CN112635632B

CN112635632B - Light emitting diode and method for manufacturing the same

Info

Publication number: CN112635632B
Application number: CN202011632783.7A
Authority: CN
Inventors: 王春; 裴向辉; 邵明镜; 王亚洲; 闫春辉
Original assignee: Shenzhen Third Generation Semiconductor Research Institute
Current assignee: Naweilang Technology Shenzhen Co ltd
Priority date: 2020-12-31
Filing date: 2020-12-31
Publication date: 2022-09-20
Anticipated expiration: 2040-12-31
Also published as: CN112635632A

Abstract

The present application relates generally to a light emitting diode and a method of manufacturing the same, the light emitting diode comprising: a substrate; the epitaxial layer is arranged on the main surface of one side of the substrate, a mesa structure is formed on one side, away from the substrate, of the epitaxial layer, and a part of the first semiconductor layer is exposed; the first current expansion line and the first pad are arranged on the exposed first semiconductor layer and are electrically connected with the first semiconductor layer, wherein two ends of the first current expansion line are respectively connected with the first pad to form a closed annular structure surrounding the mesa structure. The beneficial effect of this application is: the light emitting diode provided by the application can not only increase the uniformity of current distribution on the first semiconductor layer, but also reduce the voltage drop formed on the first current extension line, thereby improving the light emitting uniformity and the ductility of the light emitting diode.

Description

Light emitting diode and method for manufacturing the same

Technical Field

The application relates to the technical field of semiconductors, in particular to a light-emitting diode and a manufacturing method thereof.

Background

A semiconductor Light Emitting Diode (LED) is used as a solid-state illumination Light source, and has the advantages of high photoelectric conversion efficiency, environmental friendliness, long service life, high response speed, rich color, small size and the like; these advantages also make LED chips widely used in many fields.

Disclosure of Invention

The embodiment of the application provides a light emitting diode, and the light emitting diode includes: a substrate; the epitaxial layer is arranged on the main surface of one side of the substrate and comprises a first semiconductor layer, an active layer and a second semiconductor layer which are sequentially stacked in the direction away from the substrate, wherein a mesa structure is formed on one side of the epitaxial layer away from the substrate, and part of the first semiconductor layer is exposed; the first current expansion line and the first bonding pad are arranged on the exposed first semiconductor layer and are electrically connected with the first semiconductor layer, and two ends of the first current expansion line are respectively connected with the first bonding pad to form a closed annular structure surrounding the table-board structure.

The embodiment of the application also provides a manufacturing method of the light-emitting diode, which comprises the following steps: providing a substrate; forming an epitaxial layer on one main surface of the substrate, wherein the epitaxial layer comprises a first semiconductor layer, an active layer and a second semiconductor layer which are sequentially stacked in a direction away from the substrate; forming a mesa structure on one side of the epitaxial layer, which is far away from the substrate, and exposing a part of the first semiconductor layer; and forming a first current expansion line and a first bonding pad which are electrically connected with the first semiconductor layer on the exposed first semiconductor layer, wherein two ends of the first current expansion line are respectively connected with the first bonding pad so as to form a closed annular structure surrounding the mesa structure.

The beneficial effect of this application is: the utility model provides a light emitting diode forms mesa structure through the one side that deviates from the substrate at the epitaxial layer, with the first semiconductor layer of exposed portion, and first electric current extension line and the first pad that will be connected with first semiconductor layer electricity set up on exposed first semiconductor layer, make the both ends of first electric current extension line be connected in order to form the closed loop configuration who encircles above-mentioned mesa structure with first pad respectively, not only can increase the homogeneity of electric current distribution on the first semiconductor layer like this, can also reduce the pressure drop that forms on the first electric current extension line, and then improve the timely ductility of emitting diode's luminous homogeneity.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.

Fig. 1 is a schematic top view of an embodiment of a light emitting diode provided in the present application;

fig. 2 is a schematic view of a stacked structure of the light emitting diode of fig. 1;

FIG. 3 is a schematic flow chart of a method for manufacturing a light emitting diode provided herein;

FIG. 4 is a schematic diagram of the LED of FIG. 3 at a different stage in the manufacturing process;

FIG. 5 is a schematic top view of another embodiment of an LED provided herein;

fig. 6 is a schematic view of a stacked structure of the light emitting diode of fig. 5;

FIG. 7 is a schematic flow chart of another method for manufacturing a light emitting diode provided herein;

FIG. 8 is a schematic diagram of the LED of FIG. 7 at a different stage in the manufacturing process;

FIG. 9 is a schematic flow chart of yet another method for manufacturing a light emitting diode provided herein;

fig. 10 is a schematic structural diagram of the led shown in fig. 9 at a different stage in the manufacturing process.

Detailed Description

The present application will be described in further detail with reference to the following drawings and examples. It is to be noted that the following examples are only illustrative of the present application, and do not limit the scope of the present application. Likewise, the following examples are only some examples and not all examples of the present application, and all other examples obtained by a person of ordinary skill in the art without any inventive work are within the scope of the present application.

Reference in the specification to "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of the specification. It is explicitly and implicitly understood by one skilled in the art that the embodiments described herein can be combined with other embodiments. The terms "first," "second," "third," "fourth," and the like in the description and claims of this application and in the above-described drawings, if any, are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used is interchangeable under appropriate circumstances such that the embodiments of the application described herein are capable of operation in sequences other than those illustrated or described herein. Furthermore, the terms "comprises," "comprising," and "having," and any variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, system, article, or apparatus that comprises a list of steps or elements is not necessarily limited to those steps or elements expressly listed, but may include other steps or elements not expressly listed or inherent to such process, method, article, or apparatus.

The inventors of the present application found in a long-term development process: although the light emitting efficiency of the light emitting diode has been improved to a great extent, factors such as external quantum efficiency, current distribution uniformity, etc. have become another bottleneck that restrict the performance of the light emitting diode from being further improved. To this end, the present application provides the following examples.

Referring to fig. 1 and fig. 2 together, fig. 1 is a schematic top view structure diagram of an embodiment of a light emitting diode provided in the present application, and fig. 2 is a schematic laminated structure diagram of the light emitting diode in fig. 1.

In the present application, the light wave of the light emitting diode 1 may be UVC, UVB, UVA, violet, blue, green, yellow, red, infrared, and the like.

Referring to fig. 1 and 2, the light emitting diode 1 may include a substrate 10 and an epitaxial layer 20 disposed on one main surface of the substrate 10. The epitaxial layer 20 may be formed on the substrate 1 by a Metal-organic Chemical Vapor Deposition (MOCVD) process, and may serve as a main body of the light emitting diode 1 for emitting light.

Referring to fig. 2, the epitaxial layer 20 may include a first semiconductor layer 21, an active layer 22, and a second semiconductor layer 23 sequentially stacked in a direction away from the substrate 10. Wherein the first semiconductor layer 21 may be an n-type semiconductor layer; the second semiconductor layer 23 may be a p-type semiconductor layer. Of course, the first semiconductor layer 21 may be a p-type semiconductor layer, and the second semiconductor layer 23 may be an n-type semiconductor layer.

Further, a mesa structure is formed on a side of the epitaxial layer 20 facing away from the substrate 10 to expose a portion of the first semiconductor layer 21. In other words, the area of the first semiconductor layer 21 may be larger than the area of the active layer 22 (and the second semiconductor layer 23) when viewed in a direction perpendicular to the substrate 10, so that the active layer 22 and the second semiconductor layer 23 are stepped with the first semiconductor layer 21. Based on this, in conjunction with fig. 1, the light emitting diode 1 may further include a first current spreading line 30 and a first pad 40. Referring to fig. 2, the first current spreading line 30 and the first pad 40 are disposed on the exposed first semiconductor layer 21 and electrically connected to the first semiconductor layer 21. Further, the first pad 40 may be used to be electrically connected to the outer electrode, and both ends of the first current spreading line 30 may be connected to the first pad 40, respectively, to form a closed ring structure surrounding the mesa structure. In other words, referring to fig. 1, the first current spreading line 30 may surround the active layer 22 and the second semiconductor layer 23.

In this way, compared with the non-closed and/or non-annular current spreading line, the present embodiment not only can increase the uniformity of the current distribution on the first semiconductor layer 21, but also can reduce the voltage drop formed on the first current spreading line 30, thereby improving the light emitting uniformity and the time delay of the light emitting diode 1. Of course, the design of the second current spreading line 70 may also be added indirectly. In addition, since the first current spreading line 30 is disposed outside the active layer 22, the etching area of the active layer 22 can be reduced, that is, the utilization rate of the active layer 22 is increased (by about 4.9% -6.8%), so as to increase the light emitting area of the light emitting diode 1.

As an example, in connection with fig. 1, the first current spreading line 30 may be provided in a rectangular shape. At this time, the first pads 40 may be disposed at corners of a rectangle; and may be in the shape of a rounded rectangle or a quarter circle. Of course, the first pad 40 may be disposed on any one side of a rectangle, and may have a rounded rectangle shape or a semicircular shape. Further, the first current spreading line 30 may have other regular shapes such as a circle, a diamond, and an ellipse, or may have other irregular shapes. At this time, the shapes of the first semiconductor layer 21 and the mesa structures (i.e., the active layer 22 and the second semiconductor layer 23) are accordingly changed.

Illustratively, the line width of the first current spreading line 30 may be 0.5 μm to 2.5 μm, as viewed in a direction perpendicular to the substrate. Further, the thickness of the first current spreading line 30 may be 0.001 μm to 5 μm. Accordingly, the thickness of the first pad 40 may also be 0.001 μm to 5 μm.

With reference to fig. 2, the light emitting diode 1 may further include a current spreading layer 50 disposed on a side of the second semiconductor layer 23 facing away from the first semiconductor layer 21. Wherein the edge of the current spreading layer 50 is spaced apart from the edge of the mesa structure by a predetermined distance to expose a portion of the second semiconductor layer 23. In other words, the edge of the current spreading layer 50 is recessed a certain distance compared to the edge of the mesa structure, i.e. the area of the current spreading layer 50 may be smaller than the area of the second semiconductor layer 23 when viewed in a direction perpendicular to the substrate 10. As an example, the current spreading layer 50 may be spaced from the mesa structure by 2 μm to 5 μm. Based on this, the light emitting diode 1 may further include an insulating layer 60, where the insulating layer 60 may be disposed on a side surface of the mesa structure, and may cover the exposed second semiconductor layer 23 to at least wrap edges of the active layer 22 and the second semiconductor layer 23, thereby preventing the active layer 22 and/or the second semiconductor layer 23 from being short-circuited with the first current spreading line 30 and/or the first pad 40 due to leakage, and reducing an etched area of the active layer 22 in a manufacturing process, so that the active layer 22 is fully utilized. At this time, the edge of the current spreading layer 50 may be bordered by the insulating layer 60.

Illustratively, the thickness of the insulating layer 60 may be 80nm to 400 nm.

Referring to fig. 1 and 2, the light emitting diode 1 may further include a second current spreading line 70, a second pad 80, and a current blocking layer 90. Wherein the second current spreading line 70 and the second pad 80 are disposed on a side of the current spreading layer 50 facing away from the second semiconductor layer 23, and are electrically connected to the current spreading layer 50. At this time, the second pad 80 may be used to be electrically connected to the external electrode, and at least one end of the second current spreading line 70 may be electrically connected to the second pad 80 and used to increase uniformity of current distribution on the current spreading layer 50. Further, the current blocking layer 90 is disposed between the current spreading layer 50 and the second semiconductor layer 23, and directly under the second current spreading line 70 and the second pad 80. With this arrangement, the current flowing from the second bonding pad 80 and the second current spreading line 70 is prevented from directly flowing to the second semiconductor layer 23, the current density in the active layer 22 under and near the second bonding pad 80 and the second current spreading line 70 is reduced, which is beneficial to alleviating the current crowding effect near the second bonding pad 80 and the second current spreading line 70, and further improving the light emitting uniformity and the ductility of the light emitting diode 1. The current blocking layer 90 and the insulating layer 60 may be formed by patterning the same insulating material, so as to simplify the process and improve the manufacturing efficiency of the light emitting diode 1.

It should be noted that: the second pad 80 may also be in direct contact with the second semiconductor layer 23 to form an electrical connection.

As an example, in conjunction with fig. 1, the second current spreading line 70 may be disposed in a line shape, and one end thereof may be electrically connected to the second pad 80. Of course, the second current spreading line 70 may also be in the shape of a curve, a spiral, a fish bone, or the like.

Illustratively, the line width of the second current spreading line 70 may be 0.5 μm to 2.5 μm, as viewed in a direction perpendicular to the substrate. Further, the thickness of the second current spreading line 70 may be 0.001 μm to 5 μm. Accordingly, the thickness of the second pad 80 may also be 0.001 μm to 5 μm.

Referring to fig. 2, the light emitting diode 1 may further include a passivation layer 100, and the passivation layer 100 may cover the first current spreading line 30, the current spreading layer 50, the second current spreading line 70, and the like to perform a protective function; and the first and

second pads

40 and 80, etc. are exposed to facilitate bonding with the external electrodes.

Illustratively, the thickness of the passivation layer 100 may be 80nm to 200 nm.

Referring to fig. 3 and 4, fig. 3 is a schematic flow chart of a method for manufacturing the light emitting diode provided by the present application, and fig. 4 is a schematic structural diagram of the light emitting diode in fig. 3 corresponding to different stages in the manufacturing process. It should be noted that: for ease of illustration and understanding, the light emitting diodes are shown as individual devices in the manufacturing process. It should be understood, however, that multiple leds are typically fabricated at the wafer level, and that individual leds may be singulated in subsequent process steps. Nevertheless, the fabrication methods described herein may also be used to fabricate a single device. It should also be understood that although the steps of manufacturing are shown in a particular order below, the light emitting diode may be manufactured with steps in a different order and may include additional or fewer steps.

With reference to fig. 3 and 4, the manufacturing method may include:

step S10: a substrate is provided.

By way of example, the substrate 10 may be one of sapphire, silicon carbide, gallium nitride, silicon, and the like, or other suitable materials.

Step S20: and forming an epitaxial layer on one main surface of the substrate, wherein the epitaxial layer comprises a first semiconductor layer, an active layer and a second semiconductor layer which are sequentially stacked in a direction away from the substrate.

As an example, the first semiconductor layer 21, the active layer 22 and the second semiconductor layer 23 may be formed by sequentially growing on the substrate 10 by using a method such as metal organic compound chemical vapor deposition (mocvd) or Molecular Beam Epitaxy (MBE), that is, the epitaxial layer 20 may be formed on one main surface of the substrate 10.

The first semiconductor layer 21 may be an n-type semiconductor layer, which mainly functions to provide electrons for composite light emission, and may be a gallium nitride compound semiconductor (e.g., GaN, AlGaN, InGaN, etc.) doped with at least one of Si, Ge, and Sn. The active layer 22 is an electron-hole recombination region and may have a structure of a single heterojunction, a double heterojunction, a single quantum hydrazine, and a multiple quantum hydrazine. The second semiconductor layer 23 may Be a P-type semiconductor layer, which mainly functions to provide holes for recombination light emission, and specifically may Be a gallium nitride-based compound semiconductor (e.g., GaN, AlGaN, InGaN, etc.) doped with at least one of Mg, Zn, Be, Ca, Sr, and Ba.

Step S30: and forming a mesa structure on one side of the epitaxial layer, which is far away from the substrate, to expose part of the first semiconductor layer.

As an example, this step may etch the active layer 22 and the second semiconductor layer 23 through a mask and etch process to form a mesa structure to expose a portion of the first semiconductor layer 21. The etching process may include dry etching, wet etching, or a combination thereof. At this time, the area of the first semiconductor layer 21 may be larger than the area of the active layer 22 (and the second semiconductor layer 23) when viewed in a direction perpendicular to the substrate 10, so that the active layer 22 and the second semiconductor layer 23 are stepped with the first semiconductor layer 21.

Further, the first semiconductor layer 21 may be etched to a certain depth in this step, so as to ensure that the first semiconductor layer 21 can be effectively exposed after the active layer 22 and the second semiconductor layer 23 are etched.

Step S40: and forming a first current expansion line and a first bonding pad which are electrically connected with the first semiconductor layer on the exposed first semiconductor layer, wherein two ends of the first current expansion line are respectively connected with the first bonding pad so as to form a closed annular structure surrounding the mesa structure.

As an example, the present step may form the first current spreading line 30 and the first pad 40 on the exposed first semiconductor layer 21 by using a thermal evaporation method, an electron beam evaporation method, a magnetron sputtering evaporation method, or the like, which are in direct contact with each other to be electrically connected to each other.

The material of the first current spreading line 30 and the first pad 40 may be a metal material, or a mixture or compound doped with a metal material, and may be a transparent material or an opaque material. For example: both may be Transparent Conductive Oxide (TCO) layers formed of Indium Tin Oxide (ITO), zinc Oxide (ZnO), or the like, or may be single layers or stacked layers formed of any one metal of nickel (Ni), chromium (Cr), titanium (Ti), aluminum (Al), silver (Ag), platinum (Pt), gold (Au), and tungsten (W), or an alloy of any two or more of these metals. The material of the first current spreading line 30 may be the same as or different from that of the first pad 40.

Step S50: an insulating layer and a current blocking layer are formed on the second semiconductor layer, and a portion of the second semiconductor layer is exposed.

As an example, this step may first deposit an insulating material on the second semiconductor layer 23 by using a sputtering, spraying, ALD or PECVD deposition process, and then etch the insulating material through a mask and etching process to form the insulating layer 60 and the current blocking layer 90 and expose a portion of the second semiconductor layer 23. The etching process may include dry etching, wet etching, or a combination thereof. At this time, the insulating layer 60 may at least wrap the edges of the active layer 22 and the second semiconductor layer 23 to prevent short-circuit leakage caused by contamination or misalignment in the subsequent processes.

Wherein the insulating layer 60 may be silicon oxide (SiO) containing ₂ ) Silicon nitride (Si) ₃ N ₄ ) Silicon oxynitride (SiO) _x N _y X, y is not less than 1), Distributed Bragg Reflector (DBR), aluminum oxide (Al) ₂ O ₃ ) A single layer or a laminate of at least one of silicone, resin or acrylic.

Step S60: and forming a current spreading layer electrically connected with the second semiconductor layer on the exposed second semiconductor layer.

As an example, the current spreading layer 50 may be formed on the exposed second semiconductor layer 23 by thermal evaporation, electron beam evaporation, magnetron sputtering evaporation, or the like, and they are in direct contact with each other and thus electrically connected to each other.

The material of the current spreading layer 50 may be a metal material, a mixture or a compound doped with a metal material, and may be a transparent material or an opaque material. For example: both may be Transparent Conductive Oxide (TCO) layers formed of Indium Tin Oxide (ITO), zinc Oxide (ZnO), or the like, or may be single layers or stacked layers formed of any one metal of nickel (Ni), chromium (Cr), titanium (Ti), aluminum (Al), silver (Ag), platinum (Pt), gold (Au), and tungsten (W), or an alloy of any two or more of these metals.

Further, the obtained semi-finished product may be subjected to a high temperature annealing treatment in a nitrogen atmosphere to reduce the contact resistance between the current spreading layer 50 and the second semiconductor layer 23.

Step S70: and forming a second current spreading line and a second pad electrically connected to the current spreading layer on the current spreading layer.

As an example, the step may first perform a patterning process on the current spreading layer 50 through a mask and etching process, and then form the second current spreading line 70 and the second pad 80 in the development region by using a method such as thermal evaporation, electron beam evaporation, and magnetron sputtering evaporation, which are in direct contact with each other and are electrically connected to each other.

The second current spreading line 70 and the second pad 80 may be made of a metal material, a mixture or a compound doped with a metal material, a transparent material or an opaque material. For example: both may be Transparent Conductive Oxide (TCO) layers formed of Indium Tin Oxide (ITO), zinc Oxide (ZnO), or the like, or may be single layers or stacked layers formed of any one metal of nickel (Ni), chromium (Cr), titanium (Ti), aluminum (Al), silver (Ag), platinum (Pt), gold (Au), and tungsten (W), or an alloy of any two or more of these metals. The material of the second current spreading line 70 may be the same as or different from that of the second pad 80.

Step S80: and forming a passivation layer on the first current spreading line, the current spreading layer and the second current spreading line, and exposing the first bonding pad and the second bonding pad.

As an example, this step may first deposit an insulating material on the second semiconductor layer 23 by using a sputtering, spraying, ALD or PECVD deposition process, and then etch the insulating material through a mask and etching process to form the passivation layer 100 and expose the first and

second pads

40 and 80. The etching process may include dry etching, wet etching, or a combination thereof.

The passivation layer 100 may be silicon oxide (SiO) containing ₂ ) Silicon nitride (Si) ₃ N ₄ ) Silicon oxynitride (SiO) _x N _y X, y is not less than 1), Distributed Bragg Reflector (DBR), aluminum oxide (Al) ₂ O ₃ ) A single layer or a laminate of at least one of silicone, resin or acrylic.

Referring to fig. 5 and fig. 6 together, fig. 5 is a schematic top view structure diagram of another embodiment of the light emitting diode provided in the present application, and fig. 6 is a schematic laminated structure diagram of the light emitting diode in fig. 5.

The main differences from the above embodiments are: in this embodiment, referring to fig. 5 and 6, a groove 24 exposing the first semiconductor layer 21 is disposed along an edge of the epitaxial layer 20 on a side of the epitaxial layer 20 away from the substrate 10. The recess 24 has an inner groove wall 241 facing the inner side of the epitaxial layer 20 and an outer groove wall 242 facing the edge of the epitaxial layer 20. At this time, the first current spreading line 30 is disposed between the inner trench wall 241 and the outer trench wall 242, and is electrically connected to the first semiconductor layer 21. In other words, the edge of the epitaxial layer 20 and the substrate 10 is partially remained. With such an arrangement, the first current spreading line 30 can be sandwiched between the inside and the outside of the epitaxial layer 20, so as to effectively prevent the first current spreading line 30 from being scratched in the manufacturing process and the subsequent cutting process, thereby increasing the reliability and appearance quality of the first current spreading line 30.

As an example, the inner trench walls 241 may be spaced apart from the edge of the epitaxial layer 20 by a distance (W1) of 7 μm to 14 μm, preferably 8 μm to 12 μm, as viewed in a direction perpendicular to the substrate; the inner slot wall 241 may be spaced from the outer slot wall 242 by a distance (W2) of 3 μm to 5 μm. Further, the depth (H) of the groove 24 in a direction perpendicular to the substrate 10 may be 1.0um to 1.6 um.

Further, a recessed region 25 is disposed on a side of the epitaxial layer 20 away from the substrate 10, exposing the first semiconductor layer 21 and communicating with the groove 24. At this time, the first pad 40 is disposed in the recess 25 and electrically connected to the first semiconductor layer 21; and is further electrically connected to the first current spreading wire 30. In other words, referring to fig. 5, the first current spreading line 30 and the first pad 40 are sandwiched between the epitaxial layer 20. Accordingly, the mesa structure described above is also formed inside the groove 24 and the recessed region 25.

Similarly, the edge of the current spreading layer 50 is spaced a distance from the inner trench wall 241 to expose a portion of the second semiconductor layer 23. At this time, the insulating layer 60 wraps at least edges of the active layer 22 and the second semiconductor layer 23; that is, the insulating layer 60 covers the inner sidewall 241 and further covers the exposed second semiconductor layer 23. Wherein, the spacing distance (W3) between the edge of current spreading layer 50 and inner slot wall 241 may be 2 μm-5 μm. Further, when the first semiconductor layer 21 is also partially etched, the insulating layer 60 may extend into the first semiconductor layer 21 to a depth of 0.5um to 1.0 um.

Referring to fig. 7 and 8, fig. 7 is a schematic flow chart of another manufacturing method of the light emitting diode provided by the present application, and fig. 8 is a schematic structural diagram corresponding to different stages in the manufacturing process of the light emitting diode in fig. 7.

The main differences from the above described embodiment are: with reference to fig. 7 and 8, the manufacturing method may further include steps related to forming recesses and recess regions. The method comprises the following specific steps:

step S10: a substrate is provided.

Step S30: and forming a groove on one side of the epitaxial layer, which is far away from the substrate, wherein the groove exposes the first semiconductor layer and is provided with an inner side groove wall and an outer side groove wall which are arranged at intervals.

As an example, this step may etch the active layer 22 and the second semiconductor layer 23 through a mask and etch process to form the groove 24 and expose a portion of the first semiconductor layer 21. The etching process may include dry etching, wet etching, or a combination thereof. Further, the groove 24 has an inner groove wall 241 and an outer groove wall 242 which are spaced apart from each other. Wherein, the inner slot wall 241 faces the inner part of the epitaxial layer 20; and outer trench walls 242 are oriented outwardly of the edges of epitaxial layer 20.

Further, the first semiconductor layer 21 may be etched to a certain depth to ensure that the first semiconductor layer 21 is effectively exposed after the active layer 22 and the second semiconductor layer 23 are etched.

It should be noted that: a recess 25 exposing the first semiconductor layer 21 and communicating with the recess 24 may be further formed in this step on a side of the epitaxial layer 20 facing away from the substrate 10.

Step S40: a first current spreading line is formed between the inner and outer trench walls such that the first current spreading line is electrically connected to the first semiconductor layer.

As an example, the first current spreading lines 30 may be formed between the inner groove wall 241 and the outer groove wall 242 by thermal evaporation, electron beam evaporation, magnetron sputtering evaporation, or the like. At this time, since the first current spreading line 30 is in contact with the first semiconductor layer 21, both are also electrically connected to each other.

It should be noted that: a first pad 40 electrically connected to the first semiconductor layer 21 may also be formed in the recess region 25 in this step. At this time, since the recess 25 communicates with the groove 24, the first pad 40 may be further electrically connected to the first current spreading line 30, so that the first pad 40 and the first current spreading line 30 can form a closed loop structure.

As an example, the step may first deposit an insulating material on the second semiconductor layer 23 by using a sputtering, spraying, ALD, or PECVD deposition process, and then etch the insulating material through a mask and etching process to form the insulating layer 60 and the current blocking layer 90 and expose a portion of the second semiconductor layer 23. The etching process may include dry etching, wet etching, or a combination thereof. At this time, the insulating layer 60 may at least cover the edges of the active layer 22 and the second semiconductor layer 23, and of course, also cover the inner sidewall 241 to avoid short circuit and leakage caused by contamination or misalignment in the subsequent process.

second pads

Step S90: and cutting the substrate and the epitaxial layer at the outer side of the outer groove wall.

As an example, since the above steps can be generally performed on a wafer, the present step can cut the substrate 10 and the epitaxial layer 20 by means of a diamond or the like type tool 2 outside the outer groove wall 242 to obtain individual light emitting diodes. At this time, since the edges of the epitaxial layer 20 and the substrate 10 are partially remained, the first current spreading line 30 and the inner structure thereof can be effectively protected, thereby increasing the quality of the light emitting diode 1 and improving the yield of the manufacturing process.

Referring to fig. 9 and 10, fig. 9 is a schematic flow chart of another manufacturing method of the light emitting diode provided by the present application, and fig. 10 is a schematic structural diagram corresponding to different stages in the manufacturing process of the light emitting diode in fig. 9.

With reference to fig. 9 and 10, the manufacturing method may include:

step S10: a substrate is provided.

As an example, this step may etch the active layer 22 and the second semiconductor layer 23 through a mask and etching process to form the recess 24 and expose a portion of the first semiconductor layer 21. The etching process may include dry etching, wet etching, or a combination thereof. Further, the groove 24 has an inner groove wall 241 and an outer groove wall 242 which are spaced apart from each other. Wherein, the inner slot wall 241 faces the inner part of the epitaxial layer 20; and outer slot walls 242 are oriented outward of the edges of epitaxial layer 20.

Step S40: an insulating layer and a current blocking layer are formed on the second semiconductor layer, and a portion of the second semiconductor layer is exposed.

As an example, this step may first deposit an insulating material on the second semiconductor layer 23 by using a sputtering, spraying, ALD or PECVD deposition process, and then etch the insulating material through a mask and etching process to form the insulating layer 60 and the current blocking layer 90 and expose a portion of the second semiconductor layer 23. The etching process may include dry etching, wet etching, or a combination thereof. At this time, the insulating layer 60 may at least cover the edges of the active layer 22 and the second semiconductor layer 23, and of course, also cover the inner sidewall 241 to avoid short circuit and leakage caused by contamination or misalignment in the subsequent process.

Step S50: and forming a current spreading layer electrically connected with the second semiconductor layer on the exposed second semiconductor layer.

Step S60: and forming a passivation layer on the current spreading layer, and partially exposing the first semiconductor layer and the current spreading layer.

For example, the step may first deposit an insulating material on the second semiconductor layer 23 by using a sputtering, spraying, ALD or PECVD deposition process, and then etch the insulating material by using a mask and an etching process to form the passivation layer 100, and expose the first current spreading line 30 and the regions corresponding to the first pad 40, the second current spreading line 70 and the second pad 80. The etching process may include dry etching, wet etching, or a combination thereof.

Step S70: a first current spreading line and a first bonding pad are formed on the exposed first semiconductor layer, and a second current spreading line and a second bonding pad are formed on the exposed current spreading layer.

As an example, the present step may employ thermal evaporation, electron beam evaporation, magnetron sputtering evaporation, and the like to form the first current spreading line 30 and the first pad 40 on the exposed first semiconductor layer 21, and to form the second current spreading line 70 and the second pad 80 on the exposed current spreading layer 50. At this time, since the first current spreading line 30 and the first pad 40 are in contact with the first semiconductor layer 21, they are also electrically connected to each other. Similarly, since the second current spreading line 70 and the second pad 80 are in contact with the current spreading layer 50, they are also electrically connected to each other.

Step S80: and cutting the substrate and the epitaxial layer at the outer side of the outer groove wall.

As an example, since the above steps can be generally fabricated on a wafer, the substrate 10 and the epitaxial layer 20 can be cut by the diamond or the like type tool 2 outside the outer trench wall 242 to obtain individual light emitting diodes. At this time, since the edges of the epitaxial layer 20 and the substrate 10 are partially remained, the first current spreading line 30 and the inner structure thereof can be effectively protected, thereby increasing the quality of the light emitting diode 1 and improving the yield of the manufacturing process.

Through the mode, the first current expansion line and the first bonding pad, and the second current expansion line and the second bonding pad (collectively referred to as electrodes) can be completed in one process, so that the passivation layer and the electrodes can share one photoetching, and the preparation efficiency of the light-emitting diode is improved.

The above description is only a part of the embodiments of the present application, and not intended to limit the scope of the present application, and all equivalent devices or equivalent processes performed by the content of the present application and the attached drawings, or directly or indirectly applied to other related technical fields, are also included in the scope of the present application.

Claims

1. A light emitting diode, comprising:

a substrate;

the epitaxial layer is arranged on the main surface of one side of the substrate and comprises a first semiconductor layer, an active layer, a second semiconductor layer and a current expansion layer which are sequentially stacked in the direction far away from the substrate, and a groove for exposing the first semiconductor layer and a concave area communicated with the groove are arranged on one side of the epitaxial layer, which is far away from the substrate, along the edge of the epitaxial layer;

the first current spreading line and the first pad are respectively arranged in the groove and the recessed area and are electrically connected with the first semiconductor layer, wherein two ends of the first current spreading line are respectively connected with the first pad to form a closed annular structure, and the first current spreading line is arranged in a rectangular shape;

second current extension line and current barrier layer, second current extension line set up in the current extension layer deviates from one side of second semiconductor layer, and with the current extension layer electricity is connected, current barrier layer set up in the current extension layer with between the second semiconductor layer, and be located under the second current extension line.

2. The led of claim 1, wherein the first bonding pad is disposed at a corner of the rectangle.

3. The led of claim 1, wherein the first current spreading line has a line width of 0.5 μm to 2.5 μm, as viewed in a direction perpendicular to the substrate.

4. The led of claim 1, wherein the trench has an inner trench wall facing the interior of the epitaxial layer and an outer trench wall facing the edge of the epitaxial layer, the inner trench wall being spaced from the edge of the epitaxial layer by a distance of 7 μm to 14 μm and the inner trench wall being spaced from the outer trench wall by a distance of 3 μm to 5 μm, as viewed in a direction perpendicular to the substrate.

5. The LED of claim 4, wherein the depth of the groove in a direction perpendicular to the substrate is 1.0 μm-1.6 μm.

6. The LED of claim 4 wherein the LED comprises an insulating layer covering the inner trench walls.

7. The light-emitting diode of claim 6, wherein the edge of the current spreading layer is spaced apart from the inner trench wall by a distance to expose a portion of the second semiconductor layer, the insulating layer further covering the exposed portion of the second semiconductor layer.

8. The led of claim 7, wherein the current spreading layer edge is spaced from the inner trench wall by a distance of 2 μm to 5 μm.

9. The led of claim 8, wherein the current blocking layer and the insulating layer are patterned from the same layer of insulating material.

10. A method of manufacturing a light emitting diode, the method comprising:

providing a substrate;

forming an epitaxial layer on one main surface of the substrate, wherein the epitaxial layer comprises a first semiconductor layer, an active layer and a second semiconductor layer which are sequentially stacked in a direction away from the substrate;

arranging a groove exposing the first semiconductor layer and a concave area communicated with the groove on one side of the epitaxial layer, which is far away from the substrate, along the edge of the epitaxial layer;

forming a current blocking layer, a current spreading layer and a second current spreading line in sequence on the second semiconductor layer, wherein the second current spreading line is electrically connected with the current spreading layer, and the current blocking layer is positioned right below the second current spreading line;

the groove and the depressed area are internally provided with a first current expansion line and a first pad which are electrically connected with the first semiconductor layer, wherein two ends of the first current expansion line are respectively connected with the first pad to form a closed annular structure, and the first current expansion line is arranged in a rectangular shape.