Light-emitting diode, manufacturing method thereof and light-emitting device

Abstract

The invention provides a light-emitting diode and a manufacturing method thereof and a light-emitting device, the light-emitting diode comprises a substrate and a semiconductor lamination layer formed above the substrate, the light-emitting diode further comprises a first insulating layer, and the first insulating layer covers the surface and the side wall of the insulating reflecting layer and extends to the surface of the substrate covering the peripheral area. The first insulating layer is an insulating layer obtained by an atomic layer deposition method, such as an aluminum oxide layer. And almost all exposed surfaces and side walls of the light-emitting diode are covered, so that the coating property of a chip film layer is improved, and water vapor can be effectively prevented from entering. In addition, the film layer obtained through atomic layer deposition has good compactness and adhesion, and the risk of film layer cracking is prevented. Secondly, the side wall of the insulating reflecting layer has an included angle larger than 60 degrees relative to the surface of the substrate, the area of the exposed side wall of the insulating reflecting layer is reduced as much as possible through the included angle, and the number of channels which may cause water vapor to enter is reduced.

Description

Technical Field

[0001] This invention relates to the field of semiconductor devices, and more specifically, to a light-emitting diode, a method for manufacturing the same, and a light-emitting device. Background Art

[0002] Light-emitting diodes (LEDs), due to their high reliability, long lifespan, and low power consumption, are widely used in display devices, lighting, and other fields. GaN-based flip-chip diodes, with their advantages of good heat dissipation, high luminous efficiency, and good stability, are increasingly favored by the market. Flip-chip high-voltage LEDs used in backlight applications need to withstand relatively stringent high-temperature and high-humidity aging tests. However, with the gradual increase in chip size, some products are unable to pass the stringent high-temperature and high-humidity aging tests, often resulting in film delamination and cracking during these tests.

[0003] Analysis of aging failure causes reveals that as chip size increases, the stress on the chip after die bonding also increases. This stress tears the film layer, allowing moisture to enter during the aging process and leading to chip failure. Analysis of aging-failed chips revealed that the film layer cracking manifests primarily in the following two ways:

[0004] 1. In some chips, the front film layer is directly torn by stress, causing moisture to enter;

[0005] 2. Some chips have no cracks on the front side, but the chip failure starts from the side and gradually spreads. This is because the film layer is torn open by stress on the side, allowing moisture to enter.

[0006] To improve the reliability and resistance to high temperature and humidity aging of chips, it is necessary to provide a solution to the aforementioned chip film cracking problem. Summary of the Invention

[0007] In view of the defects and shortcomings of existing flip diodes, the purpose of this invention is to provide a light-emitting diode, its manufacturing method and light-emitting device.

[0008] To achieve the above and other related objectives, the present invention provides a light-emitting diode, comprising:

[0009] Substrate;

[0010] A semiconductor stack is formed above the substrate, comprising a first semiconductor layer, an active layer, and a second semiconductor layer stacked sequentially from bottom to top, wherein the substrate between the edge of the semiconductor stack and the edge of the substrate forms the peripheral region of the light-emitting diode;

[0011] An insulating reflective layer covers a portion of the surface of the substrate, including the semiconductor stack and the peripheral region.

[0012] A first insulating layer covers the surface and sidewalls of the insulating reflective layer and extends to the surface of the substrate covering the peripheral area.

[0013] Another aspect of the present invention provides a method for manufacturing a light-emitting diode, comprising the following steps:

[0014] A substrate is provided, and a semiconductor stack is formed on the substrate, the semiconductor stack comprising a first semiconductor layer, an active layer and a second semiconductor layer stacked sequentially from bottom to top;

[0015] The semiconductor stack is etched sequentially from top to bottom, including the second semiconductor layer, the active layer, and a portion of the first semiconductor layer, to form an electrode mesa exposing the first semiconductor layer. The unetched portion of the semiconductor stack is formed as a light-emitting mesa. The portion of the first semiconductor layer exposed by the electrode mesa is then etched to expose the substrate and separate the semiconductor stack. The exposed substrate forms a dicing region.

[0016] An insulating reflective layer is formed, which covers the surface of the semiconductor stack and the exposed sidewalls, and also covers the surface of the substrate in the diced region;

[0017] The insulating reflective layer is etched in the area corresponding to the cutting area to expose the substrate;

[0018] A first insulating layer is formed on the surface of the insulating reflective layer and the exposed sidewalls, as well as on the surface of the substrate in the cut area, by an atomic layer deposition method.

[0019] The first insulating layer and the substrate are sequentially cut in the cutting area to obtain independent light-emitting diodes.

[0020] Another aspect of the present invention provides a light-emitting device, which includes a substrate and a plurality of light-emitting units located on the substrate. A circuit layer is formed on the substrate, and the light-emitting units include the light-emitting diodes provided in this application. The light-emitting diodes are electrically connected to the circuit layer via a pad structure.

[0021] As described above, the light-emitting diode, its manufacturing method, and the light-emitting device provided by the present invention have at least the following beneficial technical effects:

[0022] The light-emitting diode (LED) of this application includes a substrate and a semiconductor stack formed on the substrate. The edge of the semiconductor stack and the edge of the substrate form the peripheral region of the LED. An insulating reflective layer covers a portion of the substrate surface of the semiconductor stack and the peripheral region. The LED also includes a first insulating layer that covers the surface and sidewalls of the aforementioned insulating reflective layer and extends to the surface of the substrate covering the peripheral region. This first insulating layer is an insulating layer obtained by atomic layer deposition, such as an aluminum oxide layer. It covers almost all the exposed surfaces and sidewalls of the LED, improving the encapsulation of the chip film and effectively preventing moisture ingress. In addition, since the film obtained by atomic layer deposition has good density and adhesion, it prevents the risk of film cracking. Furthermore, the sidewalls of the insulating reflective layer have an angle greater than 60° relative to the substrate surface. This angle minimizes the exposed sidewall area of ​​the insulating reflective layer, which helps to reduce channels that may allow moisture ingress. Attached Figure Description

[0023] Figure 1 The diagram shown is a schematic diagram of the structure of a light-emitting diode in the prior art.

[0024] Figure 2 The diagram shown is a schematic diagram of the structure of a light-emitting diode provided in Embodiment 1 of this application.

[0025] Figure 3 Display as Figure 2 A magnified view of part A of the insulating reflective layer.

[0026] Figure 4 The diagram shown is a schematic diagram of the structure of a light-emitting diode provided in Embodiment 2 of this application.

[0027] Figure 5 The diagram shown is a flowchart of the LED manufacturing method provided in Embodiment 3 of this application.

[0028] Figures 6 to 12 Display as Figure 5 A schematic diagram of the structure formed in the intermediate steps.

[0029] Figure 13 The diagram shown is a schematic diagram of the structure of the light-emitting device provided in Embodiment 4 of this application.

[0030] Figure Labels

[0031] 10. Substrate; 11. Epitaxial stack; 12. Insulating layer.

[0032] 110. Substrate; 120. Semiconductor stack; 121. Buffer layer; 122. First semiconductor layer; 123. Active layer; 124. Second semiconductor layer; 125. Light-emitting mesa; 126. Electrode mesa; 127. Peripheral region; 127′. Cutting region; 131. First contact layer; 132. Current spreading layer; 141. First electrode; 142. Second electrode; 150. Insulating reflective layer; 1500. DBR structure; 151. First material layer; 152. Second material layer; 153. Third material layer; 154. Fourth material layer; 160. First insulating layer; 170. Second insulating layer.

[0033] 200. Light-emitting device; 201. Circuit board; 202. Circuit layer; 203. Light-emitting unit; 204. Pad structure. Detailed Implementation

[0034] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention.

[0035] It should be noted that the illustrations provided in this embodiment are only schematic representations of the basic concept of the present invention. Although the illustrations only show components related to the present invention and are not drawn according to the actual number, shape and size of the components, the shape, quantity, positional relationship and proportion of each component can be arbitrarily changed under the premise of realizing the technical solution of this invention, and the layout of the components may also be more complex.

[0036] like Figure 1 As shown, existing LED chips, especially flip-chip LED chips, typically include a substrate 10, an epitaxial stack formed on the substrate 10, and an insulating layer 12 formed on the epitaxial stack 11. When separating the LED chip, the insulating layer 12 and the substrate must be cut, thus exposing the sidewalls of both the insulating layer 12 and the substrate 10. These exposed sidewalls of the insulating layer 12 create channels for moisture and other impurities to enter the LED chip, causing damage and preventing it from passing high-temperature and high-humidity aging tests. Furthermore, during the cutting process, the insulating layer may crack to varying degrees due to stress. After cracking, moisture and other impurities can more easily enter the chip, causing damage and affecting the reliability of the LED chip.

[0037] To overcome the aforementioned problems and defects, this application provides a light-emitting diode, its manufacturing method, and a light-emitting device, which will now be described in detail through the following specific embodiments.

[0038] An embodiment of the present invention provides a light-emitting diode, which includes:

[0039] Substrate;

[0040] A semiconductor stack is formed above the substrate, comprising a first semiconductor layer, an active layer, and a second semiconductor layer stacked sequentially from bottom to top, wherein the substrate between the edge of the semiconductor stack and the edge of the substrate forms the peripheral region of the light-emitting diode;

[0041] An insulating reflective layer covers a portion of the surface of the substrate, including the semiconductor stack and the peripheral region.

[0042] A first insulating layer covers the surface and sidewalls of the insulating reflective layer and extends to the surface of the substrate covering the peripheral area.

[0043] The first insulating layer covers the surface and sidewalls of the insulating reflective layer and extends to the surface of the substrate covering the peripheral area. This first insulating layer is an insulating layer obtained by atomic layer deposition, such as an aluminum oxide layer. It covers almost all the exposed surfaces and sidewalls of the light-emitting diode, improving the encapsulation of the chip film and effectively preventing moisture ingress.

[0044] Optionally, the first insulating layer is an aluminum oxide layer formed by atomic layer deposition.

[0045] Because the films obtained by atomic layer deposition have good density and adhesion, the risk of film cracking is prevented.

[0046] Optionally, the thickness of the first insulating layer is less than or equal to 125 nm.

[0047] The aforementioned thickness control of the first insulating layer ensures that it is not too thick and will not affect the light emission efficiency of the LED.

[0048] Optionally, the insulating reflective layer has a sidewall above the peripheral region, the sidewall having a first acute angle with respect to the surface of the substrate, the semiconductor stack forming a light-emitting mesa and an electrode mesa surrounding the light-emitting mesa, the sidewall of the electrode mesa having a second acute angle with respect to the surface of the substrate, the first acute angle being greater than the second acute angle.

[0049] Optionally, the first acute angle is greater than or equal to 60°.

[0050] The angle between the sidewalls of the insulating reflective layer and the substrate surface is greater than 60°. This angle minimizes the exposed sidewall area of ​​the insulating reflective layer, which helps reduce channels that may allow moisture to enter. The first acute angle being greater than the second acute angle prevents over-etching of the electrode mesa 126 during the etching of the insulating reflective layer in the LED manufacturing process, thus improving device stability.

[0051] Optionally, the light-emitting diode further includes a second insulating layer located between the insulating reflective layer and the semiconductor stack, wherein the first insulating layer covers the sidewall of the second insulating layer.

[0052] The second insulating layer forms a continuous structure with the first insulating layer, which has the best adhesion and encapsulation properties. This improves the encapsulation of the first insulating layer on the insulating reflective layer, further preventing moisture and other substances from entering the light-emitting diode, and thus improving the reliability of the light-emitting diode.

[0053] Optionally, the light-emitting diode further includes an electrode structure, the electrode structure comprising:

[0054] The first electrode is formed above the first insulating layer on the electrode platform and is electrically connected to the first semiconductor layer;

[0055] The second electrode is formed above the first insulating layer on the light-emitting platform and is electrically connected to the second semiconductor layer.

[0056] Another embodiment of the present invention provides a method for manufacturing a light-emitting diode, comprising the following steps:

[0057] A substrate is provided, and a semiconductor stack is formed on the substrate, the semiconductor stack comprising a first semiconductor layer, an active layer and a second semiconductor layer stacked sequentially from bottom to top;

[0058] The semiconductor stack is etched sequentially from top to bottom, including the second semiconductor layer, the active layer, and a portion of the first semiconductor layer, to form an electrode mesa exposing the first semiconductor layer. The unetched portion of the semiconductor stack is formed as a light-emitting mesa. The portion of the first semiconductor layer exposed by the electrode mesa is then etched to expose the substrate and separate the semiconductor stack. The exposed substrate forms a dicing region.

[0059] An insulating reflective layer is formed, which covers the surface of the semiconductor stack and the exposed sidewalls, and also covers the surface of the substrate in the diced region;

[0060] The insulating reflective layer is etched in the area corresponding to the cutting area to expose the substrate;

[0061] A first insulating layer is formed on the surface of the insulating reflective layer and the exposed sidewalls, as well as on the surface of the substrate in the cut area, by an atomic layer deposition method.

[0062] The first insulating layer and the substrate are sequentially cut in the cutting area to obtain independent light-emitting diodes.

[0063] In this method, after forming the insulating reflective layer, the insulating reflective layer is etched in the cutting area to expose the substrate. This ensures that the subsequently formed first insulating layer covers almost all the exposed surfaces and sidewalls of the LED. Finally, after separating the LED by cutting the first insulating layer and substrate from the cutting area, only the sidewalls of the first insulating layer and substrate are exposed, while the remaining surfaces and sidewalls, especially the sidewalls of the insulating reflective layer, remain covered by the first insulating layer. Therefore, the encapsulation of the chip film is improved, effectively preventing moisture ingress.

[0064] Optionally, before forming the insulating reflective layer, the method further includes: forming a second insulating layer, which is formed by atomic layer deposition on the surface of the semiconductor stack and the exposed sidewalls, as well as on the surface of the substrate of the diced region, with the insulating reflective layer formed over the second insulating layer.

[0065] The second insulating layer forms a continuous structure with the first insulating layer, which has the best adhesion and encapsulation properties. This improves the encapsulation of the first insulating layer on the insulating reflective layer, further preventing moisture and other substances from entering the light-emitting diode, and thus improving the reliability of the light-emitting diode.

[0066] Optionally, forming an insulating reflective layer includes:

[0067] A first material layer is formed on the surface of the substrate exposed in the semiconductor stack and the diced region;

[0068] A second material layer and a third material layer are alternately formed on top of the first material layer. The second material layer and the third material layer have different refractive indices to form a DBR structure.

[0069] A fourth material layer is formed on top of the DBR structure.

[0070] Another aspect of the present invention provides a light-emitting device, which includes a substrate and a plurality of light-emitting units located on the substrate. A circuit layer is formed on the substrate, and the light-emitting units include the light-emitting diodes provided in this application. The light-emitting diodes are electrically connected to the circuit layer via a pad structure.

[0071] Example 1

[0072] This embodiment provides a light-emitting diode, such as Figure 2As shown, the light-emitting diode of this embodiment includes a substrate 110 and a semiconductor stack 120 formed on the substrate. In optional embodiments, the substrate 110 can be made of sapphire, silicon carbide, silicon, or gallium nitride. In this embodiment, the substrate 110 is a sapphire substrate with good light transmittance. Further, a patterned microstructure, such as a frustum-shaped protrusion, can be formed on the side of the sapphire substrate where the semiconductor stack 120 is formed. In this embodiment, the side of the substrate 110 opposite to the semiconductor stack 120 is the light-emitting side of the light-emitting diode.

[0073] Similarly, refer to Figure 2 The aforementioned semiconductor stack 120 is located above the substrate 110 and includes a first semiconductor layer 122, an active layer 123, and a second semiconductor layer 124 stacked sequentially from bottom to top. The material of the semiconductor stack 120 includes Al. x In y Ga (1-x-y) N or A1 x In y Ga (1-x-y)P is a group III-V semiconductor material, where 0≤x, y≤1; x+y≤1. Depending on the material of the active layer 123, when the material of the semiconductor stack 120 is AlInGaP, it can emit red light with wavelengths between 610nm and 650nm or yellow light with wavelengths between 550nm and 570nm. When the material of the semiconductor stack 120 is InGaN, it can emit blue or deep blue light with wavelengths between 420nm and 490nm or green light with wavelengths between 490nm and 550nm. When the material of the semiconductor stack 120 is AlGaN, it can emit UV light with wavelengths between 190nm and 420nm. The active layer 123 can be a single heterostructure (SH), a double heterostructure (DH), a double-side double heterostructure (DDH), or a multi-quantum well (MQW). The active layer 123 can be made of i-type, p-type, or n-type semiconductor. In one embodiment, the active layer 123 is an ultraviolet-emitting layer having a well layer and a barrier layer, the repetition number of which is, for example, between 1 and 10. The well layer is, for example, an AlGaN layer, and the barrier layer is, for example, an AlGaN layer, but the Al composition of the well layer is lower than the Al composition of the barrier layer. The second semiconductor layer 124 is, for example, a p-type AlGaN layer or a p-type GaN layer, or a layer formed by sequentially stacking p-type AlGaN layers and p-type GaN layers. The second semiconductor layer 124 includes a p-type GaN surface layer with a thickness of 5 nm or more and 50 mm or less. By setting a thin-film GaN, both the internal quantum luminescence efficiency and the external quantum luminescence efficiency of the device can be balanced. Specifically, the p-type GaN layer within this thickness range facilitates the lateral current expansion of the p-side current without causing excessive light absorption.

[0074] Before forming the first semiconductor layer 122, a buffer layer 121 can be formed on the surface of the substrate 110 to improve the lattice mismatch between the substrate 110 and the semiconductor stack 120. The buffer layer 121 can be made of a nitride-based material. In one embodiment, an aluminum nitride layer (not shown in the figure) can be formed on the surface of the substrate 110 as a bottom layer, which is in direct contact with the surface of the substrate 110 and preferably has a thickness of less than 1 μm. Further, the aluminum nitride bottom layer may also sequentially include a low-temperature layer, an intermediate layer, and a high-temperature layer from the side closest to the substrate, enabling the growth of a semiconductor layer with excellent crystallinity. In some other preferred embodiments, a series of pore structures are formed in the aluminum nitride bottom layer, which helps to release stress in the semiconductor layer sequence. This series of pores is preferably a series of elongated holes extending along the thickness of the aluminum nitride, and its depth can be, for example, between 0.5 μm and 1.5 μm.

[0075] In this embodiment, as Figure 2 As shown, the semiconductor stack 120 is etched to form a light-emitting mesa 125 and an electrode mesa 126 surrounding the light-emitting mesa. Specifically, the second semiconductor layer 124 and the active layer 123 are etched from top to bottom, or a portion of the first semiconductor layer 122 is further etched to form the electrode mesa 126 exposing the first semiconductor layer 122. The unetched semiconductor stack forms the light-emitting mesa 125. Further, the electrode mesa 126 is formed around or on one side of the light-emitting mesa 125. The area between the edge of the electrode mesa 126 and the edge of the substrate 110 is the peripheral region 127 of the light-emitting diode, and the surface of the peripheral region 127 is the surface of the exposed substrate 110. The sidewalls of the electrode mesa 126 are inclined sidewalls, and there is a second acute angle α2 between the sidewalls and the surface of the substrate 110. The second acute angle α2 satisfies: 30°≤α2<90°, further, 45°≤α2<70°, and even further, 45°≤α2<60°.

[0076] Alternatively, as Figure 2As shown, a first contact layer 131 can be disposed above the first semiconductor layer 122 exposed on the electrode mesa 126. This first contact layer 131 forms a good ohmic contact layer with the first semiconductor layer 122, improving current diffusion. A current spreading layer 132 can also be disposed above the second semiconductor layer 124 on the light-emitting mesa 125 to improve the current diffusion in the second semiconductor layer 124, making the current distribution more uniform, reducing the operating voltage of the light-emitting diode, and improving the light-emitting performance of the light-emitting diode. The current spreading layer 132 can be made of a transparent conductive material, which may include indium tin oxide (ITO), indium zinc oxide (IZO), indium oxide (InO), tin oxide (SnO), cadmium tin oxide (CTO), antimony tin oxide (ATO), aluminum zinc oxide (AZO), zinc tin oxide (ZTO), gallium-doped zinc oxide (GZO), tungsten-doped indium oxide (IWO), or zinc oxide (ZnO), but the embodiments disclosed herein are not limited thereto.

[0077] The current spreading layer 132 can completely cover the second semiconductor layer 124. However, to prevent defects such as leakage, the current spreading layer 132 does not cover the edges of the second semiconductor layer 124. The thickness of the current spreading layer 132 is generally not limited, but in a preferred embodiment, it can be approximately [thickness value missing]. to Within the range of thicknesses, even better, it can be... to The thickness of the current spreading layer 132 is within a certain range. If the thickness of the current spreading layer 132 is too thick, it will absorb light passing through the current spreading layer 132 and cause light loss. Therefore, the thickness of the current spreading layer 132 is preferably limited to a certain range. the following.

[0078] like Figure 2As shown, in this embodiment, the light-emitting diode further includes an insulating reflective layer 150, which is formed above the semiconductor stack 120 and the peripheral region 127. Specifically, the insulating layer 150 covers the current spreading layer 132 on the light-emitting mesa 125 side, the exposed surface and sidewalls of the semiconductor stack 120, and the exposed surface and sidewalls of the first contact layer 131 and the first semiconductor layer 122 on the electrode mesa 126 side. It also extends to cover a portion of the surface of the substrate 110 in the peripheral region 127, that is, the surface of the substrate 110 retaining a portion of the edge region 127 between the edge of the insulating reflective layer 150 and the edge of the substrate 110. Optionally, the sidewall of the insulating reflective layer 150 is formed as an inclined sidewall, and the sidewall has a first acute angle α1 with the surface of the substrate 110. The second acute angle α1 satisfies: 40°≤α1<90°, further, 50°≤α1<80°, even further, 60°≤α1<80°, and even further, α1>α2. The angle of the first acute angle α1 is preferably greater than 60°, which can minimize the surface area of ​​the sidewall of the insulating reflective layer 150 and reduce the channels that may allow moisture to enter. At the same time, the first acute angle α1 is greater than the second acute angle α2, which can prevent over-etching of the electrode mesa 126 during the etching of the insulating reflective layer in the manufacturing process of the light-emitting diode, which is beneficial to improving the stability of the device.

[0079] In an optional embodiment, the insulating reflective layer 150 is a multilayer structure, such as a multilayer structure including a DBR structure. Specifically, as Figure 2 and Figure 3 As shown, in the direction gradually moving away from the semiconductor stack 120 (i.e. Figure 2 and Figure 3 From bottom to top, the insulating reflective layer includes a first material layer 151, a DBR structure 1500, and a fourth material layer 154. The DBR structure includes a second material layer 152 and a third material layer 153 stacked alternately in sequence, with the second material layer 152 and the third material layer 153 having different refractive indices. In optional embodiments, the second material layer 152 and the third material layer 153 respectively include low-refractive-index materials such as SiO2, Al2O3, SiON, or MgF2, and high-refractive-index materials such as TiO, NB2O5, TA2O5, HfO2, or ZrO2. The first material layer 151 and the fourth material layer 154 can be the same material layer or different material layers; optionally, for example, both can be SiO2 layers. In some embodiments, the light extraction efficiency can be improved by utilizing the refractive index difference between the insulating reflective layer 150 and the current spreading layer 132. Optionally, the thickness of the first material layer 151 is between... Furthermore, given The thickness of the DBR structure is between 1500 and... Furthermore, given The fourth material layer 154 serves as a protective layer for the DBR structure, and its thickness is relatively thick, for example, between 5μm and 20μm, and even further, between 10μm and 15μm.

[0080] Refer again Figure 2 The light-emitting diode in this embodiment further includes a first insulating layer 160, which is formed above the insulating reflective layer 150, covering the surface of the insulating reflective layer 150 and its exposed sidewalls, and simultaneously covering a portion of the surface of the substrate 110 in the edge region 127. Thus, the first insulating layer 160 completely covers and encapsulates the insulating reflective layer 150, and the sidewalls of the insulating reflective layer 150 are encapsulated by the first insulating layer 160. In an optional embodiment, the first insulating layer 160 is a material layer formed by atomic layer deposition, such as an Al2O3 layer. This first insulating layer 160 has good density and adhesion, thus forming a good encapsulation with the insulating reflective layer 150, preventing the entry of moisture and other contaminants, and improving the reliability of the light-emitting diode. Furthermore, since the first insulating layer 160 is formed using atomic layer deposition, its thickness can be controlled, preventing it from becoming too thick and affecting the light extraction efficiency of the light-emitting diode. For example, in an optional embodiment, the thickness of the first insulating layer 160 is between... Furthermore, given

[0081] Similarly, Figure 2 As shown, the light-emitting diode in this embodiment further includes an electrode structure formed above the first insulating layer 160. This electrode structure includes a first electrode 141 electrically connected to the first semiconductor layer 122 and a second electrode 142 electrically connected to the second semiconductor layer 124. Figure 2 As shown, the first electrode 141 penetrates the first insulating layer 160 and the insulating reflective layer 150 in the corresponding region of the first contact layer 131 and is electrically connected to the first contact layer 131. The second electrode 142 is formed above the light-emitting platform 125, penetrating the first insulating layer 160 and the insulating reflective layer 150, and is electrically connected to the current spreading layer 132. The first electrode 141 and the second electrode 142 can be Al, Cr / Al, or Ni / Al structural layers, etc.

[0082] Example 2

[0083] This embodiment also provides a light-emitting diode, such as... Figure 4 As shown, the light-emitting diode of this embodiment includes a substrate 110 and a semiconductor stack 120 formed on the substrate. In optional embodiments, the substrate 110 can be made of sapphire, silicon carbide, silicon, or gallium nitride. In this embodiment, the substrate 110 is a sapphire substrate with good light transmittance. In this embodiment, the side of the substrate 110 opposite to the semiconductor stack 120 is the light-emitting side of the light-emitting diode.

[0084] Similarly, Figure 4 As shown, the light-emitting diode also includes an insulating reflective layer 150 and a first insulating layer 160. The arrangement of the insulating reflective layer 150 and the first insulating layer 160 is the same as that in Embodiment 1. The similarities between this embodiment and Embodiment 1 will not be repeated here; the differences are as follows:

[0085] like Figure 4 As shown, the light-emitting diode in this embodiment further includes a second insulating layer 170, which is formed between the semiconductor stack 120 and the insulating reflective layer 150. Optionally, the second insulating layer 170 is also an insulating material layer formed by atomic layer deposition. More specifically, the second insulating layer 170 and the first insulating layer 160 are made of the same material, such as an Al2O3 layer. The thickness of the second insulating layer 170 is preferably less than or equal to the thickness of the first insulating layer 160; for example, the thickness of the second insulating layer 170 is between […]. Furthermore, given The first insulating layer 160 covers the sidewall of the insulating reflective layer 150 and the sidewall of the second insulating layer 170 at the same time. Since the second insulating layer 170 and the first insulating layer 160 are made of the same material, when they form a continuous structure, they have the best adhesion and encapsulation. This can improve the encapsulation of the first insulating layer 160 on the insulating reflective layer 150, further prevent moisture and other substances from entering the light-emitting diode, and help improve the reliability of the light-emitting diode.

[0086] Example 3

[0087] This embodiment provides a method for manufacturing a light-emitting diode, such as... Figure 5 As shown, the manufacturing method includes the following steps:

[0088] S100: A substrate is provided, and a semiconductor stack is formed on the substrate, the semiconductor stack including a first semiconductor layer, an active layer and a second semiconductor layer stacked sequentially from bottom to top.

[0089] S200: The second semiconductor layer, the active layer, and a portion of the first semiconductor layer of the semiconductor stack are etched sequentially from top to bottom to form an electrode mesa exposing the first semiconductor layer. The unetched semiconductor stack is formed as a light-emitting mesa. The portion of the first semiconductor layer exposed by the electrode mesa is then etched to expose the substrate and separate the semiconductor stack. The exposed substrate forms a dicing region.

[0090] S300: Form an insulating reflective layer that covers the surface of the semiconductor stack and the exposed sidewalls, and covers the surface of the substrate in the diced region.

[0091] S400: Etch the insulating reflective layer in the area corresponding to the cutting area to expose the substrate.

[0092] S500: Forming a first insulating layer by atomic layer deposition on the surface of the insulating reflective layer and the exposed sidewalls, as well as on the surface of the substrate in the cut area.

[0093] S600: The first insulating layer and the substrate are sequentially cut in the cutting area to obtain an independent light-emitting diode.

[0094] Reference Figure 6 First, a substrate 110 is provided. This substrate 110 can be any substrate suitable for epitaxial growth, such as a silicon substrate, a silicon carbide substrate, a silicon-on-insulator substrate, a sapphire substrate, etc. In this embodiment, the substrate 110 is preferably a sapphire substrate. The surface of the sapphire substrate on which the semiconductor material layer is grown can be formed with a patterned microstructure, that is, the sapphire substrate is formed as a patterned substrate to improve the growth quality of the semiconductor material layer grown thereon.

[0095] A buffer layer 121 is first grown on a sapphire substrate, followed by the sequential growth of a first semiconductor layer 122, an active layer 123, and a second semiconductor layer 124 to form a semiconductor stack 120. The arrangement of these layers can be referred to the description in Embodiment 1.

[0096] Reference Figure 7 After forming the aforementioned semiconductor stack 120, the second semiconductor layer 124 and the active layer 123 are etched downwards from one side of the second semiconductor layer 124, or a portion of the first semiconductor layer 122 is further etched to expose the first semiconductor layer 122 to form an electrode mesa 126. The unetched semiconductor stack 120 located in the middle of the electrode mesa 126 forms a light-emitting mesa 125, and the area between adjacent electrode mesas is the cut area 127' of the light-emitting diode. Etching of the first semiconductor layer 122, i.e., the buffer layer 121, continues from this cut area 127' until the substrate 110 is exposed to separate the semiconductor stack. At this time, as... Figure 7 As shown, a second acute angle α2 is formed between the sidewall of the electrode mesa 126 and the surface of the substrate 110. This second acute angle α2 satisfies the following conditions: 30°≤α2<90°, further, 45°≤α2<70°, and even further, 45°≤α2<60°.

[0097] After that, as Figure 8 As shown, in Figure 7 An insulating reflective layer 150 is formed on the structure shown. For example... Figure 8 As shown, the insulating reflective layer 150 covers Figure 7All exposed surfaces and sidewalls of the structure shown form a continuous structure. The specific structure of the insulating reflective layer 150 can be referred to the description of Embodiment 1. Prior to this, a current spreading layer 132 is first formed above the light-emitting mesa 125, and a first contact layer 131 is formed above the electrode mesa 126. The specific details can also be referred to the description of Embodiment 1.

[0098] In optional embodiments, such as Figure 9 As shown, before forming the insulating reflective layer 150, firstly in Figure 7 A second insulating layer 170 is formed on top of the structure shown. This second insulating layer 170, as shown in Embodiment 2, is formed by atomic layer deposition. See the description of Embodiment 2 for details. An insulating reflective layer 150 is then formed on top of the second insulating layer 170.

[0099] like Figure 10 As shown, after forming the insulating reflective layer 150, the insulating reflective layer 150 is etched along the cutting region 127' to expose the substrate 110. At this time, a first acute angle α1 is formed between the sidewall of the insulating reflective layer 150 and the surface of the substrate 110. The first acute angle α1 satisfies: 40°≤α1<90°, further, 50°≤α1<80°, even further, 60°≤α1<80°, and even further, α1>α2. The angle of the first acute angle α1 is preferably greater than 60°, which can minimize the surface area of ​​the sidewall of the insulating reflective layer 150 and reduce the channels that may cause moisture to enter. At the same time, the first acute angle α1 is greater than the second acute angle α2, which can prevent over-etching of the electrode mesa 126 during the etching of the insulating reflective layer, which is beneficial to improving the stability of the device.

[0100] After that, as Figure 11 As shown, a first insulating layer 160 is formed over the etched insulating reflective layer 150. This first insulating layer 160 covers the surface of the insulating reflective layer 150 and the sidewalls exposed after etching, forming a continuous structure over the insulating reflective layer 150 and the exposed surfaces of the substrate 110. Subsequently, as... Figure 12 As shown, a first electrode 141 and a second electrode 412 are formed above the first insulating layer 160. For example, through holes penetrating the first insulating layer 160 and the insulating reflective layer 150 are first formed above the electrode mesa 126 and the light-emitting mesa 125, respectively, and then metal material is deposited in the through holes to form the first electrode 141 and the second electrode 142, respectively.

[0101] As described above, in this embodiment, after forming the insulating reflective layer, the insulating reflective layer is etched in the cutting area to expose the substrate. This ensures that the subsequently formed first insulating layer covers almost all the exposed surfaces and sidewalls of the LED. Finally, after separating the LED by cutting the first insulating layer and substrate from the cutting area, only the sidewalls of the first insulating layer and substrate are exposed, while the remaining surfaces and sidewalls, especially the sidewalls of the insulating reflective layer, remain covered by the first insulating layer. Therefore, the encapsulation of the chip film is improved, effectively preventing moisture ingress.

[0102] Finally, Figure 12 Above the structure shown, the first insulating layer 160 and the substrate 110 are sequentially cut along the cutting area 127' to separate and obtain the light-emitting diode provided in Embodiment 1 or Embodiment 2.

[0103] Example 4

[0104] This embodiment provides a light-emitting device, such as... Figure 13 As shown, the light-emitting device 200 includes a substrate 201 and a plurality of light-emitting units 203 located on the substrate 201. A circuit layer 202 is formed on the substrate 201, and the circuit layer 202 includes several sets of pad structures 204. The light-emitting unit 203 in this embodiment includes the light-emitting diodes provided in Embodiment 1 and / or Embodiment 2 of this application. The electrode structure of the light-emitting diode is electrically connected to the pad structure 204 above the circuit layer 902. The light-emitting device 200 in this embodiment includes the light-emitting diodes provided in Embodiment 1 and / or Embodiment 2, and therefore has good reliability and light emission effect.

[0105] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in the present invention should still be covered by the claims of the present invention.

Claims

1. A light-emitting diode, characterized in that, At least including: Substrate; A semiconductor stack is formed above the substrate, comprising a first semiconductor layer, an active layer, and a second semiconductor layer stacked sequentially from bottom to top, wherein the substrate between the edge of the semiconductor stack and the edge of the substrate forms the peripheral region of the light-emitting diode; An insulating reflective layer covers a portion of the surface of the substrate, including the semiconductor stack and the peripheral region. A first insulating layer covers the surface and sidewalls of the insulating reflective layer and extends to the surface of the substrate covering the peripheral area.

2. The light-emitting diode according to claim 1, characterized in that, The first insulating layer is an aluminum oxide layer formed by atomic layer deposition.

3. The light-emitting diode according to claim 1, characterized in that, The thickness of the first insulating layer is less than or equal to 125 nm.

4. The light-emitting diode according to claim 1, characterized in that, The insulating reflective layer has a sidewall above the peripheral region, the sidewall having a first acute angle with respect to the surface of the substrate, the semiconductor stack forming a light-emitting mesa and an electrode mesa surrounding the light-emitting mesa, the sidewall of the electrode mesa having a second acute angle with respect to the surface of the substrate, the first acute angle being greater than the second acute angle.

5. The light-emitting diode according to claim 4, characterized in that, The first acute angle is greater than or equal to 60°.

6. The light-emitting diode according to claim 1, characterized in that, It also includes a second insulating layer, which is located between the insulating reflective layer and the semiconductor stack, and the first insulating layer covers the sidewall of the second insulating layer.

7. The light-emitting diode according to claim 1 or 6, characterized in that, It also includes an electrode structure, which comprises: The first electrode is formed above the first insulating layer on the electrode platform and is electrically connected to the first semiconductor layer; The second electrode is formed above the first insulating layer on the light-emitting platform and is electrically connected to the second semiconductor layer.

8. A method for manufacturing a light-emitting diode, characterized in that, The following steps are involved: A substrate is provided, and a semiconductor stack is formed on the substrate, the semiconductor stack comprising a first semiconductor layer, an active layer and a second semiconductor layer stacked sequentially from bottom to top; The second semiconductor layer, the active layer, and a portion of the first semiconductor layer of the semiconductor stack are etched sequentially from top to bottom to form an electrode mesa exposing the first semiconductor layer. The unetched semiconductor stack is formed as a light-emitting mesa. Continue etching the portion of the first semiconductor layer exposed by the electrode mesa to expose the substrate and separate the semiconductor stack, with the exposed substrate forming a dicing region; An insulating reflective layer is formed, which covers the surface of the semiconductor stack and the exposed sidewalls, and also covers the surface of the substrate in the diced region; The insulating reflective layer is etched in the area corresponding to the cutting area to expose the substrate; A first insulating layer is formed on the surface of the insulating reflective layer and the exposed sidewalls, as well as on the surface of the substrate in the cut area, by an atomic layer deposition method. The first insulating layer and the substrate are sequentially cut in the cutting area to obtain independent light-emitting diodes.

9. The method for manufacturing a light-emitting diode according to claim 8, characterized in that, Prior to forming the insulating reflective layer, the method further includes forming a second insulating layer by means of atomic layer deposition on the surface of the semiconductor stack and the exposed sidewalls, and on the surface of the substrate of the diced region, wherein the insulating reflective layer is formed over the second insulating layer.

10. The method for manufacturing a light-emitting diode according to claim 8, characterized in that, The formation of an insulating reflective layer includes: A first material layer is formed on the surface of the substrate exposed in the semiconductor stack and the diced region; A second material layer and a third material layer are alternately formed on top of the first material layer. The second material layer and the third material layer have different refractive indices to form a DBR structure. A fourth material layer is formed on top of the DBR structure.

11. A light-emitting device, characterized in that, The device includes a substrate and a plurality of light-emitting units located on the substrate. A circuit layer is formed on the substrate. The light-emitting units include light-emitting diodes according to any one of claims 1 to 7. The light-emitting diodes are electrically connected to the circuit layer via a pad structure.

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