CN116960250A

CN116960250A - Light emitting diode and light emitting device

Info

Publication number: CN116960250A
Application number: CN202210389394.9A
Authority: CN
Inventors: 王晶; 杨洋; 张昀
Original assignee: Quanzhou Sanan Semiconductor Technology Co Ltd
Current assignee: Quanzhou Sanan Semiconductor Technology Co Ltd
Priority date: 2022-04-13
Filing date: 2022-04-13
Publication date: 2023-10-27

Abstract

The invention provides a light-emitting diode, which comprises an epitaxial structure, a first contact electrode, a second contact electrode and a high-resistance layer, wherein the epitaxial structure sequentially comprises a first semiconductor layer, a light-emitting layer and a second semiconductor layer from the lower surface to the upper surface, the first contact electrode and the second contact electrode are both positioned on the upper surface of the epitaxial structure and are respectively and electrically connected with the first semiconductor layer and the second semiconductor layer, the high-resistance layer extends downwards from the upper surface of the epitaxial structure to the first semiconductor layer, a penetrating electric area is arranged in the epitaxial structure, the penetrating electric area is at least in the same horizontal plane with the light-emitting layer and the second semiconductor layer, the boundary of the penetrating electric area is in contact with the high-resistance layer, and the first contact electrode is positioned on the penetrating electric area and is electrically connected with the first semiconductor layer through the penetrating electric area. Therefore, the first contact electrode and the second contact electrode are positioned on the same horizontal plane, the height difference of the first contact electrode and the second contact electrode is eliminated, the light-emitting diode with the balanced symmetrical structure is obtained, and the product yield is improved.

Description

Light emitting diode and light emitting device

Technical Field

The present invention relates to the field of semiconductor manufacturing technology, and in particular, to a light emitting diode and a light emitting device.

Background

A light emitting diode (Light Emitting Diode, abbreviated as LED) is a semiconductor light emitting element, generally made of a semiconductor such as GaN, gaAs, gaP, gaAsP, and has a core of a PN junction having a light emitting property, in which electrons are injected from an N region into a P region and holes are injected from the P region into the N region under a forward voltage, and the electrons and holes are recombined to make the light emitting diode emit light. LEDs have the advantages of high luminous intensity, high efficiency, small volume, long service life, etc., and are considered to be one of the most potential light sources at present.

Micro LEDs, i.e., micro LEDs, generally refer to chips with smaller sizes, and due to the characteristics of small chip size, high integration level, self-luminescence, etc., micro LEDs have greater advantages in terms of brightness, resolution, contrast, energy consumption, service life, response speed, thermal stability, etc., compared with LCDs and OLEDs in terms of display.

As shown in fig. 1, the conventional Micro LED structure is generally designed as a horizontal structure, which includes a substrate 80, an epitaxial structure 81, an N-type electrode 82, a P-type electrode 83, an insulating layer 84, an N-type pad 85, and a P-type pad 86. Specifically, the epitaxial structure includes an N-type semiconductor layer 811, a light-emitting layer 812, and a P-type semiconductor layer 813, which are sequentially stacked over a substrate. In the case of disposing the N-type electrode 82, a recess 814 is etched down at the P-type semiconductor layer 813 to form an electrode mesa 815, and the electrode mesa 815 exposes the N-type semiconductor layer 811, and the electrode mesa 815 is used for disposing the N-type electrode 82. Inevitably, this method needs to dig out part of the epitaxial structure 81 to form the electrode mesa 815, so that the Micro LED becomes unbalanced, the N-type bonding pad 85 and the P-type bonding pad 86 are not located on the same horizontal plane any more, and further, due to the unbalance of the Micro LED design, phenomena such as overturning or position deviation and the like occur in the process of transferring and falling of the Micro LED, so that the transfer yield of the Micro LED is reduced. In addition, the difference in height between the N-type electrode 82 and the P-type electrode 83 also increases the difficulty of the process flow, which is not beneficial to the preparation of Micro LEDs.

Disclosure of Invention

The invention provides a light emitting diode, which comprises an epitaxial structure, a first contact electrode, a second contact electrode and a high-resistance layer.

The epitaxial structure is provided with a first surface and a second surface which are opposite, and the epitaxial structure sequentially comprises a first semiconductor layer, a light-emitting layer and a second semiconductor layer from the first surface to the second surface. The first contact electrode is positioned on the second surface of the epitaxial structure and is electrically connected with the first semiconductor layer. The second contact electrode is positioned on the second surface of the epitaxial structure and is electrically connected with the second semiconductor layer. The high-resistance layer is located in the epitaxial structure and extends downwards from the second surface of the epitaxial structure to the first semiconductor layer. The epitaxial structure is internally provided with a penetration electric area, the penetration electric area is at least in the same horizontal plane with the light-emitting layer and the second semiconductor layer, the boundary of the penetration electric area is contacted with the high-resistance layer, and the first contact electrode is positioned on the penetration electric area and is electrically connected with the first semiconductor layer through the penetration electric area.

In an embodiment, the first contact electrode extends towards the first surface of the epitaxial structure with a diffusion electrode passing through the percolation region to contact the first semiconductor layer.

In one embodiment, the diffusion electrode is formed by utilizing the difference of diffusion depths of multiple metals in the first contact electrode after fusion.

In an embodiment, the semiconductor type of the percolation region is the same as the first semiconductor layer.

In an embodiment, the semiconductor type of the percolation region is made the same as the semiconductor type of the first semiconductor layer by way of an ion placement process.

In an embodiment, the percolation region contacts the light emitting layer and the second semiconductor layer, where the percolation region contacts the light emitting layer and the second semiconductor layer acts as the high-resistance layer.

In an embodiment, the first contact electrode is at the same level as the second contact electrode.

In an embodiment, no groove is formed below the first contact electrode.

In an embodiment, the light emitting diode further includes an insulating reflective layer covering at least the second surface of the epitaxial structure, and having a first opening for exposing the first contact electrode and a second opening for exposing the second contact electrode.

In an embodiment, the light emitting diode further includes a first pad connected to the first contact electrode and a second pad connected to the second contact electrode, and the first pad is flush with an upper surface of the second pad.

In an embodiment, the light emitting diode is a balanced symmetrical structure.

In an embodiment, the first contact electrode at least includes an alloy material of one of gold germanium nickel, gold beryllium, gold germanium, gold zinc, and gold nickel.

In one embodiment, the material of the high-resistance layer can be selected from SiO ₂ One or more of SiNx, tiOx, alOx.

In one embodiment, the size of the light emitting diode is less than or equal to 100 μm.

The invention also provides a light-emitting device which can adopt the light-emitting diode according to any embodiment.

The invention provides a light emitting diode and a light emitting device, wherein the high-resistance layer and the penetration electric region are matched, an electrode table surface is not required to be etched on an epitaxial structure to set a first contact electrode, the first contact electrode is directly arranged on a second surface of the epitaxial structure, the first contact electrode and the second contact electrode are positioned on the same horizontal plane, the height difference between the first contact electrode and the second contact electrode is eliminated, the light emitting diode with a balanced and symmetrical structure is obtained, and the product yield is improved.

Additional features and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objectives and other advantages of the invention will be realized and attained by the structure particularly pointed out in the written description and claims hereof as well.

Drawings

For a clearer description of embodiments of the invention or of the solutions of the prior art, the drawings that are needed in the description of the embodiments or of the prior art will be briefly described, it being obvious that the drawings in the description below are some embodiments of the invention, and that other drawings can be obtained from them without inventive effort for a person skilled in the art; in the following description, the positional relationship described in the drawings is based on the orientation of the components shown in the drawings unless otherwise specified.

FIG. 1 is a schematic diagram of a conventional Micro LED structure;

FIG. 2 is a schematic diagram of a light emitting diode according to an embodiment of the present invention;

FIGS. 3-7 are schematic views of the structure of the LED of FIG. 2 at various stages in the manufacturing process according to the present invention;

FIG. 8 is a schematic diagram of a light emitting diode according to another embodiment of the present invention;

FIGS. 9-14 are schematic views of the structure of the LED of FIG. 8 at various stages in the manufacturing process according to the present invention;

fig. 15 is a schematic structural diagram of a light emitting diode according to another embodiment of the present invention.

Reference numerals:

1. 2, 3-light emitting diodes; 12-a substrate; a 14-epi structure; 141-a first surface; 142-a second surface; 143-a first semiconductor layer; 144-a light emitting layer; 145-a second semiconductor layer; 16-a high-resistance layer; 18-an insulating reflective layer; 181-a first opening; 182-a second opening; 20-an osmotic electrical zone; 21-a first contact electrode; 211-a diffusion electrode; 22-a second contact electrode; 31-a first bonding pad; 32-a second bonding pad; 40-bonding layer.

Detailed Description

For the purpose of making the objects, technical solutions and advantages of the embodiments of the present invention more clear, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention, and it is apparent that the described embodiments are some embodiments of the present invention, but not all embodiments of the present invention; the technical features designed in the different embodiments of the invention described below can be combined with each other as long as they do not conflict with each other; all other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.

In the description of the present invention, it should be understood that the terms "center," "lateral," "upper," "lower," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," and the like indicate orientations or positional relationships based on the orientation or positional relationships shown in the drawings, merely to facilitate describing the present invention and simplify the description, and do not indicate or imply that the devices or components referred to must have a specific orientation or be configured and operated in a specific orientation, and thus should not be construed as limiting the present invention. Furthermore, the terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include one or more such feature. In the description of the present invention, unless otherwise indicated, the meaning of "a plurality" is two or more. In addition, the term "comprising" and any variations thereof are meant to be "at least inclusive".

Referring to fig. 2, fig. 2 is a schematic structural diagram of a light emitting diode 1 according to an embodiment of the invention. To achieve at least one of the advantages and other advantages, an embodiment of the present invention provides a light emitting diode 1. As shown in the figures, the light emitting diode 1 comprises an epitaxial structure 14, a first contact electrode 21, a second contact electrode 22, and a high resistance layer 16.

Epitaxial structure 14 is disposed on substrate 12. The substrate 12 may be an insulating substrate, and preferably the substrate 12 may be made of a transparent material or a translucent material. In the illustrated embodiment, the substrate 12 is a sapphire substrate. In some embodiments, substrate 12 may be a patterned sapphire substrate, but the present patent is not so limited. The substrate 12 may also be made of a conductive material or a semiconductor material. For example: the substrate 12 material may include at least one of silicon carbide (SiC), silicon (Si), magnesium oxide (MgO), and gallium nitride (GaN).

The epitaxial structure 14 has a first surface 141 and a second surface 142 opposite to each other, and in this embodiment, the first surface 141 is a lower surface of the epitaxial structure 14 and the second surface 142 is an upper surface of the epitaxial structure 14. The epitaxial structure 14 includes, in order from the first surface 141 to the second surface 142, a first semiconductor layer 143, a light emitting layer 144, and a second semiconductor layer 145. The first surface 141 of the epitaxial structure 14 contacts the substrate 12, that is, the first semiconductor layer 143, the light emitting layer 144, and the second semiconductor layer 145 are sequentially stacked on the substrate 12.

The first semiconductor layer 143 may be an N-type semiconductor layer, and may supply electrons to the light emitting layer 144 under the power supply. In some embodiments, the first semiconductor layer 143 includes an N-type doped nitride layer. The N-doped nitride layer may include one or more N-type impurities of a group IV element. The N-type impurity may include one of Si, ge, sn, or a combination thereof. In some embodiments, the N-type semiconductor layer may be a doped AlGaInP layer. In some embodiments, a further buffer layer is provided between the first semiconductor layer 143 and the substrate 12 to mitigate lattice mismatch between the substrate 12 and the first semiconductor layer 143. The buffer layer may include an unintentionally doped GaN layer, or an unintentionally doped AlGaN layer, or an unintentionally doped AlN layer.

The light emitting layer 144 may be a quantum well structure. In some embodiments, the light emitting layer 144 may also be a multiple quantum well structure, wherein the multiple quantum well structure includes a plurality of quantum well layers and a plurality of quantum barrier layers alternately arranged in a repetitive manner, such as a multiple quantum well structure that may be AlGaInP/GaInP, gaN/AlGaN, inAlGaN/InAlGaN or InGaN/AlGaN. The composition and thickness of the well layer in the light-emitting layer 144 determine the wavelength of the generated light. To increase the light emitting efficiency of the light emitting layer 144, this may be achieved by varying the depth of the quantum wells, the number of layers, thickness, and/or other characteristics of the pairs of quantum wells and quantum barriers in the light emitting layer 144.

The second semiconductor layer 145 may be a P-type semiconductor layer, and may provide holes to the light emitting layer 144 under the power supply. In some embodiments, the second semiconductor layer 145 includes an AlInP layer doped with P-type dopant, which may be Mg, C, or the like. In some embodiments, the second semiconductor layer 145 includes a P-type doped nitride layer. The P-doped nitride layer may include one or more P-type impurities of a group II element. The P-type impurity may include one of Mg, zn, be, or a combination thereof. The second semiconductor layer 145 may have a single-layer structure or a multi-layer structure, and the multi-layer structure may have different compositions. In addition, the arrangement of the epitaxial structure 14 is not limited thereto, and other types of epitaxial structures 14 may be selected according to actual requirements.

The first contact electrode 21 and the second contact electrode 22 are located on the same surface of the epitaxial structure 14. Specifically, the first contact electrode 21 is located on the second surface 142 of the epitaxial structure 14 and is electrically connected to the first semiconductor layer 143. The second contact electrode 22 is located on the second surface 142 of the epitaxial structure 14 and is electrically connected to the second semiconductor layer 145. The first contact electrode 21 may have a multi-layer structure including at least one alloy material of gold germanium nickel, gold beryllium, gold germanium, gold zinc, and gold nickel, for example, the stacked structure of the first contact electrode 21 may be Au/Ni/Au/augeneni/Au.

The second contact electrode 22 may be made of a transparent conductive material or a metal material, and may be adaptively selected according to the doping condition of the surface layer of the second semiconductor layer 145. In some embodiments, the second contact electrode 22 is made of transparent conductive material, and the material may include indium tin oxide, zinc indium oxide, or zinc oxide, but the embodiment of the disclosure is not limited thereto.

The high-resistance layer 16 is located in the epitaxial structure 14, and the high-resistance layer 16 extends downward from the second surface 142 of the epitaxial structure 14 to the first semiconductor layer 143, so as to electrically insulate the percolation region 20 and the second semiconductor layer 145 from each other, thereby avoiding a short circuit. The high-resistance layer 16 may be a physical barrier layer or an insulating structure layer with a high resistance value.

The epitaxial structure 14 has a percolation region 20 therein, and the percolation region 20 is at least on the same level as both the light emitting layer 144 and the second semiconductor layer 145, i.e. part of the percolation region 20 is on the same level as the light emitting layer 144, and part of the percolation region 20 is on the same level as the second semiconductor layer 145, i.e. on the same level. The boundary of the osmotic electrical zone 20 contacts the high-resistance layer 16. The first contact electrode 21 is located on the percolation region 20 and is electrically connected to the first semiconductor layer 143 through the percolation region 20. By means of the collocation arrangement of the osmotic electric area 20 and the high-resistance layer 16, the electrode table top is not required to be etched on the epitaxial structure 14 to set the first contact electrode 21 like that shown in fig. 1, but the first contact electrode 21 is directly arranged on the second surface 142 of the complete epitaxial structure 14, so that the first contact electrode 21 and the second contact electrode 22 are positioned on the same horizontal plane, the height difference between the first contact electrode 21 and the second contact electrode 22 is eliminated, the light-emitting diode 1 with a balanced symmetrical structure is obtained, the problem of poor transfer caused by symmetry and balance in the transfer process of the light-emitting diode 1 is solved, and meanwhile, the manufacturing process is simpler due to the fact that the height difference on the whole structure is reduced.

Note that the extent of the percolation region 20 is shown in fig. 2 by a dashed line, but it should be noted that the percolation region 20 does not cross the high-resistance layer 16, and the dashed line is shown to exceed the boundary of the high-resistance layer 16. Also within the percolation region 20 of fig. 2 is still the light emitting layer 144 and the second semiconductor layer 145.

Specifically, in the present embodiment, as shown in fig. 2, the first contact electrode 21 extends toward the first surface 141 of the epitaxial structure 14 with the diffusion electrode 211, and the diffusion electrode 211 passes through the percolation region 20 to contact the first semiconductor layer 143, so that the first contact electrode 21 is electrically connected to the first semiconductor layer 143. Preferably, the diffusion electrode 211 may be formed by using the difference in diffusion depth of the plurality of metals in the first contact electrode 21 after the fusion process. Note that, the shape and size of the diffusion electrode 211 in fig. 2 are only schematic, and the diffusion electrode 211 is realized by fusion diffusion, so that the structure formed by each diffusion is not necessarily identical.

Compared with the Micro LED structure shown in fig. 1, the recess is not formed under the first contact electrode 21 in this embodiment. The light emitting diode 1 of the present embodiment can be in a balanced and symmetrical structure by the matching arrangement of the diffusion electrode 211, the penetration electrical region 20 and the high-resistance layer 16. Balancing means that the first contact electrode 21 and the second contact electrode 22 are at the same level, the upper surfaces of the first contact electrode and the second contact electrode are substantially flush, and the balance of the epitaxial structure 14 is destroyed without purposely etching the electrode mesa on the epitaxial structure 14. The symmetry means that the light emitting diode 1 is a symmetrical structure with a central line as a symmetry axis, but is not completely symmetrical. The light-emitting diode 1 with the balanced and symmetrical structure effectively solves the problem of poor transfer caused by the asymmetry and unbalance of the light-emitting diode 1 in the transfer process.

In an embodiment, the light emitting diode 1 may further include an insulating reflective layer 18, a first pad 31, and a second pad 32.

The insulating reflective layer 18 covers at least the second surface 142 of the epitaxial structure 14 and has a first opening 181 and a second opening 182, the first opening 181 exposing the first contact electrode 21, and the second opening 182 exposing the second contact electrode 22. The insulating reflective layer 18 may be silicon dioxide, silicon nitride, titanium oxide, tantalum oxide, niobium oxide, barium titanate, or a combination thereof, for example, a bragg reflector (DBR) formed by repeatedly stacking two materials, or a total reflection mirror (ODR) formed by a low refractive index transparent dielectric layer (such as silicon oxide, magnesium fluoride, etc.) and a high reflective metal layer (such as Au, ag, al, etc.).

The first pad 31 is connected to the first contact electrode 21 through the first opening 181, the second pad 32 is connected to the second contact electrode 22 through the second opening 182, and the first pad 31 is flush with the upper surface of the second pad 32. The first and second pads 31 and 32 may be formed together using the same material in the same process, and thus may have the same layer configuration. However, the present invention is not limited thereto, and the first bonding pad 31 and the second bonding pad 32 may be made of a suitable material and layer structure according to the actual requirements of wire bonding package.

A method for manufacturing the light emitting diode 1 shown in fig. 2 is disclosed below. Referring to fig. 3 to 7, fig. 3 to 7 are schematic structural views of the led 1 shown in fig. 2 at various stages in the manufacturing process according to the present invention.

First, referring to fig. 3, the epitaxial structure 14 is first disposed on the substrate 12, and the disposed positions of the first contact electrode 21 and the second contact electrode 22 are determined on the second surface 142 of the epitaxial structure 14. Then, vapor deposition of the upper metal is started, and the first contact electrode 21 and the second contact electrode 22 are formed at the determined positions on the second surface 142. The first contact electrode 21 is, for example, an Au/Ni/Au/AuGeNi/Au stack, and the second contact electrode 22 is, for example, an Au/AuZn/Au stack.

Next, referring to fig. 4, a high-resistance layer 16 is provided in the epitaxial structure 14 around the first contact electrode 21 to avoid a short circuit. The high-resistance layer 16 may be formed by performing an ICP dry etching process directly on the epitaxial structure 14, and filling an insulating material in the portion of the isolation, thereby forming the high-resistance layer 16. The material of the high-resistance layer 16 may be selected from SiO ₂ One or more of SiNx, tiOx, alOx. In addition, the insulating material may not be filled in the isolation portion, but the physical isolation effect may be achieved by air, and the percolation region 20 and the second semiconductor layer 145 may be electrically insulated from each other; the high-resistance layer 16 may be formed in other ways, and it is only necessary to electrically insulate the percolation region 20 and the second semiconductor layer 145 from each other. For example, the high-resistance layer 16 may be a dielectric layer, or the processed epitaxial structure 14 (e.g., a structure with a high resistance value formed by wet oxygen, ion implantation, etc.).

Next, referring to fig. 5, the diffusion electrode 211 is formed by diffusing the plurality of different metals in the first contact electrode 21 to the first surface 141 due to the difference of diffusion depths after the fusion process, and the diffusion depth is controlled to be finally diffused to the first semiconductor layer 143 so that the first contact electrode 21 is electrically connected to the first semiconductor layer 143. The second contact electrode 22 may also form a good ohmic contact with the second semiconductor layer 145 by means of a fusion process. Ohmic contact of the first contact electrode 21 and the second contact electrode 22 may be achieved by one fusion or may be achieved by two fusion. In addition, the two steps of forming the high-resistance layer 16 and forming the diffusion electrode 211 may be exchanged, and preferably, the diffusion electrode 211 is preferentially formed, and then the high-resistance layer 16 is formed around the first contact electrode 21.

Subsequently, referring to fig. 6, an insulating reflective layer 18 is provided on the epitaxial structure 14, the first contact electrode 21 and the second contact electrode 22. The insulating reflective layer 18 is perforated to form a first opening 181 and a second opening 182, the first opening 181 is used for exposing the first contact electrode 21, and the second opening 182 is used for exposing the second contact electrode 22.

Finally, referring to fig. 7, a first pad 31 and a second pad 32 are provided on the insulating reflective layer 18, the first pad 31 being connected to the first contact electrode 21 through a first opening 181, and the second pad 32 being connected to the second contact electrode 22 through a second opening 182. Preferably, the first bonding pad 31 is directly connected to the first contact electrode 21, so that the phenomenon of poor and unstable electrical connection caused by poor climbing due to the inclined side wall in the conventional chip is avoided.

Referring to fig. 8, fig. 8 is a schematic structural diagram of a light emitting diode 2 according to another embodiment of the invention. To achieve at least one of the advantages or other advantages, another embodiment of the present invention further provides a light emitting diode 2. Compared to the led 1 shown in fig. 2, the led 2 of the present embodiment mainly differs in the penetration electrical region 20. Specifically, the semiconductor type in the percolation region 20 in the present embodiment is the same as the first semiconductor layer 143. In other words, taking the first semiconductor layer 143 and the second semiconductor layer 145 as an N-type semiconductor layer and a P-type semiconductor layer respectively as examples, in the first epitaxial structure 14, the second semiconductor layer 145 in the percolation region 20 is a P-type semiconductor layer, and then, in this embodiment, N-type conductive ions are injected into the percolation region 20 by performing ion placement treatment on the percolation region 20, so that the second semiconductor layer 145 and the light emitting layer 144 in the percolation region 20 are changed into N-type semiconductor layers, which are the same as the semiconductor type of the first semiconductor layer 143, so that the first contact electrode 21 can be electrically connected to the N-type semiconductor layer. In this embodiment, the region where the ion-disposed second semiconductor layer 145 and the light-emitting layer 144 are located is the region where the percolation region 20 is located.

A method for manufacturing the light emitting diode 2 shown in fig. 8 is disclosed below. Referring to fig. 9 to 14, fig. 9 to 14 are schematic views of the structure of the led 2 shown in fig. 8 at various stages in the manufacturing process according to the present invention.

First, referring to fig. 9, the epitaxial structure 14 is first disposed on the substrate 12, and the disposed position of the second contact electrode 22 is determined on the second surface 142 of the epitaxial structure 14. Then, vapor deposition of the upper metal is started, and the second contact electrode 22 is formed at a well-defined position on the second surface 142.

Next, referring to fig. 10, the extent of the ferroelectric region 20 is determined within the epitaxial structure 14, after which a high-resistance layer 16 is provided at the boundary of the ferroelectric region 20. The high-resistance layer 16 extends from the second surface 142 of the epitaxial structure 14 down to the first semiconductor layer 143 for electrically insulating the percolation region 20 and the second semiconductor layer 145 from each other. The high-resistance layer 16 may be formed in the manner described above with reference to fig. 2 and 4 for the high-resistance layer 16.

Next, referring to fig. 11, an ion arrangement process is performed to the epitaxial structure 14 where the percolation region 20 is located, and the second semiconductor layer 145 and the light emitting layer 144 in the percolation region 20 are changed to be the same semiconductor type as the first semiconductor layer 143. In an embodiment, the step of fig. 10 may be omitted, and instead, a P-N junction naturally formed on the boundary between the ion-disposed percolation region 20 and the untreated second semiconductor layer 145 is used as the high-resistance layer 16, where the resistance of the naturally formed P-N junction is much greater than the resistances of the percolation region 20 and the first semiconductor layer 143, so that the current flows along the vertical direction (refer to the vertical direction from the percolation region 20 to the first semiconductor layer 143 shown in fig. 11). That is, the place where the percolation electric field 20 contacts the light-emitting layer 144 and the second semiconductor layer 145 serves as the high-resistance layer 16.

Subsequently, referring to fig. 12, the first contact electrode 21 is disposed on the percolation region 20 which has become the same semiconductor type as the first semiconductor layer 143 such that the first contact electrode 21 is electrically connected to the first semiconductor layer 143.

Next, referring to fig. 13, an insulating reflective layer 18 is provided on the epitaxial structure 14, the first contact electrode 21, and the second contact electrode 22. The insulating reflective layer 18 is perforated to form a first opening 181 and a second opening 182, the first opening 181 is used for exposing the first contact electrode 21, and the second opening 182 is used for exposing the second contact electrode 22.

Finally, referring to fig. 14, a first pad 31 and a second pad 32 are provided on the insulating reflective layer 18, the first pad 31 being connected to the first contact electrode 21 through a first opening 181, and the second pad 32 being connected to the second contact electrode 22 through a second opening 182.

In summary, in any of the embodiments described above, the present invention mainly aims at providing the first contact electrode 21 without forming a recess on the epitaxial structure 14 to form an electrode mesa, but uses the concept of penetrating the electrical region 20 to enable the first contact electrode 21 to be electrically connected with the first semiconductor layer 143, so that the first contact electrode 21 and the second contact electrode 22 are in the same horizontal plane, the height difference between the first contact electrode 21 and the second contact electrode 22 is eliminated, the light emitting diode 1, 2 with a balanced and symmetrical structure is obtained, and the product yield is improved. The region where the percolation region 20 is located may be understood as the entire region surrounded by the high-resistance layer 16 and at the same level as the light emitting layer 144 and the second semiconductor layer 145.

It should be noted that, in the light emitting diodes 1 and 2 of any of the embodiments, the light emitting surface may be further provided with a roughened structure and a reflective structure, so as to further improve the light emitting performance of the light emitting diodes 1 and 2. In one embodiment, the overall size of the LEDs 1, 2 is 100 μm or less, that is, the LEDs 1, 2 are micro LEDs.

The light emitting structure 14 in any of the foregoing embodiments may be formed by directly growing on the substrate 12, but the present disclosure is not limited thereto. In another embodiment, a buffer layer and an etch stop layer may be grown sequentially on an epitaxial growth substrate (e.g., gallium arsenide). The buffer layer may be gallium arsenide and the etch stop layer is for subsequent removal of the epitaxial growth substrate. Next, the epitaxial structure continues to be grown, that is, the second semiconductor layer 145, the light emitting layer 144, and the first semiconductor layer 143 are sequentially grown on the etch stop layer. Subsequently, as shown in fig. 15, the epitaxial structure 14 is transferred onto the substrate 12 through the bonding layer 40 to form the epitaxial structure 14 with the first semiconductor layer 143 under and the second semiconductor layer 145 over, and then the preparation is continued to form the light emitting diode 3. Specifically, epitaxial structure 14 is separated from the epitaxial growth substrate at the etch stop layer (i.e., epitaxial structure 14 is peeled away from the epitaxial growth substrate) and epitaxial structure 14 is attached to substrate 12 by bonding layer 40.

The material of the bonding layer 40 may be an insulating material and/or a conductive material. Insulating materials include, but are not limited to, polyimide (PI), benzocyclobutene (BCB), perfluorocyclobutane (PFCB), magnesium oxide (MgO), epoxy (Epoxy), acrylic (Acrylics resin), cyclic olefin polymer (COC), polymethyl methacrylate (PMMA), polyethylene terephthalate (PET), polycarbonate (PC), polyetherimide (Polyetheride), fluorocarbon polymer (fluorocarbon Polymer), glass (Glass), alumina (Al ₂ O ₃ ) Silicon oxide (SiOx), titanium oxide (TiO) ₂ ) Tantalum oxide (Ta) ₂ O ₅ ) Silicon nitride (SiNx) or spin-on glass (SOG). The conductive material includes, but is not limited to, indium Tin Oxide (ITO), indium oxide (InO), tin oxide (SnO), cadmium Tin Oxide (CTO), antimony Tin Oxide (ATO), aluminum Zinc Oxide (AZO), zinc Tin Oxide (ZTO), zinc oxide (ZnO), indium Zinc Oxide (IZO), diamond-like carbon film (DLC), gallium Zinc Oxide (GZO), or the like.

An embodiment of the present invention proposes a light emitting device employing the light emitting diode 1, 2 as described in any of the previous embodiments. The light emitting device has high reliability.

In summary, the present invention provides a light emitting diode 1, 2 and a light emitting device, in which the high-resistance layer 16 and the percolation region 20 are disposed in a matched manner, the electrode mesa is not required to be etched on the epitaxial structure 14 to form the first contact electrode 21, but the first contact electrode 21 is directly disposed on the second surface 142 of the epitaxial structure 14, so that the first contact electrode 21 and the second contact electrode 22 are in the same horizontal plane, the height difference between the first contact electrode 21 and the second contact electrode 22 is eliminated, and the light emitting diode 1, 2 with a balanced and symmetrical structure is obtained, and the product yield is improved.

In addition, it should be understood by those skilled in the art that although many problems exist in the prior art, each embodiment or technical solution of the present invention may be modified in only one or several respects, without having to solve all technical problems listed in the prior art or the background art at the same time. Those skilled in the art will understand that nothing in one claim should be taken as a limitation on that claim.

Finally, it should be noted that: the above embodiments are only for illustrating the technical solution of the present invention, and not for limiting the same; although the invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical scheme described in the foregoing embodiments can be modified or some or all of the technical features thereof can be replaced by equivalents; such modifications and substitutions do not depart from the spirit of the invention.

Claims

1. A light emitting diode, characterized by: the light emitting diode includes:

an epitaxial structure, which is provided with a first surface and a second surface which are opposite, and sequentially comprises a first semiconductor layer, a light-emitting layer and a second semiconductor layer from the first surface to the second surface;

the first contact electrode is positioned on the second surface of the epitaxial structure and is electrically connected with the first semiconductor layer;

the second contact electrode is positioned on the second surface of the epitaxial structure and is electrically connected with the second semiconductor layer;

the high-resistance layer is positioned in the epitaxial structure and extends downwards from the second surface of the epitaxial structure to the first semiconductor layer;

the epitaxial structure is internally provided with a penetration electric area, the penetration electric area is at least in the same horizontal plane with the light-emitting layer and the second semiconductor layer, the boundary of the penetration electric area is in contact with the high-resistance layer, and the first contact electrode is positioned on the penetration electric area and is electrically connected with the first semiconductor layer through the penetration electric area.

2. A light emitting diode according to claim 1 wherein: the first contact electrode extends toward the first surface of the epitaxial structure with a diffusion electrode passing through the percolation region to contact the first semiconductor layer.

3. A light emitting diode according to claim 2 wherein: the diffusion electrode is formed by utilizing the difference of diffusion depths of multiple metals in the first contact electrode after fusion.

4. A light emitting diode according to claim 2 wherein: the first contact electrode at least comprises alloy material of one of gold germanium nickel, gold beryllium, gold germanium, gold zinc or gold nickel.

5. A light emitting diode according to claim 1 wherein: the semiconductor type of the percolation region is the same as the first semiconductor layer.

6. A light emitting diode according to claim 5 wherein: the semiconductor type of the percolation region is made the same as the semiconductor type of the first semiconductor layer by way of ion placement processing.

7. A light emitting diode according to claim 5 or 6 wherein: the percolation region contacts the light emitting layer and the second semiconductor layer, where the percolation region contacts the light emitting layer and the second semiconductor layer, as the high-resistance layer.

8. A light emitting diode according to any one of claims 1 to 6, characterized in thatThe method is characterized in that: the material of the high-resistance layer can be selected from SiO ₂ One or more of SiNx, tiOx, alOx.

9. A light emitting diode according to claim 1 wherein: the first contact electrode and the second contact electrode are in the same horizontal plane.

10. A light emitting diode according to claim 1 wherein: and a groove is not formed below the first contact electrode.

11. A light emitting diode according to claim 1 wherein: the light emitting diode further comprises an insulating reflecting layer, wherein the insulating reflecting layer at least covers the second surface of the epitaxial structure and is provided with a first opening and a second opening, the first opening is used for exposing the first contact electrode, and the second opening is used for exposing the second contact electrode.

12. A light emitting diode according to claim 1 wherein: the light emitting diode further comprises a first bonding pad and a second bonding pad, wherein the first bonding pad is connected with the first contact electrode, the second bonding pad is connected with the second contact electrode, and the first bonding pad is flush with the upper surface of the second bonding pad.

13. A light emitting diode according to claim 1 wherein: the light emitting diode is of a balanced symmetrical structure.

14. A light emitting diode according to claim 1 wherein: the size of the light emitting diode is less than or equal to 100 mu m.

15. A light emitting device, characterized in that: use of a light emitting diode according to any one of claims 1-14.