LED chip with complementary pattern dielectric layer and manufacturing method

文档序号:1546816 发布日期:2020-01-17 浏览:35次 中文

阅读说明:本技术 一种具有互补图形介质层的led芯片及制作方法 (LED chip with complementary pattern dielectric layer and manufacturing method ) 是由 徐洲 邹微微 王洪占 彭钰仁 陈凯轩 蔡端俊 于 2019-10-21 设计创作,主要内容包括:本发明公开了一种具有互补图形介质层的LED芯片及制作方法,采用具有互补图形的介质层,即导电介质层和绝缘介质层的区域图形以一定图形互补,共同构成介质层,在第一方向上介质层仍为单层结构,在垂直于第一方向的方向上,导电介质层和绝缘介质层按一定图形互补形成,二者的面积占比总和为100%,即在P型窗口层和ODR金属反射层之间,介质层整面平铺,不存在介质层空缺的区域,进而不存在介质层通孔处的金属发生断层导致导电不良的问题,不存在介质层通孔处金属向P型窗口层扩散导致吸光的问题,同时大幅度减少ODR金属反射层和金属键合层之间的空洞,从而降低焊线过程中由于金属空洞引起的外延层碎裂风险。(The invention discloses an LED chip with a complementary pattern dielectric layer and a manufacturing method thereof, which adopts the dielectric layer with a complementary pattern, namely, the regional patterns of the conductive dielectric layer and the insulating dielectric layer are complementary in a certain pattern to jointly form the dielectric layer, the dielectric layer is still in a single-layer structure in the first direction, the conductive dielectric layer and the insulating dielectric layer are complementarily formed according to a certain pattern in the direction vertical to the first direction, the sum of the area of the conductive dielectric layer and the insulating dielectric layer is 100 percent, namely, the whole dielectric layer is tiled between the P-type window layer and the ODR metal reflecting layer, and no area of the dielectric layer is left, thereby avoiding the problem of poor conduction caused by the fault of the metal at the through hole of the dielectric layer and the problem of light absorption caused by the diffusion of the metal at the through hole of the dielectric layer to the P-type window layer, and meanwhile, the cavity between the ODR metal reflecting layer and the metal bonding layer is greatly reduced, so that the risk of epitaxial layer fragmentation caused by the metal cavity in the wire welding process is reduced.)

1. An LED chip having complementary patterned dielectric layers, said LED chip comprising:

a permanent substrate;

the metal bonding layer, the ODR metal reflecting layer, the dielectric layer and the P-type window layer are sequentially arranged on the permanent substrate in a first direction, and the first direction is perpendicular to the permanent substrate and points to the metal bonding layer from the permanent substrate;

the dielectric layer comprises a conductive dielectric layer and an insulating dielectric layer which are both in direct contact with the ODR reflecting layer, a conductive area pattern of the conductive dielectric layer and an insulating area pattern of the insulating dielectric layer are in a complementary pattern, no vacant area exists between the conductive area pattern and the insulating dielectric layer, and the conductive dielectric layer and the insulating dielectric layer are both in a single-layer structure and are not overlapped in the first direction.

2. The LED chip of claim 1, wherein the region of the conductive dielectric layer is a via region.

3. The LED chip of claim 1, wherein the region of the conductive medium layer is a separate island region.

4. The LED chip of claim 1, wherein the area of said conductive dielectric layer is between 5% and 90% of the area of said dielectric layer.

5. The LED chip of claim 1, wherein the thickness of the conductive medium layer is (2k +1) λ/4n, where k is 0 and a positive integer, n is the refractive index of the conductive medium layer, and λ is the emission peak wavelength of the LED chip;

the thickness of the insulating medium layer is (2k +1) lambda/4 m, wherein k is 0 and a positive integer, m is the refractive index of the insulating medium layer, and lambda is the light-emitting peak wavelength of the LED chip.

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

the P-type limiting layer, the MQW active layer, the N-type limiting layer, the N-type current spreading layer, the N-type coarsening layer, the N-type ohmic contact layer and the N electrode are sequentially arranged on the P-type window layer in the first direction;

and the P electrode is arranged on the side, facing away from the metal bonding layer, of the permanent substrate.

7. The LED chip of claim 6, wherein a projection of a region of the conductive medium layer and a region of the N electrode in the first direction do not overlap.

8. The LED chip of claim 1, wherein said P-type window layer comprises:

and the P-type ohmic contact layer and the P-type current spreading layer are sequentially arranged in the first direction.

9. A manufacturing method of an LED chip with a complementary pattern dielectric layer is characterized by comprising the following steps:

providing a temporary substrate;

sequentially epitaxially growing an N-type buffer layer, an N-type corrosion stop layer, an N-type ohmic contact layer, an N-type coarsening layer, an N-type current expansion layer, an N-type limiting layer, an MQW active layer, a P-type limiting layer and a P-type window layer on the temporary substrate in a second direction, wherein the second direction is perpendicular to the temporary substrate and points to the N-type buffer layer from the temporary substrate;

forming a dielectric layer on the P-type window layer, wherein the dielectric layer comprises a conductive dielectric layer and an insulating dielectric layer, a conductive area pattern of the conductive dielectric layer and an insulating area pattern of the insulating dielectric layer are complementary patterns, no vacant area exists between the conductive area pattern and the insulating dielectric layer, and the conductive dielectric layer and the insulating dielectric layer are both in a single-layer structure and are not overlapped in the second direction;

forming an ODR metal reflecting layer on the dielectric layer;

providing a permanent substrate;

forming a metal bonding layer on the permanent substrate;

bonding the metal bonding layer and the ODR metal reflecting layer;

and removing the temporary substrate, the N-type buffer layer and the N-type corrosion stop layer.

10. The method of manufacturing of claim 9, further comprising:

and carrying out patterning treatment on the N-type ohmic contact layer and forming an N electrode.

11. The method of manufacturing of claim 9, further comprising:

etching from the N-type rough layer to the P-type window layer to form a reserved cutting path.

12. The method of manufacturing of claim 9, further comprising:

and roughening the surface of the N-type roughened layer.

13. The method of manufacturing of claim 9, further comprising:

thinning the permanent substrate;

and forming a P electrode on the side of the permanent substrate, which faces away from the metal bonding layer.

14. The manufacturing method of claim 9, wherein the P-type window layer comprises a P-type ohmic contact layer and a P-type current spreading layer which are overlapped;

the P-type ohmic contact layer is adjacent to the dielectric layer;

the P-type current spreading layer is adjacent to the P-type confinement layer.

15. The method of manufacturing of claim 9, further comprising:

and etching the N-type coarsening layer to the P-type ohmic contact layer along a reserved cutting path.

Technical Field

The invention relates to the technical field of LED chips, in particular to an LED chip with a complementary pattern dielectric layer and a manufacturing method thereof.

Background

With the continuous development of science and technology, various LED chips are widely applied to the life, work and industry of people, and bring great convenience to the daily life of people.

In the current LED chip with a vertical film structure, most of the ODR reflective layers are flat ODR reflective layers, and referring to fig. 1, fig. 1 is a schematic structural diagram of an ODR reflective layer in the prior art, wherein a dielectric layer of the ODR reflective layer is a transparent film with low refractive index and insulation, and a metal layer is a conventional metal.

However, since the dielectric layer of the ODR reflective layer is an insulating material, in order to allow current to be conducted from the underlying permanent substrate to the overlying epitaxial layer, a via must be formed in the dielectric layer so that the metal layer conducts electricity through the dielectric via, which necessarily results in a loss of the effective area of the dielectric layer.

Furthermore, the metal penetrating through the via hole of the dielectric layer needs to be alloyed at a certain temperature in order to form an ohmic contact with the P-type window layer. Referring to fig. 2, fig. 2 is a schematic view of an optical microscope of a dielectric layer via hole in the prior art, in which metal is diffused toward a P-type window layer to form a mixed layer of semiconductor and metal, the appearance of the mixed layer is usually black, so that the mixed layer has a light absorption effect, and light is absorbed at the via hole of the dielectric layer and cannot be effectively reflected.

In addition, referring to fig. 3, fig. 3 is a schematic view of a scanning electron microscope showing that the ODR reflective layer in the prior art has a problem, because the dielectric layer has a certain thickness, a metal at a through hole of the dielectric layer may be broken, resulting in poor conduction, and along with such a metal fracture phenomenon, a cavity is inevitably present between the metal bonding layer and the ODR metal reflective layer, and during a wire bonding process, pressure of a cleaver of a wire bonding machine is transmitted to the cavity, resulting in a risk of cracking of the epitaxial layer.

Disclosure of Invention

In view of the above, in order to solve the above problems, the present invention provides an LED chip with a complementary pattern dielectric layer and a manufacturing method thereof, and the technical scheme is as follows:

an LED chip having complementary patterned dielectric layers, said LED chip comprising:

a permanent substrate;

the metal bonding layer, the ODR metal reflecting layer, the dielectric layer and the P-type window layer are sequentially arranged on the permanent substrate in a first direction, and the first direction is perpendicular to the permanent substrate and points to the metal bonding layer from the permanent substrate;

the dielectric layer comprises a conductive dielectric layer and an insulating dielectric layer which are both in direct contact with the ODR reflecting layer, a conductive area pattern of the conductive dielectric layer and an insulating area pattern of the insulating dielectric layer are in a complementary pattern, no vacant area exists between the conductive area pattern and the insulating dielectric layer, and the conductive dielectric layer and the insulating dielectric layer are both in a single-layer structure and are not overlapped in the first direction.

Preferably, in the LED, the region of the conductive medium layer is a connected region.

Preferably, in the LED, the region of the conductive medium layer is a separate island-type region.

Preferably, in the above LED, the area of the conductive medium layer accounts for 5% -90% of the area of the medium layer.

Preferably, in the above LED, the thickness of the conductive medium layer is (2k +1) λ/4n, where k is 0 and a positive integer, n is the refractive index of the conductive medium layer, and λ is the light emission peak wavelength of the LED chip;

the thickness of the insulating medium layer is (2k +1) lambda/4 m, wherein k is 0 and a positive integer, m is the refractive index of the insulating medium layer, and lambda is the light-emitting peak wavelength of the LED chip.

Preferably, in the above LED, the LED chip further includes:

the P-type limiting layer, the MQW active layer, the N-type limiting layer, the N-type current spreading layer, the N-type coarsening layer, the N-type ohmic contact layer and the N electrode are sequentially arranged on the P-type window layer in the first direction;

and the P electrode is arranged on the side, facing away from the metal bonding layer, of the permanent substrate.

Preferably, in the LED, a projection of a region of the conductive medium layer and a projection of a region of the N electrode in the first direction do not overlap.

Preferably, in the above LED, the P-type window layer includes:

and the P-type ohmic contact layer and the P-type current spreading layer are sequentially arranged in the first direction.

A manufacturing method of an LED chip with a complementary pattern dielectric layer comprises the following steps:

providing a temporary substrate;

sequentially epitaxially growing an N-type buffer layer, an N-type corrosion stop layer, an N-type ohmic contact layer, an N-type coarsening layer, an N-type current expansion layer, an N-type limiting layer, an MQW active layer, a P-type limiting layer and a P-type window layer on the temporary substrate in a second direction, wherein the second direction is perpendicular to the temporary substrate and points to the N-type buffer layer from the temporary substrate;

forming a dielectric layer on the P-type window layer, wherein the dielectric layer comprises a conductive dielectric layer and an insulating dielectric layer, a conductive area pattern of the conductive dielectric layer and an insulating area pattern of the insulating dielectric layer are complementary patterns, no vacant area exists between the conductive area pattern and the insulating dielectric layer, and the conductive dielectric layer and the insulating dielectric layer are both in a single-layer structure and are not overlapped in the second direction;

forming an ODR metal reflecting layer on the dielectric layer;

providing a permanent substrate;

forming a metal bonding layer on the permanent substrate;

bonding the metal bonding layer and the ODR metal reflecting layer;

and removing the temporary substrate, the N-type buffer layer and the N-type corrosion stop layer.

Preferably, in the above manufacturing method, the manufacturing method further includes:

and carrying out patterning treatment on the N-type ohmic contact layer and forming an N electrode.

Preferably, in the above manufacturing method, the manufacturing method further includes:

etching from the N-type rough layer to the P-type window layer to form a reserved cutting path.

Preferably, in the above manufacturing method, the manufacturing method further includes:

and roughening the surface of the N-type roughened layer.

Preferably, in the above manufacturing method, the manufacturing method further includes:

thinning the permanent substrate;

and forming a P electrode on the side of the permanent substrate, which faces away from the metal bonding layer.

Preferably, in the above manufacturing method, the P-type window layer includes a P-type ohmic contact layer and a P-type current spreading layer which are overlapped;

the P-type ohmic contact layer is adjacent to the dielectric layer;

the P-type current spreading layer is adjacent to the P-type confinement layer.

Preferably, in the above manufacturing method, the manufacturing method further includes:

and etching the N-type coarsening layer to the P-type ohmic contact layer along a reserved cutting path.

Compared with the prior art, the invention has the following beneficial effects:

the invention provides an LED chip, which adopts a dielectric layer with complementary patterns, namely, the regional patterns of a conductive dielectric layer and an insulating dielectric layer are complementary in a certain pattern to jointly form the dielectric layer, the dielectric layer is still in a single-layer structure in the first direction, the conductive dielectric layer and the insulating dielectric layer are complementarily formed according to a certain pattern in the direction vertical to the first direction, the sum of the area of the conductive dielectric layer and the insulating dielectric layer is 100 percent, namely, the whole dielectric layer is tiled between the P-type window layer and the ODR metal reflecting layer, and no area of the dielectric layer is left, thereby avoiding the problem of poor conduction caused by the fault of the metal at the through hole of the dielectric layer, avoiding the problem of light absorption caused by the diffusion of the metal at the through hole of the dielectric layer to the P-type window layer, improving the reflectivity of the ODR metal reflecting layer, and meanwhile, the cavity between the ODR metal reflecting layer and the metal bonding layer is greatly reduced, so that the risk of epitaxial layer fragmentation caused by the metal cavity in the wire welding process is reduced.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings 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 diagram of a prior art ODR reflective layer;

FIG. 2 is a schematic view of an optical microscope for a via of a dielectric layer in the prior art;

FIG. 3 is a schematic view of a scanning electron microscope showing a problem with the ODR reflective layer in the prior art;

FIG. 4 is a schematic diagram of a partial structure of an LED chip having a dielectric layer with a complementary pattern according to an embodiment of the present invention;

fig. 5 is a schematic structural diagram of a dielectric layer according to an embodiment of the present invention;

FIG. 6 is a schematic structural diagram of another dielectric layer according to an embodiment of the present invention;

FIG. 7 is a schematic structural diagram of another LED chip with a complementary patterned dielectric layer according to an embodiment of the present invention;

FIG. 8 is a schematic structural diagram of a P-type window layer according to an embodiment of the present invention;

FIG. 9 is a schematic diagram illustrating the positions of a dielectric layer and an N electrode according to an embodiment of the present invention;

FIG. 10 is a schematic diagram of the positions of another dielectric layer and an N electrode according to an embodiment of the present invention;

FIG. 11 is a flowchart illustrating key steps of a method for manufacturing an LED chip with a complementary patterned dielectric layer according to an embodiment of the present invention;

FIG. 12 is a flowchart illustrating key steps of another method for fabricating an LED chip with a dielectric layer having a complementary pattern according to an embodiment of the present invention;

FIG. 13 is a flowchart illustrating key steps of a method for fabricating an LED chip with a dielectric layer having a complementary pattern according to another embodiment of the present invention;

fig. 14 is a flowchart illustrating key steps of a method for manufacturing an LED chip having a dielectric layer with a complementary pattern according to another embodiment of the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

In order to make the aforementioned objects, features and advantages of the present invention comprehensible, embodiments accompanied with figures are described in further detail below.

Referring to fig. 4, fig. 4 is a schematic partial structure diagram of an LED chip having a complementary pattern dielectric layer according to an embodiment of the present invention.

The LED chip includes:

a permanent substrate 11;

the metal bonding layer 12, the ODR metal reflecting layer 13, the dielectric layer 14 and the P-type window layer 15 are sequentially arranged on the permanent substrate 11 in a first direction, the first direction is perpendicular to the permanent substrate 11, and the metal bonding layer 12 is pointed by the permanent substrate 11;

the dielectric layer 14 includes a conductive dielectric layer 141 and an insulating dielectric layer 142 both in direct contact with the ODR reflective layer 13, a conductive region pattern of the conductive dielectric layer 141 and an insulating region pattern of the insulating dielectric layer 142 are complementary patterns, and there is no vacant region between the conductive region pattern and the insulating dielectric layer 142, and in the first direction, the conductive dielectric layer 141 and the insulating dielectric layer 142 are both of a single-layer structure and are not overlapped with each other.

In this embodiment, the dielectric layer 14 with complementary patterns is adopted, that is, the patterns of the regions of the conductive dielectric layer 141 and the insulating dielectric layer 142 are complementary in a certain pattern to form the dielectric layer 14, the dielectric layer 14 still has a single-layer structure in the first direction, the conductive dielectric layer 141 and the insulating dielectric layer 142 are complementary in a certain pattern in the direction perpendicular to the first direction, the area ratio of the conductive dielectric layer 141 and the insulating dielectric layer 142 is 100%, that is, the dielectric layer 14 is tiled in the whole surface between the P-type window layer 15 and the ODR metal reflective layer 13, and there is no region where the dielectric layer 14 is vacant, so that there is no problem of poor conductivity caused by the metal fault at the through hole of the dielectric layer, there is no problem of light absorption caused by the metal at the through hole of the dielectric layer diffusing to the P-type window layer, the reflectivity of the ODR metal reflective layer is improved, and the, thereby reducing the risk of epitaxial layer fragmentation caused by metal voids during wire bonding.

Further, based on the above embodiment of the present invention, referring to fig. 5, fig. 5 is a schematic structural diagram of a dielectric layer according to an embodiment of the present invention.

The region of the conductive medium layer 141 is a connected region.

In this embodiment, the region of the conductive dielectric layer 141 and the region of the insulating dielectric layer 142 are both connected regions, which together constitute a dielectric layer.

Further, based on the above embodiment of the present invention, referring to fig. 6, fig. 6 is a schematic structural diagram of another dielectric layer provided in the embodiment of the present invention.

The region of the conductive medium layer 141 is a separate island-type region.

In this embodiment, the conductive dielectric layer 141 is a separate island region, and the conductive regions of the P-type window layer and the ODR metal reflective layer are formed.

Further, based on the above embodiment of the present invention, the area of the conductive medium layer 141 occupies 5% to 90% of the area of the medium layer 14.

In this embodiment, the area ratio of the area of the conductive medium layer 141 to the area of the insulating medium layer 142 may be determined according to the actual operating current of the LED chip, that is, the current to be conducted by the conductive medium layer 141 is determined, the minimum value of the area ratio of the conductive medium layer 141 is greater than or equal to 5%, and the maximum value may reach 90%.

Further, based on the above embodiment of the present invention, the thickness of the conductive medium layer 141 is (2k +1) λ/4n, where k is 0 and a positive integer, n is the refractive index of the conductive medium layer 141, and λ is the light-emitting peak wavelength of the LED chip;

the thickness of the insulating medium layer 142 is (2k +1) lambda/4 m, wherein k is 0 and a positive integer, m is the refractive index of the insulating medium layer 142, and lambda is the light-emitting peak wavelength of the LED chip.

In this embodiment, the thickness of the conductive dielectric layer 141 and the thickness of the insulating dielectric layer 142 may be the same or different, and normally, the thicknesses of the conductive dielectric layer and the insulating dielectric layer are respectively set to be optimal according to the thickness formula.

However, when the area of one of the dielectric layers is small, the thicknesses of the two dielectric layers may be set uniformly, and both may be set to the optimum thicknesses of the dielectric layers having a larger area.

Further, referring to fig. 7 based on the above embodiments of the present invention, fig. 7 is a schematic structural diagram of another LED chip with a complementary pattern dielectric layer according to an embodiment of the present invention.

The LED chip further includes:

a P-type confinement layer 16, an MQW active layer 17, an N-type confinement layer 18, an N-type current spreading layer 19, an N-type coarsening layer 20, an N-type ohmic contact layer 21 and an N-type electrode 22 which are sequentially arranged on the P-type window layer 15 in the first direction;

a P-electrode 23 arranged on the side of the permanent substrate 11 facing away from the metal bonding layer 12.

In this embodiment, the LED chip also includes other functional layers, which are described herein by way of example only.

For example, referring to fig. 8, fig. 8 is a schematic structural diagram of a P-type window layer according to an embodiment of the present invention, and the P-type window layer 15 may further include a P-type ohmic contact layer 151 and a P-type current spreading layer 152 sequentially disposed in the first direction.

Further, based on the above embodiment of the present invention, referring to fig. 9, fig. 9 is a schematic position diagram of a dielectric layer and an N electrode provided in the embodiment of the present invention, and referring to fig. 10, fig. 10 is a schematic position diagram of another dielectric layer and an N electrode provided in the embodiment of the present invention.

The projection of the area of the conductive medium layer 141 and the area of the N electrode 22 in the first direction do not overlap.

In this embodiment, the conductive medium layer 141 serves as a conductive channel for injecting current from the P electrode 23, and since the N electrode 22 is opaque, in order to guide electron-hole pairs excited by the injected current to be as little recombined as possible under the N electrode 22, so as to improve the light extraction efficiency, the region of the conductive medium layer 141 is arranged at the periphery of the N electrode 22 and not arranged right under the N electrode 22.

Furthermore, as shown in fig. 9 and 10, in order to reduce the risk of leakage of the LED chip and to more effectively utilize the function of the conductive medium layer 141 as a conductive channel, the conductive medium layer is not arranged in the scribe line region.

Based on all the above embodiments of the present invention, in another embodiment of the present invention, a method for manufacturing an LED chip with a complementary pattern dielectric layer is further provided, referring to fig. 11, fig. 11 is a schematic flow chart of key steps of the method for manufacturing an LED chip with a complementary pattern dielectric layer according to the embodiment of the present invention.

The manufacturing method comprises the following steps:

s101: a temporary substrate is provided.

In this step, the temporary substrate includes, but is not limited to, a GaAs temporary substrate.

S102: and sequentially epitaxially growing an N-type buffer layer, an N-type corrosion stop layer, an N-type ohmic contact layer, an N-type coarsening layer, an N-type current expansion layer, an N-type limiting layer, an MQW active layer, a P-type limiting layer and a P-type window layer on the temporary substrate in a second direction, wherein the second direction is perpendicular to the temporary substrate and is pointed to the N-type buffer layer by the temporary substrate.

In this step, an N-type GaAs buffer layer, an N-type GaInP corrosion stop layer, an N-type GaAs ohmic contact layer, an N-type AlGaInP coarsening layer, an N-type AlGaInP current spreading layer, an N-type AlGaInP confinement layer, an MQW active layer, a P-type AlGaInP confinement layer, and a P-type GaP window layer are epitaxially grown in this order on a GaAs temporary substrate using MOCVD (Metal Organic Chemical Vapor Deposition).

Wherein the thickness of the P-type GaP window layer is 1um-10um, preferably 3um, and the doping concentration of the main body part of the P-type GaP window layer is 1E18/cm3The surface layer doping concentration reaches 1E19/cm3The above.

Incidentally, AlGaInP means AlxGayIn(1-x-y)P material, respective AlxGayIn(1-x-y)The components of the P functional layer may be adjusted according to actual requirements, and are not limited in the embodiment of the present invention.

S103: and forming a dielectric layer on the P-type window layer, wherein the dielectric layer comprises a conductive dielectric layer and an insulating dielectric layer, a conductive area pattern of the conductive dielectric layer and an insulating area pattern of the insulating dielectric layer are complementary patterns, no vacant area exists between the conductive area pattern and the insulating dielectric layer, and the conductive dielectric layer and the insulating dielectric layer are of single-layer structures and are not overlapped in the second direction.

In this step, an ITO transparent conductive layer is deposited or sputtered on the P-type window layer, and a preferable thickness of the ITO transparent conductive layer is calculated from (2k +1) λ/4n, where k is 0, and an ITO refractive index n is 1.86 for a wavelength of red light λ 630nm, and the preferable thickness is calculated as

Figure BDA0002241532320000091

And spin-coating photoresist on the surface of the ITO, defining a pattern area of the conductive medium layer after exposure and development, and etching the ITO outside the required area by adopting ITO etching liquid.

Photoresist on the surface of the ITO is reserved, and an insulating medium layer MgF is evaporated on the whole surface2The preferred thickness of the dielectric layer is calculated from (2k +1) λ/4m, taking k 0 and MgF for a red light λ 630nm wavelength2Refractive index m is 1.38, and the preferred thickness is calculated to be

Figure BDA0002241532320000092

Because the surface of the conductive medium layer of the ITO material is provided with the photoresist, the photoresist and the MgF on the surface of the conductive medium layer can be removed by adopting a Lift-off process2Thereby forming ITO + MgF2A dielectric layer having a complementary pattern.

The material of the conductive dielectric layer includes, but is not limited to, a transparent conductive layer such as ITO, IZO, and IGZO or a composite layer thereof, and the material of the insulating dielectric layer includes, but is not limited to, MgF2And SiO2

In the process of coating the conductive medium layer, the conductive medium layer can directly form ohmic contact with the P-type window layer, and extra high-temperature annealing treatment is not needed.

S104: and forming an ODR metal reflecting layer on the dielectric layer.

In the step, an ODR metal reflecting layer is deposited on the surface of the manufactured dielectric layer and is electrically connected with the P-type window layer through a conductive dielectric layer to form a P-surface current injection channel.

S105: a permanent substrate is provided.

In this step, the permanent substrate includes, but is not limited to, a low resistivity silicon wafer.

S106: and forming a metal bonding layer on the permanent substrate.

S107: and bonding the metal bonding layer and the ODR metal reflecting layer.

In this step, the metal bonding layer and the ODR metal reflective layer are bonded to the permanent substrate by interdiffusion bonding during the bonding process under heat and pressure.

S108: and removing the temporary substrate, the N-type buffer layer and the N-type corrosion stop layer.

Further, based on the above embodiments of the present invention, referring to fig. 12, fig. 12 is a schematic flow chart of key steps of another method for manufacturing an LED chip with a complementary pattern dielectric layer according to an embodiment of the present invention.

The manufacturing method further comprises the following steps:

s109: and carrying out patterning treatment on the N-type ohmic contact layer and forming an N electrode.

In this step, an N-type ohmic contact layer pattern is formed by photolithography, wet etching, and the like, and an N-electrode is formed by photolithography, evaporation, lift-off, annealing, and the like.

S110: and etching the N-type coarsening layer to the P-type window layer along the reserved cutting path.

In this step, a reserved scribe line is etched from the N-type roughened layer to the P-type window layer by photolithography and dry etching.

S111: and roughening the surface of the N-type roughened layer.

S112: and thinning the permanent substrate, and forming a P electrode on one side of the permanent substrate, which is far away from the metal bonding layer.

Finally, the wafer is cut into discrete LED chips through the processes of tangent, back cutting, splitting and the like, and the reversed polarity AlGaInP-based infrared LED chip is formed.

Based on all the above embodiments of the present invention, another method for manufacturing an LED chip with a complementary patterned dielectric layer is further provided in another embodiment of the present invention, and referring to fig. 13, fig. 13 is a schematic flow chart illustrating a key step of the method for manufacturing an LED chip with a complementary patterned dielectric layer according to another embodiment of the present invention.

The manufacturing method comprises the following steps:

s201: a temporary substrate is provided.

In this step, the temporary substrate includes, but is not limited to, a GaAs temporary substrate.

S202: and sequentially epitaxially growing an N-type buffer layer, an N-type corrosion stop layer, an N-type ohmic contact layer, an N-type coarsening layer, an N-type current expansion layer, an N-type limiting layer, an MQW active layer, a P-type limiting layer, a P-type current expansion layer and a P-type ohmic contact layer on the temporary substrate in a second direction, wherein the second direction is perpendicular to the temporary substrate and is pointed to the N-type buffer layer by the temporary substrate.

In this step, an N-type GaAs buffer layer, an N-type GaInP corrosion-stop layer, an N-type GaAs ohmic contact layer, an N-type AlGaAs coarsening layer, an N-type AlGaAs current spreading layer, an N-type AlGaAs confinement layer, an MQW active layer, a P-type AlGaAs confinement layer, a P-type AlGaAs current spreading layer, and a P-type GaP ohmic contact layer are epitaxially grown in this order on a GaAs temporary substrate using MOCVD (Metal Organic Chemical Vapor Deposition).

The P-type AlGaAs current spreading layer and the P-type GaP ohmic contact layer jointly form a P-type window layer.

Wherein, the thickness of P type AlGaAs current spreading layer is 0.9um-9.9um, and preferred thickness is 3um, the thickness of P type GaP ohmic contact layer is 0.1um-1um, and preferred thickness is 0.2 um.

The doping concentration of the P-type AlGaAs current expansion layer is 1E18/cm3The doping concentration of the P-type GaP ohmic contact layer reaches 1E19/cm3The above.

Incidentally, AlGaAs means AlxGa(1-x)As material, respective AlxGa(1-x)The composition of the As functional layer may be adjusted according to actual requirements, and is not limited in the embodiment of the present invention.

S203: and forming a dielectric layer on the P-type ohmic contact layer, wherein the dielectric layer comprises a conductive dielectric layer and an insulating dielectric layer, a conductive region pattern of the conductive dielectric layer and an insulating region pattern of the insulating dielectric layer are complementary patterns, no vacant region exists between the conductive region pattern and the insulating dielectric layer, and the conductive dielectric layer and the insulating dielectric layer are of single-layer structures and are not overlapped in the second direction.

In this step, an ITO transparent conductive layer is deposited or sputtered on the P-type ohmic contact layer, and a preferable thickness of the ITO transparent conductive layer is calculated from (2k +1) λ/4n, where k is 0, and an ITO refractive index n is 1.76 for infrared light having a wavelength λ of 850nm, and the preferable thickness is calculated to be 1.76

Figure BDA0002241532320000111

And spin-coating photoresist on the surface of the ITO, defining a pattern area of the conductive medium layer after exposure and development, and etching the ITO outside the required area by adopting ITO etching liquid.

Photoresist on the surface of the ITO is reserved, and an insulating medium layer MgF is evaporated on the whole surface2The preferred thickness of the dielectric layer is calculated from (2k +1) λ/4m, k being 0 and MgF for infrared light with a wavelength λ of 850nm2Refractive index m is 1.38, and the preferred thickness is calculated to be

Figure BDA0002241532320000112

Because the surface of the conductive medium layer of the ITO material is provided with the photoresist, the photoresist and the MgF on the surface of the conductive medium layer can be removed by adopting a Lift-off process2Thereby forming ITO + MgF2A dielectric layer having a complementary pattern.

The material of the conductive dielectric layer includes, but is not limited to, a transparent conductive layer such as ITO, IZO, and IGZO or a composite layer thereof, and the material of the insulating dielectric layer includes, but is not limited to, MgF2And SiO2

In the process of coating the conductive medium layer, the conductive medium layer can directly form ohmic contact with the P-type window layer, and extra high-temperature annealing treatment is not needed.

S204: and forming an ODR metal reflecting layer on the dielectric layer.

In the step, an ODR metal reflecting layer is deposited on the surface of the manufactured dielectric layer and is electrically connected with the P-type window layer through a conductive dielectric layer to form a P-surface current injection channel.

S205: a permanent substrate is provided.

In this step, the permanent substrate includes, but is not limited to, a low resistivity silicon wafer.

S206: and forming a metal bonding layer on the permanent substrate.

S207: and bonding the metal bonding layer and the ODR metal reflecting layer.

In this step, the metal bonding layer and the ODR metal reflective layer are bonded to the permanent substrate by interdiffusion bonding during the bonding process under heat and pressure.

S208: and removing the temporary substrate, the N-type buffer layer and the N-type corrosion stop layer.

Further, based on the above embodiments of the present invention, referring to fig. 14, fig. 14 is a schematic flow chart of key steps of a method for manufacturing an LED chip having a complementary pattern dielectric layer according to an embodiment of the present invention.

The manufacturing method further comprises the following steps:

s209: and carrying out patterning treatment on the N-type ohmic contact layer and forming an N electrode.

In this step, an N-type ohmic contact layer pattern is formed by photolithography, wet etching, and the like, and an N-electrode is formed by photolithography, evaporation, lift-off, annealing, and the like.

S210: and etching the N-type coarsening layer to the P-type ohmic contact layer along a reserved cutting path.

In this step, a reserved scribe line is etched from the N-type roughened layer to the P-type window layer by photolithography and dry etching.

S211: and roughening the surface of the N-type roughened layer.

S212: and thinning the permanent substrate, and forming a P electrode on one side of the permanent substrate, which is far away from the metal bonding layer.

Finally, the wafer is cut into discrete LED chips through the processes of tangent, back cutting, splitting and the like, and the reversed polarity AlGaAs base infrared LED chips are formed.

As can be seen from the above description, the LED chip adopts the dielectric layers with complementary patterns, i.e. the regional patterns of the conductive dielectric layer and the insulating dielectric layer are complementary in a certain pattern to form the dielectric layers together, the dielectric layer is still in a single-layer structure in the first direction, the conductive dielectric layer and the insulating dielectric layer are complementarily formed according to a certain pattern in the direction vertical to the first direction, the sum of the area of the conductive dielectric layer and the insulating dielectric layer is 100 percent, namely, the whole dielectric layer is tiled between the P-type window layer and the ODR metal reflecting layer, and no area of the dielectric layer is left, thereby avoiding the problem of poor conduction caused by the fault of the metal at the through hole of the dielectric layer, avoiding the problem of light absorption caused by the diffusion of the metal at the through hole of the dielectric layer to the P-type window layer, improving the reflectivity of the ODR metal reflecting layer, and meanwhile, the cavity between the ODR metal reflecting layer and the metal bonding layer is greatly reduced, so that the risk of epitaxial layer fragmentation caused by the metal cavity in the wire welding process is reduced.

In addition, in the manufacturing process, the seamless splicing of the conductive medium layer and the insulating medium layer is realized by adopting a simple Lift-off process, and in the manufacturing process of the conductive medium layer, the conductive medium layer can directly form ohmic contact with the P-type window layer or the P-type ohmic contact layer without additional high-temperature annealing treatment.

The LED chip with the complementary pattern dielectric layer and the manufacturing method thereof provided by the present invention are described in detail above, and the principle and the implementation of the present invention are explained herein by applying specific examples, and the description of the above examples is only used to help understanding the method and the core idea of the present invention; meanwhile, for a person skilled in the art, according to the idea of the present invention, there may be variations in the specific embodiments and the application scope, and in summary, the content of the present specification should not be construed as a limitation to the present invention.

It should be noted that, in the present specification, the embodiments are all described in a progressive manner, each embodiment focuses on differences from other embodiments, and the same and similar parts among the embodiments may be referred to each other. 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 an … …" does not exclude the presence of other identical elements 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.

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