Light emitting diode with a reflective layer and method of manufacturing the same

Abstract

The present disclosure provides a light emitting diode with a reflective layer and a preparation method thereof, and belongs to the technical field of semiconductors. The light emitting diode comprises a substrate, and a reflective layer, a buffer layer, a semiconductor layer of a first conduction type, a light emitting layer and a semiconductor layer of a second conduction type which are sequentially grown on one side of the substrate; the one side of the substrate has a plurality of grooves which are arranged at intervals; the reflective layer comprises a plurality of reflective bumps which correspond to the plurality of grooves one by one; the reflective bump comprises a first part and a second part, the first part is located in the corresponding groove, and the second part is located outside the groove. The present disclosure can improve the light extraction efficiency.

Description

Technical Field

[0001] This disclosure belongs to the field of semiconductor technology, and specifically relates to a light-emitting diode with a reflective layer and its fabrication method. Background Technology

[0002] Light-emitting diodes (LEDs) are semiconductor optoelectronic devices that can directly convert electrical energy into light energy. Due to their high energy efficiency, fast response speed, long service life and environmental friendliness, they are receiving increasing attention.

[0003] In related technologies, light-emitting diodes (LEDs) have an epitaxial wafer, which includes a substrate and an epitaxial layer grown on one side of the substrate. During operation, the epitaxial layer emits light, and some of the light shines onto the substrate and is reflected.

[0004] However, the substrate has limited reflectivity, which causes the light illuminating the substrate to be absorbed, affecting the light extraction efficiency of the light-emitting diode. Summary of the Invention

[0005] This disclosure provides a light-emitting diode with a reflective layer and a method for fabricating the same, which can improve light extraction efficiency. The technical solution is as follows:

[0006] On one hand, embodiments of this disclosure provide a light-emitting diode, including a substrate, and a reflective layer, a semiconductor layer of a first conductivity type, a light-emitting layer, and a semiconductor layer of a second conductivity type sequentially grown on one side of the substrate;

[0007] The substrate has a plurality of grooves on one side, and the plurality of grooves are arranged at intervals between each other;

[0008] The reflective layer includes a plurality of reflective bumps, each of which corresponds to a plurality of grooves. Each reflective bump includes a first part and a second part, wherein the first part is located inside the corresponding groove and the second part is located outside the groove.

[0009] In one implementation of this disclosure, the centers of each groove are distributed on at least two circular tracks, each circular track is concentric with the substrate, and each circular track is spaced apart from the others.

[0010] In one implementation of this disclosure, the radial distance between each of the circular trajectories is 2.1-8.4 μm.

[0011] In one implementation of this disclosure, the inner contour of the groove is frustum-shaped;

[0012] The end with the smaller inner diameter of the groove is the opening of the groove, and the end with the larger inner diameter of the groove is the bottom of the groove.

[0013] The outer contour of the first part matches the inner contour of the groove.

[0014] In one implementation of this disclosure, the inner diameter of the groove opening is 1-3 μm, the inner diameter of the groove bottom is 1.4-5.6 μm, and the depth of the groove in the epitaxial growth direction is 0.5-2 μm.

[0015] In one implementation of this disclosure, the outer contour of the second part is a frustum shape;

[0016] The larger outer diameter end of the second part is connected to the smaller outer diameter end of the first part, and the smaller outer diameter end of the second part extends away from the second part.

[0017] In one implementation of this disclosure, the outer diameter of the larger end of the second part is the same as the outer diameter of the smaller end of the first part, and the taper of the second part is the same as the taper of the first part.

[0018] On the other hand, embodiments of this disclosure provide a method for fabricating a light-emitting diode, comprising:

[0019] Provide a substrate;

[0020] Multiple grooves are formed on one side of the substrate, and the multiple grooves are arranged at intervals between each other;

[0021] A reflective layer is prepared on the side of the substrate having the grooves, such that each groove has a reflective bump;

[0022] A semiconductor layer of a first conductivity type, a light-emitting layer, and a semiconductor layer of a second conductivity type are sequentially grown on the side of the reflective layer facing away from the substrate.

[0023] In one implementation of this disclosure, a plurality of grooves are formed on one side of the substrate, including:

[0024] Photoresist is coated on one side of the substrate;

[0025] The pattern corresponding to the groove is exposed and developed on the photoresist;

[0026] The groove is etched into one side of the substrate;

[0027] Clean off any remaining photoresist.

[0028] In one implementation of this disclosure, a reflective layer is prepared on the side of the substrate having the grooves, such that each groove has one reflective bump, including:

[0029] A reflective stack is deposited on one side of the substrate, and the reflective stack fills each of the grooves;

[0030] Photoresist is applied to the side of the reflective stack facing away from the substrate;

[0031] The pattern corresponding to the reflective bump is exposed and developed on the photoresist;

[0032] The reflective stack is etched to retain a second portion of the reflective bump on one side of the substrate and a first portion of the reflective bump within the groove;

[0033] Clean off any remaining photoresist.

[0034] The beneficial effects of the technical solutions provided in this disclosure are:

[0035] Because the first part of the reflective bump is located inside the groove of the substrate, and the second part is located outside the groove, the space of the groove is utilized, effectively increasing the volume of the reflective bump. During the operation of the LED, the light-emitting layer emits light, and some of this light shines towards the substrate. Since the second part of the reflective bump is outside the groove, the light can be reflected in advance by the second part of the reflective bump. Because the first part of the reflective bump is located inside the groove, the remaining light, when it shines into the substrate, can also be reflected by the first part of the reflective bump.

[0036] In other words, by placing the first part of the reflective bump inside the groove and the second part outside the groove, the volume of the reflective bump can be effectively increased, which is more conducive to reflecting light and improving the light reflection efficiency of the reflective bump, thereby improving the light extraction efficiency of the light-emitting diode. Attached Figure Description

[0037] 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.

[0038] Figure 1 This is a schematic diagram of the structure of a light-emitting diode provided in an embodiment of this disclosure;

[0039] Figure 2 This is a top view of a light-emitting diode provided in an embodiment of this disclosure;

[0040] Figure 3 This is a flowchart of a method for fabricating a light-emitting diode according to an embodiment of this disclosure;

[0041] Figure 4 This is a flowchart of another method for fabricating a light-emitting diode provided in this disclosure embodiment;

[0042] Figure 5 This is a schematic diagram of the fabrication process of a light-emitting diode provided in an embodiment of this disclosure;

[0043] Figure 6 This is a schematic diagram of the fabrication process of a light-emitting diode provided in an embodiment of this disclosure;

[0044] Figure 7 This is a schematic diagram of the fabrication process of a light-emitting diode provided in an embodiment of this disclosure;

[0045] Figure 8 This is a schematic diagram of the fabrication process of a light-emitting diode provided in an embodiment of this disclosure.

[0046] The symbols in the diagram represent the following meanings:

[0047] 10. Substrate;

[0048] 110. Groove;

[0049] 20. Reflective layer;

[0050] 210. Reflective bump; 211. First part; 212. Second part;

[0051] 30. Buffer layer;

[0052] 40. A semiconductor layer of the first conductivity type;

[0053] 50. Emissive layer;

[0054] 60. A semiconductor layer of the second conductivity type;

[0055] 70. Circular trajectory;

[0056] 80. Reflective layering. Detailed Implementation

[0057] 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.

[0058] Light-emitting diodes (LEDs) are semiconductor optoelectronic devices that can directly convert electrical energy into light energy. Due to their high energy efficiency, fast response speed, long service life and environmental friendliness, they are receiving increasing attention.

[0059] In related technologies, light-emitting diodes (LEDs) have an epitaxial wafer, which includes a substrate and an epitaxial layer grown on one side of the substrate. During operation, the epitaxial layer emits light, and some of the light shines onto the substrate and is reflected.

[0060] However, the substrate has limited reflectivity, which causes the light illuminating the substrate to be absorbed, affecting the light extraction efficiency of the light-emitting diode.

[0061] To address the aforementioned technical problems, this disclosure provides a light-emitting diode with a reflective layer. Figure 1 See the schematic diagram of the structure of this light-emitting diode. Figure 1 In this embodiment, the photodiode includes a substrate 10, and a reflective layer 20, a buffer layer 30, a semiconductor layer 40 of a first conductivity type, a light-emitting layer 50, and a semiconductor layer 60 of a second conductivity type, which are sequentially grown on one side of the substrate 10.

[0062] The substrate 10 has a plurality of grooves 110 on one side, the plurality of grooves 110 being arranged at intervals between each other, the reflective layer 20 includes a plurality of reflective bumps 210, the plurality of reflective bumps 210 corresponding one-to-one with the plurality of grooves 110, the reflective bumps 210 including a first part 211 and a second part 212, the first part 211 being located inside the corresponding groove 110, and the second part 212 being located outside the groove 110.

[0063] In this embodiment, the reflective layer 20 is a DBR layer, and the reflective bump 210 is a DBR bump. DBR refers to a distributed Bragg reflector, which is a periodic structure composed of two materials with different refractive indices arranged alternately in an ABAB manner. The optical thickness of each material layer is 1 / 4 of the central reflection wavelength, and the reflectivity of DBR can reach more than 99%.

[0064] For example, the reflective layer 20 is a stack of silicon oxide and titanium oxide.

[0065] For example, the first conductivity type semiconductor layer 40 is an n-type GaN layer, the second conductivity type semiconductor layer 60 is a p-type GaN layer, and the light-emitting layer 50 is a quantum hydrazine layer.

[0066] Since the first portion 211 of the reflective bump 210 is located inside the groove 110 of the substrate 10, and the second portion 212 of the reflective bump 210 is located outside the groove 110 of the substrate 10, the space of the groove 110 is utilized, effectively increasing the volume of the reflective bump 210. During the operation of the photodiode, the light-emitting layer 50 emits light, and some of the light shines towards the substrate 10. Since the second portion 212 of the reflective bump 210 is located outside the groove 110 of the substrate 10, the light can be reflected in advance by the second portion 212 of the reflective bump 210. Since the first portion 211 of the reflective bump 210 is located inside the groove 110 of the substrate 10, the remaining light can also be reflected by the first portion 211 of the reflective bump 210 when it shines into the interior of the substrate 10.

[0067] In other words, by setting the first part 211 of the reflective bump 210 inside the groove 110 and setting the second part 212 of the reflective bump 210 outside the groove 110, the volume of the reflective bump 210 can be effectively increased, which is more conducive to reflecting light, improving the light reflection efficiency of the reflective bump 210, and thus improving the light extraction efficiency of the light-emitting diode.

[0068] Figure 2 This is a top view of a light-emitting diode, combined with... Figure 2 In this embodiment, the centers of each groove 110 are distributed on at least two circular tracks 70, each circular track 70 is concentric with the substrate 10, and each circular track 70 is spaced apart from each other.

[0069] In the above implementation, since each circular trajectory 70 is concentric with the substrate 10 and spaced apart from each other, distributing the grooves 110 on the circular trajectories 70 allows for a more uniform distribution of the grooves 110 on the substrate 10, which in turn results in a more uniform distribution of the reflective bumps 210 on the substrate 10. This facilitates the full reflection of light by the reflective bumps 210, further improving the light extraction efficiency of the light-emitting diode.

[0070] For example, the centers of each groove 110 are evenly spaced on the circular trajectory 70, thereby further improving the uniformity of the distribution of the reflective bumps 210 on the substrate 10.

[0071] For example, the radial distance between each circular trajectory 70 is 2.1-8.4 μm.

[0072] In the above implementation, designing the radial distance between each pair of adjacent circular trajectories 70 to be the same can further improve the uniformity of the distribution of the reflective bumps 210 on the substrate 10.

[0073] In some examples, the radial distance between each circular trajectory 70 is 4.2 μm.

[0074] The radial distance between each circular track 70 is designed to the above value, which can ensure that a sufficient number of reflective bumps 210 are arranged on the substrate 10, and that there is sufficient space between two adjacent circular tracks 70 to arrange reflective bumps 210.

[0075] See you again Figure 1 In this embodiment, the inner contour of the groove 110 is frustum-shaped, the end with the smaller inner diameter of the groove 110 is the opening of the groove 110, and the end with the larger inner diameter of the groove 110 is the bottom of the groove 110. The outer contour of the first part 211 matches the inner contour of the groove 110.

[0076] In the above implementation, the inner contour of the groove 110 is designed as a frustum. Since the outer contour of the first part 211 of the reflective bump 210 matches the inner contour of the groove 110, the outer contour of the first part 211 of the reflective bump 210 is also frustum-shaped. The end with the smaller outer diameter of the first part 211 of the reflective bump 210 is the first end, located at the opening of the groove 110, and the end with the larger outer diameter of the first part 211 of the reflective bump 210 is the second end, located at the bottom of the groove 110. In this way, the area of ​​the first part 211 of the reflective bump 210 facing the light direction can be increased, which is more conducive to the reflection of light by the first part 211 of the reflective bump 210. Furthermore, since the end with the larger outer diameter of the first part 211 of the reflective bump 210 is located inside the groove 110, it will not significantly affect the growth space of the buffer layer 30 on one side of the substrate 10.

[0077] In some examples, the first portion 211 of the reflective bump 210 can also be other shapes, but it is necessary to ensure that the first end dimension of the first portion 211 of the reflective bump 210 is smaller than the second end dimension. In this way, it is possible to increase the area of ​​the first portion 211 of the reflective bump 210 facing the direction of incoming light. For example, it can be hemispherical, elliptical, conical, etc., and this disclosure does not limit it.

[0078] Of course, as the inner contour shape of the groove 110 changes, the outer contour shape of the first part 211 of the reflective protrusion 210 also changes, which will not be elaborated further.

[0079] When the groove 110 is frustoconical, for example, the inner diameter of the groove opening of the groove 110 is 1-3 μm, the inner diameter of the groove bottom of the groove 110 is 1.4-5.6 μm, and the depth of the groove 110 in the epitaxial growth direction is 0.5-2 μm.

[0080] In some examples, the inner diameter of the groove 110 opening is 2 μm, the inner diameter of the groove bottom is 2.8 μm, and the depth of the groove 110 in the epitaxial growth direction is 1 μm.

[0081] It should be noted that, since the outer contour of the first part 211 of the reflective bump 210 matches the inner contour of the groove 110, the size of the first part 211 of the reflective bump 210 corresponds to the size of the groove 110.

[0082] In some examples, the outer diameter of the first end is 2 μm, the outer diameter of the second end of the first portion 211 of the reflective bump 210 is 2.8 μm, and the height of the first portion 211 of the reflective bump 210 is 1 μm.

[0083] See also Figure 1 In this embodiment, the outer contour of the second part 212 is frustum-shaped, the end with the larger outer diameter of the second part 212 is connected to the end with the smaller outer diameter of the first part 211, and the end with the smaller outer diameter of the second part 212 extends away from the second part 212.

[0084] In the above implementation, the smaller outer diameter end of the second portion 212 of the reflective bump 210 is the first end, protruding from the substrate 10, and the larger outer diameter end of the second portion 212 of the reflective bump 210 is the second end, located at the opening of the groove 110 and connected to the first end of the first portion 211 of the reflective bump 210. This increases the area of ​​the second portion 212 of the reflective bump 210 facing the light-facing direction, making it more effective for the second portion 212 of the reflective bump 210 to reflect light. Furthermore, since the larger outer diameter end of the second portion 212 of the reflective bump 210 is located at the opening of the groove 110, it does not excessively affect the growth space of the buffer layer 30 on one side of the substrate 10.

[0085] For example, the larger outer diameter end of the second part 212 has the same outer diameter as the smaller outer diameter end of the first part 211, and the taper of the second part 212 is the same as the taper of the first part 211.

[0086] In the above implementation, the dimensions of the first part 211 and the second part 212 of the reflective bump 210 are designed in such a way that the second part 212 and the first part 211 together form a frustum-shaped whole, which is beneficial to the fabrication of the reflective bump 210.

[0087] For example, the outer diameter of the first end of the second part 212 is 0.58-2.32 μm.

[0088] In some examples, the outer diameter of the first end of the second part 212 is 1.16 μm.

[0089] In this embodiment, the substrate 10 is an insulating substrate 10 such as sapphire, silicon carbide, gallium oxide, or diamond, and its size can be 2 inches or larger.

[0090] As an example, in this embodiment of the disclosure, the substrate 10 is patterned sapphire. The sapphire substrate 10 is a commonly used substrate 10, with mature technology and low cost.

[0091] In this embodiment, the buffer layer 30 fills the gap between the second portions 212 of each adjacent reflective bump 210 and covers the first end of the second portion 212 of the reflective bump 210.

[0092] In the above implementation, the buffer layer 30 is prepared in such a way that the lattice mismatch between the substrate 10 and the semiconductor layer 40 of the first conductivity type can be effectively eliminated.

[0093] Figure 3 This is a flowchart illustrating a method for fabricating a light-emitting diode (LED) according to an embodiment of the present disclosure. This method is capable of fabricating... Figure 1 The light-emitting diode shown is combined with Figure 3 The preparation method includes:

[0094] Step 301: Provide a substrate 10.

[0095] Step 302: A plurality of grooves 110 are prepared on one side of the substrate 10, and the plurality of grooves 110 are arranged at intervals.

[0096] Step 303: Prepare a reflective layer 20 on the side of the substrate 10 with grooves 110, such that each groove 110 has a reflective bump 210.

[0097] Step 304: A buffer layer 30, a semiconductor layer 40 of the first conductivity type, a light-emitting layer 50, and a semiconductor layer 60 of the second conductivity type are sequentially grown on the side of the reflective layer 20 facing away from the substrate 10.

[0098] The light-emitting diode (LED) fabricated using the method provided in this embodiment utilizes the space of the groove 110, effectively increasing the volume of the reflective bump 210, since the first portion 211 of the reflective bump 210 is located within the groove 110 of the substrate 10 and the second portion 212 of the reflective bump 210 is located outside the groove 110 of the substrate 10. During LED operation, the light-emitting layer 50 emits light, and some of the light shines towards the substrate 10. Because the second portion 212 of the reflective bump 210 is located outside the groove 110 of the substrate 10, the light can be reflected in advance by the second portion 212 of the reflective bump 210. Because the first portion 211 of the reflective bump 210 is located within the groove 110 of the substrate 10, the remaining light can also be reflected by the first portion 211 of the reflective bump 210 when it shines into the interior of the substrate 10.

[0099] In other words, by setting the first part 211 of the reflective bump 210 inside the groove 110 and setting the second part 212 of the reflective bump 210 outside the groove 110, the volume of the reflective bump 210 can be effectively increased, which is more conducive to reflecting light, improving the light reflection efficiency of the reflective bump 210, and thus improving the light extraction efficiency of the light-emitting diode.

[0100] Figure 4 This is a flowchart illustrating another method for fabricating a light-emitting diode (LED) according to an embodiment of this disclosure. This method is capable of fabricating... Figure 1 The light-emitting diode shown is combined with Figure 4 The preparation method includes:

[0101] Step 401: Provide a substrate 10 (see...) Figure 5 ).

[0102] Step 402: Coat one side of the substrate 10 with photoresist.

[0103] For example, the photoresist is a negative photoresist. Of course, in other embodiments, the photoresist may also be a positive photoresist, and this disclosure is not limiting in this regard.

[0104] Step 403: Expose and develop the photoresist to create a pattern corresponding to the groove 110.

[0105] In step 403, since the groove 110 on the substrate 10 is circular, multiple circular patterns are exposed and developed on the photoresist.

[0106] Step 404: Etch a groove 110 on one side of the substrate 10.

[0107] In step 404, a plurality of grooves 110 are etched on the substrate 10 using dry etching technology.

[0108] In this embodiment, the inner contour of the groove 110 is frustum-shaped, the end with the smaller inner diameter of the groove 110 is the groove opening of the groove 110, and the end with the larger inner diameter of the groove 110 is the groove bottom of the groove 110.

[0109] Step 405: Clean off any remaining photoresist to complete the fabrication of multiple grooves 110 on one side of the substrate 10 (see [link]). Figure 6 ).

[0110] Step 406: A reflective stack 80 is deposited on one side of the substrate 10, and the reflective stack 80 fills each groove 110.

[0111] In step 406, the reflective stack 80 is a DBR stack. The substrate 10 with the groove 110 is placed in a DBR evaporation machine for evaporation, thereby depositing the reflective stack 80 on one side of the substrate 10 (see...). Figure 7 ).

[0112] It should be noted that the thickness of the reflective stack 80 needs to be greater than the depth of the groove 110 in the epitaxial growth direction. In this way, it can be ensured that the reflective stack 80 fills each groove 110 and prepares the foundation for the subsequent formation of the reflective bump 210.

[0113] For example, the thickness of the reflective stack 80 in the epitaxial growth direction is 1-4 μm.

[0114] In some examples, the thickness of the reflective stack 80 in the epitaxial growth direction is 2 μm. This design of the thickness of the reflective stack 80 ensures that the reflective stack 80 fills each groove 110, preparing the foundation for the subsequent formation of the reflective bump 210, while also avoiding the introduction of other adverse factors due to the excessive height of the reflective stack 80.

[0115] Step 407: Apply photoresist to the side of the reflective stack 80 that is away from the substrate 10.

[0116] Step 408: Expose and develop the pattern corresponding to the reflective bump 210 on the photoresist.

[0117] In step 408, a photomask is placed on the side of the reflective stack 80 facing away from the substrate 10, and exposure and development are performed.

[0118] In step 408, since the first end face of the reflective bump 210 is circular, multiple circular patterns are exposed and developed on the photoresist.

[0119] Step 409: Etch the reflective stack 80 to retain a second portion 212 of the reflective bump 210 on one side of the substrate 10 and a first portion 211 of the reflective bump 210 in the groove 110.

[0120] Step 410: Clean off any remaining photoresist to complete the fabrication of the reflective layer 20 on the side of the substrate 10 with the groove 110 (see [link]). Figure 8 ).

[0121] Step 411: On the side of the reflective layer 20 facing away from the substrate 10, a buffer layer 30, a semiconductor layer 40 of the first conductivity type, a light-emitting layer 50, and a semiconductor layer 60 of the second conductivity type are sequentially grown (see...). Figure 1 ).

[0122] The light-emitting diode (LED) fabricated using the method provided in this embodiment utilizes the space of the groove 110, effectively increasing the volume of the reflective bump 210, since the first portion 211 of the reflective bump 210 is located within the groove 110 of the substrate 10 and the second portion 212 of the reflective bump 210 is located outside the groove 110 of the substrate 10. During LED operation, the light-emitting layer 50 emits light, and some of the light shines towards the substrate 10. Because the second portion 212 of the reflective bump 210 is located outside the groove 110 of the substrate 10, the light can be reflected in advance by the second portion 212 of the reflective bump 210. Because the first portion 211 of the reflective bump 210 is located within the groove 110 of the substrate 10, the remaining light can also be reflected by the first portion 211 of the reflective bump 210 when it shines into the interior of the substrate 10.

[0123] In other words, by setting the first part 211 of the reflective bump 210 in the groove 110 and the second part 212 of the reflective bump 210 in the groove 110, the volume of the reflective bump 210 can be effectively increased, which is more conducive to reflecting light, improving the light reflection efficiency of the reflective bump 210, and thus improving the light extraction efficiency of the light-emitting diode.

[0124] 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,” etc., are used only to indicate relative positional relationships; when the absolute position of the described objects changes, the relative positional relationship may also change accordingly.

[0125] 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, It includes a substrate (10), and a reflective layer (20), a semiconductor layer (40) of a first conductivity type, a light-emitting layer (50), and a semiconductor layer (60) of a second conductivity type, which are sequentially grown on one side of the substrate (10). The substrate (10) has a plurality of grooves (110) on one side, the plurality of grooves (110) are arranged at intervals, the inner contour of the groove (110) is frustum-shaped, the end of the groove (110) with a smaller inner diameter is the groove opening of the groove (110), and the end of the groove (110) with a larger inner diameter is the groove bottom of the groove (110). The reflective layer (20) includes a plurality of reflective bumps (210), each of which corresponds to a plurality of grooves (110). Each reflective bump (210) includes a first part (211) and a second part (212). The outer contour of the first part (211) matches the inner contour of the groove (110). The first part (211) is located inside the corresponding groove (110), and the second part (212) is located outside the groove (110).

2. The light-emitting diode according to claim 1, characterized in that, The centers of each of the grooves (110) are distributed on at least two circular tracks (70), each of the circular tracks (70) is concentric with the substrate (10), and each of the circular tracks (70) is spaced apart from each other.

3. The light-emitting diode according to claim 2, characterized in that, The radial distance between each of the circular trajectories (70) is 2.1-8.4 μm.

4. The light-emitting diode according to claim 1, characterized in that, The groove (110) has an inner diameter of 1-3 μm at the opening, an inner diameter of 1.4-5.6 μm at the bottom, and a depth of 0.5-2 μm in the epitaxial growth direction.

5. The light-emitting diode according to claim 3, characterized in that, The outer contour of the second part (212) is frustum-shaped; The larger outer diameter end of the second part (212) is connected to the smaller outer diameter end of the first part (211), and the smaller outer diameter end of the second part (212) extends away from the second part (212).

6. The light-emitting diode according to claim 5, characterized in that, The larger outer diameter end of the second part (212) has the same outer diameter as the smaller outer diameter end of the first part (211), and the taper of the second part (212) is the same as the taper of the first part (211).

7. A method for fabricating a light-emitting diode, characterized in that, include: Provide a substrate (10); Multiple grooves (110) are prepared on one side of the substrate (10). The multiple grooves (110) are arranged at intervals. The inner contour of the groove (110) is frustum-shaped. The end of the groove (110) with a smaller inner diameter is the groove opening of the groove (110), and the end of the groove (110) with a larger inner diameter is the groove bottom of the groove (110). A reflective layer (20) is prepared on one side of the substrate (10) having the groove (110), such that each groove (110) has a reflective bump (210), the reflective bump (210) including a first part (211) and a second part (212), the outer contour of the first part (211) matching the inner contour of the groove (110), the first part (211) being located inside the corresponding groove (110), and the second part (212) being located outside the groove (110); A first conductivity type semiconductor layer (40), a light-emitting layer (50), and a second conductivity type semiconductor layer (60) are sequentially grown on the side of the reflective layer (20) facing away from the substrate (10).

8. The preparation method according to claim 7, characterized in that, A plurality of grooves (110) are formed on one side of the substrate (10), including: Photoresist is coated on one side of the substrate (10); The pattern corresponding to the groove (110) is exposed and developed on the photoresist; The groove (110) is etched on one side of the substrate (10). Clean off any remaining photoresist.

9. The preparation method according to claim 7, characterized in that, A reflective layer (20) is prepared on one side of the substrate (10) having the grooves (110), such that each groove (110) has a reflective bump (210), including: A reflective stack (80) is deposited on one side of the substrate (10), and the reflective stack (80) fills each of the grooves (110). Photoresist is applied to the side of the reflective stack (80) facing away from the substrate (10); The pattern corresponding to the reflective bump (210) is exposed and developed on the photoresist; The reflective stack (80) is etched to retain a second portion (212) of the reflective bump (210) on one side of the substrate (10) and a first portion (211) of the reflective bump (210) is retained in the groove (110). Clean off any remaining photoresist.

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