A reverse polarity small aperture light emitting LED chip and a manufacturing method thereof

Abstract

The application provides a LED chip with reverse polarity and small hole light emission and a manufacturing method thereof. The epitaxial layer of the LED chip comprises a P-type window layer and an MQW light emitting layer. The doping concentration of a first region in the P-type window layer is greater than that of a second region, which can limit current expansion and improve light emitting efficiency. An ODR dielectric film layer and an ODR metal reflection layer form an ODR mirror at the bottom of the epitaxial layer. An insulating passivation layer and an N electrode on the sidewall of the epitaxial layer can form an ODR mirror on the sidewall of the epitaxial layer. The N electrode also has a first hollow region. The ODR mirror can be used to reflect light, so that the light emitted by the MQW light emitting layer is only emitted from the first hollow region, and stray light emitted by the sidewall is suppressed. In addition, the orthographic projection of the first hollow region in the first direction completely covers the P ohmic contact metal unit, so that the electron hole recombination region is located in the MQW light emitting layer under the orthographic projection of the first hollow region, and the light emitting efficiency is further improved.

Description

Technical Field

[0001] This invention relates to the field of semiconductor light-emitting diode technology, and more specifically, to an LED chip with reverse polarity aperture light emission and a method for manufacturing the same. Background Technology

[0002] With the continuous development of science and technology, LEDs (Light Emitting Diodes), as a new type of light-emitting device, have been widely used in people's lives and work due to their advantages such as energy saving, environmental protection, good color rendering, and fast response speed. Furthermore, because the N-type material layer is placed on top in reverse polarity LED chips, and the N-type material layer has high conductivity, reverse polarity LED chips have higher luminous efficiency than positive polarity LED chips, and their application range is becoming increasingly wider.

[0003] Currently, conventional reverse-polarity LED chips mainly consist of a conductive substrate, an ODR mirror, an epitaxial structure layer, and electrodes. The light emission direction includes the front and sidewalls, making it a five-sided light-emitting chip. However, in special applications such as precision through-beam photoelectric switches, a very small emission angle and no stray light emission from the sidewalls are required. Conventional reverse-polarity LED chips, with emission angles ranging from 120° to 180°, cannot meet these requirements. Existing positive-polarity pinhole-emitting LED chips include a back electrode, a conductive substrate, a DBR mirror, a p-type confinement layer, an n-type confinement layer, an MQW active layer, and an insulating passivation layer and a main electrode metal layer covering the sidewalls. While this can meet the requirement of no stray light emission from the sidewalls, the effective emission power and electro-optical conversion efficiency are low because the electron-hole recombination region cannot be controlled and confined. Summary of the Invention

[0004] In view of this, to solve the above problems, the present invention provides an LED chip with reverse polarity micro-aperture light emission and its manufacturing method, the technical solution of which is as follows:

[0005] An LED chip with reverse polarity micro-aperture light emission, the LED chip comprising:

[0006] First substrate;

[0007] In a first direction, an ODR metal reflective layer, an ODR dielectric film layer, and an epitaxial layer are sequentially located on one side of the first substrate. The first direction is perpendicular to the plane where the first substrate is located and points from the first substrate to the ODR metal reflective layer.

[0008] Multiple first vias penetrating the ODR dielectric film layer, and P-ohm contact metal units located within the first vias;

[0009] The epitaxial layer includes a P-type window layer and an MQW light-emitting layer sequentially located on the side of the ODR dielectric film layer facing away from the first substrate. The surface of the P-type window layer facing the first substrate includes a first region and a second region. The doping concentration of the first region is greater than that of the second region. The first region is connected to the ODR metal reflective layer through the P-ohm contact metal unit. The sidewall of the epitaxial layer is an inclined sidewall, and the angle θ between the inclined sidewall and the plane where the first substrate is located is an acute angle.

[0010] The LED chip further includes: an insulating passivation layer and an N-electrode, wherein the N-electrode covers the sidewalls of the epitaxial layer and partially covers the first surface of the epitaxial layer, and the first surface of the epitaxial layer is the surface of the epitaxial layer facing away from the first substrate; the insulating passivation layer is located between the N-electrode and the epitaxial layer;

[0011] The N electrode has a first hollow area, which exposes a portion of the first surface of the epitaxial layer so that light emitted by the MQW light-emitting layer can be emitted from the first hollow area.

[0012] In the first direction, the orthographic projection of the first hollow area completely covers the P-ohm contact metal unit.

[0013] Preferably, in the above-mentioned LED chip with reverse polarity aperture light emission, the epitaxial layer further includes:

[0014] A P-type confinement layer located between the P-type window layer and the MQW light-emitting layer;

[0015] In the first direction, the N-type confinement layer, the N-type current spreading layer, the N-type roughening layer, and the N-electrode bonding layer are located sequentially on the side of the MQW light-emitting layer opposite to the P-type confinement layer.

[0016] Preferably, in the above-mentioned LED chip with reverse polarity aperture light emission, the LED chip further includes:

[0017] In the first direction, an N-ohm contact layer and an N-ohm contact metal layer are sequentially located on one side of the first surface of the epitaxial layer and between the N-electrode and the N-electrode bonding layer.

[0018] Preferably, in the above-mentioned LED chip with reverse polarity aperture light emission, the thickness of the P-type window layer ranges from 0.1µm to 10µm, and the doping concentration of the first region is greater than 10. 19 / cm 3 The doping concentration in the second region is greater than 10. 18 / cm 3 .

[0019] Preferably, in the above-mentioned LED chip with reverse polarity aperture light emission, the angle θ between the inclined sidewall and the plane where the first substrate is located ranges from 5°≤θ≤85°.

[0020] Preferably, in the above-mentioned LED chip with reverse polarity aperture light emission, the LED chip further includes a dicing groove, the depth of which in the first direction reaches the P-type window layer or the ODR dielectric film layer.

[0021] Preferably, in the above-mentioned LED chip with reverse polarity aperture light emission, the insulating passivation layer covers the inclined sidewall and the side of the dicing groove facing away from the first substrate, and the edge of the first surface has an area with a width of at least 1 micrometer covered by the insulating passivation layer.

[0022] Preferably, in the above-mentioned LED chip with reverse polarity aperture light emission, the N electrode partially covers the side of the dicing groove away from the first substrate, and the N electrode also has a second hollow area, which exposes a portion of the dicing groove away from the first substrate.

[0023] Preferably, in the above-mentioned LED chip with reverse polarity aperture light emission, the LED chip further includes:

[0024] A metal bonding layer located between the first substrate and the ODR metal reflective layer;

[0025] The P electrode is located on the side of the first substrate opposite to the metal bonding layer.

[0026] A method for manufacturing an LED chip with reverse polarity micro-aperture light emission, the method comprising:

[0027] Provide a first substrate and a second substrate;

[0028] An epitaxial layer is formed on one side of the second substrate, the epitaxial layer comprising an MQW light-emitting layer and a P-type window layer sequentially located on one side of the second substrate;

[0029] The surface of the P-type window layer facing away from the MQW light-emitting layer is processed so that the surface of the P-type window layer facing away from the MQW light-emitting layer includes a first region and a second region, wherein the doping concentration of the first region is greater than the doping concentration of the second region.

[0030] An ODR dielectric film layer is formed on the side of the P-type window layer opposite to the MQW light-emitting layer;

[0031] The ODR dielectric film layer is processed to form multiple first through holes penetrating the ODR dielectric film layer;

[0032] A P-ohm contact metal unit is formed, which fills the first via; an ODR metal reflective layer is formed on the side of the ODR dielectric film layer away from the P-type window layer; and the first substrate is formed on the side of the ODR metal reflective layer away from the second substrate.

[0033] Remove the second substrate and process the epitaxial layer so that the sidewalls of the epitaxial layer are inclined sidewalls, and the angle θ between the inclined sidewalls and the plane where the first substrate is located is an acute angle;

[0034] An insulating passivation layer and an N-electrode are formed, wherein the N-electrode covers the sidewalls of the epitaxial layer and partially covers the first surface of the epitaxial layer, wherein the first surface of the epitaxial layer is the surface of the epitaxial layer facing away from the first substrate; the insulating passivation layer is located between the N-electrode and the epitaxial layer;

[0035] The N electrode has a first hollow area, which exposes a portion of the first surface of the epitaxial layer so that light emitted by the MQW light-emitting layer can be emitted from the first hollow area.

[0036] In the first direction, the orthographic projection of the first hollow area completely covers the P-ohm contact metal unit, the first direction is perpendicular to the plane where the first substrate is located, and points from the first substrate to the epitaxial layer.

[0037] Preferably, in the above-described method for manufacturing an LED chip with reverse polarity aperture light emission, the step of forming an epitaxial layer on one side of the second substrate further includes:

[0038] An N-type buffer layer, an N-type corrosion stop layer, an N-ohm contact layer, an N-electrode bonding layer, an N-type roughening layer, an N-type current spreading layer, and an N-type confinement layer are sequentially formed on the side of the second substrate facing the MQW light-emitting layer.

[0039] A P-type confinement layer is formed on one side of the P-type window layer on the MQW light-emitting layer.

[0040] Preferably, in the above-described method for manufacturing an LED chip with reverse polarity aperture light emission, the manufacturing method further includes:

[0041] The N-type buffer layer and the N-type etch stop layer are removed simultaneously with the removal of the second substrate;

[0042] The N-type roughened layer is roughened on the side facing the N-electrode bonding layer;

[0043] The N-ohm contact layer is processed to expose a portion of the N-electrode bonding layer.

[0044] An N-ohm contact metal layer is formed on the side of the N-ohm contact layer that is away from the N-electrode bonding layer.

[0045] Preferably, in the above-described method for manufacturing an LED chip with reverse polarity aperture light emission, the manufacturing method further includes:

[0046] A metal bonding layer is formed on the side of the epitaxial layer opposite to the second substrate;

[0047] The first substrate is formed on the side of the metal bonding layer opposite to the epitaxial layer;

[0048] A dicing trench is formed on the side of the epitaxial layer away from the first substrate, and an inclined sidewall is formed on the epitaxial layer. The depth of the dicing trench in the first direction reaches the P-type window layer or the ODR dielectric film layer.

[0049] The insulating passivation layer is formed on the side of the inclined sidewall and the dicing groove opposite to the first substrate, and the insulating passivation layer is formed on a region at least 1 micrometer wide at the edge of the first surface;

[0050] The N electrode is formed on the side of the dicing trench away from the first substrate, and the N electrode also has a second hollow area that exposes a portion of the dicing trench on the side away from the first substrate.

[0051] A P-electrode is formed on the side of the first substrate opposite to the epitaxial layer;

[0052] Cutting is performed in the second hollowed-out area to form multiple LED chips.

[0053] Compared with the prior art, the beneficial effects achieved by the present invention are as follows:

[0054] This invention provides a reverse polarity pinhole light-emitting LED chip and its manufacturing method. The LED chip includes a first substrate, an ODR metal reflective layer, an ODR dielectric film layer, a P-ohm contact metal unit, an epitaxial layer, an insulating passivation layer, and an N-electrode. The epitaxial layer further includes a P-type window layer and an MQW light-emitting layer. The side of the P-type window layer facing away from the MQW light-emitting layer is processed so that the surface of the P-type window layer facing the first substrate includes a first region and a second region. The doping concentration of the first region is greater than that of the second region, thereby limiting current spread and improving luminous efficiency. The N-electrode has a first cutout region, which exposes a portion of the first surface of the epitaxial layer, allowing the MQW light-emitting layer to emit light. The light emitted from the light-emitting layer exits from the first hollowed-out area. In the first direction, the orthographic projection of the first hollowed-out area completely covers the P-ohm contact metal unit. This guides the electrons and holes injected into the MQW light-emitting layer, so that the electron-hole recombination region is located exactly under the orthographic projection of the first hollowed-out area of ​​the MQW light-emitting layer, reducing recombination outside the first hollowed-out area and thus further improving the luminous efficiency. The sidewall of the epitaxial layer is an inclined sidewall. An insulating passivation layer and an N-electrode are covered on the inclined sidewall, which can form an ODR reflector of the inclined sidewall to reflect the light incident on the inclined sidewall. In addition, the ODR reflector layer also reflects the light, so that the light only exits from the first hollowed-out area, thereby suppressing stray light emitted from the sidewall. Attached Figure Description

[0055] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0056] Figure 1 A schematic diagram of the structure of an LED chip with reverse polarity micro-aperture light emission provided in an embodiment of the present invention;

[0057] Figure 2 This is a schematic diagram of light emission from a reverse polarity pinhole LED chip, as exemplified in an embodiment of the present invention.

[0058] Figure 3 A top view schematic diagram of an LED chip with reverse polarity aperture light emission provided in an embodiment of the present invention;

[0059] Figure 4 A schematic diagram of another LED chip with reverse polarity aperture light emission provided in an embodiment of the present invention;

[0060] Figure 5A schematic diagram of the structure of another LED chip with reverse polarity aperture light emission provided in an embodiment of the present invention;

[0061] Figure 6 A schematic flowchart illustrating a method for manufacturing an LED chip with reverse polarity aperture light emission, provided in an embodiment of the present invention;

[0062] Figure 7 A schematic diagram of the epitaxial layer structure of an LED chip with reverse polarity aperture light emission provided in an embodiment of the present invention;

[0063] Figure 8 This is a schematic diagram of the epitaxial layer structure of another LED chip with reverse polarity aperture light emission provided in an embodiment of the present invention. Detailed Implementation

[0064] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0065] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0066] This invention provides an LED chip with reverse polarity aperture light emission, referenced... Figure 1 , Figure 1 This is a schematic diagram of the structure of an LED chip with reverse polarity micro-aperture light emission provided in an embodiment of the present invention, combined with... Figure 1 The LED chip with reverse polarity aperture light emission includes:

[0067] First substrate 1; specifically, in the embodiments of the present invention, the first substrate 1 includes, but is not limited to, a conductive permanent substrate, which has conductivity and can increase the luminous efficiency of the LED chip.

[0068] In the first direction A, an ODR metal reflective layer 2, an ODR dielectric film layer 3, and an epitaxial layer 4 are sequentially located on one side of the first substrate 1. The first direction A is perpendicular to the plane where the first substrate 1 is located and points from the first substrate 1 to the ODR metal reflective layer 2.

[0069] Specifically, in this embodiment of the invention, the ODR dielectric film layer 3 is located on the side of the ODR metal reflective layer 2 that is away from the first substrate 1, and the epitaxial layer 4 is located on the side of the ODR dielectric film layer 3 that is away from the ODR metal reflective layer 2.

[0070] Multiple first through holes penetrating the ODR dielectric film layer 3, and P-ohm contact metal units 5 located within the first through holes.

[0071] Specifically, in this embodiment of the invention, the P-ohm contact metal unit 5 at least fills the first through hole, and the number of the P-ohm contact metal units 5 is the same as the number of the first through holes. It should also be noted that the plurality of P-ohm contact metal units 5 exist independently, and each of the P-ohm contact metal units 5 is not connected to each other.

[0072] The epitaxial layer 4 includes a P-type window layer 6 and an MQW light-emitting layer 7, which are sequentially located on the side of the ODR dielectric film layer 3 facing away from the first substrate 1. The surface of the P-type window layer 6 facing the first substrate 1 includes a first region and a second region. The doping concentration of the first region is greater than that of the second region. The first region is connected to the ODR metal reflective layer 2 through the P-ohm contact metal unit 5. The sidewall of the epitaxial layer 4 is an inclined sidewall, and the angle θ between the inclined sidewall and the plane where the first substrate 1 is located is an acute angle.

[0073] Specifically, in this embodiment of the invention, the MQW light-emitting layer 7 is located on the side of the P-type window layer 6 facing away from the first substrate 1; the angle θ between the inclined sidewall and the plane where the first substrate 1 is located ranges from 5°≤θ≤85°, and in this embodiment of the invention, the preferred range of the angle θ is 45°≤θ≤75°; the P-type window layer 6 can be divided into a main body part and a surface part, the surface part being the surface of the P-type window layer 6 facing the ODR dielectric film layer 3, the doping concentration of the surface part being greater than the doping concentration of the main body part, the surface part of the P-type window layer 6 being processed to form the first region of the P-type window layer 6, and the main body part of the P-type window layer 6 being the second region of the P-type window layer 6.

[0074] Wherein, the doping concentration in the first region is greater than 10. 19 / cm 3 The doping concentration in the second region is greater than 10. 18 / cm 3The thickness of the P-type window layer 6 ranges from 0.1µm to 10µm, and can take any value within this range. In this embodiment, the preferred thickness range of the P-type window layer 6 is 0.5µm to 3µm. For example, the thickness of the P-type window layer 6 can be 0.5µm, 1µm, 1.5µm, 2.7µm, 3µm, etc. The thickness of the P-type window layer 6 can be determined based on the performance of the LED chip with the reverse polarity light-emitting aperture. It should also be noted that the thickness of the P-type window layer 6 mentioned above refers to the thickness in the first direction A.

[0075] The LED chip further includes an insulating passivation layer 8 and an N-electrode 9. The N-electrode 9 covers the sidewall of the epitaxial layer 4 and partially covers the first surface of the epitaxial layer 4. The first surface of the epitaxial layer 4 is the surface of the epitaxial layer 4 that is away from the first substrate 1. The insulating passivation layer 8 is located between the N-electrode 9 and the epitaxial layer 4.

[0076] Specifically, in this embodiment of the invention, the first surface of the epitaxial layer 4 can also be understood as the top of the epitaxial layer 4, the insulating passivation layer 8 covers the sidewall of the epitaxial layer 4 away from the first substrate 1, and the edge of the first surface has an area with a width of at least 1 micrometer covered by the insulating passivation layer 8; the N electrode 9 covers the side of the insulating passivation layer 8 away from the first substrate 1 and partially covers the first surface of the epitaxial layer 4.

[0077] The N electrode 9 has a first hollow region 20, which exposes a portion of the first surface of the epitaxial layer 4 so that light emitted by the MQW light-emitting layer 7 is emitted from the first hollow region 20; wherein, in the first direction A, the orthographic projection of the first hollow region 20 completely covers the P-ohm contact metal unit 5.

[0078] Specifically, in the embodiments of the present invention, such as Figure 2 As shown, Figure 2 This is a schematic diagram illustrating the light emission of an LED chip with reverse polarity pinhole emission, as exemplified by an embodiment of the present invention. Figure 2In this invention, the first hollow area 20 is the only light-emitting area of ​​the LED chip; the insulating passivation layer 8 and the N electrode 9 can form an ODR reflector on the inclined sidewall, used to reflect light rays incident on the sidewall of the epitaxial layer 4; the ODR metal reflector layer 2 and the ODR dielectric film layer 3 can form an ODR reflector at the bottom of the epitaxial layer 4, used to reflect light rays incident on the bottom of the epitaxial layer 4; therefore, the light emitted from the first hollow area 20 includes not only the light emitted from the MQW light-emitting layer 7, but also the light reflected from the inclined sidewall of the epitaxial layer 4 and the ODR metal reflector layer 2, thereby preventing light rays from escaping from the sidewall of the epitaxial layer 4 and increasing the brightness of the light emitted from the first hollow area 20.

[0079] As described above, the present invention provides an LED chip with reverse polarity small aperture light emission. The LED chip includes a first substrate 1, an ODR metal reflective layer 2, an ODR dielectric film layer 3, a P-ohm contact metal unit 5, an epitaxial layer 4, an insulating passivation layer 8, and an N-electrode 9. The epitaxial layer 4 further includes a P-type window layer 6 and an MQW light-emitting layer 7. The side of the P-type window layer 6 facing away from the MQW light-emitting layer 7 is processed so that the surface of the P-type window layer 6 facing the first substrate 1 includes a first region and a second region. The doping concentration of the first region is greater than that of the second region, thereby limiting current spread and improving luminous efficiency. The N-electrode 9 has a first hollow region 20, which exposes a portion of the first surface of the epitaxial layer 4, allowing the... The light emitted by the MQW light-emitting layer 7 exits from the first hollow region 20. In the first direction A, the orthographic projection of the first hollow region 20 completely covers the P-ohm contact metal unit 5. This guides the electrons and holes injected into the MQW light-emitting layer 7, so that the electron-hole recombination region is located exactly under the orthographic projection of the first hollow region 20. This reduces recombination outside the first hollow region 20, thereby further improving the luminous efficiency. The sidewall of the epitaxial layer 4 is an inclined sidewall. An insulating passivation layer 8 and an N-electrode 9 are covered on the inclined sidewall, which can form an ODR reflector of the inclined sidewall to reflect the light incident on the inclined sidewall. In addition, the ODR reflective layer 2 also reflects the light, so that the light only exits from the first hollow region 20, thereby suppressing stray light emitted from the sidewall.

[0080] Optionally, in another embodiment of the invention, combined with Figure 1 The LED chip with reverse polarity aperture emission is described in detail above. The epitaxial layer 4 further includes:

[0081] A P-type confinement layer 10 is located between the P-type window layer 6 and the MQW light-emitting layer 7.

[0082] In the first direction A, the N-type confinement layer 11, the N-type current spreading layer 12, the N-type roughening layer 13 and the N-electrode bonding layer 14 are located sequentially on the side of the MQW light-emitting layer 7 away from the P-type confinement layer 10.

[0083] Specifically, in this embodiment of the invention, the N-type current spreading layer 12 is located on the side of the N-type confinement layer 11 that is away from the MQW light-emitting layer 7; the N-type roughening layer 13 is located on the side of the N-type current spreading layer 12 that is away from the N-type confinement layer 11; and the N-electrode bonding layer 14 is located on the side of the N-type roughening layer 13 that is away from the N-type current spreading layer 12.

[0084] Specifically, in this embodiment of the invention, the P-type window layer 6 is a P-type GaP window layer, the P-type confinement layer 10 is a P-type AlGaInP confinement layer, the N-type confinement layer 11 is an N-type AlGaInP confinement layer, the N-type current spreading layer 12 is an N-type AlGaInP current spreading layer, the N-type roughening layer 13 is an N-type AlGaInP roughening layer, and the N-electrode bonding layer 14 is an N-type GaInP electrode bonding layer; wherein, AlGaInP material refers to Al x Ga y In (1-x-y) P material, each Al x Ga y In (1-x-y) The components of the P functional layer can be adjusted individually as needed.

[0085] Specifically, in this embodiment of the invention, the surface of the N-type roughened layer 13 with the first hollowed-out region 20 on the side opposite to the N-type current extension layer 12 is roughened; the N-electrode bonding layer 14 exposes the roughened surface of the N-type roughened layer 13.

[0086] Optionally, in another embodiment of the present invention, for the above-mentioned anti-micro-aperture LED chip, another optional epitaxial layer 4 structure is provided, wherein the MQW light-emitting layer 7 is an AlGaInAs-based MQW light-emitting layer, and the epitaxial layer 4 includes:

[0087] A P-type AlGaAs confinement layer, a P-type AlGaAs current spreading layer, and a P-type GaP ohmic contact layer are sequentially located on the AlGaInAs-based MQW light-emitting surface facing the first substrate 1, wherein the P-type AlGaAs current spreading layer and the P-type GaP ohmic contact layer constitute a P-type window layer 6.

[0088] The AlGaInAs-based MQW light-emitting layer consists of an N-type AlGaAs confinement layer, an N-type AlGaAs current spreading layer, an N-type AlGaAs roughening layer, and an N-type GaInP electrode bonding layer, which are sequentially located on the side of the AlGaInAs-based MQW light-emitting layer opposite to the first substrate 1.

[0089] Among them, AlGaInAs material refers to Al x Ga y In (1-x-y) As material, each Al x Ga y In (1-x-y) The functional layer composition of AlGaAs can be adjusted individually as needed. AlGaAs material refers to Al x Ga y In (1-x-y) In the case of 1-xy=0 in As, x and y can be different.

[0090] Optionally, in another embodiment of the invention, combined with Figure 1 The LED chip with reverse polarity aperture emission is described in detail above, and the LED chip further includes:

[0091] In the first direction A, there are N-ohm contact layer 15 and N-ohm contact metal layer 16 located sequentially on one side of the first surface of the epitaxial layer 4 and between the N-electrode 9 and the N-electrode bonding layer 14.

[0092] Specifically, in the embodiments of the present invention, such as Figure 3 As shown, Figure 3 This is a top view schematic diagram of an LED chip with reverse polarity micro-aperture light emission provided in an embodiment of the present invention, combined with... Figure 3 The area where the P-ohm contact metal unit 5 is distributed is smaller than the first hollow area 20. The N-ohm contact metal layer 16 surrounds the periphery of the first hollow area 20. The N-ohm contact metal layer 16 also exposes a part of the N-electrode bonding layer 14. The exposed part of the N-electrode bonding layer 14 is in direct contact with the N-electrode 9, so that the N-electrode 9 obtains strong adhesion when connected to the bonding wire 19, which can solve the problem of the N-electrode 9 falling off during the bonding process.

[0093] In addition, such as Figure 4 As shown, Figure 4 This is a schematic diagram of another LED chip with reverse polarity aperture light emission provided in an embodiment of the present invention, combined with... Figure 4 The N-electrode 9 covers and protects the N-ohm contact layer 15 and the N-ohm contact metal layer 16. This is to prevent the roughening liquid from eroding and damaging the N-ohm contact layer 15, thus avoiding high chip voltage issues. Figure 4In this process, the P-ohm contact metal unit 5 is used to guide hole injection into the MQW light-emitting layer 7, and the N-ohm contact layer 15 and the N-ohm contact metal layer 16 are used to guide electron injection into the MQW light-emitting layer 7, so that the electron-hole recombination region is located exactly below the first hollow region 20, thereby reducing recombination in the region outside the first hollow region 20 and thus improving the luminous efficiency.

[0094] Optionally, in another embodiment of the invention, reference is made to... Figure 5 , Figure 5 This is a schematic diagram of the structure of another LED chip with reverse polarity aperture light emission provided in an embodiment of the present invention, combined with... Figure 5 The LED chip with reverse polarity aperture emission is described in detail above, and the LED chip further includes:

[0095] The cutting groove 21 has a depth in the first direction A that reaches the P-type window layer 6 or the ODR dielectric film layer 3.

[0096] The insulating passivation layer 8 covers the inclined sidewall and the dicing groove 21 on the side opposite to the first substrate 1, and the edge of the first surface has an area at least 1 micrometer wide covered by the insulating passivation layer 8.

[0097] Specifically, in this embodiment of the invention, the N electrode 9 fully covers the side of the insulating passivation layer 8 away from the first substrate 1, and the N electrode 9 covers a region on the first surface with a width greater than 1 micrometer.

[0098] The N electrode 9 partially covers the side of the dicing groove 21 away from the first substrate 1. The N electrode 9 also has a second hollow area 22, which exposes a portion of the dicing groove 21 away from the first substrate 1, so as to facilitate subsequent dicing of the LED chip.

[0099] A metal bonding layer 17 is located between the first substrate 1 and the ODR metal reflective layer 2; a P electrode 18 is located on the side of the first substrate 1 opposite to the metal bonding layer 17.

[0100] Specifically, in this embodiment, the use of a metal bonding layer 17 to bond the epitaxial layer 4 to the first substrate 1 is beneficial to improving the conductivity of the LED chip; the use of a P electrode 18 is beneficial to improving the photoelectric conversion efficiency of the LED chip.

[0101] This invention also provides a method for manufacturing an LED chip with reverse polarity pinhole light emission, which is described in the following embodiments: Figure 6 , Figure 6This is a schematic flowchart illustrating a method for manufacturing an LED chip with reverse polarity aperture light emission, provided by an embodiment of the present invention. Figure 6 The manufacturing method includes the following steps:

[0102] S101, Provide a first substrate 1 and a second substrate.

[0103] Specifically, in step S101, the first substrate 1 includes, but is not limited to, a conductive permanent substrate, and the second substrate includes, but is not limited to, a GaAs temporary substrate.

[0104] S102. An epitaxial layer 4 is formed on one side of the second substrate. The epitaxial layer 4 includes an MQW light-emitting layer 7 and a P-type window layer 6 located sequentially on one side of the second substrate.

[0105] S103. The surface of the P-type window layer 6 facing away from the MQW light-emitting layer 7 is processed so that the surface of the P-type window layer 6 facing away from the MQW light-emitting layer 7 includes a first region and a second region, wherein the doping concentration of the first region is greater than the doping concentration of the second region.

[0106] Specifically, in step S103, the P-type window layer 6 is a P-type GaP window layer. The surface of the P-type GaP window layer facing away from the MQW light-emitting layer 7 is etched to etch the highly GaP-doped surface of the P-type GaP window layer, while retaining the highly GaP in the first region without being etched, thus exposing the second region.

[0107] S104. An ODR dielectric film layer 3 is formed on the side of the P-type window layer 6 opposite to the MQW light-emitting layer 7.

[0108] Specifically, in step S104, the preferred thickness of the ODR dielectric film 3 can be calculated based on (2k+1)λ / 4n. For example, taking the SiO2 dielectric film as an example, with k=0, its red light wavelength λ=630nm, and the refractive index of SiO2 n=1.45, the preferred thickness of the SiO2 dielectric film can be calculated to be 108.6nm.

[0109] S105. The ODR dielectric film layer 3 is processed to form a plurality of first through holes penetrating the ODR dielectric film layer 3.

[0110] Specifically, in step S105, multiple first through holes penetrating the ODR dielectric film 3 can be formed in the ODR dielectric film 3 by photolithography or etching.

[0111] S106. Form a P-ohm contact metal unit 5, which fills the first through hole; form an ODR metal reflective layer 2 on the side of the ODR dielectric film layer 3 away from the P-type window layer 6; and form the first substrate 1 on the side of the ODR metal reflective layer 2 away from the second substrate.

[0112] Specifically, in step S106, if multiple first vias are formed by photolithography in step S105, the photoresist needs to be removed after the first vias are formed, and then an ODR metal reflective layer 2 is formed on the side of the ODR dielectric film layer 3 away from the P-type window layer 6; if multiple first vias are formed by etching in step S105, the ODR metal reflective layer 2 can be formed directly on the side of the ODR dielectric film layer 3 away from the P-type window layer 6 after the first vias are formed; the ODR metal reflective layer 2 is connected to the first region of the P-type window layer 6 through multiple first vias, and the P-ohm contact metal unit 5 is formed in the multiple first vias after annealing.

[0113] Specifically, in step S106, several different alternative implementations are provided for the above-described process of forming the first substrate 1 on the side of the ODR metal reflective layer 2 facing away from the second substrate:

[0114] In the first embodiment, a metal bonding layer 17 is formed on the side of the epitaxial layer 4 opposite to the second substrate; and the first substrate 1 is formed on the side of the metal bonding layer 17 opposite to the epitaxial layer 4.

[0115] The second method involves forming a first metal bonding layer on the side of the epitaxial layer 4 away from the second substrate; forming a second metal bonding layer on one side of the first substrate 1; and bonding the first metal bonding layer and the second metal bonding layer together through mutual diffusion during a heating and pressurizing bonding process, thereby bonding the epitaxial layer 4 to the first substrate 1; wherein the first metal bonding layer and the second metal bonding layer are the same type of metal bonding layer.

[0116] S107. Remove the second substrate and process the epitaxial layer 4 so that the sidewall of the epitaxial layer 4 is an inclined sidewall, and the angle θ between the inclined sidewall and the plane where the first substrate 1 is located is an acute angle.

[0117] S108. An insulating passivation layer 8 and an N-electrode 9 are formed. The N-electrode 9 covers the sidewall of the epitaxial layer 4 and partially covers the first surface of the epitaxial layer 4. The first surface of the epitaxial layer 4 is the surface of the epitaxial layer 4 that is away from the first substrate 1. The insulating passivation layer 8 is located between the N-electrode 9 and the epitaxial layer 4.

[0118] The N electrode has a first hollow region 20, which exposes a portion of the first surface of the epitaxial layer 4 so that the light emitted by the MQW light-emitting layer 7 can be emitted from the first hollow region 20. In the first direction A, the orthographic projection of the first hollow region 20 completely covers the P-ohm contact metal unit 5. The first direction A is perpendicular to the plane where the first substrate 1 is located and points from the first substrate 1 to the epitaxial layer 4.

[0119] Specifically, in step S108, the N electrode 9 can be formed by processes such as photolithography, vapor deposition, stripping, and annealing, so that the N electrode 9 covers the sidewalls of the epitaxial layer 4 and partially covers the first surface of the epitaxial layer 4.

[0120] S109. A P-electrode 18 is formed on the side of the first substrate 1 opposite to the epitaxial layer 4.

[0121] Specifically, in step S109, the side of the first substrate 1 away from the epitaxial layer 4 is thinned by grinding, and then P electrode 18 is formed by vapor deposition and annealing.

[0122] This invention provides a method for manufacturing a reverse-polarity pinhole-emitting LED chip. The method includes: providing a first substrate 1 and a second substrate; forming an epitaxial layer 4 on one side of the second substrate, the epitaxial layer 4 including an MQW light-emitting layer 7 and a P-type window layer 6 sequentially located on one side of the second substrate; processing the surface of the P-type window layer 6 facing away from the MQW light-emitting layer 7, such that the surface of the P-type window layer 6 facing away from the MQW light-emitting layer 7 includes a first region and a second region, the doping concentration of the first region being greater than the doping concentration of the second region. This processing enables… To limit current spread and improve luminous efficiency, an ODR dielectric film layer 3 is formed on the side of the P-type window layer 6 away from the MQW light-emitting layer 7. The ODR dielectric film layer 3 is processed to form multiple first through-holes penetrating it. A P-ohm contact metal unit 5 is formed, filling the first through-holes. An ODR metal reflective layer 2 is formed on the side of the ODR dielectric film layer 3 away from the P-type window layer 6. The ODR metal reflective layer 2 and the ODR dielectric film layer 3 can constitute an ODR reflector at the bottom of the epitaxial layer 4, reflecting light towards the epitaxial layer. Light from the bottom of layer 4; the epitaxial layer 4 is processed to make its sidewalls inclined, with an acute angle θ between the inclined sidewalls and the plane containing the first substrate 1; an insulating passivation layer 8 and an N-electrode 9 are formed on the side of the inclined sidewall facing away from the first substrate 1, which can form an ODR mirror of the inclined sidewall to reflect the light incident on the inclined sidewall, so that the light only exits from the first hollow area 20, thereby suppressing stray light emitted from the sidewall; the N-electrode 9 has a first hollow area 20, which exposes part of the first surface of the epitaxial layer 4. The MQW light-emitting layer 7 is divided into regions so that the light emitted from the MQW light-emitting layer 7 exits from the first hollow region 20. In the first direction A, the orthographic projection of the first hollow region 20 completely covers the P-ohm contact metal unit 5. This guides the electrons and holes injected into the MQW light-emitting layer 7, so that the electron-hole recombination region is located exactly under the orthographic projection of the first hollow region 20, reducing recombination outside the first hollow region 20. The current expansion is controlled by oxidizing the MQW light-emitting layer 7 in an oxidation furnace, so that the current only passes through the first hollow region 20 to further improve the luminous efficiency.

[0123] Optionally, in another embodiment of the present invention, the process of forming an epitaxial layer 4 on one side of the second substrate in step S102 of the above-described method for manufacturing an LED chip with reverse polarity aperture light emission will be described in detail. The manufacturing method further includes:

[0124] An N-type buffer layer, an N-type corrosion cutoff layer, an N-ohm contact layer 15, an N-electrode bonding layer 14, an N-type roughening layer 13, an N-type current spreading layer 12, and an N-type confinement layer 11 are sequentially formed on the side of the second substrate facing the MQW light-emitting layer 7; a P-type confinement layer 10 is formed on the side of the MQW light-emitting layer 7 facing the P-type window layer 6.

[0125] Specifically, several different optional implementation methods are introduced in the embodiments of the present invention:

[0126] The first type, such as Figure 7 As shown, Figure 7 This is a schematic diagram of the epitaxial layer structure of an LED chip with reverse polarity micro-aperture light emission provided in an embodiment of the present invention, combined with... Figure 7 In this embodiment of the invention, an antipolar AlGaInP-based red LED epitaxial wafer is formed on the side of the second substrate 23 facing the MQW light-emitting layer 7 using MOCVD, as detailed below:

[0127] On the side of the second substrate 23 facing the MQW light-emitting layer 7, an N-type buffer layer 24, an N-type corrosion cutoff layer 25, an N-ohm contact layer 15, an N-electrode bonding layer 14, an N-type roughening layer 13, an N-type current spreading layer 12, and an N-type confinement layer 11 are formed sequentially; and on the side of the MQW light-emitting layer 7 facing the P-type window layer 6, a P-type confinement layer 10 is formed.

[0128] Among them, the N-type buffer layer 24 and the N-ohm contact layer 15 are made of GaAs, the N-type corrosion stop layer 25 and the N-electrode bonding layer 14 are made of GaInP, and the N-type roughening layer 13, the N-type current spreading layer 12, the N-type confinement layer 11 and the P-type confinement layer 10 are made of AlGaInP. AlGaInP refers to Al... x Ga y In (1-x-y) P material, each Al x Ga y In (1-x-y) The components of the P functional layer can be adjusted individually as needed.

[0129] The second type, such as Figure 8 As shown, Figure 8 This is a schematic diagram of the epitaxial layer structure of an LED chip with reverse polarity micro-aperture light emission provided in an embodiment of the present invention, combined with... Figure 8 In this embodiment of the invention, an antipolar AlGaInAs-based infrared LED epitaxial wafer is formed on the side of the second substrate 23 facing the MQW light-emitting layer 7 using MOCVD, as detailed below:

[0130] On the side of the second substrate 23 facing the MQW light-emitting layer 7, an N-type buffer layer 24, an N-type corrosion cutoff layer 25, an N-type ohmic contact layer 15, an N-type electrode bonding layer 14, an N-type roughening layer 13, an N-type current spreading layer 12, and an N-type confinement layer 11 are formed sequentially; on the side of the MQW light-emitting layer 7 away from the N-type confinement layer 11, a P-type confinement layer 10, a P-type current spreading layer 26, and a P-type ohmic contact layer 27 are formed sequentially, and the P-type current spreading layer 26 and the P-type ohmic contact layer 27 can constitute the P-type window layer 6.

[0131] Among them, the N-type buffer layer 24 and the N-type ohmic contact layer 15 are made of GaAs, the N-type corrosion stop layer 25 and the N-type electrode bonding layer 14 are made of GaInP, the N-type roughening layer 13, the N-type current spreading layer 12, the N-type confinement layer 11, the P-type confinement layer 10 and the P-type current spreading layer 26 are made of AlGaAs, and the P-type ohmic contact layer 27 is made of GaP; where AlGaInAs refers to Al x Ga y In (1-x-y) As material, each Al x Ga y In (1-x-y) The functional layer composition of AlGaAs can be adjusted individually as needed. AlGaAs material refers to Al x Ga y In (1-x-y) In the case of 1-xy=0 in As, x and y can be different.

[0132] In the two optional embodiments above, it should also be noted that, for the N-type GaAs buffer layer 24 and N-type GaInP etch stop layer 25 sequentially formed on the side of the second substrate 23 facing the MQW light-emitting layer 7, in step S107, when removing the second substrate 23, it is also necessary to remove the N-type GaAs buffer layer 24 and the N-type GaInP etch stop layer 25.

[0133] The N-ohm contact layer 15 is processed to expose a portion of the N-electrode bonding layer 14; an N-ohm contact metal layer 16 is formed on the side of the N-ohm contact layer 15 opposite to the N-electrode bonding layer 14.

[0134] Specifically, in this embodiment of the invention, the N-ohm contact layer 15 can be fabricated by photolithography and wet etching, exposing a portion of the N-electrode bonding layer 14. Then, the N-ohm contact metal layer 16 can be fabricated by photolithography, vapor deposition, stripping, and annealing processes, so that the N-ohm contact layer 15 and the N-ohm contact metal layer 16 form a good ohm contact.

[0135] The side of the N-type roughened layer 13 facing the N-electrode bonding layer 14 is roughened.

[0136] Specifically, in this embodiment of the invention, during the roughening process of the N-type roughening layer 13, the inclined sidewalls of the epitaxial layer 4 can also be roughened.

[0137] Optionally, in another embodiment of the present invention, the manufacturing method of the above-mentioned LED chip with reverse polarity aperture light emission is described in detail, and the manufacturing method further includes:

[0138] A dicing trench 21 is formed on the side of the epitaxial layer 4 away from the first substrate 1, and an inclined sidewall is formed on the epitaxial layer 4. The depth of the dicing trench 21 in the first direction A reaches the P-type window layer 6 or the ODR dielectric film layer 3.

[0139] Specifically, in this embodiment of the invention, photoresist is spin-coated on the side of the epitaxial layer 4 away from the first substrate 1. After exposure and development, the dicing trench 21 region is defined. The first hollow area 20 is protected by photoresist, while the dicing trench 21 is not protected by photoresist. The dicing trench 21 is formed by dry etching. At the same time, by adjusting parameters such as gas flow rate, chamber pressure, and radio frequency power in the dry etching process, the sidewalls of the epitaxial layer 4 are etched into inclined sidewalls.

[0140] The formation of the insulating passivation layer 8 further includes: forming the insulating passivation layer 8 on the side of the inclined sidewall facing away from the first substrate 1 and on the side of the dicing trench 21 facing away from the first substrate 1, and forming the insulating passivation layer 8 in a region with a width of at least 1 micrometer at the edge of the first surface of the epitaxial layer 4.

[0141] Specifically, in this embodiment of the invention, SiN can be deposited on the side of the inclined sidewall facing away from the first substrate 1 and on the side of the dicing trench 21 facing away from the first substrate 1. x An insulating passivation layer 8 made of materials such as SiO2, Al2O3, and MgF2 is formed, and the first surface of the epitaxial layer 4 is etched to expose the N-ohm contact layer 15 and the N-ohm contact metal layer 16, so that the N electrode 9 can communicate with the N-ohm contact layer 15 and the N-ohm contact metal layer 16.

[0142] The formation of the N electrode 9 further includes: forming the N electrode 9 on the side of the dicing groove 21 away from the first substrate 1, the N electrode 9 also having a second hollow area 22, the second hollow area 22 exposing a portion of the dicing groove 21 away from the first substrate 1, the second hollow area 22 facilitating subsequent cutting to form the LED chip.

[0143] Cutting is performed in the second hollow area 22 to form multiple LED chips.

[0144] Specifically, in this embodiment of the invention, the wafer can be cut into discrete LED chips by means of slicing, back-slicing, or dicing processes in the second hollow area 22, thereby completing the manufacturing process of the LED chips.

[0145] The present invention provides a detailed description of an LED chip with reverse polarity aperture emission and its manufacturing method. Specific examples have been used to illustrate the principle and implementation of the present invention. The description of the above embodiments is only for the purpose of helping to understand the method and core idea of ​​the present invention. At the same time, for those skilled in the art, there will be changes in the specific implementation and application scope based on the idea of ​​the present invention. Therefore, the content of this specification should not be construed as a limitation of the present invention.

[0146] It should be noted that the various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the apparatus disclosed in the embodiments, since it corresponds to the method disclosed in the embodiments, the description is relatively simple; relevant parts can be referred to the method section.

[0147] It should also be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that elements inherent to a process, method, article, or apparatus that comprises a list of elements, or elements inherent to such processes, methods, articles, or apparatus, are also included. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0148] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those 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 invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A reverse-polarity micro-aperture light-emitting LED chip, characterized in that, The LED chip includes: First substrate; In a first direction, an ODR metal reflective layer, an ODR dielectric film layer, and an epitaxial layer are sequentially located on one side of the first substrate. The first direction is perpendicular to the plane where the first substrate is located and points from the first substrate to the ODR metal reflective layer. Multiple first vias penetrating the ODR dielectric film layer, and P-ohm contact metal units located within the first vias; The epitaxial layer includes a P-type window layer and an MQW light-emitting layer sequentially located on the side of the ODR dielectric film layer facing away from the first substrate. The surface of the P-type window layer facing the first substrate includes a first region and a second region. The doping concentration of the first region is greater than that of the second region. The first region is connected to the ODR metal reflective layer through the P-ohm contact metal unit. The P-type window layer includes a main portion and a surface portion. The surface portion is the surface of the P-type window layer facing the ODR dielectric film layer, which is the first region, and the main portion is the second region. The sidewall of the epitaxial layer is an inclined sidewall, and the angle θ between the inclined sidewall and the plane where the first substrate is located is an acute angle. The LED chip further includes: an insulating passivation layer and an N-electrode, wherein the N-electrode covers the sidewalls of the epitaxial layer and partially covers the first surface of the epitaxial layer, and the first surface of the epitaxial layer is the surface of the epitaxial layer facing away from the first substrate; the insulating passivation layer is located between the N-electrode and the epitaxial layer; The N electrode has a first hollow area, which exposes a portion of the first surface of the epitaxial layer so that light emitted by the MQW light-emitting layer can be emitted from the first hollow area. In the first direction, the orthographic projection of the first hollow area completely covers the P-ohm contact metal unit; The epitaxial layer further includes: A P-type confinement layer located between the P-type window layer and the MQW light-emitting layer; In the first direction, an N-type confinement layer, an N-type current spreading layer, an N-type roughening layer, and an N-electrode bonding layer are sequentially located on the side of the MQW light-emitting layer opposite to the P-type confinement layer. The LED chip also includes: In the first direction, an N-ohm contact layer and an N-ohm contact metal layer are sequentially located on one side of the first surface of the epitaxial layer and between the N electrode and the N electrode bonding layer; the N-ohm contact metal layer also exposes a portion of the N electrode bonding layer, and the exposed portion of the N electrode bonding layer is in direct contact with the N electrode; the N electrode covers the N-ohm contact layer and the N-ohm contact metal layer.

2. The LED chip according to claim 1, characterized in that, The thickness of the P-type window layer ranges from 0.1µm to 10µm, and the doping concentration in the first region is greater than 10. 19 / cm 3 The doping concentration in the second region is greater than 10. 18 / cm 3 .

3. The LED chip according to claim 1, characterized in that, The angle θ between the inclined sidewall and the plane containing the first substrate ranges from 5° to 85°.

4. The LED chip according to claim 1, characterized in that, The LED chip also includes a dicing groove, the depth of which in the first direction reaches the P-type window layer or the ODR dielectric film layer.

5. The LED chip according to claim 4, characterized in that, The insulating passivation layer covers the inclined sidewall and the dicing groove on the side opposite to the first substrate, and the edge of the first surface has an area at least 1 micrometer wide covered by the insulating passivation layer.

6. The LED chip according to claim 4, characterized in that, The N-electrode partially covers the side of the dicing trench away from the first substrate, and the N-electrode also has a second cutout area that exposes a portion of the dicing trench away from the first substrate.

7. The LED chip according to claim 1, characterized in that, The LED chip also includes: A metal bonding layer located between the first substrate and the ODR metal reflective layer; The P electrode is located on the side of the first substrate opposite to the metal bonding layer.

8. A method for manufacturing an LED chip with reverse polarity micro-aperture light emission, characterized in that, The method for manufacturing an LED chip with reverse polarity micro-aperture light emission as described in any one of claims 1-7 comprises: Provide a first substrate and a second substrate; An epitaxial layer is formed on one side of the second substrate, the epitaxial layer comprising an MQW light-emitting layer and a P-type window layer sequentially located on one side of the second substrate; The surface of the P-type window layer facing away from the MQW light-emitting layer is processed to make the surface of the P-type window layer facing away from the MQW light-emitting layer include a first region and a second region. The doping concentration of the first region is greater than that of the second region. The P-type window layer includes a main body portion and a surface portion. The surface portion is the surface of the P-type window layer facing the ODR dielectric film layer. The surface portion is the first region, and the main body portion is the second region. An ODR dielectric film layer is formed on the side of the P-type window layer opposite to the MQW light-emitting layer; The ODR dielectric film layer is processed to form multiple first through-holes penetrating the ODR dielectric film layer; A P-ohm contact metal unit is formed, which fills the first via; an ODR metal reflective layer is formed on the side of the ODR dielectric film layer away from the P-type window layer; and the first substrate is formed on the side of the ODR metal reflective layer away from the second substrate. Remove the second substrate and process the epitaxial layer so that the sidewalls of the epitaxial layer are inclined sidewalls, and the angle θ between the inclined sidewalls and the plane where the first substrate is located is an acute angle; An insulating passivation layer and an N-electrode are formed, wherein the N-electrode covers the sidewalls of the epitaxial layer and partially covers the first surface of the epitaxial layer, wherein the first surface of the epitaxial layer is the surface of the epitaxial layer facing away from the first substrate; the insulating passivation layer is located between the N-electrode and the epitaxial layer; The N electrode has a first hollow area, which exposes a portion of the first surface of the epitaxial layer so that light emitted by the MQW light-emitting layer can be emitted from the first hollow area. In the first direction, the orthographic projection of the first hollow area completely covers the P-ohm contact metal unit, the first direction is perpendicular to the plane where the first substrate is located, and points from the first substrate to the epitaxial layer.

9. The manufacturing method according to claim 8, characterized in that, The method of forming an epitaxial layer on one side of the second substrate further includes: An N-type buffer layer, an N-type corrosion stop layer, an N-ohm contact layer, an N-electrode bonding layer, an N-type roughening layer, an N-type current spreading layer, and an N-type confinement layer are sequentially formed on the side of the second substrate facing the MQW light-emitting layer. A P-type confinement layer is formed on one side of the P-type window layer on the MQW light-emitting layer.

10. The manufacturing method according to claim 9, characterized in that, The manufacturing method further includes: The N-type buffer layer and the N-type etch stop layer are removed simultaneously with the removal of the second substrate; The N-type roughened layer is roughened on the side facing the N-electrode bonding layer; The N-ohm contact layer is processed to expose a portion of the N-electrode bonding layer. An N-ohm contact metal layer is formed on the side of the N-ohm contact layer that is away from the N-electrode bonding layer.

11. The manufacturing method according to claim 8, characterized in that, The manufacturing method further includes: A metal bonding layer is formed on the side of the epitaxial layer opposite to the second substrate; The first substrate is formed on the side of the metal bonding layer opposite to the epitaxial layer; A dicing trench is formed on the side of the epitaxial layer away from the first substrate, and an inclined sidewall is formed on the epitaxial layer. The depth of the dicing trench in the first direction reaches the P-type window layer or the ODR dielectric film layer. The insulating passivation layer is formed on the side of the inclined sidewall and the dicing groove opposite to the first substrate, and the insulating passivation layer is formed on a region at least 1 micrometer wide at the edge of the first surface; The N electrode is formed on the side of the dicing trench away from the first substrate, and the N electrode also has a second hollow area that exposes a portion of the dicing trench on the side away from the first substrate. A P-electrode is formed on the side of the first substrate opposite to the epitaxial layer; Cutting is performed in the second hollowed-out area to form multiple LED chips.

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