CN106206898B - A kind of production method of light emitting diode - Google Patents

Abstract

The present invention proposes a method for manufacturing a light-emitting diode, comprising: providing an epitaxial wafer, and depositing a metal Ni layer; patterning the metal Ni layer, defining the metal Ni layer on the P-type semiconductor region to remain, and the N-type semiconductor region The metal Ni layer on the epiwafer is removed; the epiwafer with the patterned metal Ni layer is annealed, and after annealing, the metal Ni layer presents a granular distribution on the epiwafer; a mask layer is formed on the metal Ni particles; The metal Ni particles and the mask layer are used as a mask structure, and the etching process is carried out. The first step of etching is first performed to make the mask layer shrink inward, and then the second step of etching is performed to obtain a light-emitting diode with an inclined surface, and the inclined surface form nanostructures.

Description

A method of manufacturing a light emitting diode

technical field

The invention relates to the technical field of semiconductors, in particular to a method for manufacturing a light-emitting diode with inclined side surfaces of nano-microstructures.

Background technique

In the existing LED structure with slanted sides, after making N electrodes, most of them are yellow light masks, and then directly use dry etching to etch to the N-type semiconductor layer, and then make electrodes, so there will be two problems: (1) The metal N electrode absorbs side light; (2) The smooth side makes the light emitted inside the LED chip easy to exit and cannot be used, as shown in Figure (1).

Chinese patent CN105378950A discloses a top-emitting semiconductor light-emitting device, which proposes to fix each independent light-emitting unit on the carrier at a fixed distance, and then distribute or mold a transparent layer or particles between the two light-emitting units to achieve The purpose of reflecting light, but this method has some shortcomings: (1) A layer of medium is deposited around the light-emitting component, which is easy to introduce impurities, causing the side P layer, MQW layer and N layer to be connected, and finally short-circuited. In the actual LED production, a large part of the failures such as leakage or ESD explosion occurs around the light-emitting components. (2) Only arrange a layer of transparent layer or particles around the light-emitting component, and the absorption part of the N electrode cannot be avoided.

Contents of the invention

The object of the present invention is to: propose a kind of manufacturing method of light-emitting diode, its inclined side forms nanometer structure, has increased the diffuse reflection of light, makes the light that chip side sends changes optical path, sends out from positive direction, reduces N electrode to light Light absorption increases the brightness; the nano-microstructure is homogeneous with the chip material, and will not cause leakage or ESD burst due to the introduction of other materials.

According to a first aspect of the present invention, a method for manufacturing a light emitting diode is provided, comprising the steps of:

(1) Provide an epitaxial wafer and deposit a metal Ni layer;

(2) Patterning the metal Ni layer, defining that the metal Ni layer on the P-type semiconductor region is retained, and the metal Ni layer on the N-type semiconductor region is removed;

(3) Annealing the epiwafer with the patterned metal Ni layer, after annealing, the metal Ni layer presents a granular distribution on the epiwafer;

(4) forming a mask layer on the metal Ni particles;

(5) Using the metal Ni particles and the mask layer as a mask structure, an etching process is performed. First, the first step of etching is performed to shrink the mask layer, and then the second step of etching is performed to obtain a luminescent surface with an inclined surface. Diode, and the inclined surface forms nano-microstructures.

According to the second aspect of the present invention, there is also provided another method for manufacturing a light emitting diode, comprising the steps of:

(1) Provide an epitaxial wafer and deposit a metal Ni layer;

(2) Annealing the epiwafer with the metal Ni layer, after annealing, the metal Ni layer presents a granular distribution on the epiwafer;

(3) Patterning the metal Ni particles, defining that the metal Ni particles on the P-type semiconductor region are retained, and the metal Ni particles on the N-type semiconductor region are removed;

(4) forming a mask layer on the metal Ni particles;

(5) Using the metal Ni particles and the mask layer as a mask structure, an etching process is performed. First, the first step of etching is performed to shrink the mask layer, and then the second step of etching is performed to obtain a luminescent surface with an inclined surface. Diode, and the inclined surface forms nano-microstructures.

Preferably, the thickness of the metal Ni layer is 3-200 nm.

Preferably, the annealing treatment conditions: the temperature is 500-800° C., and the time is 0.5-10 min.

Preferably, the mask layer in the step (4) is selected from photoresist or oxide or metal.

Preferably, before the step (4), a step is further included: depositing an insulating protection layer for protecting the epitaxial layer located in the N-type semiconductor region from being etched first in the etching process of the step (5).

Preferably, the first step of etching in the step (5) is used to shrink the mask layer by 0.1-1 μm.

Preferably, the first step of etching in the step (5) adopts a wet etching or dry etching process.

Preferably, the first dry etching process in the step (5) includes: introducing oxygen or carbon tetrafluoride or a combination of the above, upper electrode power: 150~2000W, lower electrode power: 0~400W, time: 20~200s.

Preferably, the second etching step in the step (5) adopts a dry etching process.

Preferably, the second dry etching process in the step (5) includes: feeding boron trichloride or chlorine gas or the aforementioned combination, upper electrode power: 150~500W, lower electrode power: 50~500W, time: 300~600s.

In the prior art, the LED structure with sloped side is manufactured by first manufacturing the P-type semiconductor region and the N-type semiconductor region. At this time, the sloped surface of the core particle is a smooth structure, and then depositing or molding particles on the side of the core particle. Compared with the prior art, a method for manufacturing a light-emitting diode provided by the present invention at least includes the following technical effects:

(1) The process flow of the prior art is relatively complicated and the cost is high, but the present invention uses metal particles and a mask layer as a mask structure, and at the same time of making the P-type semiconductor region and the N-type semiconductor region of the light-emitting diode, on the inclined side The nano-microstructure is formed to increase the diffuse reflection of light, so that the light emitted from the side of the chip changes the optical path, and is emitted from the positive direction, reducing the light absorption of the N electrode and increasing the brightness;

(2) In the prior art, heterogeneous materials are introduced by depositing or molding particles on the side of the core particle, while the present invention forms a nano-microstructure on the inclined side of the light-emitting diode, which is homogeneous with the chip material and will not be caused by the introduction of other materials. The material causes electric leakage or ESD explosion point.

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

Description of drawings

The accompanying drawings are used to provide a further understanding of the present invention, and constitute a part of the description, and are used together with the embodiments of the present invention to explain the present invention, and do not constitute a limitation to the present invention. In addition, the drawing data are descriptive summaries and are not drawn to scale.

FIG. 1 is a schematic structural diagram of a conventional LED with inclined sides.

FIG. 2 is a flowchart of a method for manufacturing a light emitting diode according to Embodiment 1 of the present invention.

3-8 are the manufacturing process of a light emitting diode according to Embodiment 1 of the present invention.

FIG. 9 is a flow chart of a method for manufacturing a light emitting diode according to Embodiment 2 of the present invention.

10-15 are the manufacturing process of a light emitting diode according to Embodiment 2 of the present invention.

The symbols in the figure are as follows:

100: Epiwafer; 101: Substrate; 102: N-type semiconductor layer; 103: Light-emitting layer; 104: P-type semiconductor layer; 200: Metal Ni layer; 201: Metal Ni particles; 205: Nano microstructure; 300: Mask Film layer; 400: insulation protection layer.

Detailed ways

The specific implementation of the present invention will be described in detail below in conjunction with the embodiments and the accompanying drawings.

Example 1

As shown in Fig. 2, a flow chart of manufacturing a light-emitting diode is disclosed, including steps S101 to S105, including: providing an epitaxial wafer and depositing a metal Ni layer; patterning the metal Ni layer to define a P-type semiconductor The metal Ni layer on the region remains, and the metal Ni layer on the N-type semiconductor region is removed; the epiwafer with the patterned metal Ni layer is annealed, and after annealing, the metal Ni layer presents a granular distribution on the epiwafer; A mask layer is formed on the Ni particles; the metal Ni particles and the mask layer are used as the mask structure to carry out the etching process, and the first step of etching is performed to make the mask layer retract, and then the second step of etching is performed to obtain a The light-emitting diodes on the surface, and the inclined surface forms nano-microstructures. The progress of each step is described below.

Step S101: As shown in FIG. 3, an epitaxial wafer 100 is provided, the epitaxial wafer includes a substrate 101 and an epitaxial layer, and the epitaxial layer includes an N-type semiconductor layer 101, a light-emitting layer 102, and a P-type semiconductor layer 103; The metal Ni layer 200 is deposited on the epiwafer 100 with a thickness between 3-200 nm. The deposition method can be vapor deposition or sputtering or atomic layer deposition or other coating methods. The vapor deposition method is preferred in this embodiment.

Step S102: As shown in FIG. 4, the metal Ni layer 200 is patterned to define that the metal Ni layer on the P-type semiconductor region is retained, and the metal Ni layer on the N-type semiconductor region is removed. The P-type semiconductor region is used for subsequent fabrication of P The electrode, the N-type semiconductor region is used for subsequent fabrication of the N electrode.

Step S103: As shown in FIG. 5, the epiwafer 100 with the patterned metal Ni layer 201 is subjected to annealing treatment. After annealing, the metal Ni layer presents a granular distribution on the epiwafer. The annealing treatment conditions include: the temperature is 500~ 800°C, the time is 0.5~10min, the atmosphere is N ₂ : 25~95L.

Step S104: As shown in FIG. 6, a mask layer 300 is formed on the metal Ni particles 201. The area of the mask layer is equivalent to that of the metal Ni particles. The material of the mask layer can be photoresist, oxide or metal. In this embodiment The photoresist is preferably used as the mask layer, the thickness of the photoresist can be 0.5~3μm, and the pattern composed of columnar photoresist is produced by using the yellow light process. This process can use a stepper exposure machine, a contact exposure machine, and a projection exposure machine. or embossing method.

Step S105: As shown in FIG. 7 , the metal Ni particles 201 and the mask layer 300 are used as the mask structure, and the inductively coupled plasma etching process is performed, and the first step of dry etching is performed first, so that the mask layer shrinks inward by 0.1-1 μm , the first step of dry etching process, the parameters include: oxygen 100~200sccm, upper electrode power: 1000~2000W, lower electrode power: 0~50W, time: 20~200s; then as shown in Figure 8, proceed The second step is dry etching, so that the epitaxial layer forms an inclined surface with nano-microstructure 205 and exposes part of the N-type semiconductor layer 102. The etching process parameters include: feeding boron trichloride 5~50 sccm, feeding chlorine gas 60~ 180sccm, upper electrode power: 150~500W, lower electrode power: 50~500W, time: 300~600s, finally make P electrode 600 and N electrode 500 on P type semiconductor layer 104 and exposed N type semiconductor layer 102 respectively, A light emitting diode with an inclined surface is obtained, and the inclined surface forms a nanostructure 105, as shown in FIG. 8 .

Example 2

As shown in FIG. 9, another flow chart for manufacturing a light-emitting diode is disclosed, including steps S201 to S205, including: providing an epitaxial wafer and depositing a metal Ni layer; annealing the epitaxial wafer with the metal Ni layer, After annealing, the metal Ni layer presents a granular distribution on the epiwafer; the metal Ni particles are patterned to define that the metal Ni particles on the P-type semiconductor region are retained, and the metal Ni particles on the N-type semiconductor region are removed; A mask layer is formed on the metal Ni particles; the metal Ni particles and the mask layer are used as a mask structure to carry out an etching process, and the first step of etching is first performed to shrink the mask layer, and then the second step of etching is performed, A light-emitting diode with an inclined surface is obtained, and the inclined surface forms a nanometer structure. The progress of each step is described below.

Step S201: As shown in FIG. 10, an epitaxial wafer 100 is provided, the epitaxial wafer includes a substrate 101 and an epitaxial layer, and the epitaxial layer includes an N-type semiconductor layer 101, a light-emitting layer 102, and a P-type semiconductor layer 103; A metal Ni layer 200 is deposited on the epiwafer 100 with a thickness between 3-200 nm. The deposition method can be vapor deposition, sputtering, atomic layer deposition or other coating methods. The sputtering method is preferred in this embodiment.

Step S202: As shown in FIG. 11 , the epiwafer 100 of the epiwafer 201 with the metal Ni layer is annealed. After annealing, the metal Ni layer presents a granular distribution on the epiwafer. The annealing conditions include: the temperature is 500 ~800℃, the time is 0.5~10min, the atmosphere is N ₂ : 25~95L.

Step S203: As shown in Figure 12, pattern the metal Ni particles 201, define the metal Ni particles on the P-type semiconductor region to be retained, and the metal Ni particles on the N-type semiconductor region to be removed, and the P-type semiconductor region is used for subsequent manufacturing of P The electrode, the N-type semiconductor region is used for subsequent fabrication of the N electrode.

Step S204 : as shown in FIG. 13 , first deposit an insulating protection layer 400 on the metal Ni particles 201 , and then form a mask layer 300 . The insulating protective layer 400 can be made of SiO ₂ or SiN or Al ₂ O ₃ . In this embodiment, SiO ₂ with a thickness of 10-30 nm is preferably formed by chemical vapor deposition (CVD). Ni particles), used to protect the epitaxial layer located in the N-type semiconductor region from being etched first in the step S205 etching process, as a buffer; the area of the mask layer 300 is equivalent to the metal Ni particles, and the material of the mask layer can be Use photoresist or oxide or metal. In this embodiment, photoresist is preferred as the mask layer. The thickness of the photoresist can be 0.5 μm to 3 μm. Exposure machine, contact exposure machine, projection exposure machine or embossing method.

Step S205: As shown in FIG. 14, the metal Ni particles 201, the insulating protective layer 400 and the mask layer 300 are used as the mask structure to perform an inductively coupled plasma etching process, and the first step of dry etching is performed first, so that the insulating protective layer 1. The unilateral size of the mask layer is shrunk inward by 0.1~1μm relative to the metal Ni particles. The first step of the dry etching process includes: introducing carbon tetrafluoride 50~300sccm, oxygen 5~200sccm, and the upper electrode Power: 150~900W, lower electrode power: 50~400W, time: 20~200s; then, as shown in Figure 15, the second step of dry etching is carried out, so that the epitaxial layer forms an inclined surface with nano-microstructure 205 and Part of the N-type semiconductor layer 102 is exposed, and the etching process parameters include: boron trichloride 5~50 sccm, chlorine gas 60~180 sccm, upper electrode power: 150~500W, lower electrode power: 50~500W, time: 300 ~600s, finally make P-electrode 600 and N-electrode 500 respectively on P-type semiconductor layer 104 and exposed N-type semiconductor layer 102, obtain light-emitting diode with inclined surface, and the inclined surface forms nano-microstructure 105, as shown in Figure 15 Show.

Example 3

This embodiment discloses yet another method for manufacturing a light-emitting diode, including process steps:

(1) Provide an epitaxial wafer, and deposit a metal Ni layer;

(2) Patterning the metal Ni layer, defining that the metal Ni layer on the P-type semiconductor region is retained, and the metal Ni layer on the N-type semiconductor region is removed;

(3) Annealing the epiwafer with the patterned metal Ni layer, after annealing, the metal Ni layer presents a granular distribution on the epiwafer;

(4) forming a mask layer on the metal Ni particles, and using wet etching to shrink the mask layer;

(5) Using the metal Ni particles and the mask layer as a mask structure, performing inductively coupled plasma etching to obtain a light emitting diode with an inclined surface, and the inclined surface forms a nano-microstructure.

The difference between this embodiment and Embodiment 1 is that the retraction of the mask layer above the metal Ni particles in step S105 of Embodiment 1 is accomplished by a dry etching process, while the retraction of the mask layer in this embodiment is achieved by The wet etching process is completed. In this embodiment, the shrinkage of the mask layer adopts a wet etching process with low cost, simple process conditions, and is convenient for production operation; while the dry etching process is used for the shrinkage of the mask layer in Embodiment 1 to facilitate the control of the uniformity of related dimensions.

To sum up, the present invention uses metal particles and a mask layer as a mask structure to form nano-microstructures on the inclined surface of core grains while making P-type semiconductor regions and N-type semiconductor regions. Compared with the existing technology, it has the following technical advantages:

(1) Make full use of the technical conditions and materials of the existing production line, and will not introduce new process steps and new materials;

(2) Nano particles formed on the inclined surface of the core particle are homogeneous with the epitaxial layer, so as to avoid the connection between the side P-type semiconductor layer, the light-emitting layer and the P-type semiconductor layer, and finally short circuit, resulting in leakage or ESD explosion point;

(3) Not only is the nano-microstructure arranged around the light-emitting area of the LED core particle, but at the same time, since the nano-microstructure is located around the N electrode, the absorption of light by the N metal electrode is avoided.

It should be understood that the above specific embodiments are only some preferred embodiments of the present invention, and various combinations and modifications can be made to the above embodiments. The scope of the present invention is not limited to the above embodiments, and any changes made according to the present invention are within the protection scope of the present invention.

Claims (10)

1. a kind of production method of light emitting diode, including step：

（1）One epitaxy piece is provided, and deposits a W metal layer；

（2）By the W metal pattern layers, the W metal layer defined in P-type semiconductor region retains, on N-type semiconductor region W metal layer removal；

（3）The epitaxy piece for having pattern metal Ni layers is made annealing treatment, after annealing, W metal layer is in the presentation of epitaxy on piece Granular distribution；

（4）Mask layer is formed on the metallic Ni particles；

（5）Using the metallic Ni particles and mask layer as mask structure, technique is etched, first step etching is first carried out, makes It obtains mask layer to inside contract, then carries out the second step etching again, obtain the light emitting diode with inclined surface, and inclined surface is formed Nano-micro structure.

2. a kind of production method of light emitting diode, including step：

（1）One epitaxy piece is provided, and deposits a W metal layer；

（2）The epitaxy piece for having W metal layer is made annealing treatment, after annealing, graininess point is presented in epitaxy on piece in W metal layer Cloth；

（3）The metallic Ni particles are patterned, the metallic Ni particles defined in P-type semiconductor region retain, N-type semiconductor area Metallic Ni particles removal on domain；

（4）Mask layer is formed on the metallic Ni particles；

（5）Using the metallic Ni particles and mask layer as mask structure, technique is etched, first step etching is first carried out, makes It obtains mask layer to inside contract, then carries out the second step etching again, obtain the light emitting diode with inclined surface, and inclined surface is formed Nano-micro structure.

3. a kind of production method of light emitting diode according to claim 1 or 2, it is characterised in that：The W metal layer Thickness be 3 ~ 200nm.

4. a kind of production method of light emitting diode according to claim 1 or 2, it is characterised in that：The annealing Condition：Temperature is 500 ~ 800 DEG C, and the time is 0.5 ~ 10min.

5. a kind of production method of light emitting diode according to claim 1 or 2, it is characterised in that：The step（4）It Before further include step：Deposit an insulating protective layer for protect be located at the N-type semiconductor region epitaxial layer in step（5）Erosion It is not etched first in carving technology.

6. a kind of production method of light emitting diode according to claim 1 or 2, it is characterised in that：The step（5）In First step etching is for first so that mask layer inside contracts 0.1 ~ 1 μm.

7. a kind of production method of light emitting diode according to claim 1 or 2, it is characterised in that：The step（5）In First step etching uses wet etching or dry method etch technology.

8. a kind of production method of light emitting diode according to claim 7, it is characterised in that：The step（5）In One step dry method etch technology, including：It is passed through oxygen or carbon tetrafluoride or aforementioned combinatorial, upper electrode power：150 ~ 2000W, lower electricity Pole power：0 ~ 400W, time：20~200s.

9. a kind of production method of light emitting diode according to claim 1 or 2, it is characterised in that：The step（5）In Second step etching uses dry method etch technology.

10. a kind of production method of light emitting diode according to claim 9, it is characterised in that：The step（5）In Two step dry method etch technologies, including：It is passed through boron chloride or chlorine or aforementioned combinatorial, upper electrode power：150 ~ 500W, lower electrode Power：50 ~ 500W, time：300~600s.