Light emitting diode and method of fabricating the same

Abstract

This disclosure provides a light-emitting diode and a method for manufacturing the same. The light-emitting diode includes an epitaxial structure; the epitaxial structure has a plurality of protrusions located on a first surface, and the epitaxial structure also has a mesh-like isolation groove formed on a second surface and extending toward the first surface, the epitaxial structure being divided into a plurality of epitaxial units by the isolation groove; the bottom of the isolation groove is spaced apart from the first surface; in a direction perpendicular to the second surface of the epitaxial structure, the connection between the sidewall of the isolation groove and the bottom surface of the isolation groove corresponds to the middle portion of the protrusion; the first surface and the second surface are two opposite surfaces of the epitaxial structure.

Description

Technical Field

[0001] This disclosure relates to the field of light-emitting devices, and in particular to a light-emitting diode and a method for manufacturing the same. Background Technology

[0002] Light-emitting diodes (LEDs) are widely used in display, decoration, and communication fields due to their small size and high brightness.

[0003] In related technologies, light-emitting diodes typically include an epitaxial structure with an isolation trench. The bottom of the isolation trench is located inside the epitaxial structure, and the isolation trench divides the epitaxial structure into multiple epitaxial units.

[0004] In this light-emitting diode, the stress at the isolation trench is high, and the epitaxial structure is prone to breakage at the isolation trench, causing damage to the epitaxial structure and leading to a decrease in the reliability of the light-emitting diode. Summary of the Invention

[0005] This disclosure provides a substrate, a light-emitting diode (LED), and a method for fabricating the same, reducing the risk of epitaxial structure breakage at the isolation trench and improving the reliability of the LED. The technical solution is as follows: On the one hand, a light-emitting diode is provided, the light-emitting diode including an epitaxial structure; The epitaxial structure has a plurality of protrusions on a first surface, and the epitaxial structure also has a mesh-like isolation groove formed on a second surface and extending toward the first surface, the epitaxial structure being divided into a plurality of epitaxial units by the isolation groove; The bottom of the isolation groove is spaced apart from the first surface; in the direction perpendicular to the second surface of the extension structure, the connection between the sidewall of the isolation groove and the bottom surface of the isolation groove corresponds to the middle part of the protrusion. The first surface and the second surface are two opposite surfaces of the epitaxial structure.

[0006] Optionally, in a direction perpendicular to the second surface, the connection between the sidewall of the isolation groove and the bottom surface of the isolation groove corresponds to the apex of the protrusion.

[0007] Optionally, the projection of the protrusion onto the plane containing the second surface of the epitaxial structure is circular, and the diameter of the circle is 3~4μm.

[0008] Optionally, the height of the protrusion in the direction perpendicular to the second surface of the epitaxial structure is 1.5~1.7μm, and the distance between the vertices of two adjacent protrusions is 3~4μm.

[0009] Optionally, the depth of the isolation groove is 3~5μm.

[0010] Optionally, the light-emitting diode further includes: a substrate; The epitaxial structure is located on the substrate, the substrate including a plurality of recesses, and the plurality of protrusions are respectively located within the plurality of recesses.

[0011] On the other hand, a method for manufacturing a light-emitting diode is provided, the method comprising: An epitaxial structure is provided, the epitaxial structure having a plurality of protrusions located on a first surface; A mesh-like isolation groove extending toward the first surface is formed on the second surface of the epitaxial structure. The epitaxial structure is divided into multiple epitaxial units by the isolation groove. The bottom of the isolation groove is spaced apart from the first surface. In a direction perpendicular to the second surface of the epitaxial structure, the connection between the sidewall of the isolation groove and the bottom surface of the isolation groove corresponds to the middle part of the protrusion. The first surface and the second surface are two opposite surfaces of the epitaxial structure.

[0012] Optionally, the method further includes: A substrate is fabricated, the substrate including a plurality of recesses, the plurality of recesses being respectively used to place the plurality of protrusions of the epitaxial structure.

[0013] Optionally, the projection of the protrusion onto the plane containing the second surface of the epitaxial structure is circular, and the diameter of the circle is 3~4μm.

[0014] Optionally, the height of the protrusion in the direction perpendicular to the second surface of the epitaxial structure is 1.5~1.7μm, and the distance between the vertices of two adjacent protrusions is 3~4μm.

[0015] The beneficial effects of the technical solutions provided in this disclosure are: In this embodiment of the present disclosure, one side of the epitaxial structure of the light-emitting diode includes multiple protrusions. When light is emitted from this side, the light enters the interior of the protrusion. Each reflection on the inner wall of the protrusion causes the light to deviate from the critical angle of total internal reflection, and finally refracts from the surface of the protrusion into the air, thus preventing the light from being totally reflected back to the epitaxial layer, thereby destroying the total internal reflection condition, making it easier for the light to escape from the protrusion, and improving the light extraction efficiency.

[0016] The other side of the epitaxial structure includes a mesh-like isolation groove extending towards the first surface. The function of the isolation groove is to prevent optical crosstalk between different epitaxial units. In the above structure, the connection between the sidewall and the bottom surface of the isolation groove is most prone to breakage. Therefore, in the structure provided in this embodiment, in the direction perpendicular to the second surface of the epitaxial structure, the connection between the sidewall and the bottom surface of the isolation groove is aligned with the center of the protrusion, thereby thickening this area. This allows the epitaxial structure to withstand greater stress at the connection between the sidewall and the bottom surface of the isolation groove, significantly reducing the risk of edge chipping and cracking of the epitaxial structure, and improving the manufacturing yield and reliability of the light-emitting diode. Attached Figure Description

[0017] 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.

[0018] Figure 1 This is a structural diagram of a light-emitting diode provided in an embodiment of the present disclosure; Figure 2 This is a top view of a light-emitting diode provided in an embodiment of this disclosure; Figure 3 This is a flowchart of a method for manufacturing a light-emitting diode provided in an embodiment of the present disclosure; Figure 4 This is a flowchart of another method for manufacturing a light-emitting diode provided in this disclosure embodiment; Figure 5 This is a structural diagram of a light-emitting diode manufacturing process provided in an embodiment of this disclosure; Figure 6 This is a structural diagram of a light-emitting diode manufacturing process provided in an embodiment of this disclosure; Figure 7 This is a structural diagram of a light-emitting diode manufacturing process provided in an embodiment of this disclosure; Figure 8 This is a structural diagram of a light-emitting diode manufacturing process provided in an embodiment of this disclosure; Figure 9 This is a structural diagram of a light-emitting diode manufacturing process provided in an embodiment of this disclosure.

[0019] The attached figures are labeled as follows: 10: Epitaxial structure; 11: Epitaxial unit; 1001: Protrusion; 1002: Recess; 1003: Through-hole in the first insulating layer; 2001: Isolation trench; 2002: Step; 3001: First surface; 3002: Second surface; 100: Substrate; 101: First semiconductor layer; 102: Active layer; 103: Second semiconductor layer; 104: Contact layer; 105: First insulating layer; 106: First electrode; 107: Second electrode; 108: Second insulating layer; 109: Electrode pad; H: Height of the protrusion in the direction perpendicular to the second surface of the extension structure; L: Distance between the vertices of two adjacent protrusions; D: Depth of the isolation groove; P: Angle between the sidewall and top surface of the step. Detailed Implementation

[0020] 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.

[0021] Figure 1 This is a structural diagram of a light-emitting diode provided in an embodiment of this disclosure. See also... Figure 1 , extensional structure 10.

[0022] The epitaxial structure 10 has a plurality of protrusions 1001 located on the first surface 3001. The epitaxial structure 10 also has a mesh-like isolation groove 2001 opened on the second surface 3002 and extending toward the first surface 3001. The epitaxial structure 10 is divided into a plurality of epitaxial units 11 by the isolation groove 2001.

[0023] The bottom of the isolation groove 2001 is spaced apart from the first surface 3001; in the direction perpendicular to the second surface 3002 of the extension structure 10, the connection between the side wall of the isolation groove 2001 and the bottom surface of the isolation groove 2001 corresponds to the middle part of the protrusion 1001. The first surface 3001 and the second surface 3002 are two opposite surfaces of the epitaxial structure 10.

[0024] In this embodiment of the present disclosure, one side of the epitaxial structure of the light-emitting diode includes multiple protrusions. When light is emitted from this side, the light enters the interior of the protrusion. Each reflection on the inner wall of the protrusion causes the light to deviate from the critical angle of total internal reflection, and finally refracts from the surface of the protrusion into the air, thus preventing the light from being totally reflected back to the epitaxial layer, thereby destroying the total internal reflection condition, making it easier for the light to escape from the protrusion, and improving the light extraction efficiency.

[0025] The other side of the epitaxial structure includes a mesh-like isolation groove extending towards the first surface. The function of the isolation groove is to prevent optical crosstalk between different epitaxial units. In the above structure, the connection between the sidewall and the bottom surface of the isolation groove is most prone to breakage. Therefore, in the structure provided in this embodiment, in the direction perpendicular to the second surface of the epitaxial structure, the connection between the sidewall and the bottom surface of the isolation groove is aligned with the center of the protrusion, thereby thickening this area. This allows the epitaxial structure to withstand greater stress at the connection between the sidewall and the bottom surface of the isolation groove, significantly reducing the risk of edge chipping and cracking of the epitaxial structure, and improving the manufacturing yield and reliability of the light-emitting diode.

[0026] The connection between the sidewall of the isolation groove 2001 and the bottom surface of the isolation groove 2001 corresponds to the middle part of the protrusion 1001. This means that the projection of the connection between the sidewall of the isolation groove 2001 and the bottom surface of the isolation groove 2001 on the second surface 3002 is located at the projection of the middle part of the protrusion 1001 on the second surface 3002.

[0027] In this embodiment of the disclosure, in the direction perpendicular to the second surface 3002, the connection between the sidewall of the isolation groove 2001 and the bottom surface of the isolation groove 2001 corresponds to the vertex of the protrusion 1001.

[0028] The connection between the sidewall of the isolation groove 2001 and the bottom surface of the isolation groove 2001 corresponds to the vertex of the protrusion 1001. This means that the projection of the connection between the sidewall of the isolation groove 2001 and the bottom surface of the isolation groove 2001 on the second surface 3002 is located at the projection of the vertex of the protrusion 1001 on the second surface 3002.

[0029] That is, the projection of the connection between the sidewall of the isolation groove 2001 and the bottom surface of the isolation groove 2001 on the second surface 3002 coincides with the line connecting the projections of the vertices of the multiple protrusions 1001 on the second surface 3002.

[0030] In this implementation, at the connection point between the sidewall and the bottom surface of the isolation groove in the direction perpendicular to the second surface, the vertex of the protrusion corresponds to the thickest part of the epitaxial structure. This can maximize the stress that the epitaxial structure can withstand at the connection point between the sidewall and the bottom surface of the isolation groove, and minimize the risk of edge chipping and cracking of the epitaxial structure.

[0031] The vertex of the protrusion is the point on the protrusion that is farthest from the second surface 3002.

[0032] In other embodiments, in a direction perpendicular to the second surface 3002, the connection between the sidewall of the isolation groove 2001 and the bottom surface of the isolation groove 2001 corresponds to other points near the apex of the middle portion of the protrusion 1001.

[0033] In this embodiment of the present disclosure, the projection of the protrusion 1001 onto the plane containing the second surface 3002 of the epitaxial structure 10 is circular, and the diameter of the circle is 3~4μm.

[0034] In this implementation, the projection of the protrusion onto the plane of the second surface of the epitaxial structure is circular. The circular shape can make the epitaxial structure uniformly stressed, avoid stress concentration, and reduce the risk of edge chipping and cracking of the epitaxial structure. The diameter of the circle is 3~4μm, which can ensure that the light extraction efficiency is improved while avoiding the stress generated by patterning from damaging the epitaxial structure.

[0035] For example, the diameter of the circle is 3.5 μm.

[0036] In other embodiments, the protrusion 1001 may also be other shapes, such as rectangles or triangles.

[0037] In this embodiment of the disclosure, the protrusion 1001 can be hemispherical.

[0038] In other embodiments, the protrusion 1001 may also be conical.

[0039] In this embodiment of the present disclosure, the height H of the protrusion 1001 in the direction perpendicular to the second surface of the epitaxial structure 10 is 1.5~1.7μm, and the distance L between the vertices of two adjacent protrusions 1001 is 3~4μm.

[0040] In this implementation, the height of the protrusion in the direction perpendicular to the second surface of the epitaxial structure is 1.5~1.7μm. This height ensures the protrusion is not excessive while allowing the epitaxial structure to withstand greater stress, significantly reducing the risk of edge chipping and cracking. The distance between two adjacent protrusion vertices is 3~4μm. Too close a distance would require excessively high precision during patterning, making fabrication difficult; conversely, too large a distance would result in a smaller number of protrusions, hindering the improvement of light emission from the epitaxial structure.

[0041] For example, the height H of the protrusion 1001 in the direction perpendicular to the second surface of the epitaxial structure 10 is 1.6 μm, and the distance L between the vertices of two adjacent protrusions 1001 is 3.5 μm.

[0042] In this embodiment of the disclosure, the depth D of the isolation groove 2001 is 3~5μm.

[0043] In this implementation, the depth of the isolation groove is 3~5μm, which can ensure the anti-crosstalk effect between epitaxial structures while the depth of the isolation groove is not too deep, which would cause the epitaxial structure to break.

[0044] For example, the depth D of the isolation groove 2001 is 4 μm.

[0045] Figure 2 This is a top view of a light-emitting diode provided in an embodiment of this disclosure. Figure 2 Only a portion of the membrane is shown. Figure 1 yes Figure 2 The cross-section at point A-A'. See also Figure 2 The mesh-like isolation groove 2001 includes a horizontal isolation groove 2001 and a vertical isolation groove 2001, with the horizontal isolation groove 2001 and the vertical isolation groove 2001 being perpendicular to each other.

[0046] In this embodiment of the disclosure, the sidewall of the isolation groove 2001 is an inclined surface.

[0047] In this embodiment of the disclosure, the angle between the connection between the sidewall of the isolation groove 2001 and the bottom surface of the isolation groove 2001 is 75 to 85 degrees.

[0048] For example, the angle between the sidewall of the isolation groove 2001 and the bottom surface of the isolation groove 2001 is 80 degrees.

[0049] In other embodiments, the sidewall of the isolation groove 2001 may also be perpendicular to the bottom surface of the isolation groove 2001.

[0050] In this embodiment of the disclosure, the distance between the bottom surface of the isolation groove 2001 and the vertex of the protrusion 1001 is 1~1.5μm.

[0051] For example, the distance between the bottom surface of the isolation groove 2001 and the vertex of the protrusion 1001 is 1.2 μm.

[0052] In this embodiment of the disclosure, the light-emitting diode further includes a substrate 100.

[0053] The epitaxial structure 10 is located on the substrate 100, which includes a plurality of recesses 1002 and a plurality of protrusions 1001 located in the plurality of recesses 1002 respectively.

[0054] In this implementation, the substrate includes multiple recesses, the epitaxial structure is located on the substrate, and multiple protrusions are located in the multiple recesses respectively. By fabricating the epitaxial structure on the substrate including multiple recesses, an epitaxial structure with protrusions can be obtained.

[0055] In this embodiment of the disclosure, the substrate 100 can be any one of a sapphire substrate, a Si substrate, or a SiC substrate, and the material of the substrate is not limited in this embodiment of the disclosure.

[0056] For example, substrate 100 is a sapphire substrate.

[0057] In this embodiment of the disclosure, each of the plurality of epitaxial units 11 includes a first semiconductor layer 101, an active layer 102 and a second semiconductor layer 103 sequentially stacked on a substrate 100.

[0058] In this embodiment of the disclosure, the first semiconductor layer 101 can be an N-type semiconductor layer, and the second semiconductor layer 103 can be a P-type semiconductor layer.

[0059] In another example, the first semiconductor layer 101 can be a P-type semiconductor layer, and the second semiconductor layer 103 can be an N-type semiconductor layer.

[0060] In this embodiment of the disclosure, the active layer 102 can be a multi-quantum well layer, for example, the multi-quantum well layer can include multiple periodically alternating stacked quantum well layers and quantum barrier layers.

[0061] In this embodiment of the present disclosure, the light-emitting diode further includes a contact layer 104.

[0062] The contact layer 104 is located on the second semiconductor layer 103.

[0063] In this embodiment of the disclosure, the contact layer 104 can be an indium tin oxide (ITO) layer, which has excellent current spreadability.

[0064] In this embodiment of the present disclosure, the extension unit 11 also has a step 2002 at the opening of the isolation groove, and the included angle P between the side wall and the top surface of the step 2002 can be a right angle.

[0065] In other embodiments, the sidewall and top surface of the step 2002 may also be a smooth arc.

[0066] In this embodiment of the present disclosure, the light-emitting diode further includes a first insulating layer 105.

[0067] The first insulating layer 105 covers the epitaxial structure 10 and the contact layer 104.

[0068] In this embodiment of the disclosure, the first insulating layer 105 may be a SiO2 insulating layer.

[0069] In another example, the first insulating layer 105 can also be a SiN insulating layer.

[0070] In this embodiment of the disclosure, the light-emitting diode further includes a first electrode 106 and a second electrode 107.

[0071] The first electrode 106 passes through the through hole 1003 of the first insulating layer 105 and is electrically connected to the contact layer 104. The second electrode 107 has a mesh structure and is located in the isolation trench 2001. The second electrode 107 passes through the through hole 1003 of the first insulating layer 105 and is electrically connected to the first semiconductor layer 101.

[0072] In this embodiment of the disclosure, the first electrode 106 and the second electrode 107 may be electrodes formed of at least one of Cr, Pt and Au, or electrodes composed of a stack of at least two of them.

[0073] In this embodiment of the disclosure, the light-emitting diode further includes a second insulating layer 108.

[0074] The second insulating layer 108 covers the first electrode 106 and the first insulating layer 105.

[0075] In this embodiment of the disclosure, the second insulating layer 108 may be a SiO2 insulating layer.

[0076] In this embodiment of the disclosure, the light-emitting diode further includes an electrode pad 109.

[0077] The electrode pad 109 passes through the second insulating layer 108 and is electrically connected to the first electrode 106.

[0078] In this embodiment of the disclosure, the electrode pad 109 may be an electrode formed of at least one of Cr, Pt and Au, or an electrode composed of a stack of at least two of them.

[0079] Figure 3 This is a flowchart illustrating a method for manufacturing a light-emitting diode (LED) according to an embodiment of this disclosure. See also... Figure 3 The method includes the following steps: S11. Provide an epitaxial structure having a plurality of protrusions located on a first surface.

[0080] S12. A mesh-like isolation groove extending toward the first surface is formed on the second surface of the epitaxial structure. The epitaxial structure is divided into multiple epitaxial units by the isolation groove. The bottom of the isolation groove is spaced apart from the first surface. In the direction perpendicular to the second surface of the epitaxial structure, the connection between the sidewall of the isolation groove and the bottom surface of the isolation groove corresponds to the middle part of the protrusion. The first surface and the second surface are two opposite surfaces of the epitaxial structure.

[0081] In this embodiment of the present disclosure, one side of the epitaxial structure of the light-emitting diode includes multiple protrusions. When light is emitted from this side, the light enters the interior of the protrusion. Each reflection on the inner wall of the protrusion causes the light to deviate from the critical angle of total internal reflection, and finally refracts from the surface of the protrusion into the air, thus preventing the light from being totally reflected back to the epitaxial layer, thereby destroying the total internal reflection condition, making it easier for the light to escape from the protrusion, and improving the light extraction efficiency.

[0082] The other side of the epitaxial structure includes a mesh-like isolation groove extending towards the first surface. The function of the isolation groove is to prevent optical crosstalk between different epitaxial units. In the above structure, the connection between the sidewall and the bottom surface of the isolation groove is most prone to breakage. Therefore, in the structure provided in this embodiment, in the direction perpendicular to the second surface of the epitaxial structure, the connection between the sidewall and the bottom surface of the isolation groove is aligned with the center of the protrusion, thereby thickening this area. This allows the epitaxial structure to withstand greater stress at the connection between the sidewall and the bottom surface of the isolation groove, significantly reducing the risk of edge chipping and cracking of the epitaxial structure, and improving the manufacturing yield and reliability of the light-emitting diode.

[0083] Figure 4 This is a flowchart of another method for manufacturing a light-emitting diode (LED) according to an embodiment of this disclosure. See also... Figure 4 The method includes the following steps: S21, Fabrication of the substrate.

[0084] In this embodiment of the disclosure, the substrate can be any one of sapphire substrate, Si substrate and SiC substrate, and the material of the substrate is not limited in this embodiment of the disclosure.

[0085] For example, the substrate is a sapphire substrate.

[0086] In one example, step S21 includes: The first step is to fabricate a SiO2 mask layer on the substrate.

[0087] The second step is to coat a layer of photoresist onto the SiO2 mask layer.

[0088] The third step is to expose and develop the photoresist to form a photoresist mask layer.

[0089] The fourth step is to pattern the SiO2 mask layer under the cover of the photoresist mask layer.

[0090] Step 5: Remove the photoresist mask layer.

[0091] The sixth step is to pattern the substrate under the cover of the SiO2 mask layer.

[0092] Step 7: Remove the SiO2 mask layer.

[0093] In other embodiments, the substrate may be patterned using only a photoresist mask.

[0094] In this embodiment of the disclosure, the substrate includes a plurality of recesses and a plurality of protrusions located within the plurality of recesses.

[0095] In this implementation, the substrate includes multiple recesses, the epitaxial structure is located on the substrate, and multiple protrusions are located in the multiple recesses respectively. By fabricating the epitaxial structure on the substrate including multiple recesses, an epitaxial structure with protrusions can be obtained.

[0096] S22. Sequentially fabricate a first semiconductor layer, an active layer, a second semiconductor layer, and a contact layer on a substrate to form an epitaxial structure.

[0097] In one example, step S22 includes: The first step is to fabricate the first semiconductor layer on the substrate.

[0098] In this embodiment of the disclosure, the first semiconductor layer may be an N-type semiconductor layer.

[0099] In another example, the first semiconductor layer can be a P-type semiconductor layer.

[0100] The second step is to fabricate an active layer on the first semiconductor layer.

[0101] In this embodiment of the disclosure, the active layer is a multi-quantum well layer, comprising multiple periodically alternating quantum well layers and quantum barrier layers.

[0102] For example, a metal-organic chemical vapor deposition (MOCVD) apparatus is used to alternately grow multiple quantum well layers and quantum barrier layers on the surface of the first semiconductor layer.

[0103] The third step is to fabricate a second semiconductor layer on the active layer.

[0104] In this embodiment of the disclosure, the second semiconductor layer may be a P-type semiconductor layer.

[0105] In another example, the second semiconductor layer can be an N-type semiconductor layer.

[0106] The fourth step is to fabricate a contact layer on the second semiconductor layer.

[0107] In this embodiment, the contact layer can be an ITO layer. ITO has excellent transparency and conductivity, allowing light to pass through while also conducting current to form an electrical connection.

[0108] The above epitaxial structure is only an example. In other embodiments, the epitaxial layer and the material of the film layer can be adjusted and optimized according to different semiconductor material systems and device application requirements.

[0109] In this embodiment of the present disclosure, the projection of the protrusion onto the plane of the second surface of the epitaxial structure is a circle with a diameter of 3~4μm.

[0110] In this implementation, the projection of the protrusion onto the plane of the second surface of the epitaxial structure is circular. The circular shape can make the epitaxial structure uniformly stressed, avoid stress concentration, and reduce the risk of edge chipping and cracking of the epitaxial structure. The diameter of the circle is 3~4μm, which can ensure that the light extraction efficiency is improved while avoiding the stress generated by patterning from damaging the epitaxial structure.

[0111] For example, the diameter of the circle is 3.5 μm.

[0112] In other embodiments, the protrusions may also be other shapes, such as rectangles or triangles.

[0113] In this embodiment of the disclosure, the protrusion may be semi-circular.

[0114] In other embodiments, the protrusion may also be conical.

[0115] In this embodiment of the present disclosure, the height of the protrusion in the direction perpendicular to the second surface of the epitaxial structure is 1.5~1.7μm, and the distance between two adjacent protrusion vertices is 3~4μm.

[0116] In this implementation, the height of the protrusion in the direction perpendicular to the second surface of the epitaxial structure is 1.5~1.7μm. This height ensures the protrusion is not excessive while allowing the epitaxial structure to withstand greater stress, significantly reducing the risk of edge chipping and cracking. The distance between two adjacent protrusion vertices is 3~4μm. Too close a distance would require excessively high precision during patterning, making fabrication difficult; conversely, too large a distance would result in a smaller number of protrusions, hindering the improvement of light emission from the epitaxial structure.

[0117] For example, the height of the protrusion in the direction perpendicular to the second surface of the epitaxial structure is 1.6 μm, and the distance between two adjacent protrusion vertices is 3.5 μm.

[0118] Figure 5 This is a structural diagram of a light-emitting diode (LED) fabrication process provided in an embodiment of this disclosure. See also... Figure 5 The first semiconductor layer 101, the active layer 102, the second semiconductor layer 103, and the contact layer 104 are sequentially stacked on the substrate 100.

[0119] S23. The epitaxial structure is graphically processed to form isolation slots, which divide the epitaxial structure into multiple epitaxial units.

[0120] In one example, step S23 includes: The first step is to deposit a photoresist film on the epitaxial layer.

[0121] The second step is to expose and develop the photoresist film to obtain a photoresist mask.

[0122] The third step involves etching the epitaxial structure under the cover of the photoresist mask to obtain isolation trenches, which divide the epitaxial structure into multiple epitaxial units.

[0123] In this embodiment of the disclosure, the epitaxial layer is etched by inductively coupled plasma etching (ICP).

[0124] In this embodiment of the disclosure, when etching the epitaxial layer, the sidewall of the isolation trench is aligned with the vertex of the protrusion, and the offset is adjusted by focused ion beam (FIB) until it is completely aligned with the vertex of the protrusion.

[0125] The fourth step is to remove the photoresist mask.

[0126] The fifth step is to etch the opening of the isolation groove to form a step.

[0127] In other embodiments, the included angle P between the step sidewall and the top surface can be a right angle.

[0128] In other embodiments, the step sidewall and top surface may also be a smooth arc.

[0129] In this implementation, in the direction perpendicular to the second surface, the connection between the sidewall of the isolation trench and the bottom surface of the isolation trench corresponds to the highest point of the protrusion. The highest point of the protrusion is the thickest part of the epitaxial structure, which allows the epitaxial structure to withstand greater stress at the connection between the sidewall of the isolation trench and the bottom surface of the isolation trench. This significantly reduces the risk of edge chipping and cracking of the epitaxial structure, and improves the manufacturing yield and reliability of the light-emitting diode.

[0130] In this embodiment of the disclosure, the bottom of the isolation groove is located on the extension structure 10.

[0131] In this embodiment of the disclosure, the depth of the isolation groove is 3~5μm.

[0132] In this implementation, the depth of the isolation groove is 3~5μm, which can ensure the anti-crosstalk effect between epitaxial structures while the depth of the isolation groove is not too deep, which would cause the epitaxial structure to break.

[0133] For example, the depth of the isolation groove is 4 μm.

[0134] In this embodiment of the disclosure, the mesh-like isolation groove includes a horizontal isolation groove and a vertical isolation groove, with the horizontal isolation groove and the vertical isolation groove being perpendicular to each other.

[0135] In this embodiment of the disclosure, the sidewall of the isolation groove is an inclined surface.

[0136] In this embodiment of the disclosure, the angle between the sidewall of the isolation trench and the bottom surface of the isolation trench is 75 to 85 degrees.

[0137] For example, the angle between the sidewall of the isolation trench and the bottom surface of the isolation trench is 80 degrees.

[0138] In other embodiments, the sidewalls of the isolation trench may also be perpendicular to the bottom surface of the isolation trench.

[0139] In this embodiment of the disclosure, the distance between the bottom surface of the isolation groove and the apex of the protrusion is 1~1.5μm.

[0140] For example, the distance between the bottom surface of the isolation groove and the apex of the protrusion is 1.2 μm.

[0141] Figure 6 This is a structural diagram of a light-emitting diode (LED) fabrication process provided in an embodiment of this disclosure. See also... Figure 6 The bottom of the isolation trench 2001 is located in the first semiconductor layer 101, and the connection between the sidewall of the isolation trench 2001 and the bottom surface of the isolation trench 2001 corresponds to the apex of the protrusion 1001.

[0142] S24. Fabricate a first insulating layer, which covers the epitaxial structure and the contact layer.

[0143] In one example, step S24 includes: The first step is to fabricate a first insulating film, which covers the epitaxial structure and the contact layer.

[0144] The second step is to fabricate a layer of photoresist on the first insulating film.

[0145] The third step is to expose and develop the photoresist to form a photoresist mask layer.

[0146] The fourth step involves patterning the first insulating film under the cover of the photoresist mask layer to form the first insulating layer.

[0147] Figure 7 This is a structural diagram of a light-emitting diode (LED) fabrication process provided in an embodiment of this disclosure. See also... Figure 7 The first insulating layer 105 covers the epitaxial structure 10 and the contact layer 104, and the first insulating layer 105 has through holes between the contact layer 104 and the plurality of epitaxial units 11.

[0148] S25. Fabricate the first and second electrodes.

[0149] In this embodiment, the first electrode passes through the first insulating layer and is electrically connected to the contact layer, and the second electrode has a mesh structure and is located between multiple epitaxial units.

[0150] In this embodiment of the disclosure, the first electrode and the second electrode may be electrodes formed of at least one of Cr, Pt and Au, or electrodes composed of a stack of at least two of them.

[0151] Figure 8 This is a structural diagram of a light-emitting diode (LED) fabrication process provided in an embodiment of this disclosure. See also... Figure 8 The first electrode 106 passes through the through hole of the first insulating layer 105 and is electrically connected to the contact layer 104. The second electrode 107 is located in the isolation groove 2001 and passes through the first insulating layer 105 to be electrically connected to the epitaxial unit 11.

[0152] S26. Fabricate a second insulating layer, which covers the first electrode and the first insulating layer.

[0153] In one example, step S26 includes: The first step is to fabricate a second insulating film, which covers the first electrode and the first insulating layer.

[0154] The second step is to fabricate a layer of photoresist on the second insulating film.

[0155] The third step is to expose and develop the photoresist to form a photoresist mask layer.

[0156] The fourth step involves patterning the second insulating film under the cover of the photoresist mask layer to form the second insulating layer.

[0157] In this embodiment of the disclosure, the second insulating layer may be a SiO2 insulating layer.

[0158] Figure 9 This is a structural diagram of a light-emitting diode (LED) fabrication process provided in an embodiment of this disclosure. See also... Figure 9 The second insulating layer 108 covers the first electrode 106 and the first insulating layer 105, and the second insulating layer 108 has a through hole at the first electrode 106.

[0159] S27. Fabricate electrode pads, which pass through the second insulating layer and are electrically connected to the first electrode.

[0160] In this embodiment of the disclosure, the electrode pads pass through a through-hole in the second insulating layer at the first electrode and are electrically connected to the first electrode.

[0161] In this embodiment of the disclosure, the electrode pad can be an electrode formed of at least one of Cr, Pt and Au, or an electrode composed of a stack of at least two of them.

[0162] The above description is merely an optional embodiment of this disclosure and is not intended to limit this disclosure. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this disclosure should be included within the protection scope of this disclosure.

Claims

1. A light-emitting diode, characterized in that, The light-emitting diode includes an epitaxial structure (10); The epitaxial structure (10) has a plurality of protrusions (1001) located on the first surface (3001), and the epitaxial structure (10) also has a mesh-like isolation groove (2001) opened on the second surface (3002) and extending toward the first surface. The epitaxial structure (10) is divided into a plurality of epitaxial units (11) by the isolation groove (2001). The bottom of the isolation groove (2001) is spaced apart from the first surface (3001); in the direction perpendicular to the second surface (3002) of the extension structure (10), the connection between the sidewall of the isolation groove (2001) and the bottom surface of the isolation groove (2001) corresponds to the middle part of the protrusion (1001); The first surface (3001) and the second surface (3002) are two opposite surfaces of the epitaxial structure (10).

2. The light-emitting diode according to claim 1, characterized in that, In a direction perpendicular to the second surface (3002), the connection between the sidewall of the isolation groove (2001) and the bottom surface of the isolation groove (2001) corresponds to the vertex of the protrusion (1001).

3. The light-emitting diode according to claim 1 or 2, characterized in that, The projection of the protrusion (1001) onto the plane of the second surface (3002) of the epitaxial structure (10) is circular, and the diameter of the circle is 3~4μm.

4. The light-emitting diode according to claim 1 or 2, characterized in that, The height of the protrusion (1001) in the direction perpendicular to the second surface (3002) of the epitaxial structure (10) is 1.5~1.7μm, and the distance between the vertices of two adjacent protrusions (1001) is 3~4μm.

5. The light-emitting diode according to claim 1 or 2, characterized in that, The depth of the isolation groove (2001) is 3~5μm.

6. The light-emitting diode according to claim 1 or 2, characterized in that, The light-emitting diode further includes: a substrate (100). The epitaxial structure (10) is located on the substrate (100), which includes a plurality of recesses (1002) and a plurality of protrusions (1001) located within the plurality of recesses (1002).

7. A method for manufacturing a light-emitting diode, characterized in that, The method includes: An epitaxial structure is provided, the epitaxial structure having a plurality of protrusions located on a first surface; A mesh-like isolation groove extending toward the first surface is formed on the second surface of the epitaxial structure. The epitaxial structure is divided into multiple epitaxial units by the isolation groove. The bottom of the isolation groove is spaced apart from the first surface. In a direction perpendicular to the second surface of the epitaxial structure, the connection between the sidewall of the isolation groove and the bottom surface of the isolation groove corresponds to the middle part of the protrusion. The first surface and the second surface are two opposite surfaces of the epitaxial structure.

8. The method according to claim 7, characterized in that, The method further includes: A substrate is fabricated, the substrate including a plurality of recesses, the plurality of recesses being respectively used to place the plurality of protrusions of the epitaxial structure.

9. The method according to claim 7 or 8, characterized in that, The projection of the protrusion onto the plane of the second surface of the epitaxial structure is circular, and the diameter of the circle is 3~4μm.

10. The method according to claim 7 or 8, characterized in that, The height of the protrusion in the direction perpendicular to the second surface of the epitaxial structure is 1.5~1.7μm, and the distance between the vertices of two adjacent protrusions is 3~4μm.

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