CN108808446B - GaN-based laser epitaxial structure with dislocation fracture structure and growth method thereof - Google Patents

Abstract

The invention relates to a GaN-based laser with a dislocation fracture structureThe epitaxial structure comprises a substrate, a nucleating layer, a high-temperature GaN layer, an n-type optical limiting layer, an n-type waveguide layer, a light-emitting layer, an electron blocking layer, a P-type GaN waveguide layer, a P-type GaN/AlGaN optical limiting layer and a surface ohmic contact layer from bottom to top in sequence, wherein a dislocation fracture is arranged in the n-type optical limiting layer and is Al_xGa_1‑xN and Si₃N₄X is more than 0 and less than or equal to 0.6. The insertion dislocation fracture layer can break the threading dislocation generated in the growth of the GaN-based laser structure, thereby reducing the threading dislocation density extending to the luminescent layer, improving the performance and prolonging the service life of the GaN-based laser.

Description

GaN-based laser epitaxial structure with dislocation fracture structure and growth method thereof

Technical Field

The invention relates to a GaN-based laser epitaxial structure with a dislocation fracture structure and a growth method thereof, belonging to the technical field of Laser (LD) preparation.

Background

Wide bandgap semiconductors are the third generation of semiconductor materials following silicon and gallium arsenide, have received more and more attention in recent years, and currently, extensive research mainly includes III-V and II-VI compound semiconductor materials, silicon carbide (SiC), diamond films, and the like, and have been widely applied to blue-green light, ultraviolet LEDs, LDs, detectors, microwave power devices, and the like. Due to its excellent characteristics and wide applications, it is receiving a great deal of attention. Particularly gallium nitride (GaN) materials among iii-v semiconductor materials, are the hot research points in the global semiconductor field today due to their commercial application in semiconductor illumination stress.

Group iii nitride materials include AlN, GaN, InN and their alloys, and their compositions are controlled to continuously vary their forbidden bandwidths from 0.9eV for InN to 6.2eV for AlN, with a corresponding wavelength range covering the entire visible region and extending into the ultraviolet region. The material is a direct band gap material, has the characteristics of high thermal conductivity, high luminous efficiency, small dielectric constant, stable chemical property, high hardness, high temperature resistance and the like, and is an ideal material for manufacturing devices such as Laser Diodes (LDs), high-brightness blue-green Light Emitting Diodes (LEDs), Heterojunction Field Effect Transistors (HFETs) and the like.

In the prior art, a large amount of threading dislocation can be generated in the growth process of a GaN-based Laser (LD) to release stress in an epitaxial thin film, so that more non-radiative recombination centers and larger leakage current exist in the working process of the laser, the performance of the GaN-based laser is affected, and even the service life of the laser is affected with fatality.

Therefore, there is a need to provide an LD growth process to reduce the threading dislocation density generated during the growth of GaN-based lasers, improve the crystal quality, and improve the performance and lifetime of LD products.

Chinese patent document CN105552186A discloses a blue LED epitaxial structure with a polarization-inhibiting barrier layer, which is a polarization-inhibiting barrier layer inserted between a shallow quantum well layer and an active region in a Light Emitting Diode (LED) growth process, wherein the polarization-inhibiting barrier layer includes an AlGaN layer and an SiN layer from bottom to top. Therefore, the stress is released, the polarization is inhibited, the defect density is reduced, the radiation recombination probability is improved, and the polarization effect is reduced, so that the aim of enhancing the quantum efficiency in the LED is fulfilled. The method is applied to the LED process, and a novel barrier layer is inserted into a shallow quantum well and an active region, so that the polarization effect is reduced, the quantum efficiency in the LED is improved, and Al is introduced in front of the active region_xGa_1-xThe N structure can cause the change of the barrier height to block the injection of electrons, but can influence the density of the injected electrons to influence the performance, and the method does not relate to the growth process of the GaN-based laser.

Chinese patent document CN102214740A discloses a method for improving the antistatic ability of a gallium nitride-based light emitting diode, which comprises: selecting a substrate; growing a gallium nitride nucleation layer on the substrate; growing an unintentionally doped gallium nitride layer on the gallium nitride nucleation layer; growing an aluminum gallium nitride/gallium nitride superlattice insertion layer on the unintentionally doped gallium nitride layer; growing an N-type doped gallium nitride layer on the aluminum gallium nitride/gallium nitride superlattice insertion layer; growing an aluminum gallium indium nitride multi-quantum well light-emitting layer on the N-type doped gallium nitride layer; growing a P-type doped aluminum gallium indium nitride layer on the aluminum gallium indium nitride multi-quantum well light-emitting layer; and growing a P-type doped gallium nitride layer on the P-type doped aluminum gallium indium nitride layer. However, the patent is applied to the LED process, and in the invention, the aluminum gallium nitride/gallium nitride superlattice structure is mainly used for modulating the stress, the turning and merging effects on defects in the crystal are very limited, and the structure still belongs to a GaN system material and cannot play a role in breaking or blocking dislocation extension and propagation.

Disclosure of Invention

Aiming at the defects of the prior art, the invention provides a GaN-based laser epitaxial structure with a dislocation fracture structure;

the invention also provides a growth method of the GaN-based laser epitaxial structure;

aiming at the problem of service life reduction caused by larger threading dislocation density in the existing GaN-based Laser (LD) growth technology, the invention can reduce the threading dislocation density generated in the GaN-based laser growth process, improve the crystal quality, and improve the performance and the service life of an LD product.

Interpretation of terms:

1. MOCVD equipment, metal organic chemical vapor deposition equipment;

2. TMAl, trimethylaluminum;

3. TMGa, trimethyl gallium;

4. dislocations, also known as dislocations, refer in the material sciences to an internal microscopic defect of a crystalline material, i.e. a local irregular arrangement of atoms (crystallographic defect).

The technical scheme of the invention is as follows:

a GaN-based laser epitaxial structure with a dislocation fracture structure sequentially comprises a substrate, a nucleation layer, a high-temperature GaN layer, an n-type optical limiting layer, an n-type waveguide layer, a light emitting layer, an electronic barrier layer, a P-type GaN waveguide layer, a P-type GaN/AlGaN optical limiting layer and a surface ohmic contact layer from bottom to top, wherein the n-type optical limiting layer is arranged on the substrate, and the n-type optical limiting layer is arranged on the surface of the substrateThe limiting layer is internally provided with a dislocation fault which is Al_xGa_1-xN and Si₃N₄X is more than or equal to 0 and less than or equal to 0.6.

Due to Si₃N₄Material properties of, Si in dislocation fracture₃N₄Layered on Al_xGa_1-xThe surface epitaxial growth mode of the N layer is preferential transverse epitaxial growth, namely the N layer grows along the two-dimensional direction of which the interface is preferentially parallel to the interface direction, the preferential transverse epitaxial growth mode can prevent the dislocation from continuously spreading and regenerating, and the dislocation can not pass through Si₃N₄The layer is used for reducing the propagation of crystal dislocation tending to extend from the active region in the n-type optical limiting layer, reducing the dislocation density in the device, and improving the performance and the service life of the device. By optimizing Al_xGa_1-xThe value of x in the N layer is beneficial to Si₃N₄The epitaxial growth profile of the layer at the interface, and the number of limit cycles that are conducive to promoting dislocation fracture growth.

More preferably, 0. ltoreq. x.ltoreq.0.16.

Si₃N₄The epitaxial growth appearance of the layer at the interface is better, and the limit period number of the dislocation fracture layer can be improved more.

Particularly preferably, x is 0.08.

Si₃N₄The epitaxial growth profile of the layer at the interface is optimal and the limit cycle number of the dislocation break layer can be raised to the maximum.

According to the invention, the Al is preferably_xGa_1-xN and Si₃N₄Has a superlattice structure of Al_xGa_1-xN layer, Si₃N₄The layers are periodically alternating in composition.

According to the invention, the Al is preferably_xGa_1-xN and Si₃N₄Has a period thickness of 1.1-130nm, and Al in one period_xGa_1-xThe thickness of the N layer is 1-100nm, and Si is₃N₄The thickness of the layer is 0.1-30 nm.

It is further preferred that the first and second liquid crystal compositions,the Al is_xGa_1-xN and Si₃N₄Has a period thickness of 5.2-90nm, and has a period of Al_xGa_1-xThe thickness of the N layer is 5-80nm, and Si is added₃N₄The thickness of the layer is 0.2-10 nm.

Particularly preferably, the Al_xGa_1-xN and Si₃N₄Has a period of 12nm thickness and a period of Al_xGa_1-xThe thickness of the N layer is 10nm, and Si is₃N₄The thickness of the layer was 2 nm.

According to the invention, the Al is preferably_xGa_1-xN and Si₃N₄The number of cycles of the superlattice structure of (1) to (50).

Through the setting of the number of the periods, the propagation of crystal dislocation tending to extend from an active region in the n-type optical limiting layer can be reduced as much as possible, the internal dislocation density of the device is reduced, and the performance and the service life of the device are improved.

According to the invention, the Al is preferably_xGa_1-xThe doping concentration of Si in the N layer is 0-1E +19cm^-3。

By setting the doping concentration, the electrical characteristics and the service life of the device can be improved.

According to the invention, the substrate is preferably a C-plane sapphire substrate, a SiC substrate or a GaN substrate;

the n-type light limiting layer is an n-type AlGaN layer or an n-type GaN/AlGaN superlattice layer structure;

the n-type waveguide layer is n-type GaN or InGaN, the mole ratio of In the n-type waveguide layer is 0-0.5, and the doping concentration of Si In the n-type waveguide layer is 0-1E +19cm^-3。

The light-emitting layer is composed of In_aGa_1-aN layer and In_bGa_1-bThe N layers are periodically and alternately composed, a is 0.1-0.2, b is 0-0.15, the period number of the luminous layer is 1-10, and In a single period_aGa_1-aThe thickness of the N layer is 1-15nm, and In_bGa_1-bThe thickness of the N layer is 1-20 nm.

The growth method of the GaN-based laser epitaxial structure comprises the following steps:

(1) growing the nucleating layer, the high-temperature GaN layer and the n-type optical limiting layer on the substrate in sequence in a reaction chamber of MOCVD equipment;

(2) growing a dislocation fracture layer in the n-type light confinement layer;

(3) and (3) sequentially growing the n-type waveguide layer, the light-emitting layer, the electron blocking layer, the P-type GaN waveguide layer, the P-type GaN/AlGaN optical limiting layer and the surface ohmic contact layer on the epitaxial structure generated in the step (2).

According to the invention, preferably, the step (2) of growing the dislocation fracture layer comprises growing for 1-50 cycles, and the growth process of a single cycle comprises the following steps:

A. adjusting the temperature of the reaction chamber of the MOCVD equipment to 700-₂(Nitrogen), 0-150000sccm of H₂(Hydrogen), 3000 + NH of 90000sccm₃(ammonia gas) growth of Al with a thickness of 1-100nm_xGa_1-xN layer, x is more than 0 and less than or equal to 0.6, Al_xGa_1-xThe doping concentration of Si in the N layer is 0-1E +19cm^-3(which may be doped or undoped);

B. adjusting the temperature of the reaction chamber of the MOCVD equipment to 700-1200 ℃, adjusting the pressure of the reaction chamber of the MOCVD equipment to 80-260torr, and introducing 20000-150000sccm N₂(Nitrogen), 0-150000sccm of H₂(Hydrogen), 3000 + NH of 90000sccm₃(Ammonia gas) and SiH of 5-200sccm₄(silane), Al formed in step A_xGa_1-xGrowing 1-50nm of Si on the N layer₃N₄And (3) a layer.

Preferably, In the step (3), the n-type waveguide layer is n-type GaN or InGaN, the molar ratio of In the n-type waveguide layer is 0-0.5, and the doping concentration of Si In the n-type waveguide layer is 0-1E +19cm^-3。

Preferably, In the step (3), the light-emitting layer is grown on the n-type waveguide layer, and the light-emitting layer is formed of In_aGa_1-aN layerAnd In_bGa_1-bThe N layers are periodically and alternately composed, a is 0.1-0.2, b is 0-0.15, the period number of the luminous layer is 1-10, and In a single period_aGa_1-aThe thickness of the N layer is 1-15nm, and In_bGa_1-bThe thickness of the N layer is 1-20 nm.

Preferably, in the step (3), the P-type GaN waveguide layer is epitaxially grown on the electron blocking layer, and is doped with Mg at a doping concentration of 1E +19cm^-3-5E+20cm^-3。

Removing dislocation break layer Al in said structure_xGa_1-xN and Si₃N₄The specific growth conditions of the rest layers except the superlattice structure can adopt the growth conditions of the epitaxial structure of the conventional gallium nitride-based laser. The dislocation fracture layer Al grows in the epitaxial structure of the gallium nitride-based laser_xGa_1-xN and Si₃N₄The superlattice structure of (1).

The invention has the beneficial effects that:

the invention inserts dislocation fracture Al_xGa_1-xN/Si₃N₄Superlattice structure due to Si₃N₄Material properties of, Si in dislocation fracture₃N₄Layered on Al_xGa_1-xThe surface epitaxial growth mode of the N layer is a preferential transverse epitaxial growth mode (namely, the growth is carried out along the two-dimensional direction that the interface of the N layer and the interface is preferentially parallel to the interface direction), the transverse epitaxial growth mode can prevent the dislocation from continuously spreading and regenerating, and the dislocation can not pass through the Si₃N₄The layer is used for reducing the propagation of crystal dislocation tending to extend from the active region in the n-type optical limiting layer, reducing the dislocation density in the device, and improving the performance and the service life of the device. The invention adjusts the molar ratio of Al and Al_xGa_1-xN layer and Si₃N₄The matching adjustment of the layer thickness reduces the propagation of crystal dislocation tending to extend from the active region in the n-type optical limiting layer as much as possible, and reduces the dislocation density in the device, thereby improving and prolonging the performance and the service life of the GaN-based laser.

Drawings

Fig. 1 is a schematic diagram of the epitaxial structure of a gan-based laser according to the present invention.

FIG. 2 is a schematic diagram of a dislocation fracture structure of the present invention.

Fig. 3 is a schematic diagram of the function of the dislocation break layer of the present invention.

1. Substrate, 2, nucleation layer, 3, high-temperature GaN layer, 4, n-type optical limiting layer, 5, dislocation breaking layer, 6, n-type waveguide layer, 7, light-emitting layer, 8, electron blocking layer, 9, P-type GaN waveguide layer, 10, P-type GaN/AlGaN optical limiting layer, 11, surface ohmic contact layer, 12, dislocation, 51, Al_xGa_1-xN layer, 52, Si₃N₄And (3) a layer.

Detailed Description

The invention is further defined in the following, but not limited to, the figures and examples in the description.

Example 1

A GaN-based laser epitaxial structure with dislocation fracture structure comprises asubstrate 1, a nucleation layer 2, a high-temperature GaN layer 3, an n-typeoptical confinement layer 4, an n-type waveguide layer 6, a luminescent layer 7, anelectron blocking layer 8, a P-type GaN waveguide layer 9, a P-type GaN/AlGaNoptical confinement layer 10 and a surfaceohmic contact layer 11 from bottom to top in sequence as shown in figure 1, wherein a dislocation fracture layer 5 is arranged in the n-typeoptical confinement layer 4, and the dislocation fracture layer 5 is Al_xGa_1-xN and Si₃N₄X is 0.

As shown in FIG. 3, due to Si₃N₄Material properties of (5), Si in the dislocation breaking layer 5₃N₄Layer 52 in Al_xGa_1-xThe surface epitaxial growth of theN layer 51 is carried out in a preferential lateral epitaxial growth mode, i.e. in a two-dimensional direction in which the interface between the two is preferentially parallel to the interface direction, which prevents thedislocations 12 from continuing to propagate and regenerate, so that thedislocations 12 cannot pass through the Si₃N₄And thelayer 52 is used for reducing the propagation ofcrystal dislocation 12 tending to extend from an active region in the n-type optical confinement layer, reducing the density ofdislocation 12 in the device, and improving the performance and the service life of the device. By optimizing Al_xGa_1-xThe value of x in theN layer 51 is favorable for Si₃N₄The epitaxial growth profile oflayer 52 at the interface, and the number of extreme cycles that favor growth of misfit 5.

Al_xGa_1-xN and Si₃N₄Has a superlattice structure of Al_xGa_1-xN layer 51, Si₃N₄The layers 52 are periodically alternating in composition. As shown in fig. 2.

Al_xGa_1-xN and Si₃N₄Has a period thickness of 1.1nm, and Al in one period_xGa_1-xThe thickness of theN layer 51 is 1nm, Si₃N₄The thickness oflayer 52 is 0.1 nm.

Al_xGa_1-xN and Si₃N₄The number of cycles of the superlattice structure of (1).

By setting the number of the periods, the propagation of thecrystal dislocation 12 tending to extend to the active region in the n-typeoptical confinement layer 4 can be reduced as much as possible, the dislocation density in the device is reduced, and the performance and the service life of the device are improved.

Al_xGa_1-xThe doping concentration of Si in theN layer 51 is 0-1E +19cm^-3。

By setting the doping concentration, the electrical characteristics and the service life of the device can be improved.

Thesubstrate 1 is a C-plane sapphire substrate, a SiC substrate, or a GaN substrate, and may be other conventional substrates.

The n-typelight limiting layer 4 is an n-type AlGaN layer or an n-type GaN/AlGaN superlattice layer structure;

the n-type waveguide layer 6 is n-type GaN or InGaN, the mole ratio of In the n-type waveguide layer 6 is 0-0.5, and the doping concentration of Si In the n-type waveguide layer 6 is 0-1E +19cm^-3。

The light-emitting layer 7 is composed of In_aGa_1-aN layer and In_bGa_1-bThe N layers are periodically and alternately composed, a is 0.1-0.2, b is 0-0.15, the period number of the luminous layer 7 is 1-10, In a single period_aGa_1-aThe thickness of the N layer is 1-15nm, In_bGa_1-bThe thickness of the N layer is 1-20 nm.

Example 2

A GaN-based laser epitaxial structure with dislocation breaking structure according toembodiment 1, except that:

x＝0.6。

Al_xGa_1-xn and Si₃N₄The number of cycles of the superlattice structure of (2) is 20.

Al_xGa_1-xN and Si₃N₄Has a period thickness of 130nm, and Al in one period_xGa_1-xThe thickness of theN layer 51 was 100nm, Si₃N₄The thickness oflayer 52 is 30 nm.

Example 3

A GaN-based laser epitaxial structure with dislocation breaking structure according toembodiment 1, except that:

x＝0.16。

Al_xGa_1-xn and Si₃N₄The number of cycles of the superlattice structure of (2) is 30.

Al_xGa_1-xN and Si₃N₄Has a period thickness of 90nm, and Al in one period_xGa_1-xThe thickness of theN layer 51 was 80nm, Si₃N₄The thickness oflayer 52 is 10 nm.

Example 4

A GaN-based laser epitaxial structure with dislocation breaking structure according toembodiment 1, except that:

X＝0.08。

Si₃N₄the epitaxial growth profile of thelayer 52 at the interface is optimal and the limit cycle number of the dislocation break layer 5 can be raised the most.

Al_xGa_1-xN and Si₃N₄The number of cycles of the superlattice structure of (3) is 50.

Al_xGa_1-xN and Si₃N₄Has a period of 12nm thickness and a period of Al_xGa_1-xThe thickness of theN layer 51 was 10nm, Si₃N₄The thickness oflayer 52 is 2 nm.

Example 5

The method for growing the epitaxial structure of the GaN-based laser according to any one ofembodiments 1 to 4 includes the following steps:

(1) in a reaction chamber of MOCVD equipment, a nucleation layer 2, a high-temperature GaN layer 3 and an n-type optical limitinglayer 4 are grown on asubstrate 1 in sequence;

(2) inserting dislocation fracture layer 5 at arbitrary position in n-typeoptical confinement layer 4;

(3) and (3) sequentially growing an n-type waveguide layer 6, a light-emitting layer 7, anelectron blocking layer 8, a P-type GaN waveguide layer 9, a P-type GaN/AlGaN optical limitinglayer 10 and a surfaceohmic contact layer 11 on the epitaxial structure generated in the step (2).

Step (2), growing the dislocation fracture layer 5, including growing for 1-50 cycles, wherein the growth process of a single cycle includes the following steps:

A. adjusting the temperature of the reaction chamber of the MOCVD equipment to 700-₂(Nitrogen), 0-150000sccm of H₂(Hydrogen), 3000 + NH of 90000sccm₃(ammonia gas) growth of Al with a thickness of 1-100nm_xGa_1-xN layer 51, x is more than 0 and less than or equal to 0.6, Al_xGa_1-xThe doping concentration of Si in theN layer 51 is 0-1E +19cm^-3(which may be doped or undoped);

B. adjusting the temperature of the reaction chamber of the MOCVD equipment to 700-1200 ℃, adjusting the pressure of the reaction chamber of the MOCVD equipment to 80-260torr, and introducing 20000-150000sccm N₂(Nitrogen), 0-150000sccm of H₂(Hydrogen), 3000 + NH of 90000sccm₃(Ammonia gas) and SiH of 5-200sccm₄(silane), Al formed in step A_xGa_1-x1-50nm of Si is grown on the N layer 51₃N₄Layer 52.

Dislocation breaking layer removing 5Al_xGa_1-xN and Si₃N₄The specific growth conditions of the rest layers except the superlattice structure can adopt the growth conditions of the epitaxial structure of the conventional gallium nitride-based laser. The dislocation fracture layer 5Al grows in the epitaxial structure of the gallium nitride-based laser_xGa_1-xN and Si₃N₄The superlattice structure of (1).

Claims (12)

1. A GaN-based laser epitaxial structure with a dislocation fracture structure sequentially comprises a substrate, a nucleation layer, a high-temperature GaN layer, an n-type optical limiting layer, an n-type waveguide layer, a light emitting layer, an electron blocking layer, a P-type GaN waveguide layer, a P-type GaN/AlGaN optical limiting layer and a surface ohmic contact layer from bottom to top, and is characterized in that a dislocation fracture layer is arranged in the n-type optical limiting layer and is Al_xGa_1-xN and Si₃N₄X is more than or equal to 0.16 and less than or equal to 0.6.

2. The GaN-based laser epitaxial structure with dislocation fracture structure as claimed in claim 1, wherein the Al is_xGa_1-xN and Si₃N₄Has a superlattice structure of Al_xGa_1-xN layer, Si₃N₄The layers are periodically alternating in composition.

3. The GaN-based laser epitaxial structure with dislocation fracture structure as claimed in claim 1, wherein the Al is_xGa_1-xN and Si₃N₄Has a period thickness of 1.1-130nm, and Al in one period_xGa_1-xThe thickness of the N layer is 1-100nm, and Si is₃N₄The thickness of the layer is 0.1-30 nm.

4. The GaN-based laser epitaxial structure with dislocation fracture structure as claimed in claim 3, wherein the Al is_xGa_1-xN and Si₃N₄Has a period thickness of 5.2-90nm, and has a period of Al_xGa_1-xThe thickness of the N layer is 5-80nm, and Si is added₃N₄The thickness of the layer is 0.2-10 nm.

5. A GaN-based laser with dislocation snap structure as in claim 3Optical device epitaxial structure, characterized in that said Al is_xGa_1-xN and Si₃N₄Has a period of 12nm thickness and a period of Al_xGa_1-xThe thickness of the N layer is 10nm, and Si is₃N₄The thickness of the layer was 2 nm.

6. The GaN-based laser epitaxial structure with dislocation fracture structure as claimed in claim 1, wherein the Al is_xGa_1-xN and Si₃N₄The number of cycles of the superlattice structure of (1) to (50).

7. The GaN-based laser epitaxial structure with dislocation fracture structure as claimed in claim 2, wherein the Al is_xGa_1-xThe doping concentration of Si in the N layer is 0-1E +19cm^-3。

8. The GaN-based laser epitaxial structure with the dislocation fracture structure is characterized in that the substrate is a C-plane sapphire substrate, a SiC substrate or a GaN substrate;

the n-type light limiting layer is an n-type AlGaN layer or an n-type GaN/AlGaN superlattice layer structure;

the n-type waveguide layer is n-type GaN or InGaN, the mole ratio of In the n-type waveguide layer is 0-0.5, and the doping concentration of Si In the n-type waveguide layer is 0-1E +19cm^-3；

The light-emitting layer is composed of In_aGa_1-aN layer and In_bGa_1-bThe N layers are periodically and alternately composed, a is 0.1-0.2, b is 0-0.15, the period number of the luminous layer is 1-10, and In a single period_aGa_1-aThe thickness of the N layer is 1-15nm, and In_bGa_1-bThe thickness of the N layer is 1-20 nm.

9. The method for growing a GaN-based laser epitaxial structure with a dislocation breaking structure as claimed in any one of claims 1 to 8, comprising the steps of:

(1) growing the nucleating layer, the high-temperature GaN layer and the n-type optical limiting layer on the substrate in sequence in a reaction chamber of MOCVD equipment;

(2) growing a dislocation fracture layer in the n-type light confinement layer;

(3) and (3) sequentially growing the n-type waveguide layer, the light-emitting layer, the electron blocking layer, the P-type GaN waveguide layer, the P-type GaN/AlGaN optical limiting layer and the surface ohmic contact layer on the epitaxial structure generated in the step (2).

10. The method for growing a GaN-based laser epitaxial structure with a dislocation breaking structure according to claim 9, wherein the step (2) of growing dislocation breaking layers comprises growing 1-50 cycles, and the single-cycle growing process comprises the steps of:

A. adjusting the temperature of the reaction chamber of the MOCVD equipment to 700-₂0-150000sccm of H₂3000-NH 90000sccm₃Growing Al with a thickness of 1-100nm_xGa_1-xN layer, x is more than 0 and less than or equal to 0.6, Al_xGa_1-xThe doping concentration of Si in the N layer is 0-1E +19cm^-3；

B. Adjusting the temperature of the reaction chamber of the MOCVD equipment to 700-1200 ℃, adjusting the pressure of the reaction chamber of the MOCVD equipment to 80-260torr, and introducing 20000-150000sccm N₂0-150000sccm of H₂3000-NH 90000sccm₃And SiH of 5-200sccm₄Al formed in step A_xGa_1-xGrowing 1-50nm of Si on the N layer₃N₄And (3) a layer.

11. The method for growing the epitaxial structure of GaN-based laser with dislocation breaking structure as claimed In claim 9, wherein In the step (3), the n-type waveguide layer is n-type GaN or InGaN, the molar ratio of In the n-type waveguide layer is 0-0.5, and the doping concentration of Si In the n-type waveguide layer is 0-1E +19cm^-3(ii) a The light-emitting layer is composed of In_aGa_1-aN layer and In_bGa_1-bThe N layers are periodically and alternately composed, a is 0.1-0.2, b is 0-0.15, the period number of the luminous layer is 1-10, and In a single period_aGa_1-aThe thickness of the N layer is 1-15nm, and In_bGa_1-bThe thickness of the N layer is 1-20 nm.

12. The method for growing a GaN-based laser epitaxial structure with dislocation fracture structure as claimed in any of claims 9-11, wherein in step (3), the P-type GaN waveguide layer is epitaxially grown on the electron blocking layer, and the P-type GaN waveguide layer is doped with Mg with a doping concentration of 1E +19cm^-3-5E+20cm^-3。

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