LED core particle and LED manufacturing method

Abstract

The embodiments of the present application provide an LED core and a method for manufacturing an LED. In the LED core, the epitaxial structure includes at least two epitaxial units, and different light conversion structures are provided on the light-emitting sides of different epitaxial units, so that the corresponding areas of different epitaxial units in the epitaxial structure can emit light of different colors, thereby achieving a single LED core to emit light of at least two colors. When applied to a backlight mini LED, at least two single-color LED cores can be replaced, reducing the increased package size of the LED core when used as a backlight, thereby reducing the size of the backlight mini LED, which is beneficial to the application of the backlight mini LED. Moreover, in the LED core provided by the embodiments of the present application, the epitaxial structure includes at least two epitaxial units, which are larger in size, which can reduce the process difficulty of forming the light conversion structure on the light-emitting side of the epitaxial unit.

Description

Technical Field

[0001] The present application relates to the field of LED technology, and in particular to an LED core particle and an LED manufacturing method. Background Art

[0002] With the gradual development of LED, LED lighting has completely replaced traditional lighting sources and gradually developed into the display industry. Among them, mini LED has become the main research direction of major LED companies.

[0003] At present, mini LED is mainly divided into two application directions: self-luminous mini LED and backlight mini LED. Specifically, self-luminous mini LED mainly encapsulates three mini LED core particles of red, green and blue into a very small lamp bead, and then welds the lamp bead on the same lamp board. As the light source of the mini LED display, it is a further upgrade of the small-pitch LED display technology, and its development direction is consistent with that of the small-pitch LED; while backlight mini LED mainly uses the method of dotting phosphor on mini LED to encapsulate a single mini LED and phosphor into a lamp bead, and then applies it to the backlight of the display. It has a local dimming function, which can increase the dynamic contrast and brightness of the LCD display, and has received higher attention in the industry.

[0004] However, since the existing mini LED is particularly small in size, the process of packaging a single mini LED and phosphor into a lamp bead is relatively difficult. Moreover, the existing single mini LED can only emit monochromatic light. Packaging a single mini LED and phosphor into a lamp bead, and then combining mini LEDs of different colors to form a backlight mini LED will inevitably increase the size of each lamp bead, thereby increasing the size of the backlight mini LED, resulting in a larger size of the backlight mini LED, affecting the application of the backlight mini LED. Summary of the Invention

[0005] In view of this, the present application provides an LED chip and a method for manufacturing the same, the scheme is as follows:

[0006] An LED chip, comprising:

[0007] substrate;

[0008] an epitaxial structure located on the first side surface of the substrate, the epitaxial structure comprising a stacked N-type gallium nitride layer, a multi-quantum well layer, and a P-type gallium nitride layer;

[0009] a plurality of grooves located in the epitaxial structure, the plurality of grooves including at least two first grooves, the grooves penetrating the P-type gallium nitride layer and the multi-quantum well layer and extending into the N-type gallium nitride layer;

[0010] a groove at the bottom of the first groove, the groove penetrating the N-type gallium nitride layer and extending into the substrate, the at least two first grooves and the groove at the bottom of the first groove dividing the epitaxial structure into at least two epitaxial units;

[0011] a current blocking layer located on a surface of the epitaxial structure facing away from the substrate, the current blocking layer also covering the surface of the groove, and the current blocking layer exposing a portion of the P-type gallium nitride layer in the epitaxial unit;

[0012] a P-type electrode electrically connected to the P-type gallium nitride layer and an N-type electrode electrically connected to the N-type gallium nitride layer;

[0013] a reflective structure located in the first groove and in the groove at the bottom thereof;

[0014] The light conversion structure is located on the light-emitting side of each epitaxial unit. The light conversion structure corresponds to the epitaxial unit one by one, and different epitaxial units correspond to different light conversion structures.

[0015] Optionally, the reflective structure is a metal structure or an insulating structure.

[0016] Optionally, the reflective structure is a metal structure, the P-type electrode and the N-type electrode are located on different sides of the epitaxial unit, and the N-type electrode is electrically connected to the N-type gallium nitride layer through the reflective structure.

[0017] Optionally, the N-type electrode and the P-type electrode are located on the same side of the epitaxial unit, and the multiple grooves further include at least two second grooves, which correspond one-to-one to the epitaxial unit, penetrate the P-type gallium nitride layer and the multi-quantum well layer of the epitaxial unit, and extend into the N-type gallium nitride layer; the current blocking layer also covers the sidewalls of the second groove, and the N-type electrode is electrically connected to the N-type gallium nitride layer through the second groove.

[0018] Optionally, in a direction perpendicular to the plane where the substrate is located, a surface of the reflective structure away from the substrate is not lower than a surface of the light conversion structure away from the substrate.

[0019] A method for manufacturing an LED, wherein the LED includes at least one LED core particle, the method comprising:

[0020] providing a substrate;

[0021] forming an epitaxial layer on the first side surface of the substrate, the epitaxial layer comprising a stacked N-type gallium nitride layer, a multi-quantum well layer, and a P-type gallium nitride layer, the epitaxial layer comprising at least one epitaxial structure, one epitaxial structure corresponding to one LED core;

[0022] forming a plurality of grooves in the epitaxial structure, the plurality of grooves including at least two first grooves, the grooves penetrating the P-type gallium nitride layer and the multi-quantum well layer and extending into the N-type gallium nitride layer;

[0023] forming a current blocking layer on a surface of the epitaxial structure facing away from the substrate, wherein the current blocking layer also covers the surface of the groove;

[0024] forming a trench at the bottom of the first groove, the trench penetrating the N-type gallium nitride layer and extending into the substrate, wherein the at least two first grooves and the trench at the bottom of the first groove divide the epitaxial structure into at least two epitaxial units;

[0025] Etching the current blocking layer to expose the P-type gallium nitride layer of the epitaxial unit, and forming a P-type electrode electrically connected to the P-type gallium nitride layer and an N-type electrode electrically connected to the N-type gallium nitride layer;

[0026] forming a reflective structure in the first groove and the groove at the bottom thereof;

[0027] A light conversion structure is formed on the light-emitting side of each epitaxial unit. The light conversion structure corresponds to the epitaxial unit one-to-one, and different epitaxial units correspond to different light conversion structures.

[0028] Optionally, forming a reflective structure in the first groove and the groove at the bottom thereof includes:

[0029] A first metal layer is evaporated in the first groove and the trench at the bottom thereof by using an electron beam evaporation process to form a reflective structure in the first groove and the trench at the bottom thereof.

[0030] Optionally, forming a reflective structure in the first groove and the groove at the bottom thereof includes:

[0031] Stir reflective powder into silica gel;

[0032] The silica gel stirred with reflective powder is spin-coated on the first groove and the groove at the bottom thereof to form a reflective structure in the first groove and the groove at the bottom thereof.

[0033] Optionally, in a direction perpendicular to the plane where the substrate is located, a surface of the reflective structure away from the substrate is not lower than a surface of the light conversion structure away from the substrate.

[0034] Optionally, a light conversion structure is formed on the light-emitting side of each epitaxial unit, the light conversion structure corresponds to the epitaxial unit one-to-one, and different epitaxial units correspond to different light conversion structures, including:

[0035] stirring a first phosphor in silica gel to form a first mixed structure;

[0036] Spin coating a first hybrid structure on the light-emitting side of one of the epitaxial units to form a first light conversion structure on the light-emitting side of the epitaxial unit;

[0037] stirring a second phosphor in the silica gel to form a second mixed structure, wherein the color of the second phosphor is different from the color of the first phosphor;

[0038] A second hybrid structure is spin-coated on the light-emitting side of another epitaxial unit to form a second light conversion structure on the light-emitting side of the epitaxial unit.

[0039] Optionally, the N-type electrode and the P-type electrode are located on the same side of the epitaxial unit, and the multiple grooves further include at least two second grooves, which correspond one-to-one to the epitaxial unit, penetrate the P-type gallium nitride layer and the multi-quantum well layer of the epitaxial unit, and extend into the N-type gallium nitride layer; the current blocking layer also covers the sidewalls of the second groove, and the N-type electrode is electrically connected to the N-type gallium nitride layer through the second groove.

[0040] Optionally, the method further includes:

[0041] thinning the second side of the substrate to expose the bottom of the trench;

[0042] A Bragg reflection structure is formed on the second side of the substrate.

[0043] Optionally, forming a P-type electrode electrically connected to the P-type gallium nitride layer and an N-type electrode electrically connected to the N-type gallium nitride layer includes:

[0044] forming a P-type electrode electrically connected to the P-type gallium nitride layer on a side of the epitaxial unit away from the substrate;

[0045] thinning the second side of the substrate to expose the bottom of the trench;

[0046] An N-type electrode is formed on the second side of the substrate, and the N-type electrode is electrically connected to the N-type gallium nitride layer in the epitaxial unit.

[0047] In the LED core provided in the embodiment of the present application, the epitaxial structure includes at least two epitaxial units, and different light conversion structures are provided on the light-emitting sides of different epitaxial units, so that the corresponding areas of different epitaxial units in the epitaxial structure can emit light of different colors, thereby realizing that one LED core can emit light of at least two colors. When applied to backlight mini LED, at least two monochrome LED cores can be replaced, reducing the increased package size of the LED core when used as backlight, thereby reducing the size of the backlight mini LED, which is beneficial to the application of backlight mini LED.

[0048] Moreover, in the LED core provided in the embodiment of the present application, the epitaxial structure includes at least two epitaxial units, which are relatively large in size, and can reduce the process difficulty of forming a light conversion structure on the light-emitting side of the epitaxial unit. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] In order to more clearly illustrate the technical solutions in the embodiments of the present application or related technologies, the following briefly introduces the drawings required for use in the embodiments or descriptions of the prior art. Obviously, the drawings described below are merely embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without any creative work.

[0050] The structures, proportions, sizes, etc. depicted in the drawings of this specification are only used to match the contents disclosed in the specification so as to facilitate understanding and reading by persons familiar with this technology. They are not intended to limit the conditions under which this application can be implemented, and therefore have no substantive technical significance. Any structural modifications, changes in proportional relationships, or adjustments in size, without affecting the efficacy and objectives that can be achieved by this application, should still fall within the scope of the technical contents disclosed in this application.

[0051] Figure 1 A schematic diagram of the structure of an LED core particle provided in one embodiment of the present application;

[0052] Figure 2 A top view of an LED chip provided in one embodiment of the present application;

[0053] Figure 3 A top view of an LED chip provided in another embodiment of the present application;

[0054] Figure 4 A schematic structural diagram of an LED core particle provided in another embodiment of the present application;

[0055] Figure 5-Figure 28 This is a schematic diagram of the structures involved in each step of the LED manufacturing method provided in one embodiment of the present application. DETAILED DESCRIPTION

[0056] The following will be combined with the accompanying drawings in the embodiments of this application to clearly and completely describe the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments of this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0057] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the present application is further described in detail below with reference to the accompanying drawings and specific implementation methods.

[0058] As described in the background technology section, since the existing mini LED is particularly small in size, the process of packaging a single mini LED and phosphor into a lamp bead is relatively difficult. Moreover, the existing single mini LED can only emit monochromatic light. Packaging a single mini LED and phosphor into a lamp bead, and then combining mini LED lamp beads of different colors to form a backlight mini LED will inevitably increase the size of each backlight mini LED, resulting in a larger size of the backlight mini LED, which affects the application of the backlight mini LED.

[0059] In view of this, the embodiment of the present application provides an LED chip, such as Figure 1 As shown, the LED core particle includes

[0060] Substrate 10, optionally, the substrate 10 is a sapphire substrate;

[0061] an epitaxial structure 20 located on the first side surface of the substrate 10, the epitaxial structure 20 comprising a stacked N-type gallium nitride layer 201, a multi-quantum well layer 202, and a P-type gallium nitride layer 203, i.e., the epitaxial structure comprises a stacked N-type GaN layer, a multi-quantum well layer, and a P-type GaN layer;

[0062] a plurality of grooves in the epitaxial structure 20 , the plurality of grooves including at least two first grooves, the grooves penetrating the P-type gallium nitride layer 203 and the multi-quantum well layer 202 and extending into the N-type gallium nitride layer 201 ;

[0063] a trench at the bottom of the first groove, the trench penetrating the N-type gallium nitride layer 201 and extending into the substrate 10 ; the at least two first grooves and the trench at the bottom of the first groove divide the epitaxial structure 20 into at least two epitaxial units;

[0064] a current blocking layer 40 located on a surface of the epitaxial structure 20 facing away from the substrate 10 , the current blocking layer 40 also covering the surface of the groove, and the current blocking layer 40 exposing a portion of the P-type gallium nitride layer in the epitaxial unit;

[0065] a P-type electrode (not shown in the figure) electrically connected to the P-type gallium nitride layer and an N-type electrode (not shown in the figure) electrically connected to the N-type gallium nitride layer;

[0066] a reflective structure 90 located in the first groove and the groove at the bottom thereof;

[0067] The light conversion structure 100 is located on the light-emitting side of each epitaxial unit. The light conversion structure corresponds to the epitaxial unit one by one, and different epitaxial units correspond to different light conversion structures.

[0068] It should be noted that, in this embodiment, the epitaxial structure may include two epitaxial units, three epitaxial units, or more epitaxial units. This application does not limit this, and the specific situation depends on the circumstances.

[0069] Alternatively, based on the above embodiment, in one embodiment of the present application, different epitaxial units correspond to different light conversion structures, that is, the colors of light emitted from corresponding regions of different epitaxial units are different. Specifically, in one embodiment of the present application, the thickness of the light conversion structure is 30 microns, but this application does not limit this thickness and the specific thickness depends on the circumstances.

[0070] Based on any of the above embodiments, in one embodiment of the present application, the depth of the groove extending into the substrate is in the range of 50 microns to 100 microns, that is, the distance between the bottom of the groove and the upper surface of the substrate is in the range of 50 microns to 100 microns, but the present application does not limit this and it depends on the specific circumstances.

[0071] In the LED core provided in the embodiment of the present application, the epitaxial structure includes at least two epitaxial units, and different light conversion structures are provided on the light-emitting sides of different epitaxial units, so that the corresponding areas of different epitaxial units in the epitaxial structure can emit light of different colors, thereby realizing that one LED core can emit light of at least two colors. When applied to backlight mini LED, at least two monochrome LED lamp beads can be replaced, reducing the increased package size of the LED core when used as a backlight, thereby reducing the size of the backlight mini LED, which is beneficial to the application of backlight mini LED.

[0072] Taking the backlight mini LED as an example of a white point light source formed by red, green, and blue colors, the existing single LED core can only emit monochromatic light. Therefore, when forming a white point light source, the existing LED core needs to first form its corresponding light conversion structure on three LED cores, encapsulate them, and form a monochromatic LED lamp bead to emit red, green, and blue light respectively. Then, the three LED lamp beads encapsulated with light conversion structures are encapsulated together to form a white point light source, which requires a two-step packaging process. The LED core provided in the embodiment of the present application has an epitaxial structure that can include three epitaxial units. The light-emitting side of each epitaxial unit can form a different light conversion structure to emit red, green, and blue light respectively. Then, through a one-step packaging process, the three epitaxial units and their corresponding light conversion structures are uniformly encapsulated in one LED lamp bead to realize a white point light source. It can be seen that compared with the existing technology, the present application solution only requires a one-step packaging process, thereby reducing the size of the final white point light source, which is conducive to the application of backlight mini LEDs.

[0073] Moreover, in the LED core provided in the embodiment of the present application, the epitaxial structure includes at least two epitaxial units, which are relatively large in size, and can reduce the process difficulty of forming a light conversion structure on the light-emitting side of the epitaxial unit.

[0074] In addition, in the LED core particle provided in the embodiment of the present application, a reflective structure is provided between different epitaxial units in the at least two epitaxial units included in the epitaxial structure, so that the reflective structure can be used as a light blocking layer between different epitaxial units and their corresponding light conversion structures, thereby avoiding crosstalk between the light emitted by different light conversion structures.

[0075] Based on the above embodiments, in one embodiment of the present application, the reflective structure is a metal structure, and optionally, the reflective structure is an aluminum reflective layer. In another embodiment of the present application, the reflective structure is an insulating structure, and optionally, the reflective structure is a white reflective layer, but this application does not limit this and the specific circumstances may vary. Specifically, in one embodiment of the present application, the thickness of the reflective structure ranges from 25 microns to 30 microns, but this application does not limit this and the specific circumstances may vary.

[0076] Based on any of the above embodiments, in one embodiment of the present application, in a direction perpendicular to the plane of the substrate, the surface of the reflective structure away from the substrate is not lower than the surface of the light conversion structure away from the substrate, that is, the surface of the reflective structure away from the substrate is higher than the surface of the light conversion structure away from the substrate, or is flush with the surface of the light conversion structure away from the substrate, to avoid crosstalk between light emitted by different light conversion structures. Optionally, in a direction perpendicular to the plane of the substrate, the surface of the reflective structure away from the substrate is higher than the surface of the light conversion structure away from the substrate, but this application is not limited to this, and the specific situation will depend on the circumstances.

[0077] Based on any of the above embodiments, in one embodiment of the present application, the multiple first grooves divide the P-type gallium nitride layer of the epitaxial structure into multiple etched regions, that is, the region where the P-type gallium nitride layer is located in the epitaxial unit is the etched region, and the etched region corresponds one-to-one with the epitaxial unit. Optionally, in one embodiment of the present application, the shape of the etched region is a regular shape, such as a rectangle or a square. In another embodiment of the present application, the shape of the etched region can also be an irregular shape. This application does not limit this, and the specific shape depends on the circumstances.

[0078] Based on the above embodiments, in an optional embodiment of the present application, the multiple etching areas are arranged in a matrix, but the present application is not limited to this. In other embodiments of the present application, the multiple etching areas can also be arranged in other ways, depending on the specific circumstances.

[0079] Based on any of the above embodiments, in one embodiment of the present application, the current blocking layer is a silicon dioxide layer, and the thickness of the current blocking layer ranges from 2000 angstroms to 2600 angstroms, but the present application does not impose any limitation thereto, and the thickness depends on the specific circumstances.

[0080] Optionally, in the given embodiment of the present application, the width of the current blocking layer located at the portion of the epitaxial structure away from the surface of the etching area is in the range of 1 micron to 2 microns, so as to avoid electrical connection between the reflective structure and the epitaxial structure when the reflective structure is a metal structure and is higher than the surface of the epitaxial structure. However, the present application does not impose any restrictions on this, and it depends on the specific circumstances.

[0081] Based on any of the above embodiments, in one embodiment of the present application, continue as follows Figure 1 As shown, the LED core also includes: a transparent conductive layer 80 located on the surface of the P-type gallium nitride layer 203 and electrically connected to the P-type gallium nitride layer 203. Optionally, the transparent conductive layer is an ITO layer, but this application does not limit this, and it depends on the specific situation.

[0082] It should be noted that the transparent conductive layer may only cover the surface of the P-type gallium nitride layer, or may extend to cover a portion of the current blocking area located on the surface of the P-type gallium nitride layer. This application does not impose any restrictions on this, as long as the transparent conductive layer is electrically insulated from the reflective structure.

[0083] Optionally, in one embodiment of the present application, the width of the current blocking layer covered by the transparent conductive layer located in a partial area on the surface of the P-type gallium nitride layer ranges from 0 microns to 1 micron, but the present application does not limit this and it depends on the specific circumstances.

[0084] Based on any of the above embodiments, in one embodiment of the present application, the thickness of the transparent conductive layer ranges from 600 angstroms to 1100 angstroms, but the present application does not impose a limitation thereto, and the specific thickness depends on the circumstances.

[0085] On the basis of any of the above embodiments, in one embodiment of the present application, the LED is a horizontally structured LED. In this embodiment, Figure 2 As shown, the P-type electrode 60 and the N-type electrode 70 are located on the same side of the epitaxial structure. It should be noted that in this embodiment, the multiple grooves also include at least two second grooves, each corresponding to the epitaxial unit, penetrating the P-type gallium nitride layer and the multi-quantum well layer of the epitaxial unit, and extending into the N-type gallium nitride layer. The current blocking layer also covers the sidewalls of the second grooves, and the N-type electrode is electrically connected to the N-type gallium nitride layer through the second grooves. Therefore, on the basis of achieving the electrical connection between the N-type electrode and the N-type gallium nitride layer through the second grooves, the portion of the current blocking layer 40 located on the sidewalls of the second grooves achieves electrical insulation between the N-type electrode and the P-type gallium nitride layer.

[0086] Specifically, based on the above embodiment, in one embodiment of the present application, the thickness of the P-type electrode ranges from 1.3 microns to 2.1 microns, but the present application does not limit this, and the specific thickness depends on the circumstances.

[0087] It should be noted that, based on any of the above embodiments, in one embodiment of the present application, when a transparent conductive layer is formed on the side of the P-type gallium nitride layer away from the substrate, the P-type electrode is electrically connected to the P-type gallium nitride layer through the transparent conductive layer.

[0088] Based on the above embodiment, in one embodiment of the present application, Figure 1 As shown, the LED chip further includes: a Bragg reflection layer 110 located on the second side of the substrate 10 , and the second side of the substrate 10 is opposite to the first side of the substrate 10 .

[0089] Optionally, in one embodiment of the present application, the thickness of the substrate ranges from 50 microns to 100 microns; the thickness of the Bragg reflection structure ranges from 3 microns to 5 microns, but the present application does not limit this and it depends on the specific situation.

[0090] In another embodiment of the present application, the LED is a vertical structure LED. In this embodiment, Figure 3 and Figure 4 As shown, the P-type electrode 60 and the N-type electrode 70 are located on different sides of the epitaxial structure. In this embodiment, the reflective structure 90 is a metal reflective structure. The P-type electrode 60 is located on the side of the epitaxial unit away from the substrate 10, and is electrically connected to the P-type gallium nitride layer 203 through the transparent conductive layer 80. The N-type electrode 70 is located on the side of the substrate 10 away from the epitaxial unit, and is electrically connected to the N-type gallium nitride layer 201 through the reflective structure 90, specifically, electrically connected to the N-type gallium nitride layer through the portion of the metal reflective structure located in the groove.

[0091] Since the N-type electrode and the P-type electrode are metal electrodes, compared with the N-type electrode and the P-type electrode being located on the same side, the N-type electrode and the P-type electrode are located on different sides, which can reduce the shading area of the epitaxial unit by the metal electrode and increase the light-emitting area of the epitaxial unit.

[0092] Specifically, in one embodiment of the present application, continue as follows Figure 3 As shown, the epitaxial structure includes four epitaxial units, and the LED core includes a first light conversion structure 1001, a second light conversion structure 1002, a third light conversion structure 1003 and a fourth light conversion structure 1004, which are respectively located on the light-emitting sides of the four epitaxial units, so that the LED core can emit four different colors of light, but the present application is not limited to this. In other embodiments of the present application, the LED core can also emit light of other numbers of colors, depending on the specific circumstances.

[0093] In addition, an embodiment of the present application provides a method for manufacturing an LED to manufacture the LED core particle provided in any of the above embodiments. It should be noted that in this embodiment, the LED includes at least one LED core particle. Specifically, the manufacturing method includes:

[0094] S1: If Figure 5 As shown, a substrate 10 is provided. Optionally, the substrate 10 is a sapphire substrate;

[0095] S2: If Figure 6As shown, an epitaxial layer is formed on the first side surface of the substrate 10, and the epitaxial layer includes a stacked N-type gallium nitride layer, a multi-quantum well layer and a P-type gallium nitride layer, that is, the epitaxial layer includes a stacked N-type GaN layer, a multi-quantum well layer and a P-type GaN layer, wherein the epitaxial layer includes at least one epitaxial structure 20, each epitaxial structure 20 includes a stacked N-type gallium nitride layer 201, a multi-quantum well layer 202 and a P-type gallium nitride layer 203, and one epitaxial structure 20 corresponds to one LED core particle.

[0096] Specifically, in one embodiment of the present application, an epitaxial layer is formed on the first side surface of the substrate, and the epitaxial layer includes a stacked N-type gallium nitride layer, a multi-quantum well layer, and a P-type gallium nitride layer, including:

[0097] forming an N-type GaN layer on a first side surface of the substrate;

[0098] forming a multi-quantum well layer on a side of the N-type GaN layer away from the substrate;

[0099] A P-type GaN layer is formed on a side of the multi-quantum well layer away from the N-type GaN layer to form an epitaxial layer.

[0100] S3: If Figure 7 As shown, a plurality of grooves are formed in the epitaxial structure 20 , and the plurality of grooves include at least two first grooves 30 . The grooves penetrate the P-type gallium nitride layer and the multi-quantum well layer and extend into the N-type gallium nitride layer.

[0101] Optionally, in one embodiment of the present application, a plurality of grooves are formed in the epitaxial structure, the plurality of grooves including at least two first grooves, the grooves penetrating the P-type gallium nitride layer and the multi-quantum well layer and extending into the N-type gallium nitride layer, including:

[0102] cleaning the epitaxial structure;

[0103] forming a first photoresist layer on a surface of the epitaxial structure facing away from the substrate;

[0104] exposing and developing the first photoresist layer to form a first photoresist pattern;

[0105] Using the first photoresist pattern as a mask, etching the epitaxial structure to form a plurality of grooves in the epitaxial structure, wherein the plurality of grooves include at least two first grooves, the first grooves penetrating the multi-quantum well layer and the P-type GaN layer and extending into the N-type GaN layer;

[0106] The first photoresist pattern is removed.

[0107] Specifically, in one embodiment of the present application, etching the epitaxial structure using the first photoresist pattern as a mask to form a plurality of grooves in the epitaxial structure includes:

[0108] The epitaxial structure is etched using an inductively coupled plasma (ICP) process with the first photoresist pattern as a mask to form a plurality of grooves in the epitaxial structure.

[0109] It should be noted that, in the embodiments of the present application, Figure 8 and Figure 9 As shown, the plurality of first grooves 30 divide the P-type gallium nitride layer of the epitaxial structure 20 into a plurality of etched regions a.

[0110] Optionally, in one embodiment of the present application, the shape of the etched area a is a regular pattern, such as a rectangle or a square. Figure 8 and Figure 9 As shown, in another embodiment of the present application, the shape of the etched area may also be an irregular shape, which is not limited in the present application and depends on the specific circumstances.

[0111] On the basis of the above embodiment, in an optional embodiment of the present application, the plurality of etching regions a are arranged in a matrix, as shown in FIG. Figure 8-Figure 9 As shown, this application does not limit this. In other embodiments of this application, the multiple etched areas can also be arranged in other ways, depending on the specific circumstances.

[0112] S4: As Figure 10 As shown, a current blocking layer 40 is formed on the surface of the epitaxial structure 20 facing away from the substrate 10 , and the current blocking layer 40 also covers the surface of the groove.

[0113] Specifically, in one embodiment of the present application, forming a current blocking layer on a surface of the epitaxial structure facing away from the substrate, wherein the current blocking layer also covers the surface of the groove includes:

[0114] A current blocking layer is formed on the side of the epitaxial structure away from the substrate by using a PECVD (Plasma Enhanced Chemical Vapor Deposition) process, wherein the current blocking layer covers the surface of the epitaxial structure away from the substrate and the surface of the groove.

[0115] Optionally, based on the above embodiment, in one embodiment of the present application, the current blocking layer is a silicon dioxide layer, and the thickness of the current blocking layer ranges from 2000 angstroms to 2600 angstroms. However, the present application does not limit this, and the specific thickness depends on the specific situation.

[0116] S5: If Figure 11 As shown, a groove 50 is formed at the bottom of the first groove 30, and the groove 50 penetrates the N-type gallium nitride 201 layer and extends into the substrate 10. The at least two first grooves 30 and the groove 50 at the bottom of the first groove 30 divide the epitaxial structure 20 into at least two epitaxial units 21, as shown in FIG. Figure 12 It should be noted that, in the embodiment of the present application, the region where the P-type gallium nitride layer is located in the epitaxial unit is the etched region, and the etched region corresponds to the epitaxial unit one-to-one.

[0117] Optionally, in one embodiment of the present application, forming a groove at the bottom of the first groove includes:

[0118] forming a second photoresist layer on a side of the current blocking layer away from the substrate, wherein the second photoresist layer is a positive photoresist layer with a thickness ranging from 10 microns to 18 microns;

[0119] performing soft baking, exposure, development, and hardening on the second photoresist layer to obtain a second photoresist pattern, wherein the second photoresist pattern has a first through hole;

[0120] forming a third photoresist layer on a side of the second photoresist pattern away from the substrate, wherein the third photoresist layer is a negative photoresist layer with a thickness ranging from 10 microns to 18 microns;

[0121] Soft-baking, exposing, baking, and developing the third photoresist layer to obtain a third photoresist pattern, wherein the third photoresist pattern has a second through hole, and the second through hole is located in the first through hole;

[0122] Using the third photoresist pattern as a mask, an inductively coupled plasma (ICP) process is used to etch the bottom of the first groove from a side of the first groove away from the substrate, thereby forming a trench at the bottom of the first groove, wherein the trench penetrates the N-type gallium nitride layer and extends into the substrate;

[0123] The second photoresist pattern and the third photoresist pattern are removed.

[0124] It should be noted that, in the above embodiment, since the second photoresist layer is a positive photoresist layer and the third photoresist layer is a negative photoresist layer, a first through hole is first formed in the second photoresist layer, and then a second through hole of the third photoresist layer is formed in the first through hole. This can increase the inclination of the side wall of the second through hole, thereby increasing the inclination of the side wall of the groove formed using the third photoresist pattern as a mask, reducing the size of the groove, and facilitating the miniaturization of the LED. Among them, the inclination of the side wall of the second through hole refers to the angle between the side wall of the second through hole and the plane where the substrate is located. The greater the inclination of the side wall of the second through hole, the greater the angle between the side wall of the second through hole and the plane where the substrate is located, and the closer the side wall of the second through hole is to perpendicular to the plane where the substrate is located; similarly, the inclination of the side wall of the trench refers to the angle between the side wall of the trench and the plane where the substrate is located. The greater the inclination of the side wall of the trench, the greater the angle between the side wall of the trench and the plane where the substrate is located, and the closer the side wall of the trench is to perpendicular to the plane where the substrate is located.

[0125] Optionally, based on the above embodiment, in one embodiment of the present application, the soft baking temperature of the second photoresist layer is in the range of 90°C to 100°C, the soft baking time is in the range of 100s to 300s, the exposure amount is in the range of 270mj to 400mj, the development time is in the range of 80s to 160s, the hardening temperature is in the range of 100°C to 140°C, and the hardening time is in the range of 15min to 40min; the soft baking temperature of the third photoresist layer is in the range of 90°C to 100°C, the soft baking time is in the range of 100s to 300s, the exposure amount is in the range of 100mj to 200mj, the post-exposure baking temperature is in the range of 100°C to 120°C, the baking time is in the range of 90s to 160s, and the development time is in the range of 60s to 100s. However, this application does not limit this and it depends on the specific situation.

[0126] Based on any of the above embodiments, in one embodiment of the present application, the depth of the groove extending into the substrate is in the range of 50 microns to 100 microns, that is, the distance between the bottom of the groove and the upper surface of the substrate is in the range of 50 microns to 100 microns, but the present application does not limit this and it depends on the specific circumstances.

[0127] S6: As Figure 13 and Figure 14 As shown, the current blocking layer 40 is etched to expose the P-type gallium nitride layer 203 of the epitaxial unit, and a P-type electrode 60 electrically connected to the P-type gallium nitride layer and an N-type electrode 70 electrically connected to the N-type gallium nitride layer are formed. Figure 15 and Figure 16 shown.

[0128] Specifically, in one embodiment of the present application, etching the current blocking layer to expose the P-type gallium nitride layer of the epitaxial unit includes:

[0129] forming a fourth photoresist layer on a side of the current blocking layer away from the substrate;

[0130] exposing and developing the fourth photoresist layer to obtain a fourth photoresist pattern;

[0131] Using the fourth photoresist pattern as a mask, etching the current blocking layer to expose a predetermined area of each epitaxial unit, wherein the area of the predetermined area is not larger than the area of the etched area;

[0132] The fourth photoresist pattern is removed.

[0133] Optionally, in one embodiment of the present application, the area of the preset region is smaller than the area of the etching region. Specifically, continue as follows Figure 13 As shown, the distance D1 between the boundary of the preset area and the area of the etched area ranges from 1 micron to 2 microns, but this application does not limit this and it depends on the specific situation.

[0134] Based on the above embodiments, in one embodiment of the present application, the fourth photoresist pattern is used as a mask to etch the current blocking layer to expose the preset area of each epitaxial unit, which includes: using the fourth photoresist pattern as a mask, using a wet etching process to etch the current blocking layer to expose the preset area of each epitaxial unit.

[0135] Based on any of the above embodiments, in one embodiment of the present application, Figure 17 As shown, the method further includes:

[0136] A transparent conductive layer 80 is formed on a surface of the P-type gallium nitride layer 203 away from the substrate 10 . The transparent conductive layer 80 is electrically connected to the P-type gallium nitride layer 203 .

[0137] Optionally, based on the above embodiment, in one embodiment of the present application, forming a transparent conductive layer on a surface of the P-type gallium nitride layer away from the substrate includes:

[0138] forming a transparent conductive layer on a side of the epitaxial structure away from the substrate, the transparent conductive layer covering the current blocking layer and a surface of the epitaxial structure away from the substrate, and optionally, forming the transparent conductive layer by a sputtering process;

[0139] Annealing the transparent conductive layer in a rapid annealing furnace, wherein the annealing temperature ranges from 500° C. to 650° C., and the annealing time ranges from 1 minute to 10 minutes;

[0140] forming a fifth photoresist layer on the surface of the transparent conductive layer, optionally, the fifth photoresist layer is a positive photoresist layer;

[0141] exposing and developing the fifth photoresist layer to form a fifth photoresist pattern;

[0142] Using the fifth photoresist pattern as a mask, etching the transparent conductive layer to remove a portion of the transparent conductive layer located in a first region on the surface of the current blocking layer, and retaining at least a portion of the transparent conductive layer located on the surface of the P-type gallium nitride layer in the epitaxial structure, wherein the first region on the surface of the current blocking layer is a region of the current blocking layer located on the surface of the groove;

[0143] The fifth photoresist pattern is removed.

[0144] It should be noted that, in the above embodiment, the transparent conductive layer 80 may only cover the surface of the P-type gallium nitride layer 203. Figure 18 As shown, it can also be extended to cover the current blocking 40 located on the surface of the P-type gallium nitride layer 203. Figure 17 As shown, the present application does not impose any limitation on this, as long as the transparent conductive layer and the reflective structure are electrically insulated.

[0145] It should also be noted that, since the boundary of the etched area is covered by the current blocking layer, which is an insulating layer, in the embodiment of the present application, the transparent conductive layer can also extend to cover the current blocking layer located on the surface of the P-type gallium nitride layer. Figure 17 As shown, the width D2 of the current blocking layer covered by the transparent conductive layer in the partial area on the surface of the P-type gallium nitride layer ranges from 0 micrometers to 1 micrometer, but this application does not impose a limitation on this, and it depends on the specific situation.

[0146] Based on any of the above embodiments, in one embodiment of the present application, the thickness of the transparent conductive layer ranges from 600 angstroms to 1100 angstroms, but the present application does not impose a limitation thereto, and the specific thickness depends on the circumstances.

[0147] On the basis of any of the above embodiments, in one embodiment of the present application, the LED is a horizontal structure LED. In this embodiment, the P-type electrode 60 and the N-type electrode 70 are located on the same side of the epitaxial structure. Figure 15 and Figure 16It should be noted that, in this embodiment, the plurality of grooves further include at least two second grooves, the second grooves penetrating the P-type gallium nitride layer and the multi-quantum well layer of the epitaxial unit and extending into the N-type gallium nitride layer, the current blocking layer also covering the sidewalls of the second grooves, and the N-type electrode being electrically connected to the N-type gallium nitride layer via the second grooves. Thus, on the basis of achieving electrical connection between the N-type electrode and the N-type gallium nitride layer via the second grooves, the portion of the current blocking layer located on the sidewalls of the second grooves is used to achieve electrical insulation between the N-type electrode and the P-type gallium nitride layer.

[0148] Optionally, in the above embodiment, the second groove and the first groove are formed simultaneously to simplify the process flow of manufacturing the LED, but this application does not limit this and it depends on the specific situation.

[0149] In other embodiments of the present application, the LED may also be a vertically structured LED, that is, the P-type electrode and the N-type electrode are located on different sides of the epitaxial unit. The present application does not limit this, and the specific situation may vary.

[0150] It should also be noted that, based on any of the above embodiments, in one embodiment of the present application, when a transparent conductive layer is formed on the side of the P-type gallium nitride layer away from the substrate, such as Figure 19 and Figure 20 As shown, Figure 19 and Figure 20 for Figure 17 In the top view, the P-type electrode 60 is electrically connected to the P-type gallium nitride layer through the transparent conductive layer 80.

[0151] The method for forming the P-type electrode is described below by taking the case where a transparent conductive layer is formed on the side of the P-type gallium nitride layer away from the substrate as an example.

[0152] Specifically, in one embodiment of the present application, forming a P-type electrode electrically connected to the P-type gallium nitride layer includes:

[0153] forming a sixth photoresist layer on a side of the transparent conductive layer away from the substrate, and optionally, the sixth photoresist layer is a negative photoresist layer;

[0154] exposing and developing the sixth photoresist layer to form a sixth photoresist pattern;

[0155] Using the sixth photoresist pattern as a mask, performing metal evaporation using an electron beam evaporation process to form a second metal layer;

[0156] After the evaporation is completed, the sixth photoresist pattern and the portion of the second metal layer located on the surface of the sixth photoresist pattern are peeled off to form a P-type electrode electrically connected to the transparent conductive layer.

[0157] It should be noted that when the LED is a horizontally structured LED and the P-type electrode and the N-type electrode are located on the same side of the epitaxial structure, optionally, the N-type electrode and the P-type electrode are formed simultaneously to simplify the process flow of LED production, but this application does not limit this and it depends on the specific situation.

[0158] Specifically, based on the above embodiment, in one embodiment of the present application, the thickness of the P-type electrode ranges from 1.3 microns to 2.1 microns, but the present application does not limit this, and the specific thickness depends on the circumstances.

[0159] S7: As Figure 21 As shown, a reflective structure 90 is formed in the first groove and the groove at the bottom thereof, and its top view is shown in FIG. Figure 22 and Figure 23 shown.

[0160] Optionally, in one embodiment of the present application, the reflective structure is a metal reflective structure. Specifically, in one embodiment of the present application, forming a reflective structure in the first groove and the groove at the bottom thereof includes: using an electron beam evaporation process to evaporate a first metal layer in the first groove and the groove at the bottom thereof to form a reflective structure in the first groove and the groove at the bottom thereof.

[0161] Specifically, in one embodiment of the present application, using an electron beam evaporation process to evaporate a first metal layer in the first groove and the groove at the bottom thereof to form a reflective structure in the first groove and the groove at the bottom thereof includes:

[0162] forming a seventh photoresist layer on a side of the epitaxial structure away from the substrate, optionally, the seventh photoresist layer is a negative photoresist layer;

[0163] exposing and developing the seventh photoresist layer to form a seventh photoresist pattern;

[0164] Using the seventh photoresist pattern as a mask, a first metal layer is evaporated in the first groove and the trench at the bottom thereof by an electron beam evaporation process;

[0165] The seventh photoresist pattern is removed to form a reflective structure in the first groove and the trench at the bottom thereof.

[0166] In another embodiment of the present application, forming a reflective structure in the first groove and the groove at the bottom thereof includes:

[0167] Stir reflective powder into silica gel;

[0168] The silica gel stirred with reflective powder is spin-coated on the first groove and the groove at the bottom thereof to form a reflective structure in the first groove and the groove at the bottom thereof.

[0169] Specifically, in one embodiment of the present application, spin-coating silica gel mixed with reflective powder on the first groove and the groove at the bottom thereof, and forming a reflective structure in the first groove and the groove at the bottom thereof includes:

[0170] forming an eighth photoresist layer on a side of the epitaxial structure away from the substrate, optionally, the eighth photoresist layer is a negative photoresist layer;

[0171] exposing and developing the eighth photoresist layer to form an eighth photoresist pattern;

[0172] Using the eighth photoresist pattern as a mask, spin-coating silica gel mixed with reflective powder into the first groove and the trench at the bottom thereof, thereby forming a reflective structure in the first groove and the trench at the bottom thereof;

[0173] subjecting the reflective structure to high temperature curing;

[0174] The portion of the metal structure located on the surface of the eighth photoresist pattern is removed, and only the portion of the metal structure located in the first groove and the groove and the eighth photoresist pattern are retained. Optionally, the portion of the metal structure located on the surface of the eighth photoresist pattern is removed by a film tearing process, and only the portion of the metal structure located in the first groove and the groove is retained, but this application does not limit this and it depends on the specific circumstances.

[0175] Optionally, in one embodiment of the present application, in order to ensure the light reflection effect of the reflective structure, stirring the reflective powder in the silica gel includes stirring a high concentration of reflective powder in the silica gel to increase the concentration of the reflective powder in the reflective structure, but the present application does not limit this and it depends on the specific situation.

[0176] S8: Figure 24 As shown, a light conversion structure 100 is formed on the light-emitting side of each epitaxial unit. The light conversion structure corresponds to the epitaxial unit one by one, and different epitaxial units correspond to different light conversion structures.

[0177] It should be noted that, in this embodiment, the epitaxial structure may include two epitaxial units, three epitaxial units, or more epitaxial units. This application does not limit this, and the specific situation depends on the circumstances.

[0178] Optionally, based on the above embodiment, in one embodiment of the present application, different epitaxial units correspond to different light conversion structures, that is, after the LED is manufactured, the colors of light emitted from corresponding areas of different epitaxial units are different.

[0179] The following describes the method for manufacturing the LED provided in the embodiment of the present application by taking the epitaxial structure including two epitaxial units as an example.

[0180] Optionally, in one embodiment of the present application, a light conversion structure is formed on the light-emitting side of each of the epitaxial units, the light conversion structure corresponds to the epitaxial unit one-to-one, and the light conversion structures corresponding to different epitaxial units are different, including:

[0181] stirring a first phosphor in silica gel to form a first mixed structure;

[0182] Spin coating a first hybrid structure on the light-emitting side of one of the epitaxial units to form a first light conversion structure on the light-emitting side of the epitaxial unit;

[0183] stirring a second phosphor in the silica gel to form a second mixed structure, wherein the color of the second phosphor is different from the color of the first phosphor;

[0184] A second hybrid structure is spin-coated on the light-emitting side of another epitaxial unit to form a second light conversion structure on the light-emitting side of the epitaxial unit.

[0185] In another embodiment of the present application, the epitaxial structure includes more epitaxial units. In this embodiment, a light conversion structure is formed on the light-emitting side of each epitaxial unit. The light conversion structure corresponds to the epitaxial unit one by one, and the light conversion structures corresponding to different epitaxial units are different, including:

[0186] First, the phosphor is stirred in silica gel to form a mixed structure, and then the mixed structure is spin-coated on the light-emitting side of one of the epitaxial units to form a light conversion structure corresponding to the epitaxial unit on the light-emitting side of the epitaxial unit;

[0187] Repeat the above steps until the corresponding light conversion structure is formed on the light-emitting side of each epitaxial unit.

[0188] Specifically, in one embodiment of the present application, the light emitted by the epitaxial structure is purple light. The epitaxial structure includes four epitaxial units. After the LED is manufactured, the light emitted from the corresponding areas of each epitaxial unit is blue light, green light, red light, and yellow light, respectively. In this embodiment, the light conversion structure formed on the light-emitting side of each epitaxial unit includes:

[0189] forming a ninth photoresist layer on a side of the epitaxial structure away from the substrate, wherein the ninth photoresist layer has a first thickness;

[0190] exposing and developing the ninth photoresist layer to form a ninth photoresist pattern, wherein the ninth photoresist pattern exposes the first epitaxial unit in the epitaxial structure;

[0191] Stirring a first proportion of blue phosphor in silica gel to form a first mixed structure mixed with the blue phosphor, and spin-coating the first mixed structure on a side of the first epitaxial unit away from the substrate;

[0192] curing the first mixed structure;

[0193] The ninth photoresist pattern is thinned by a planarizer until the ninth photoresist pattern has a second thickness, and the ninth photoresist pattern and the portion of the first hybrid structure located on the surface of the ninth photoresist pattern are removed to form a first light conversion structure 1001. Figure 25 shown

[0194] forming a tenth photoresist layer on a side of the epitaxial structure away from the substrate, wherein the tenth photoresist layer has a third thickness;

[0195] exposing and developing the tenth photoresist layer to form a tenth photoresist pattern, wherein the tenth photoresist pattern exposes the second epitaxial unit in the epitaxial structure;

[0196] stirring a second proportion of green phosphor in silica gel to form a second mixed structure mixed with the green phosphor, and spin-coating the second mixed structure on a side of the second epitaxial unit away from the substrate;

[0197] curing the second mixed structure;

[0198] The tenth photoresist pattern is thinned by a planarizer until the tenth photoresist pattern has a fourth thickness, and the tenth photoresist pattern and the portion of the second hybrid structure located on the surface of the nineteenth photoresist pattern are removed to form a second light conversion structure 1002. Figure 25 shown.

[0199] forming an eleventh photoresist layer on a side of the epitaxial structure away from the substrate, wherein the eleventh photoresist layer has a fifth thickness;

[0200] exposing and developing the eleventh photoresist layer to form an eleventh photoresist pattern, wherein the eleventh photoresist pattern exposes the third epitaxial unit in the epitaxial structure;

[0201] stirring a third proportion of blue phosphor in silica gel to form a third mixed structure mixed with red phosphor, and spin-coating the third mixed structure on a side of the third epitaxial unit away from the substrate;

[0202] curing the third mixed structure;

[0203] The eleventh photoresist pattern is thinned by a planarizer until the eleventh photoresist pattern has a sixth thickness, and the eleventh photoresist pattern and the portion of the third hybrid structure located on the surface of the eleventh photoresist pattern are removed to form a third light conversion structure 1003. Figure 25 shown.

[0204] forming a twelfth photoresist layer on a side of the epitaxial structure away from the substrate, wherein the twelfth photoresist layer has a seventh thickness;

[0205] exposing and developing the twelfth photoresist layer to form a twelfth photoresist pattern, wherein the twelfth photoresist pattern exposes the fourth epitaxial unit in the epitaxial structure;

[0206] stirring a fourth ratio of blue phosphor in silica gel to form a fourth mixed structure mixed with yellow phosphor, and spin-coating the fourth mixed structure on a side of the fourth epitaxial unit away from the substrate;

[0207] curing the fourth mixed structure;

[0208] The twelfth photoresist pattern is thinned by a planarizer until the twelfth photoresist pattern has an eighth thickness, and the twelfth photoresist pattern and the portion of the fourth hybrid structure located on the surface of the twelfth photoresist pattern are removed to form a fourth light conversion structure 1004. Figure 25 shown.

[0209] It should be noted that, in the above embodiment, the first ratio, the second ratio, the third ratio and the fourth ratio may be the same or different, and this application does not impose any limitation on this, and it depends on the specific circumstances.

[0210] Optionally, in the above embodiment, the first thickness, the third thickness, the fifth thickness and the seventh thickness are the same, the second thickness, the fourth thickness, the sixth thickness and the eighth thickness are the same, the first hybrid structure located on the side of the first epitaxial unit away from the substrate, the second hybrid structure located on the side of the second epitaxial unit away from the substrate, the third hybrid structure located on the side of the third epitaxial unit away from the substrate, and the fourth hybrid structure located on the side of the fourth epitaxial unit away from the substrate are the same in thickness, but this application does not limit this and it depends on the specific circumstances.

[0211] Based on any of the above embodiments, in one embodiment of the present application, in a direction perpendicular to the plane of the substrate, the surface of the reflective structure away from the substrate is not lower than the surface of the light conversion structure away from the substrate, that is, the surface of the reflective structure away from the substrate is higher than the surface of the light conversion structure away from the substrate, or is flush with the surface of the light conversion structure away from the substrate, to avoid crosstalk between light emitted by different light conversion structures. Optionally, in a direction perpendicular to the plane of the substrate, the surface of the reflective structure away from the substrate is higher than the surface of the light conversion structure away from the substrate, but this application is not limited to this, and the specific situation will depend on the circumstances.

[0212] Specifically, in one embodiment of the present application, the thickness of the light conversion structure is 30 microns. In this embodiment, the first thickness ranges from 50 microns to 60 microns; the first hybrid structure located on the side of the first epitaxial unit away from the substrate, the second hybrid structure located on the side of the second epitaxial unit away from the substrate, the third hybrid structure located on the side of the third epitaxial unit away from the substrate, and the fourth hybrid structure located on the side of the fourth epitaxial unit away from the substrate have thicknesses ranging from 30 microns to 35 microns; the second thickness ranges from 30 microns, but this application does not limit this and it depends on the specific circumstances.

[0213] Based on any of the above embodiments, in one embodiment of the present application, the method further includes: testing the photoelectric performance of the LED structure on a COW (chip on wafer) to screen out LED structures whose photoelectric performance meets preset requirements.

[0214] Based on any of the above embodiments, in one embodiment of the present application, if the P-type electrode and the N-type electrode are located on the same side of the epitaxial structure, such as Figure 26 As shown, the method further includes:

[0215] Thinning the second side of the substrate 10 until the bottom of the trench is exposed;

[0216] A Bragg reflection structure 110 is formed on the second side of the substrate 10 .

[0217] Optionally, in one embodiment of the present application, after thinning the second side of the substrate, the thickness of the substrate ranges from 50 microns to 100 microns; the thickness of the Bragg reflection structure ranges from 3 microns to 5 microns, but the present application does not limit this and it depends on the specific situation.

[0218] In another embodiment of the present application, when the P-type electrode and the N-type electrode are located on different sides of the epitaxial unit, forming the P-type electrode electrically connected to the P-type gallium nitride layer and the N-type electrode electrically connected to the N-type gallium nitride layer includes:

[0219] like Figure 27 As shown, a P-type electrode 60 electrically connected to the P-type gallium nitride layer is formed on the side of the epitaxial unit away from the substrate;

[0220] like Figure 28 As shown, the second side of the substrate 10 is thinned to expose the bottom of the trench, and the second side is opposite to the first side;

[0221] Continue as Figure 28 As shown, an N-type electrode 70 is formed on the second side of the substrate 10. The N-type electrode 70 is electrically connected to the N-type gallium nitride layer in the epitaxial unit. Optionally, the N-type electrode is a multi-layer metal electrode.

[0222] It should be noted that in the above embodiment, the trench is filled with a conductive structure, and the N-type electrode is electrically connected to the N-type gallium nitride layer via the conductive structure filled in the trench. It should also be noted that when the reflective structure is a metal reflective structure, the N-type electrode is electrically connected to the N-type gallium nitride layer via the metal reflective structure.

[0223] It should also be noted that since the N-type electrode and the P-type electrode are metal electrodes, compared to when the N-type electrode and the P-type electrode are located on the same side, the N-type electrode and the P-type electrode are located on different sides, which can reduce the shading area of the epitaxial unit by the metal electrode and increase the light-emitting area of the epitaxial unit.

[0224] Based on any of the above embodiments, in one embodiment of the present application, the epitaxial layer includes an epitaxial structure, and in another embodiment of the present application, the epitaxial layer includes multiple epitaxial structures. When the epitaxial layer includes multiple epitaxial structures, the method further includes: dividing the LED to obtain multiple LED core particles, each LED core particle includes an epitaxial structure, that is, each LED core particle includes multiple epitaxial units.

[0225] Optionally, in one embodiment of the present application, the method further includes: testing and sorting the LED core particles to obtain LED core particles that meet preset requirements and provide them to customers.

[0226] In summary, in the LED core particle and its manufacturing method provided in the embodiments of the present application, the epitaxial structure includes at least two epitaxial units, and the light-emitting sides of different epitaxial units are provided with different light conversion structures, so that the corresponding areas of different epitaxial units in the epitaxial structure can emit light of different colors, thereby realizing that one LED core particle can emit light of at least two colors. When applied to backlight mini LED, at least two monochrome LED core particles can be replaced, reducing the increased packaging size of the LED core particle when used as backlight, thereby reducing the size of the backlight mini LED, which is beneficial to the application of backlight mini LED.

[0227] Moreover, in the LED core particle and its manufacturing method provided in the embodiment of the present application, the epitaxial structure includes at least two epitaxial units with a larger size, which can reduce the process difficulty of forming a light conversion structure on the light-emitting side of the epitaxial unit.

[0228] In addition, in the LED core particle and its manufacturing method provided in the embodiment of the present application, a reflective structure is arranged between different epitaxial units in the at least two epitaxial units included in the epitaxial structure, so that the reflective structure can be used as a light blocking layer between different epitaxial units and their corresponding light conversion structures, thereby avoiding crosstalk between the light emitted by different light conversion structures.

[0229] The various embodiments in this specification are described in a progressive, parallel, or combined manner. Each embodiment focuses on the differences from other embodiments, and reference can be made to the common and similar parts between the various embodiments. For the devices disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the description is relatively simple. For relevant parts, refer to the description of the methods.

[0230] It should be noted that in the description of this application, it should be understood that the terms "upper", "lower", "top", "bottom", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore should not be understood as limiting this application. When a component is considered to be "connected" to another component, it can be directly connected to the other component or there may be a centrally located component.

[0231] It should also be noted that, in this document, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variations thereof are intended to cover non-exclusive inclusion, such that an article or device comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or elements inherent to such article or device. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of additional identical elements in the article or device comprising the aforementioned elements.

[0232] The above description of the disclosed embodiments is intended to enable one skilled in the art to implement or use the present application. Various modifications to these embodiments will be readily apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application is not limited to the embodiments shown herein, but is intended to conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. An LED chip, characterized in that: include: substrate; an epitaxial structure located on the first side surface of the substrate, the epitaxial structure comprising a stacked N-type gallium nitride layer, a multi-quantum well layer, and a P-type gallium nitride layer; a plurality of grooves located in the epitaxial structure, the plurality of grooves including at least two first grooves, the grooves penetrating the P-type gallium nitride layer and the multi-quantum well layer and extending into the N-type gallium nitride layer; a groove at the bottom of the first groove, the groove penetrating the N-type gallium nitride layer and extending into the substrate, the at least two first grooves and the groove at the bottom of the first groove dividing the epitaxial structure into at least two epitaxial units; a current blocking layer located on a surface of the epitaxial structure facing away from the substrate, the current blocking layer also covering the surface of the groove, and the current blocking layer exposing a portion of the P-type gallium nitride layer in the epitaxial unit; a P-type electrode electrically connected to the P-type gallium nitride layer and an N-type electrode electrically connected to the N-type gallium nitride layer; a reflective structure located in the first groove and in the groove at the bottom thereof; The light conversion structure is located on the light-emitting side of each epitaxial unit. The light conversion structure corresponds to the epitaxial unit one-to-one, and different epitaxial units correspond to different light conversion structures.

2. The LED chip according to claim 1, wherein: The reflective structure is a metal structure or an insulating structure.

3. The LED chip according to claim 2, wherein: The reflective structure is a metal structure. The P-type electrode and the N-type electrode are located on different sides of the epitaxial unit. The N-type electrode is electrically connected to the N-type gallium nitride layer through the reflective structure.

4. The LED chip according to claim 1, wherein: The N-type electrode and the P-type electrode are located on the same side of the epitaxial unit. The multiple grooves also include at least two second grooves. The second grooves correspond to the epitaxial unit one-to-one, penetrate the P-type gallium nitride layer and the multi-quantum well layer of the epitaxial unit, and extend into the N-type gallium nitride layer. The current blocking layer also covers the sidewalls of the second grooves, and the N-type electrode is electrically connected to the N-type gallium nitride layer through the second grooves.

5. The LED chip according to claim 1, wherein: In a direction perpendicular to the plane where the substrate is located, a surface of the reflective structure away from the substrate is not lower than a surface of the light conversion structure away from the substrate.

6. A method for manufacturing an LED, characterized in that: The LED includes at least one LED die, and the method includes: providing a substrate; forming an epitaxial layer on the first side surface of the substrate, the epitaxial layer comprising a stacked N-type gallium nitride layer, a multi-quantum well layer, and a P-type gallium nitride layer, the epitaxial layer comprising at least one epitaxial structure, one epitaxial structure corresponding to one LED core; forming a plurality of grooves in the epitaxial structure, the plurality of grooves including at least two first grooves, the grooves penetrating the P-type gallium nitride layer and the multi-quantum well layer and extending into the N-type gallium nitride layer; forming a current blocking layer on a surface of the epitaxial structure facing away from the substrate, wherein the current blocking layer also covers the surface of the groove; forming a trench at the bottom of the first groove, the trench penetrating the N-type gallium nitride layer and extending into the substrate, wherein the at least two first grooves and the trench at the bottom of the first groove divide the epitaxial structure into at least two epitaxial units; Etching the current blocking layer to expose the P-type gallium nitride layer of the epitaxial unit, and forming a P-type electrode electrically connected to the P-type gallium nitride layer and an N-type electrode electrically connected to the N-type gallium nitride layer; forming a reflective structure in the first groove and the groove at the bottom thereof; A light conversion structure is formed on the light-emitting side of each epitaxial unit. The light conversion structure corresponds to the epitaxial unit one-to-one, and different epitaxial units correspond to different light conversion structures.

7. The production method according to claim 6, characterized in that: Forming a reflective structure in the first groove and the groove at the bottom thereof includes: A first metal layer is evaporated in the first groove and the trench at the bottom thereof by using an electron beam evaporation process to form a reflective structure in the first groove and the trench at the bottom thereof.

8. The manufacturing method according to claim 6, characterized in that: Forming a reflective structure in the first groove and the groove at the bottom thereof includes: Stir reflective powder into silica gel; The silica gel stirred with reflective powder is spin-coated on the first groove and the groove at the bottom thereof to form a reflective structure in the first groove and the groove at the bottom thereof.

9. The manufacturing method according to claim 6, characterized in that: In a direction perpendicular to the plane where the substrate is located, a surface of the reflective structure away from the substrate is not lower than a surface of the light conversion structure away from the substrate.

10. The manufacturing method according to claim 6, characterized in that: A light conversion structure is formed on the light-emitting side of each epitaxial unit, wherein the light conversion structure corresponds to the epitaxial unit one by one, and the light conversion structures corresponding to different epitaxial units are different, including: stirring a first phosphor in silica gel to form a first mixed structure; Spin coating a first hybrid structure on the light-emitting side of one of the epitaxial units to form a first light conversion structure on the light-emitting side of the epitaxial unit; stirring a second phosphor in the silica gel to form a second mixed structure, wherein the color of the second phosphor is different from the color of the first phosphor; A second hybrid structure is spin-coated on the light-emitting side of another epitaxial unit to form a second light conversion structure on the light-emitting side of the epitaxial unit.

11. The manufacturing method according to claim 6, characterized in that: The N-type electrode and the P-type electrode are located on the same side of the epitaxial unit. The multiple grooves also include at least two second grooves. The second grooves correspond to the epitaxial unit one-to-one, penetrate the P-type gallium nitride layer and the multi-quantum well layer of the epitaxial unit, and extend into the N-type gallium nitride layer. The current blocking layer also covers the sidewalls of the second grooves, and the N-type electrode is electrically connected to the N-type gallium nitride layer through the second grooves.

12. The manufacturing method according to claim 11, characterized in that: The method further includes: thinning the second side of the substrate to expose the bottom of the trench; A Bragg reflection structure is formed on the second side of the substrate.

13. The manufacturing method according to claim 7, characterized in that: Forming a P-type electrode electrically connected to the P-type gallium nitride layer and an N-type electrode electrically connected to the N-type gallium nitride layer includes: forming a P-type electrode electrically connected to the P-type gallium nitride layer on a side of the epitaxial unit away from the substrate; thinning the second side of the substrate to expose the bottom of the trench; An N-type electrode is formed on the second side of the substrate, and the N-type electrode is electrically connected to the N-type gallium nitride layer in the epitaxial unit.

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