CN218414612U

CN218414612U - LED chip with light emitting from reverse-polarity small holes

Info

Publication number: CN218414612U
Application number: CN202222412532.9U
Authority: CN
Inventors: 赵鹏; 马英杰; 蔡和勋
Original assignee: Xiamen Changelight Co Ltd
Current assignee: Xiamen Changelight Co Ltd
Priority date: 2022-09-09
Filing date: 2022-09-09
Publication date: 2023-01-31
Anticipated expiration: 2032-09-09

Abstract

The utility model provides a luminous LED chip of reverse polarity aperture, the epitaxial layer of this LED chip includes P type window layer and MQW luminescent layer, and the doping concentration of first region is greater than the doping concentration of second region in the P type window layer, can restrict the current extension, improves luminous efficiency; the ODR dielectric film layer and the ODR metal reflecting layer form an ODR reflecting mirror at the bottom of the epitaxial layer, an insulating passivation layer and an N electrode are covered on the side wall of the epitaxial layer to form the ODR reflecting mirror at the side wall of the epitaxial layer, the N electrode is also provided with a first hollow area, and the ODR reflecting mirror can be used for reflecting light rays, so that the light rays emitted by the MQW light-emitting layer are emitted from the first hollow area only, and stray light emitted by the side wall is inhibited; in addition, in the first direction, the orthographic projection of the first hollow-out area completely covers the P ohmic contact metal unit, so that the electron hole recombination area is just positioned on the MQW light-emitting layer under the orthographic projection of the first hollow-out area, and the light-emitting efficiency is further improved.

Description

LED chip with light emitting from reverse-polarity small holes

Technical Field

The utility model relates to a semiconductor emitting diode technical field, more specifically say, relate to a luminous LED chip of antipolarity aperture.

Background

With the continuous development of science and technology, LED (Light Emitting Diode) is used as a novel Light Emitting device, and has the advantages of energy saving, environmental protection, good color rendering and response speed, etc. and is widely used in people's life and work. And because the N-type material layer in the reversed polarity LED chip is arranged above the reversed polarity LED chip, the conductivity of the N-type material layer is high, so that the reversed polarity LED chip has higher luminous efficiency than the positive polarity LED chip, and the application range of the reversed polarity LED chip is wider and wider.

At present, a conventional reverse-polarity LED chip mainly comprises a conductive substrate, an ODR reflector, an epitaxial structure layer and electrodes, wherein a light-emitting direction comprises a front surface and a side wall and is a five-surface light-emitting chip. However, in special occasions such as a precise opposite-emitting photoelectric switch and the like, the light-emitting angle of the LED chip is required to be very small, no stray light is emitted from the side wall, but the light-emitting angle of the conventional reversed-polarity LED chip reaches 120-180 degrees, and the use requirement cannot be met; in the prior art, an LED chip emitting light through a positive aperture includes 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 a sidewall, and although the requirement of emission without stray light from the sidewall can be met, since an electron-hole recombination region cannot be regulated and controlled, the effective emission power is low, and the electro-optical conversion rate is also low.

SUMMERY OF THE UTILITY MODEL

In view of this, in order to solve the above problem, the utility model provides a luminous LED chip of reverse polarity aperture, technical scheme is as follows:

an inverted polarity aperture emitting LED chip, said LED chip comprising:

a first substrate;

the ODR metal reflecting layer, the ODR dielectric film layer and the epitaxial layer are sequentially positioned on one side of the first substrate in a first direction, and the first direction is vertical to the plane of the first substrate and points to the ODR metal reflecting layer from the first substrate;

the first through holes penetrate through the ODR dielectric film layer, and the P ohmic contact metal units are positioned in the first through holes;

the epitaxial layer comprises a P-type window layer and an MQW (multi-quantum well) light-emitting layer which are sequentially positioned on one side, away from the first substrate, of the ODR dielectric film layer, the surface, facing one side of the first substrate, of the P-type window layer comprises a first area and a second area, the doping concentration of the first area is larger than that of the second area, and the first area is connected with the ODR metal reflecting layer through the P ohmic contact metal unit; the side wall of the epitaxial layer is an inclined side wall, and an included angle theta between the inclined side wall and the plane of the first substrate is an acute angle;

the LED chip further includes: the N electrode covers the side wall 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, which is far away from the first substrate; the insulating passivation layer is positioned between the N electrode and the epitaxial layer;

the N electrode is provided with a first hollow-out area, and the first hollow-out area exposes a partial area 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-out area;

wherein, in the first direction, the orthographic projection of the first hollow-out region completely covers the P ohmic contact metal unit.

Preferably, in the above-mentioned reverse-polarity small-hole light emitting LED chip, the epitaxial layer further includes:

a P-type confinement layer positioned between the P-type window layer and the MQW light-emitting layer;

and in the first direction, an N-type limiting layer, an N-type current spreading layer, an N-type coarsening layer and an N-electrode firm layer are sequentially positioned on one side of the MQW light-emitting layer, which is far away from the P-type limiting layer.

Preferably, in the above-mentioned reverse-polarity-aperture-emitting LED chip, the LED chip further includes:

and the N ohmic contact layer and the N ohmic contact metal layer are sequentially positioned on one side of the first surface of the epitaxial layer and between the N electrode and the N electrode firm layer in the first direction.

Preferably, in the above-mentioned reverse-polarity-aperture-light-emitting LED chip, the thickness of the P-type window layer ranges from 0.1um to 10um, and the first window layer is made of a metal materialThe doping concentration of the region is more than 10 ¹⁹ /cm ³ The doping concentration of the second region is more than 10 ¹⁸ /cm ³ 。

Preferably, in the reversed-polarity small-hole light-emitting LED chip, an included angle θ between the inclined sidewall and a plane of the first substrate is in a range of 5 ° to 85 °.

Preferably, in the LED chip emitting light through the reverse-polarity small hole, the LED chip further includes a cutting street groove, and a depth of the cutting street groove in the first direction reaches the P-type window layer or the ODR dielectric film layer.

Preferably, in the above-mentioned LED chip emitting light through a reverse-polarity hole, the insulating passivation layer covers the inclined sidewall and a side of the scribe line trench facing away from the first substrate, and an area of the edge of the first surface having a width of at least 1 μm is covered by the insulating passivation layer.

Preferably, in the LED chip emitting light through the reverse-polarity small holes, the N electrode partially covers a side of the scribe line groove away from the first substrate, and the N electrode further has a second hollow area exposing a partial area of the scribe line groove away from the first substrate.

Preferably, in the above-mentioned reverse-polarity aperture light-emitting LED chip, the LED chip further includes:

a metal bonding layer between the first substrate and the ODR metal reflective layer;

and the P electrode is positioned on one side of the first substrate, which faces away from the metal bonding layer.

A method of fabricating a reverse polarity aperture emitting LED chip, the method comprising:

providing a first substrate and a second substrate;

forming an epitaxial layer on one side of the second substrate, wherein the epitaxial layer comprises an MQW light-emitting layer and a P-type window layer which are sequentially positioned on one side of the second substrate;

processing the surface of the P-type window layer on the side away from the MQW light-emitting layer, so that the surface of the P-type window layer on the side away from the MQW light-emitting layer comprises a first area and a second area, and the doping concentration of the first area is greater than that of the second area;

forming an ODR dielectric film layer on one side of the P-type window layer, which is far away from the MQW light-emitting layer;

processing the ODR dielectric film layer to form a plurality of first through holes penetrating through the ODR dielectric film layer;

forming a P ohmic contact metal unit, wherein the P ohmic contact metal unit fills the first through hole; forming an ODR metal reflecting layer on one side of the ODR dielectric film layer deviating from the P-type window layer; forming the first substrate on a side of the ODR metal reflective layer facing away from the second substrate;

removing the second substrate, and processing the epitaxial layer to make the side wall of the epitaxial layer be an inclined side wall, wherein an included angle theta between the inclined side wall and the plane of the first substrate is an acute angle;

forming an insulating passivation layer and an N electrode, wherein the N electrode covers the side wall 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, which is far away from the first substrate; the insulating passivation layer is positioned between the N electrode and the epitaxial layer;

in the first direction, the orthographic projection of the first hollow-out area completely covers the P ohmic contact metal unit, and the first direction is perpendicular to the plane of the first substrate and is directed to the epitaxial layer from the first substrate.

Preferably, in the method for manufacturing an LED chip emitting light with reverse polarity aperture, the forming an epitaxial layer on one side of the second substrate further includes:

forming an N-type buffer layer, an N-type corrosion cut-off layer, an N-ohmic contact layer, an N-electrode firm layer, an N-type coarsening layer, an N-type current spreading layer and an N-type limiting layer on one side of the second substrate facing the MQW light-emitting layer in sequence;

and forming a P-type limiting layer on one side of the MQW light-emitting layer facing the P-type window layer.

Preferably, in the method for manufacturing an LED chip emitting light through a reverse-polarity aperture, the removing the second substrate further includes: and removing the N-type buffer layer and the N-type corrosion stop layer.

Preferably, in the method for manufacturing an LED chip emitting light from a hole with reversed polarity, the method further includes:

processing the N-type ohmic contact layer to enable the N-type ohmic contact layer to be exposed out of a partial area of the N-type electrode firm layer;

and forming an N ohmic contact metal layer on one side of the N ohmic contact layer, which is far away from the N electrode firm layer.

and forming a cutting channel groove on one side of the epitaxial layer, which is far away from the first substrate, and forming an inclined side wall of the epitaxial layer, wherein the depth of the cutting channel groove in the first direction reaches the P-type window layer or the ODR medium film layer.

Preferably, in the method for manufacturing an LED chip emitting light from a hole with reversed polarity, the forming the N electrode further includes:

and forming the N electrode on one side of the cutting channel groove, which is away from the first substrate, wherein the N electrode is also provided with a second hollow area, and the second hollow area exposes a partial area of one side of the cutting channel groove, which is away from the first substrate.

Preferably, in the above method for manufacturing an LED chip emitting light from a hole with reversed polarity, the forming the insulating passivation layer further includes:

and forming the insulating passivation layer on the inclined side wall and the side of the cutting channel groove, which faces away from the first substrate, and forming the insulating passivation layer on the region with the width of at least 1 micrometer on the edge of the first surface.

and carrying out roughening treatment on one side of the N-type roughened layer facing the N electrode firm layer.

Preferably, in the above method for manufacturing an LED chip emitting light through a reverse-polarity aperture, the forming the first substrate on a side of the ODR metal reflective layer facing away from the second substrate further includes:

forming a metal bonding layer on one side of the epitaxial layer, which faces away from the second substrate;

and forming the first substrate on the side of the metal bonding layer, which faces away from the epitaxial layer.

Preferably, in the method for manufacturing an LED chip emitting light from a hole with reversed polarity, the method further includes: and forming a P electrode on one side of the first substrate, which is far away from the epitaxial layer.

Preferably, in the method for manufacturing an LED chip emitting light from a hole with reversed polarity, the method further includes: and cutting the second hollow-out area to form a plurality of LED chips.

Compared with the prior art, the utility model discloses the beneficial effect who realizes does:

the utility model provides a luminous LED chip of reverse polarity aperture, this LED chip includes first substrate, ODR metal reflection stratum, ODR dielectric film layer, P ohmic contact metal unit, epitaxial layer, insulating passivation layer and N electrode; the epitaxial layer further comprises a P-type window layer and an MQW light-emitting layer, one side of the P-type window layer, which is far away from the MQW light-emitting layer, is processed, so that the surface, which faces one side of the first substrate, of the P-type window layer comprises a first area and a second area, and the doping concentration of the first area is greater than that of the second area, so that the current expansion can be limited, and the light-emitting efficiency is improved; the N electrode is provided with a first hollow-out area, the first hollow-out area exposes a partial area of the first surface of the epitaxial layer, so that light emitted by the MQW light-emitting layer is emitted from the first hollow-out area, in the first direction, the forward projection of the first hollow-out area completely covers the P ohmic contact metal unit, electrons and holes injected into the MQW light-emitting layer can be guided, the electron-hole recombination area is just positioned on the MQW light-emitting layer under the forward projection of the first hollow-out area, recombination outside the first hollow-out area is reduced, and therefore the light-emitting efficiency is further improved; the side wall of the epitaxial layer is an inclined side wall, an insulating passivation layer and an N electrode are covered on the inclined side wall, an ODR reflector of the inclined side wall can be formed, light rays emitted to the inclined side wall are reflected, in addition, the ODR reflector also reflects the light rays, the light rays are only emitted from the first hollow area, and accordingly stray light emitted by the side wall is restrained.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required to be used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the provided drawings without creative efforts.

Fig. 1 is a schematic structural diagram of an LED chip emitting light from a reverse-polarity aperture according to an embodiment of the present invention;

fig. 2 is a schematic diagram illustrating light ray emergence of an LED chip emitting light from a reverse-polarity aperture according to an embodiment of the present invention;

fig. 3 is a schematic top view of an LED chip with a reverse-polarity aperture for emitting light according to an embodiment of the present invention;

fig. 4 is a schematic structural diagram of another reverse-polarity LED chip with small holes for emitting light according to an embodiment of the present invention;

fig. 5 is a schematic structural diagram of another reverse-polarity LED chip provided in an embodiment of the present invention;

fig. 6 is a schematic flow chart of a manufacturing method of an LED chip emitting light from reverse-polarity small holes according to an embodiment of the present invention;

fig. 7 is a schematic view of an epitaxial layer structure of an LED chip emitting light from a reverse-polarity aperture according to an embodiment of the present invention;

fig. 8 is a schematic view of an epitaxial layer structure of another reverse-polarity LED chip with small holes for emitting light according to an embodiment of the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative work belong to the protection scope of the present invention.

In order to make the above objects, features and advantages of the present invention more comprehensible, the present invention is described in detail with reference to the accompanying drawings and the detailed description.

The embodiment of the utility model provides a luminous LED chip of antipolarity aperture, refer to fig. 1, fig. 1 is the embodiment of the utility model provides a luminous LED chip's of antipolarity aperture structural schematic diagram combines fig. 1, the luminous LED chip of antipolarity aperture includes:

a first substrate 1; specifically, in the embodiment of the present invention, the first substrate 1 includes, but is not limited to, a conductive type permanent substrate having conductivity, which can increase the light emitting efficiency of the LED chip.

In a first direction a, the ODR metal reflective layer 2, the ODR dielectric film layer 3, and the epitaxial layer 4 are sequentially located on one side of the first substrate 1, where the first direction a is perpendicular to a plane where the first substrate 1 is located, and the ODR metal reflective layer 2 is pointed by the first substrate 1.

Specifically, in the embodiment of the present invention, the ODR dielectric film layer 3 is located on one side of the ODR metal reflective layer 2 deviating from the first substrate 1, and the epitaxial layer 4 is located on one side of the ODR dielectric film layer 3 deviating from the ODR metal reflective layer 2.

A plurality of first through holes penetrating the ODR dielectric film layer 3, and a P ohmic contact metal unit 5 positioned in the first through holes.

Specifically, in the embodiment of the present invention, the P ohmic contact metal units 5 at least fill the first through holes, and the number of the P ohmic contact metal units 5 is the same as that of the first through holes, and it should be noted that the P ohmic contact metal units 5 are independent, and each of the P ohmic contact metal units 5 is not connected to each other.

The epitaxial layer 4 comprises a P-type window layer 6 and an MQW light-emitting layer 7 which are sequentially positioned on one side of the ODR dielectric film layer 3, which is far away from the first substrate 1, the surface of the P-type window layer 6, which faces one side of the first substrate 1, comprises a first area and a second area, the doping concentration of the first area is greater than that of the second area, and the first area is connected with the ODR metal reflecting layer 2 through the P ohmic contact metal unit 5; the side wall of the epitaxial layer 4 is an inclined side wall, and an included angle theta between the inclined side wall and the plane of the first substrate 1 is an acute angle.

Specifically, in the embodiment of the present invention, the MQW light-emitting layer 7 is located on a side of the P-type window layer 6 facing away from the first substrate 1; the value range of the included angle theta between the inclined side wall and the plane where the first substrate 1 is located is more than or equal to 5 degrees and less than or equal to 85 degrees, in the embodiment of the present invention, the preferable value range of the included angle theta is more than or equal to 45 degrees and less than or equal to 75 degrees; the P-type window layer 6 may be divided into a main portion and a surface portion, the surface portion is a surface of the P-type window layer 6 facing the ODR dielectric film layer 3, a doping concentration of the surface portion is greater than a doping concentration of the main portion, the surface portion of the P-type window layer 6 is processed to form a first region of the P-type window layer 6, and the main portion of the P-type window layer 6 is a second region of the P-type window layer 6.

Wherein the doping concentration of the first region is more than 10 ¹⁹ /cm ³ The doping concentration of the second region is more than 10 ¹⁸ /cm ³ The thickness range of the P-type window layer 6 is 0.1um-10um, and the thickness of the P-type window layer 6 can be any value within the range of 0.1um-10um, and is originally applicableIn the embodiment of the present invention, the preferable thickness range of the P-type window layer 6 is 0.5um-3um, for example, the thickness of the P-type window layer 6 can be 0.5um, 1um, 1.5um, 2.7um, 3um, etc., and the thickness of the P-type window layer 6 can be determined according to the performance of the LED chip with the reversed-polarity light-emitting aperture. The thickness of the P-type window layer 6 is defined as the thickness in the first direction a.

The LED chip further includes: the epitaxial layer 4 comprises an insulating passivation layer 8 and an N electrode 9, wherein the N electrode 9 covers the side wall of the epitaxial layer 4 and partially covers the first surface of the epitaxial layer 4, and the first surface of the epitaxial layer 4 is the surface of the epitaxial layer 4 facing away from the first substrate 1; the insulating passivation layer 8 is located between the N-electrode 9 and the epitaxial layer 4.

In particular, in the embodiment of the present 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 side of the sidewall of the epitaxial layer 4 away from the first substrate 1, and the edge of the first surface is covered by the insulating passivation layer 8 at least in a region with a width of 1 micron; the N-electrode 9 covers the side of the insulating passivation layer 8 facing away from the first substrate 1 and partially covers the first surface of the epitaxial layer 4.

The N electrode 9 is provided with a first hollowed-out area 20, and the first hollowed-out area 20 exposes a partial area 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 hollowed-out area 20; wherein, in the first direction a, the orthographic projection of the first hollow-out region 20 completely covers the P-ohmic contact metal unit 5.

Specifically, in the embodiment of the present invention, as shown in fig. 2, fig. 2 is a schematic light ray outgoing view of an LED chip with a light emitting from a reverse polarity aperture according to an example of the present invention, and with reference to fig. 2, the first hollow area 20 of the present invention is the only light outgoing area of the LED chip; the insulating passivation layer 8 and the N electrode 9 may constitute the inclined sidewall ODR mirror for reflecting light toward the sidewall of the epitaxial layer 4; the ODR metal reflective layer 2 and the ODR dielectric film layer 3 may form an ODR mirror at the bottom of the epitaxial layer 4, and reflect light emitted to 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 reflective layer 2, thereby preventing the light from being emitted from the sidewall of the epitaxial layer 4 and increasing the brightness of the light emitted from the first hollow area 20.

As can be seen from the above description, the LED chip provided by the embodiment of the present invention includes a first substrate 1, an ODR metal reflective layer 2, an ODR dielectric film layer 3, a P ohmic contact metal unit 5, an epitaxial layer 4, an insulating passivation layer 8, and an N electrode 9; the epitaxial layer 4 further comprises a P-type window layer 6 and an MQW light-emitting layer 7, one side of the P-type window layer 6, which is far away from the MQW light-emitting layer 7, is processed, so that the surface, facing to the first substrate 1, of the P-type window layer 6 comprises a first area and a second area, and the doping concentration of the first area is greater than that of the second area, so that current expansion can be limited, and light-emitting efficiency can be improved; the N electrode 9 has a first hollow area 20, the first hollow area 20 exposes a partial area of the first surface of the epitaxial layer 4, so that light emitted by the MQW light-emitting layer 7 exits from the first hollow area 20, wherein in the first direction a, a forward projection of the first hollow area 20 completely covers the P-ohmic contact metal unit 5, which can guide electrons and holes injected into the MQW light-emitting layer 7, so that an electron-hole recombination region is just located in the MQW light-emitting layer 7 under the forward projection of the first hollow area 20, and recombination outside the first hollow area 20 is reduced, thereby further improving light-emitting efficiency; the side wall of the epitaxial layer 4 is an inclined side wall, the inclined side wall is covered with the insulating passivation layer 8 and the N electrode 9, an ODR reflector of the inclined side wall can be formed, light rays emitted to the inclined side wall are reflected, in addition, the ODR reflecting layer 2 can also reflect the light rays, the light rays are only emitted from the first hollow area 20, and therefore stray light emitted by the side wall is restrained.

Optionally, in another embodiment of the present invention, with reference to fig. 1, the above-mentioned LED chip emitting light through the reverse-polarity aperture is described in detail, and the epitaxial layer 4 further includes:

and a P-type confinement layer 10 positioned between the P-type window layer 6 and the MQW light-emitting layer 7.

And in the first direction a, an N-type confinement layer 11, an N-type current spreading layer 12, an N-type roughened layer 13 and an N-electrode fixing layer 14 which are sequentially positioned on the side of the MQW light-emitting layer 7 away from the P-type confinement layer 10.

Specifically, in the embodiment of the present invention, the N-type current spreading layer 12 is located on a side of the N-type confinement layer 11 away from the MQW light-emitting layer 7; the N-type rough layer 13 is positioned on one side of the N-type current spreading layer 12, which is far away from the N-type confinement layer 11; the N-electrode securing layer 14 is located on a side of the N-type roughened layer 13 facing away from the N-type current spreading layer 12.

Specifically, in the embodiment of the present 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 coarsening layer 13 is an N-type AlGaInP coarsening layer, and the N-type electrode securing layer 14 is an N-type GaInP electrode securing layer; wherein the AlGaInP material is Al _x Ga _y In _(1-x-y) P material, each Al _x Ga _y In _(1-x-y) The composition of the P functional layer can be respectively adjusted according to the needs.

Specifically, in the embodiment of the present invention, the surface of the N-type roughened layer 13, which is away from the N-type current spreading layer 12 and has the first hollow area 20, is roughened; the N-electrode securing layer 14 exposes the roughened surface of the N-type roughened layer 13.

Optionally, in another embodiment of the present invention, another optional structure of the epitaxial layer 4 is further provided for the LED chip emitting light through the reverse-electrode small hole, wherein the MQW light-emitting layer 7 is an AlGaInAs-based MQW light-emitting layer, and the epitaxial layer 4 includes:

and the P-type AlGaAs limiting layer, the P-type AlGaAs current expansion layer and the P-type GaP ohmic contact layer are sequentially positioned on one side of the AlGaInAs-based MQW light-emitting layer facing the first substrate 1, wherein the P-type AlGaAs current expansion layer and the P-type GaP ohmic contact layer form a P-type window layer 6.

And the N-type AlGaAs limiting layer, the N-type AlGaAs current expanding layer, the N-type AlGaAs thickening layer and the N-type GaInP electrode fixing layer are sequentially positioned on one side, away from the first substrate 1, of the AlGaInAs-based MQW light-emitting layer.

Wherein the AlGaInAs material refers to Al _x Ga _y In _(1-x-y) As material, each Al _x Ga _y In _(1-x-y) The components of the As functional layer can be respectively adjusted according to the requirements, and the AlGaAs material refers to Al _x Ga _y In _(1-x-y) X and y may be different in the case of 1-x-y =0 in As.

Optionally, in another embodiment of the present invention, with reference to fig. 1, the above-mentioned LED chip emitting light from the reverse-polarity aperture is described in detail, and the LED chip further includes:

and in the first direction a, an N ohmic contact layer 15 and an N ohmic contact metal layer 16 are sequentially located on one side of the first surface of the epitaxial layer 4 and between the N electrode 9 and the N electrode fastening layer 14.

Specifically, in the embodiment of the present invention, as shown in fig. 3, fig. 3 is a schematic top view of an LED chip with a light emitting hole with reversed polarity provided in the embodiment of the present invention, with reference to fig. 3, a distribution area of the P ohmic contact metal units 5 is smaller than the first hollow area 20, the N ohmic contact metal layer 16 surrounds the periphery of the first hollow area 20, and the N ohmic contact metal layer 16 further exposes a partial area of the N electrode fastening layer 14; the exposed partial area of the N electrode fixing layer 14 is directly contacted with the N electrode 9, so that the N electrode 9 obtains stronger adhesive force when being communicated with the bonding wire 19, and the problem that the N electrode 9 falls off in the wire bonding process can be solved.

In addition, as shown in fig. 4, fig. 4 is a schematic structural diagram of another reverse-polarity LED chip with small holes emitting light according to an embodiment of the present invention, and with reference to fig. 4, the N electrode 9 covers and protects the N ohmic contact layer 15 and the N ohmic contact metal layer 16, so as to prevent the roughening solution from corroding and damaging the N ohmic contact layer 15, and avoid the problem of high chip voltage; in fig. 4, the P-ohmic contact metal unit 5 is used to guide holes to be injected into the MQW light-emitting layer 7, and the N-ohmic contact layer 15 and the N-ohmic contact metal layer 16 are used to guide electrons to be injected into the MQW light-emitting layer 7, so that an electron-hole recombination region is located just below the first hollow-out region 20, thereby reducing the recombination in the region beyond the first hollow-out region 20, and improving the light-emitting efficiency.

Optionally, in another embodiment of the present invention, referring to fig. 5, fig. 5 is a schematic structural diagram of another light-emitting LED chip with reversed polarity aperture provided in the embodiment of the present invention, and the light-emitting LED chip with reversed polarity aperture is described in detail with reference to fig. 5, where the LED chip further includes:

a scribe line groove 21, wherein the depth of the scribe line groove 21 in the first direction a reaches the P-type window layer 6 or the ODR dielectric film layer 3.

The insulating passivation layer 8 covers the slanted sidewalls and the side of the scribe lane trenches 21 facing away from the first substrate 1, and an area of the first surface having an edge with a width of at least 1 micrometer is covered by the insulating passivation layer 8.

Specifically, in the embodiment of the present invention, the N electrode 9 is fully covered on the side of the insulating passivation layer 8 away from the first substrate 1, and an area with a width greater than 1 μm on the first surface is covered by the N electrode 9.

The N electrode 9 partially covers a side of the scribe line groove 21 departing from the first substrate 1, the N electrode 9 further has a second hollow area 22, and the second hollow area 22 exposes a partial area of the scribe line groove 21 departing from the first substrate 1, so as to facilitate subsequent cutting of the LED chip.

A metal bonding layer 17 between the first substrate 1 and the ODR metal reflective layer 2; a P-electrode 18 on a side of the first substrate 1 facing away from the metal bonding layer 17.

Specifically, in the embodiment of the present application, the epitaxial layer 4 is bonded to the first substrate 1 by using the metal bonding layer 17, which is beneficial to improving the conductivity of the LED chip; the P-electrode 18 is beneficial to improving the photoelectric conversion efficiency of the LED chip.

The embodiment of the utility model provides a still provide the manufacturing approach of the luminous LED chip of a reverse polarity aperture, a manufacturing approach of the luminous LED chip of reverse polarity aperture, refer to fig. 6, fig. 6 is the embodiment of the utility model provides a manufacturing approach's of the luminous LED chip of reverse polarity aperture flow diagram, combine fig. 6, manufacturing approach's step includes:

s101, providing a first substrate 1 and a second substrate.

Specifically, in this 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.

S102, forming an epitaxial layer 4 on one side of the second substrate, wherein the epitaxial layer 4 comprises an MQW light-emitting layer 7 and a P-type window layer 6 which are sequentially located on one side of the second substrate.

S103, processing the surface of the P-type window layer 6 on the side away from the MQW light-emitting layer 7, so that the surface of the P-type window layer 6 on the side away from the MQW light-emitting layer 7 comprises a first area and a second area, and the doping concentration of the first area is greater than that of the second area.

Specifically, in this step S103, the P-type window layer 6 is a P-type GaP window layer, the surface of the P-type GaP window layer on the side away from the MQW light-emitting layer 7 is etched, the highly doped GaP on the surface of the P-type GaP window layer is etched, the highly doped GaP in the first region is left to be not etched, and the second region is exposed.

And S104, forming an ODR dielectric film layer 3 on one side of the P-type window layer 6, which is far away from the MQW light-emitting layer 7.

Specifically, in the step S104, the preferred thickness of the ODR dielectric film layer 3 may be calculated according to (2k + 1) λ/4n, for example, taking the SiO2 dielectric film layer as an example, k =0, the red wavelength λ =630nm, and the refractive index n =1.45 of sio2, the preferred thickness of the SiO2 dielectric film layer may be calculated to be 108.6nm.

And S105, processing the ODR dielectric film layer 3 to form a plurality of first through holes penetrating through the ODR dielectric film layer 3.

Specifically, in the step S105, a plurality of first through holes penetrating through the ODR dielectric film 3 may be formed in the ODR dielectric film 3 by photolithography or etching.

S106, forming a P ohmic contact metal unit 5, wherein the P ohmic contact metal unit 5 fills the first through hole; forming an ODR metal reflecting layer 2 on one side of the ODR dielectric film layer 3 departing from the P-type window layer 6; the first substrate 1 is formed on the side of the ODR metal reflective layer 2 facing away from the second substrate.

Specifically, in the step S106, if a plurality of first through holes are formed in the step S105 by using a photolithography method, the photoresist needs to be removed after the first through holes are formed, and then the 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 a plurality of first through holes are formed in the step S105 by etching, the ODR metal reflective layer 2 may be directly formed on a side of the ODR dielectric film layer 3 away from the P-type window layer 6 after the first through holes are formed; the ODR metal reflective layer 2 is connected to the first region of the P-type window layer 6 through a plurality of first through holes, and the P-ohmic contact metal unit 5 is formed in the plurality of first through holes after annealing.

Specifically, in the step S106, several different alternative implementations are provided for the implementation process of forming the first substrate 1 on the side of the ODR metal reflective layer 2 away from the second substrate:

firstly, a metal bonding layer 17 is formed on the side of the epitaxial layer 4 away from the second substrate; the first substrate 1 is formed on the side of the metal bonding layer 17 facing away from the epitaxial layer 4.

Secondly, forming a first metal bonding layer on one side of the epitaxial layer 4, which faces away from the second substrate; forming a second metal bonding layer on one side of the first substrate 1; bonding the first metal bonding layer and the second metal bonding layer together through mutual diffusion in a heating and pressurizing bonding process, so that the epitaxial layer 4 is bonded to the first substrate 1; wherein the first metal bonding layer and the second metal bonding layer are the same metal bonding layer.

S107, removing the second substrate, and processing the epitaxial layer 4 to make the side wall of the epitaxial layer 4 be an inclined side wall, wherein an included angle theta between the inclined side wall and the plane of the first substrate 1 is an acute angle.

S108, forming an insulating passivation layer 8 and an N electrode 9, wherein the N electrode 9 covers the side wall of the epitaxial layer 4 and partially covers the first surface of the epitaxial layer 4, and the first surface of the epitaxial layer 4 is the surface of the epitaxial layer 4, which is far away from the first substrate 1; the insulating passivation layer 8 is located between the N-electrode 9 and the epitaxial layer 4.

The N electrode has a first hollow area 20, and the first hollow area 20 exposes a partial area of the first surface of the epitaxial layer 4, so that light emitted by the MQW light-emitting layer 7 exits from the first hollow area 20; in the first direction a, an orthographic projection of the first hollow-out region 20 completely covers the P-ohmic contact metal unit 5, the first direction a is perpendicular to a plane of the first substrate 1, and is directed to the epitaxial layer 4 from the first substrate 1.

Specifically, in step S108, the N electrode 9 may be formed through a process such as photolithography, evaporation, stripping, annealing, and the like, so that the N electrode 9 covers the sidewall of the epitaxial layer 4 and partially covers the first surface of the epitaxial layer 4.

And S109, forming a P electrode 18 on one side of the first substrate 1, which is far away from the epitaxial layer 4.

Specifically, in step S109, the side of the first substrate 1 away from the epitaxial layer 4 is ground and thinned, and then evaporation and annealing operations are performed to form the P electrode 18.

The embodiment of the utility model provides a pair of manufacturing approach of luminous LED chip of reverse polarity aperture, this manufacturing approach includes: providing a first substrate 1 and a second substrate; forming an epitaxial layer 4 on one side of the second substrate, wherein the epitaxial layer 4 comprises an MQW light-emitting layer 7 and a P-type window layer 6 which are sequentially positioned on one side of the second substrate; the surface of the P-type window layer 6 on the side away from the MQW light-emitting layer 7 is processed, so that the surface of the P-type window layer 6 on the side away from the MQW light-emitting layer 7 comprises a first area and a second area, the doping concentration of the first area is greater than that of the second area, current expansion can be limited through the processing, and light-emitting efficiency is improved; forming an ODR dielectric film layer 3 on one side of the P-type window layer 6, which is far away from the MQW light-emitting layer 7; processing the ODR dielectric film layer 3 to form a plurality of first through holes penetrating through the ODR dielectric film layer 3; forming a P ohmic contact metal unit 5, wherein the P ohmic contact metal unit 5 fills the first through hole; an ODR metal reflecting layer 2 is formed on one side, away from the P-type window layer 6, of the ODR dielectric film layer 3, and the ODR metal reflecting layer 2 and the ODR dielectric film layer 3 can form an ODR reflector at the bottom of the epitaxial layer 4 and reflect light rays emitted to the bottom of the epitaxial layer 4; processing the epitaxial layer 4 to enable the side wall of the epitaxial layer 4 to be an inclined side wall, wherein an included angle theta between the inclined side wall and the plane of the first substrate 1 is an acute angle; an insulating passivation layer 8 and an N electrode 9 are formed on one side of the inclined side wall, which is far away from the first substrate 1, an ODR reflector of the inclined side wall can be formed, and light rays emitted to the inclined side wall are reflected, so that the light rays are only emitted from the first hollow area 20, and stray light emitted by the side wall is restrained; the N electrode 9 is provided with a first hollow-out area 20, and the first hollow-out area 20 exposes a partial area 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-out area 20; in the first direction a, the orthographic projection of the first hollow-out region 20 completely covers the P-ohmic contact metal unit 5, so that electrons and holes injected into the MQW light-emitting layer 7 can be guided, an electron-hole recombination region is just located in the MQW light-emitting layer 7 under the orthographic projection of the first hollow-out region 20, recombination outside the first hollow-out region 20 is reduced, current expansion is controlled by oxidizing the MQW light-emitting layer 7 by an oxidation furnace, and the current further passes through the first hollow-out region 20 to improve the light-emitting efficiency.

Optionally, in another embodiment of the present invention, a detailed description is provided for the implementation process of forming the epitaxial layer 4 on one side of the second substrate in step S102 in the manufacturing method of the LED chip emitting light from the reverse-polarity aperture, and the manufacturing method further includes:

an N-type buffer layer, an N-type corrosion stop layer, an N-ohmic contact layer 15, an N-electrode firm layer 14, an N-type rough layer 13, an N-type current spreading layer 12 and an N-type limiting layer 11 are sequentially formed on one side, facing the MQW light-emitting layer 7, of the second substrate; a P-type confinement layer 10 is formed on the MQW light-emitting layer 7 on the side facing the P-type window layer 6.

Specifically, in the embodiment of the present invention, several different optional implementation methods are introduced:

first, as shown in fig. 7, fig. 7 is the embodiment of the utility model provides a luminous LED chip's of reverse polarity aperture epitaxial layer structure sketch map combines fig. 7, the embodiment of the utility model provides a through adopting MOCVD be in second substrate 23 towards one side of MQW luminescent layer 7 forms reverse polarity AlGaInP base ruddiness LED epitaxial wafer, specifically as follows:

an N-type buffer layer 24, an N-type corrosion stop layer 25, an N-ohmic contact layer 15, an N-electrode fixing layer 14, an N-type rough layer 13, an N-type current spreading layer 12 and an N-type limiting layer 11 are sequentially formed on one side, facing the MQW light-emitting layer 7, of the second substrate 23; a P-type confinement layer 10 is formed on the MQW light-emitting layer 7 on the side facing the P-type window layer 6.

The N-type buffer layer 24 and the N-type ohmic contact layer 15 are made of GaAs material, the N-type corrosion stop layer 25 and the N-electrode fixing layer 14 are made of GaInP material, and the N-type rough 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 material, wherein the AlGaInP material is Al material _x Ga _y In _(1-x-y) P material, each Al _x Ga _y In _(1-x-y) The composition of the P functional layer can be respectively adjusted according to the needs.

The second kind, as shown in fig. 8, fig. 8 is the utility model provides a luminous LED chip's of reverse polarity aperture epitaxial layer structure sketch map combines fig. 8, the embodiment of the utility model provides a through adopting MOCVD to be in the second substrate 23 towards one side of MQW luminescent layer 7 forms reverse polarity AlGaInAs base infrared LED epitaxial wafer, specifically as follows:

an N-type buffer layer 24, an N-type corrosion stop layer 25, an N-ohmic contact layer 15, an N-electrode fixing layer 14, an N-type rough layer 13, an N-type current spreading layer 12 and an N-type limiting layer 11 are sequentially formed on one side, facing the MQW light-emitting layer 7, of the second substrate 23; a P-type confinement layer 10, a P-type current spreading layer 26 and a P-type ohmic contact layer 27 are sequentially formed on the MQW light-emitting layer 7 on the side away from the N-type confinement layer 11, and the P-type current spreading layer 26 and the P-type ohmic contact layer 27 may constitute the P-type window layer 6.

The N-type buffer layer 24 and the N-type ohmic contact layer 15 are made of GaAs materials, the N-type corrosion stop layer 25 and the N-electrode fixing layer 14 are made of GaInP materials, the N-type rough 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 materials, and the P-type ohmic contact layer 27 is made of GaP materials; wherein the AlGaInAs material refers to Al _x Ga _y In _(1-x-y) As material, each Al _x Ga _y In _(1-x-y) The components of the As functional layer can be respectively adjusted according to the requirements, and the AlGaAs material refers to Al _x Ga _y In _(1-x-y) X and y may be different in the case of 1-x-y =0 in As.

In the above two alternative embodiments, it should be further noted that, for sequentially forming the N-type GaAs buffer layer 24 and the N-type GaInP corrosion stop layer 25 on the side of the second substrate 23 facing the MQW light-emitting layer 7, in step S107, the N-type GaAs buffer layer 24 and the N-type GaInP corrosion stop layer 25 also need to be removed when the second substrate 23 is removed.

Processing the N-type ohmic contact layer 15 to expose a partial region of the N-type ohmic contact layer 15 on the N-type electrode firm layer 14; an N-ohmic contact metal layer 16 is formed on the side of the N-ohmic contact layer 15 facing away from the N-electrode fastening layer 14.

Specifically, in the embodiment of the utility model provides an in, can be through photoetching, wet etching preparation N ohmic contact layer 15, make N type ohmic contact layer 15 exposes the subregion of the firm layer 14 of N electrode, rethread photoetching, coating by vaporization, peel off, the preparation of annealing process N ohmic contact metal layer 16 makes N ohmic contact layer 15 with N ohmic contact metal layer 16 forms good ohmic contact.

The side of the N-type roughened layer 13 facing the N-electrode securing layer 14 is roughened.

Specifically, in the embodiment of the present invention, in the course of performing the roughening treatment on the N-type roughened layer 13, it is also possible to perform the roughening treatment and other operations on the inclined side wall of the epitaxial layer 4.

Optionally, in another embodiment of the present invention, a method for manufacturing the LED chip with the reversed-polarity aperture for emitting light is described in detail, the method further includes:

forming a cutting channel groove 21 on one side of the epitaxial layer 4, which is far away from the first substrate 1, and forming an inclined side wall of the epitaxial layer 4, wherein the depth of the cutting channel groove 21 in the first direction a reaches the P-type window layer 6 or the ODR dielectric film layer 3.

Specifically, in the embodiment of the present invention, a photoresist is spin-coated on one side of the epitaxial layer 4 away from the first substrate 1, the cut-off groove 21 region is defined after exposure and development, the first hollow-out region 20 is protected by the photoresist, the cut-off groove 21 is not protected by the photoresist, and the cut-off groove 21 is formed by dry etching; meanwhile, the side wall of the epitaxial layer 4 is etched into an inclined side wall by adjusting parameters such as gas flow, chamber pressure, radio frequency power and the like in the dry etching process.

The forming of the insulating passivation layer 8 further includes: the insulating passivation layer 8 is formed on the side of the inclined side wall facing away from the first substrate 1 and the side of the scribe line trench 21 facing away from the first substrate 1, and the insulating passivation layer 8 is formed on the region of the edge of the first surface of the epitaxial layer 4 with a width of at least 1 micrometer.

Specifically, in the embodiment of the present invention, siN may be deposited on one side of the first substrate 1 deviating from the inclined sidewall and one side of the scribe line trench 21 deviating from the first substrate 1 _x 、SiO ₂ 、Al ₂ O ₃ 、MgF ₂ An insulating passivation layer 8 of a material andetching the first surface of the epitaxial layer 4 to expose the N ohmic contact layer 15 and the N ohmic contact metal layer 16, so that the N electrode 9 is in communication with the N ohmic contact layer 15 and the N ohmic contact metal layer 16.

The forming the N-electrode 9 further includes: the N electrode 9 is formed on a side of the scribe line groove 21 away from the first substrate 1, the N electrode 9 further has a second hollow area 22, the second hollow area 22 exposes a partial area of the scribe line groove 21 away from the first substrate 1, and the second hollow area 22 facilitates subsequent cutting to form the LED chip.

And cutting the second hollow-out area 22 to form a plurality of LED chips.

Specifically, in the embodiment of the present invention, the second hollow area 22 can be cut in tangent, back-cut, and splitting processes, and the wafer is cut into discrete LED chips, thereby completing the manufacturing process of the LED chips.

The above detailed description is made on the LED chip with reversed-polarity small holes and the manufacturing method thereof provided by the present invention, and the specific examples are applied herein to explain the principle and the implementation of the present invention, and the description of the above embodiments is only used to help understand the method and the core idea of the present invention; meanwhile, for the general technical personnel in the field, according to the idea of the present invention, there are changes in the specific implementation and application scope, to sum up, the content of the present specification should not be understood as the limitation of the present invention.

It should be noted that, in this specification, each embodiment is described in a progressive manner, and each embodiment focuses on differences from other embodiments, and portions that are the same as and similar to each other in each embodiment may be referred to. The device disclosed by the embodiment corresponds to the method disclosed by the embodiment, so that the description is simple, and the relevant points can be referred to the method part for description.

It is further noted that, herein, relational terms such as first and second, and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include or include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising a … …" does not exclude the presence of another identical element in a process, method, article, or apparatus that comprises the element.

The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended 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. An LED chip emitting light through a reverse polarity aperture, the LED chip comprising:

a first substrate;

2. The LED chip of claim 1, wherein said epitaxial layers further comprise:

3. The LED chip of claim 1, wherein said LED chip further comprises:

4. The LED chip of claim 1, wherein an angle θ between said sloped sidewall and a plane of said first substrate is in the range of 5 ° θ 85 °.

5. The LED chip of claim 1, further comprising a dicing street trench having a depth in the first direction up to the P-type window layer or the ODR dielectric film layer.

6. The LED chip of claim 5, wherein the insulating passivation layer covers the sloped sidewalls and a side of the scribe line trench facing away from the first substrate, and wherein an edge of the first surface is covered by the insulating passivation layer over an area having a width of at least 1 micron.

7. The LED chip of claim 5, wherein the N electrode partially covers a side of the scribe line trench facing away from the first substrate, and the N electrode further has a second hollowed-out area exposing a partial area of the side of the scribe line trench facing away from the first substrate.

8. The LED chip of claim 1, wherein said LED chip further comprises: