridging metal 20 in series at the connection layer 30 and the opening location.

[0106] like Figure 5 As shown, the bridging metal 20 is located on the surface of the connecting layer 30 away from the light-emitting unit 10, and the bridging metal 20 connects the different semiconductor layers of the two light-emitting units 10 in series through the first via 31. One end of the bridging metal 20 is connected to the second semiconductor layer 13 of one light-emitting unit 10, and the other end of the bridging metal 20 is connected to the first semiconductor layer 11 of the other light-emitting unit 10.

[0107] For example, the thickness of the bridging metal 20 is greater than or equal to 0.5 μm.

[0108] The following steps may also include: First step, such as Figure 5 As shown, an insulating layer 42 covering the electrode 50 is formed on the connection layer 30 of the light-emitting device.

[0109] Optionally, the insulating layer 42 may include multiple alternating layers of first material and multiple alternating layers of second material, wherein the first and second material layers have different refractive indices. By setting alternating layers of high and low refractive index material, a distributed Bragg reflector (DBR) can be formed.

[0110] For example, the first material layer may be a silicon dioxide layer with a refractive index of 1.44 to 1.55, and the second material layer may be a titanium dioxide layer with a refractive index of 2.2 to 2.9. The two material layers have a large difference in refractive index, and only 10 to 20 cycles of material layers are needed to achieve high reflectivity and low absorption loss in the visible light region.

[0111] The second step, as Figure 5 As shown, the insulating layer 42 is etched to form a through hole 420 on the surface of the insulating layer 42 that exposes the light-emitting unit 10.

[0112] For example, a portion of the through-hole 420 of the insulating layer 42 exposes the bottom of the groove of the epitaxial layer of one light-emitting unit 10, and another portion of the through-hole 420 of the insulating layer 42 exposes the second semiconductor layer 13 of the epitaxial layer of another light-emitting unit 10.

[0113] Etching can be achieved through dry etching, or by combining photolithography with wet etching, such as etching with a mixed solution of H3PO4 / H2SO4, or by using laser front scribing.

[0114] The third step is to form an electrode 50 on the surface of the insulating layer 42 and connect the electrode 50 to the light-emitting unit 10 through the through hole 420.

[0115] For example, the light-emitting device may be provided with two electrodes 50, one electrode 50 being connected to the first semiconductor layer 11 exposed in the groove through a through hole 420, and the other electrode 50 being connected to the second semiconductor layer 13 through a through hole 420.

[0116] Step four, as Figure 6 As shown, a photosensitive adhesive layer is formed on a temporary substrate 63, the electrode 50 of the light-emitting device is bonded to the photosensitive adhesive layer, and the substrate 62 is removed.

[0117] Specifically, this may include: spin-coating photosensitive adhesive onto a temporary substrate to form a photosensitive adhesive layer, bonding the electrode 50 of the light-emitting device to the photosensitive adhesive layer, and then removing the substrate to expose the first semiconductor layer 11 of the epitaxial layer.

[0118] Fifth step, as Figure 6 As shown, the exposed first semiconductor layer 11 is etched using either dry etching or wet etching until the interconnect layer 30 inside the epitaxial layer opening is exposed. At this point, the epitaxial layer is divided into multiple spaced-apart light-emitting units 10.

[0119] Step 6, as follows Figure 6 As shown, a carrier layer 41 is formed on the surface of the first semiconductor layer 11.

[0120] Specifically, this may include: firstly, using PECVD or ion-assisted evaporation to fabricate a carrier layer 41 on the surface of the first semiconductor layer 11.

[0121] For example, the carrier layer 41 includes at least one of a silicon oxide layer, a silicon nitride layer, an aluminum oxide layer, and a titanium oxide layer.

[0122] For example, the thickness of the carrier layer 41 is 1 μm to 5 μm.

[0123] Step 7, as Figure 6 As shown, a transparent substrate 61 is bonded to the surface of the carrier layer 41; at the same time, a temporary substrate 63 is peeled off using a laser lifter.

[0124] This disclosure provides a display panel including a driving backplane and a plurality of light-emitting devices as described above, wherein the plurality of light-emitting devices are located on the driving backplane and electrically connected to the driving backplane.

[0125] Optionally, the driving backplane can be a TFT (Thin Film Transistor) substrate. The driving backplane includes multiple driving circuits arranged in an array. Each driving circuit on the driving backplane includes at least two TFTs for controlling the light emission of the connected light-emitting layer.

[0126] For example, the driving circuit includes an active layer, a gate insulating layer, a gate layer, an interlayer dielectric layer, and a source / drain layer sequentially stacked on a substrate. The light-emitting layer is connected to the source / drain layer of the corresponding driving circuit.

[0127] The TFTs driving the backplane can be made of various materials such as polycrystalline silicon and metal oxides, and this embodiment does not impose any restrictions.

[0128] The display device can be any product or component with a display function, such as a mobile phone, tablet computer, television, monitor, laptop computer, digital photo frame, or navigator.

[0129] The above is not intended to limit this disclosure in any way. Although this disclosure has been disclosed above through embodiments, it is not intended to limit this disclosure. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the technical solution of this disclosure. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of this disclosure without departing from the content of the technical solution of this disclosure shall still fall within the scope of the technical solution of this disclosure.

Claims

1. A light-emitting device, characterized in that, The light-emitting device includes at least two light-emitting units (10) and a bridging metal (20). The at least two light-emitting units (10) are arranged at intervals along a first direction (1a). The bridging metal (20) is located at least in the gap between adjacent light-emitting units (10) and is connected in series with adjacent light-emitting units (10). The ratio of the width of the bridging metal (20) in the second direction (1b) to the width of the light-emitting unit (10) in the second direction (1b) is greater than or equal to 0.5, and the first direction (1a) is perpendicular to the second direction (1b).

2. The light-emitting device according to claim 1, characterized in that, The light-emitting device further includes a connecting layer (30), which is located on the surface of the light-emitting unit (10) and within the gap between adjacent light-emitting units (10). The connecting layer (30) also has a first through hole (31) exposing the light-emitting unit (10). The bridging metal (20) is located on the surface of the connecting layer (30) away from the light-emitting unit (10) and is connected to the light-emitting unit (10) through the first via (31).

3. The light-emitting device according to claim 2, characterized in that, The ratio of the width of the connecting layer (30) in the second direction (1b) to the width of the light-emitting unit (10) in the second direction (1b) is greater than or equal to 0.

5.

4. The light-emitting device according to claim 2, characterized in that, The bottom surface of the connecting layer (30) located in the gap between adjacent light-emitting units (10) is coplanar with the bottom surface of the light-emitting unit (10) away from the bridging metal (20).

5. The light-emitting device according to claim 4, characterized in that, The light-emitting device also includes a carrier layer (41), and the bottom surface of the connecting layer (30) and the bottom surface of the light-emitting unit (10) in the gap between adjacent light-emitting units (10) are both located on the same surface of the carrier layer (41).

6. The light-emitting device according to claim 2, characterized in that, The light-emitting device further includes an insulating layer (42) located on the surface of the connecting layer (30) away from the light-emitting unit (10) and covering the bridging metal (20).

7. The light-emitting device according to claim 6, characterized in that, The light-emitting device further includes an electrode (50). The surface of the insulating layer (42) away from the light-emitting unit (10) has a through hole (420) that passes through the insulating layer (42) and the connecting layer (30) in sequence. The electrode (50) is located on the surface of the insulating layer (42) away from the light-emitting unit (10) and is connected to the light-emitting unit (10) through the through hole (420); or, The connecting layer (30) also has a second via (32) exposing the light-emitting unit (10), and the electrode (50) is located on the surface of the connecting layer (30) away from the light-emitting unit (10) and is connected to the light-emitting unit (10) through the second via (32).

8. The light-emitting device according to any one of claims 1 to 7, characterized in that, The thickness of the bridging metal (20) is greater than or equal to 0.5 μm.

9. A method for fabricating a light-emitting device, characterized in that, The preparation method includes: At least two light-emitting units (10) are formed on the substrate at intervals along the first direction (1a). A bridging metal (20) is formed in the gap between adjacent light-emitting units (10) so that the bridging metal (20) connects the adjacent light-emitting units (10) in series. The ratio of the width of the bridging metal (20) in the second direction (1b) to the width of the light-emitting unit (10) in the second direction (1b) is greater than or equal to 0.

5. The first direction (1a) is perpendicular to the second direction (1b).

10. A display panel, characterized in that, The display panel includes a driving backplate and a plurality of light-emitting devices as described in any one of claims 1 to 7, wherein the plurality of light-emitting devices are located on the driving backplate and are electrically connected to the driving backplate.

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