CN115172551A - Epitaxial wafer and manufacturing method thereof - Google Patents

Abstract

The present application discloses an epitaxial wafer and a method for manufacturing the epitaxial wafer. The epitaxial wafer includes a growth preparation layer, a quantum barrier layer grown on the growth preparation layer, and a quantum well layer grown on the quantum barrier layer, the quantum well layer and the growth preparation layer. The lattice constant of the layer satisfies (a-c)/c is greater than 1.3%, and the thickness of the quantum barrier layer is set so that the average stress characterization coefficient of the quantum barrier layer and the quantum well layer ranges from (‑0.00216)‑(‑0.00732) , where a is the lattice constant of the quantum well layer, and c is the lattice constant of the growth preparation layer. In this application, the thickness of the quantum barrier layer is set so that the average stress characterization coefficient of the quantum barrier layer and the quantum well layer is within a preset range, specifically between (‑0.00216)‑(‑0.00732), to solve the quantum problem of long-wavelength LEDs There is a serious lattice mismatch between the well layer and the growth preparation layer, which leads to the problems of In precipitation and phase separation.

Description

A kind of epitaxial wafer and epitaxial wafer manufacturing method

technical field

The present application relates to the technical field of semiconductor epitaxial growth and fabrication of devices, and in particular, to an epitaxial wafer and an epitaxial wafer fabrication method.

Background technique

At present, GaN-based LEDs (Light Emitting Diodes, light-emitting diodes) have been widely used in the field of solid-state lighting and display. Compared with the blue GaN-based LEDs that have been commercialized, the luminous efficiency of GaN-based LEDs with longer emission wavelengths will be higher. It drops rapidly and becomes more pronounced as the wavelength increases, which greatly limits the further development of Mini and MicroLED. Specifically, the MQW (multiple quantum well) layer of the LED active region is a multi-layer structure formed by alternate growth of two different semiconductor material thin layers, one of which is a quantum well layer, and the other semiconductor material thin layer. layer is a quantum barrier layer. The quantum well layers in existing MQW layers are made of InGaN, and the quantum barrier layers are usually made of undoped GaN. Among them, for long-wavelength LEDs, the high In composition content causes a serious lattice mismatch between the MQW layer and the substrate on which the epitaxial wafer is grown, resulting in phase separation and In precipitation problems, resulting in a decrease in crystal quality and a The radiative recombination efficiency is greatly increased, which affects the luminous efficiency.

SUMMARY OF THE INVENTION

The present application provides at least an epitaxial wafer and an epitaxial wafer manufacturing method to solve the problem of In precipitation and phase separation caused by serious lattice mismatch between the quantum well layer and the growth preparation layer of the long-wavelength LED in the prior art.

A first aspect of the present application provides an epitaxial wafer, the epitaxial wafer includes a growth preparation layer, a quantum barrier layer grown on the growth preparation layer, and a quantum well layer grown on the quantum barrier layer, a crystal of the quantum well layer and the growth preparation layer. The lattice constant satisfies that (a-c)/c is greater than 1.3%, the thicknesses of the quantum well layer and the quantum barrier layer are set so that the average stress characterizing coefficient of the quantum barrier layer and the quantum well layer ranges from (-0.00216)-(-0.00732), where a is the lattice constant of the quantum well layer, and c is the lattice constant of the growth preparation layer.

Optionally, (a-c)/c is further greater than 2.8%.

Optionally, the lattice constants of the quantum barrier layer and the growth preparation layer satisfy (b-c)/c greater than 0.01%.

Optionally, the quantum well layer is an InGaN material or an InGaAlN material, wherein the molar percentage content of the In component in the quantum well layer is not less than 20%, and the thickness of the quantum barrier layer is not less than 10 nm.

Optionally, the quantum well layer is an InGaN material or an InGaAlN material, wherein the molar percentage content of the In component in the quantum well layer is not less than 32%, and the thickness of the quantum barrier layer is not less than 20 nm.

Optionally, the quantum barrier layer is a GaN material or an InGaAlN material.

Optionally, the growth preparation layer is GaN material or InGaAlN material.

Optionally, the epitaxial wafer includes a plurality of quantum barrier layers and a plurality of quantum well layers, and the number of cycles of the alternately stacked quantum well layers and quantum barrier layers is 2-1000 cycles.

A second aspect of the present application provides a method for manufacturing an epitaxial wafer, and the method for manufacturing an epitaxial wafer includes:

Obtain the preset mean stress characterization coefficient;

Acquire the preset parameters of the epitaxial wafer, and the predicted parameters include the lattice constant of the preparation layer, the lattice constant of the quantum barrier layer, and the lattice constant and thickness of the quantum well layer;

Calculate the thickness of the quantum barrier layer based on the preset average stress characterization coefficient and preset parameters;

Epitaxial wafers are fabricated based on the thickness of the quantum barrier layer.

Optionally, the specific calculation formula for calculating the thickness of the quantum barrier layer based on the preset average stress characterization coefficient and preset parameters is:

Sc={[(c-b)/c]×Lb+[(c-a)/c]×La}/(Lb+La);

where Sc is the preset average stress characterization coefficient, a is the lattice constant of the quantum well layer, b is the lattice constant of the quantum barrier layer, c is the lattice constant of the growth preparation layer, La is the thickness of the quantum well layer, Lb is the thickness of the quantum barrier layer.

Different from the prior art, the present application sets the thickness of the quantum barrier layer so that the average stress characterization coefficient of the quantum barrier layer and the quantum well layer is within a preset range, specifically between (-0.00216)-(-0.00732), and then Solve the problem of In precipitation and phase separation caused by the serious lattice mismatch between the quantum well layer and the growth preparation layer of the long-wavelength LED.

It is to be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the application.

Description of drawings

In order to illustrate the technical solutions in the embodiments of the present application more clearly, the following briefly introduces the drawings that are used in the description of the embodiments. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, other drawings can also be obtained from these drawings without creative effort.

1 is a schematic structural diagram of an embodiment of an epitaxial wafer of the present application;

2 is a schematic diagram of the relationship between the quantum barrier layer thickness and wavelength of the present application;

Fig. 3 is the photoluminescence spectrum schematic diagram of the epitaxial wafer of the present application;

4 is a schematic diagram of the relative optical power of the epitaxial wafer of the present application;

FIG. 5 is a schematic flowchart of an embodiment of an epitaxial wafer manufacturing method of the present application.

Detailed ways

In order to make those skilled in the art better understand the technical solutions of the present application, the epitaxial wafer and the manufacturing method of the epitaxial wafer provided by the present application are further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the described embodiments are only a part of the embodiments of the present application, but not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present application.

The terms "first", "second", etc. in this application are used to distinguish different objects, rather than to describe a specific order. Furthermore, the terms "comprising" and "having" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device comprising a series of steps or units is not limited to the listed steps or units, but optionally also includes unlisted steps or units, or optionally also includes For other steps or units inherent to these processes, methods, products or devices.

The present application provides an epitaxial wafer to solve the problem of serious lattice mismatch between the multiple quantum well layer and the growth preparation layer caused by the high In composition of long-wavelength LEDs in the prior art, which in turn leads to In precipitation and phase separation problems, which eventually lead to problems affecting the luminous efficiency of LEDs.

Please refer to FIG. 1 , which is a schematic structural diagram of a first embodiment of an epitaxial wafer of the present application. As shown in FIG. 1 , the epitaxial wafer 10 includes a growth preparation layer 11 , a quantum barrier layer 12 and a quantum well layer 13 . The quantum barrier layer 12 is grown on the growth preparation layer 11 , and the quantum well layer 13 is grown on the quantum barrier layer 12 .

Wherein, in this embodiment, the growth preparation layer 11 may specifically include a substrate for growing a semiconductor layer and a buffer layer. Optionally, the substrate may be at least one of a double-polished sapphire substrate, a c-plane sapphire substrate, an m-plane sapphire substrate, a silicon substrate, or a silicon-like substrate.

Specifically, the lattice constant of the quantum well layer 13 is quite different from the lattice constant of the growth preparation layer 11, so that the multiple quantum well (MQW, Multiple Quantum Well) layer formed by the quantum barrier layer 12 and the quantum well layer 13 is different from the growth There is a serious lattice mismatch between the preparation layers 11 , which in turn leads to a large stress between the quantum well layer 13 and the growth preparation layer 11 . When the epitaxial wafer 10 releases the stress, it is easy to cause defects in the quantum well layer 13 , thereby affecting the luminous efficiency of the quantum well layer 13 .

Alternatively, the epitaxial wafer 10 may be in a metastable state by changing the thickness or lattice constant of the growth preparation layer 11, the thickness or lattice constant of the quantum well layer 13, or the thickness or lattice constant of the quantum barrier layer 12 , that is, in a state where the stress is not released, thereby reducing the stress released by the epitaxial wafer 10 .

In this embodiment, the lattice constants of the quantum well layer 13 and the growth preparation layer 11 are set to satisfy (a-c)/c greater than 1.3%, and the thickness of the quantum barrier layer 12 is set so that the quantum barrier layer 12 and the quantum well layer are The mean stress characterization coefficient of 13 ranges from (-0.00216) to (-0.00732). Here, a is the lattice constant of the quantum well layer 13 , and c is the lattice constant of the growth preparation layer 11 .

Optionally, in this embodiment, the lattice constants of the quantum well layer 13 and the growth preparation layer 11 may be further set to satisfy (a-c)/c greater than 1.7%, and the crystal lattice constants of the quantum well layer 13 and the growth preparation layer 11 may be further set. The lattice constant is set to satisfy (a-c)/c greater than 2.8%. At the same time, the thickness of the quantum barrier layer 12 is set so that the average stress characterization coefficient of the quantum barrier layer 12 and the quantum well layer 13 ranges between (-0.00216)-(-0.00732).

Optionally, in this implementation, the average stress characterization coefficient of the quantum barrier layer 12 and the quantum well layer 13 can be calculated by formula 1, and the calculation formula is specifically shown in the following formula:

Sc={[(c-b)/c]×Lb+[(c-a)/c]×La}/(Lb+La) (1)

Wherein, Sc is the average stress characterization coefficient, a is the lattice constant of the quantum well layer 13 , b is the lattice constant of the quantum barrier layer 12 , c is the lattice constant of the growth preparation layer 11 , and La is the thickness of the quantum well layer 13 , Lb is the thickness of the quantum barrier layer 12 . Further, [(c-b)/c] is used to characterize the strain of the quantum barrier layer 12 , and [(c-a)/c] is used to characterize the strain of the quantum well layer 13 .

Optionally, in this embodiment, the lattice constants of the quantum barrier layer 12 and the growth preparation layer 11 satisfy (b-c)/c greater than 0.01%. Specifically, the quantum barrier layer 12 and the growth preparation layer 11 can be made of the same material, so the difference between the lattice constants of the quantum barrier layer 12 and the growth preparation layer 11 is small, and the lattice constants of the quantum barrier layer 12 and the quantum well layer 13 If the difference is large, it can be obtained that the lattice constants of the quantum well layer 13 and the growth preparation layer 11 have a large difference.

Specifically, it can be seen from formula 1 that when the growth materials of the quantum well layer 13 and the growth preparation layer 11 are determined, and the doping concentration of the quantum well layer 13 is constant, that is, when the lattice constants of the quantum well layer 13 and the growth preparation layer 11 are determined , by changing the thickness of the quantum barrier layer 12, the average stress characterization coefficient of the quantum barrier layer 12 and the quantum well layer 13 can satisfy the preset condition, that is, the range of the average stress characterization coefficient of the quantum barrier layer 12 and the quantum well layer 13 is between (-0.00216)-(-0.00732).

Optionally, in this embodiment, both the quantum barrier layer 12 and the growth preparation layer 11 can be made of GaN material. Specifically, the quantum barrier layer 12 may be doped or undoped GaN, and may specifically be an InGaAlN material.

Optionally, in this embodiment, the thickness of the quantum barrier layer 12 can be adjusted so that the thickness of the quantum barrier layer 12 is not greater than 80 nm. Further, in this embodiment, the thickness of the quantum barrier layer 12 can be adjusted so that the thickness of the quantum barrier layer 12 is not greater than 45 nm.

Optionally, the thickness of the quantum well layer 13 and the thickness of the quantum barrier layer 12 are very thin relative to the thickness of the growth preparation layer 11, specifically, the thickness of the growth preparation layer 11 may be the thickness of the quantum well layer 13 and the thickness of the quantum barrier layer 12. 5000 times the thickness.

Wherein, the epitaxial wafer 10 of this embodiment can be used to generate long-wavelength light such as red light, green light or infrared light. Specifically, in the prior art, the average stress characterization coefficient of the multiple quantum well layer and the substrate of the blue LED in metastable state is within a preset range, specifically between (-0.00216)-(-0.00732), the blue light The quantum barrier layer of the LED is made of GaN material, the quantum well layer is made of InGaN material, the thickness of the quantum well layer is 3 nm, and the molar percentage content of the In component of the quantum well layer is 12%. In this embodiment, under the condition that the quantum barrier layer material, quantum well layer material and quantum well layer thickness of the blue LED remain unchanged, it is calculated by formula 1 that the epitaxial wafer 10 for outputting light of different wavelengths is in the minimum metastable state. The thickness of the quantum barrier layer can be specifically shown in FIG. 2 .

Referring to FIG. 2 in conjunction with FIG. 1 , FIG. 2 is a schematic diagram of the relationship between the thickness of the quantum barrier layer and the wavelength of the present application. As shown in FIG. 2 , when the wavelength of the light generated by the epitaxial wafer 10 is larger, the corresponding minimum thickness of the quantum barrier layer 12 is larger. Specifically, when the wavelength of the light generated by the epitaxial wafer 10 is between 400nm-420nm, the minimum thickness of the quantum barrier layer 12 is between 5nm-10nm; when the wavelength of the light generated by the epitaxial wafer 10 is between 450nm-500nm, The minimum thickness of the quantum barrier layer 12 is between 15nm-20nm; when the wavelength of the light generated by the epitaxial wafer 10 is between 540nm-560nm, the minimum thickness of the quantum barrier layer 12 is between 28nm-32nm; When the wavelength of light is between 640nm-660nm, the minimum thickness of the quantum barrier layer 12 is between 35nm-40nm.

When the epitaxial wafer 10 in this embodiment is used to generate red light, the quantum well layer 13 is made of InGaN material or InGaAlN material, and the molar content of the In component in the quantum well layer 13 is not less than 20%, and the thickness of the quantum barrier layer 12 is not less than 20%. less than 10nm. Further, the molar percentage content of the In component in the quantum well layer 13 is not less than 32%, and the thickness of the quantum barrier layer 12 is not less than 20 nm. Optionally, the thickness of the quantum barrier layer 12 may be 20nm-80nm. Optionally, the thickness of the quantum barrier layer 12 may also be 20nm-30nm, 30nm-50nm or 50nm-70nm.

Specifically, this embodiment provides the first embodiment. In this embodiment, the growth preparation layer 11 is made of GaN material, the quantum barrier layer 12 is made of GaN material, and the quantum well layer 13 is made of InGaN material. The molar percentage content of the In component is 40%, and the thickness of the quantum well layer 13 is 3 nm, and the thickness of the quantum barrier layer 12 is calculated to be 20 nm-80 nm through formula 1.

This embodiment provides a second embodiment. In this embodiment, the growth preparation layer 11 is made of GaN material, the quantum barrier layer 12 is made of GaN material, and the quantum well layer 13 is made of InGaN material, wherein the In composition in the quantum well layer 13 The molar content of the quantum well layer 13 is 25%, and the thickness of the quantum well layer 13 is 3 nm, and the thickness of the quantum barrier layer 12 can be calculated by formula 1 to be 10 nm-45 nm.

Referring to FIG. 3 in conjunction with FIG. 1 , FIG. 3 is a schematic diagram of the photoluminescence spectrum of the epitaxial wafer of the present application. As shown in FIG. 3 , the curves S1 , S2 and S3 correspond to the photoluminescence spectra generated by the quantum well layer 13 with the same molar content of In composition and the epitaxial wafer 10 with different quantum barrier layer 12 thicknesses, respectively.

Specifically, the center wavelength of the light generated by the epitaxial wafer 10 is 550 nm-600 nm, that is, the light generated by the epitaxial wafer 10 is green light. The thickness of the quantum barrier layer 12 of the epitaxial wafer 10 corresponding to the curve S1 is 2.0x, the thickness of the quantum barrier layer 12 of the epitaxial wafer 10 corresponding to the curve S2 is 1.5x, and the thickness of the quantum barrier layer of the epitaxial wafer 10 corresponding to the curve S3 12 thickness is x.

As shown in FIG. 3 , the light intensity of the light generated by the epitaxial wafer 10 corresponding to the curve S1 is greater than the light intensity of the light generated by the epitaxial wafer 10 corresponding to the curve S2 , and the light generated by the epitaxial wafer 10 corresponding to the curve S2 The light intensity is greater than the light intensity of the light generated by the epitaxial wafer 10 corresponding to the curve S3 .

Specifically, it can be seen from FIG. 3 that when the molar percentage content of the In component of the quantum well layer 13 is the same, the larger the thickness of the quantum barrier layer 12 is, the smaller the average stress characterization coefficient of the quantum barrier layer 12 and the quantum well layer 13 is, that is to say, The smaller the stress between the quantum well layer 13 and the growth preparation layer 11 is, the stress released by the epitaxial wafer 10 can be diluted, and the defects of the quantum well layer 13 generated by the stress release can be reduced, so that the light generated by the epitaxial wafer 10 can be reduced The higher the intensity, the higher the luminous efficiency of the epitaxial wafer 10 .

Optionally, in this embodiment, x can be any number from 7 nm to 12 nm, that is, when x is any number from 7 nm to 12 nm, the obtained photoluminescence spectrum of the epitaxial wafer 10 is as shown in FIG. 3 . .

The relative optical power is also a parameter to measure the luminous efficiency of the epitaxial wafer 10 . Referring to FIG. 4 in conjunction with FIG. 1 and FIG. 3 , FIG. 4 is a schematic diagram of the relative optical power of the epitaxial wafer of the present application. As shown in FIG. 4 , the epitaxial wafers 10 represented by the curves S4 , S5 , and S6 correspond to the epitaxial wafers 10 represented by the curves S1 , S2 , and S3 shown in FIG. 3 , respectively. The relative optical power of the light generated by the epitaxial wafer 10 is related to the current density applied to the epitaxial wafer 10 and the thickness of the quantum barrier layer 12 .

Specifically, as shown in FIG. 4 , when the molar percentage of the In component of the quantum well layer 13 is the same, the larger the thickness of the quantum barrier layer 12 of the epitaxial wafer 10 is, the smaller the average stress characterization coefficient of the quantum barrier layer 12 and the quantum well layer 13 is. , the smaller the stress between the quantum well layer 13 and the growth preparation layer 11 is, the smaller the stress released by the epitaxial wafer 10 is. Under the same current density, the relative optical power of the light generated by the epitaxial wafer 10 is larger, that is, the effective The luminous efficiency of the epitaxial wafer 10 is improved. That is, the relative optical power of the light generated by the epitaxial wafer 10 corresponding to the curve S4 is greater than the relative optical power of the light generated by the epitaxial wafer 10 corresponding to the curve S5, and the relative optical power of the light generated by the epitaxial wafer 10 corresponding to the curve S5 The optical power is greater than the relative optical power of the light generated by the epitaxial wafer 10 corresponding to the curve S6.

Meanwhile, when the quantum barrier layers 12 of the epitaxial wafer 10 have the same thickness, the greater the current density applied to the epitaxial wafer 10, the greater the relative optical power of the light generated by the epitaxial wafer 10. Also, as the thickness of the quantum barrier layer 12 increases, the relative optical power of the light generated by the epitaxial wafer 10 increases with the increase of the current density.

Optionally, in other embodiments, a single quantum well layer 13 and a single quantum barrier layer 12 form a period, and the epitaxial wafers 10 can be alternately stacked to provide multiple periods. Optionally, the number of cycles of the alternately stacked quantum well layers 13 and quantum barrier layers 12 may be 2-1000 cycles.

Optionally, in other embodiments, the quantum barrier layer 12 may further include at least two sub-quantum barrier layers arranged in layers. Among them, the InGaAlN composition of at least two sub-quantum barrier layers is different.

Wherein, the at least two sub-quantum barrier layers can be any combination of at least two layers of an undoped GaN layer, an InyGa1 _{-yN layer} , an _{AlfGa1 -} fN layer and a Si-doped GaN layer, where 0<y<0.15,0<f<0.3. Specifically, the Si doping concentration of the Si-doped GaN layer ranges from 1×10 ¹⁶ to 1×10 ¹⁹ atoms/cm ³ .

Optionally, in one embodiment, the at least two sub-quantum barrier layers include an InyGa1 _{-yN layer} and a GaN layer, and the InyGa1 _{-yN layer} and the GaN layer are stacked.

Optionally, in an embodiment, the at least two sub-quantum barrier layers include an _{AlfGa1 - fN} layer and an InyGa1 _{-yN layer} , and an _{AlfGa1 -} fN layer and an _{InyGa1- y} N layer stacking setup.

Optionally, in other embodiments, the at least two sub-quantum barrier layers may also be an InGaAlN layer and an undoped GaN layer, an InyGa1 _{-yN layer} , an _{AlfGa1 -} fN layer, and a Si-doped GaN layer Any combination of at least one of the layers. For example, the at least two sub-quantum barrier layers include an undoped GaN layer and an InGaAlN layer, and the undoped GaN layer and the InGaAlN layer are stacked.

In the present application, the thickness of the quantum barrier layer 12 is adjusted so that the range of the average stress characterization coefficient of the quantum barrier layer 12 and the quantum well layer 13 in the epitaxial wafer 10 for generating long-wavelength light is within a preset range, and is specifically between (-0.00216)-(-0.00732), while satisfying that the quantum well layer 13 in the epitaxial wafer 10 has a high molar content of In composition, the lattice adaptation of the quantum well layer 13 and the growth preparation layer 11 can be effectively improved, In order to solve the problem of serious lattice mismatch in the quantum well layer and quantum barrier layer of the long-wavelength LED in the prior art, and to solve the problems of In precipitation and phase separation in the long-wavelength LED in the prior art.

The present application also provides a method for manufacturing an epitaxial wafer, which is used for manufacturing the epitaxial wafer 10 shown in FIG. 1 , and a schematic flowchart of the method is shown in FIG. 5 . Please refer to FIG. 5 . FIG. 5 is a schematic flowchart of an embodiment of an epitaxial wafer manufacturing method of the present application. Specifically, the epitaxial wafer manufacturing method of this embodiment may include the following steps:

Step S11: Obtain a preset average stress characterization coefficient.

Among them, in order to realize that the long-wavelength LED is in a metastable state, that is, the stress is not released, a preset average stress characterization coefficient needs to be obtained, and the preset average stress characterization coefficient can be the average of the quantum well layer and the quantum barrier layer of the blue LED in the prior art. Stress characterization coefficient, specifically between (-0.00216)-(-0.00732). When the average stress characterization coefficients of the quantum well layer 13 and the quantum barrier layer 12 of the epitaxial wafer 10 are set to be preset average stress characterization coefficients, the epitaxial wafer 10 can be in a metastable state.

Step S12: Acquire preset parameters of the epitaxial wafer.

The prediction parameters include the lattice constant of the generation preparation layer 11 , the lattice constant of the quantum barrier layer 12 , and the lattice constant and thickness of the quantum well layer 13 . Specifically, the lattice constant is related to the substrate and its doping composition and ratio. By determining the corresponding substrate and its doping composition and ratio, the corresponding lattice constant can be obtained.

In this embodiment, the generation preparation layer 11 is made of GaN material, the quantum barrier layer 12 is made of GaN material, the quantum well layer 13 is made of InGaN material, and the thickness of the quantum well layer 13 is 3 nm. Specifically, when the manufactured epitaxial wafer 10 is used to generate red light, and the molar content of the In component of the quantum well layer 13 is 40%; when the manufactured epitaxial wafer 10 is used to generate green light, and the quantum well layer The molar content of the In component of 13 was 25%.

Step S13: Calculate the thickness of the quantum barrier layer based on the preset average stress characterization coefficient and preset parameters.

In this embodiment, the preset average stress characterization coefficient and preset parameters are input into Formula 1, and the thickness of the corresponding quantum barrier layer 12 of the epitaxial wafer 10 can be calculated, such as the molar percentage content of the In component of the quantum well layer 13 is 40%, the thickness of the quantum barrier layer 12 is 20nm-80nm; the molar content of the In component of the quantum well layer 13 is 25%, then the thickness of the quantum barrier layer 12 is 10nm-45nm.

Step S14 : manufacturing an epitaxial wafer based on the thickness of the quantum barrier layer.

The epitaxial wafer can be fabricated by obtaining the lattice constant of the preparation layer 11 of the epitaxial wafer 10, the lattice constant and thickness of the quantum barrier layer 12, and the lattice constant and thickness of the quantum well layer 13 through steps S12 and S13. 10.

The above are only the embodiments of the present application, and are not intended to limit the scope of the patent of the present application. Any equivalent structure or equivalent process transformation made by using the contents of the description and drawings of the present application, or directly or indirectly applied in other related technical fields, All the same are included in the scope of patent protection of the present application.

Claims (10)

1. An epitaxial wafer, comprising a growth preparation layer, a quantum barrier layer grown on the growth preparation layer, and a quantum well layer grown on the quantum barrier layer, wherein lattice constants of the quantum well layer and the growth preparation layer satisfy (a-c)/c, which is greater than 1.3%, and the thickness of the quantum barrier layer is set such that an average stress characterization coefficient of the quantum barrier layer and the quantum well layer ranges from (-0.00216) - (-0.00732), wherein a is the lattice constant of the quantum well layer, and c is the lattice constant of the growth preparation layer.

2. An epitaxial wafer according to claim 1, characterized in that (a-c)/c is further greater than 2.8%.

3. The epitaxial wafer of claim 1, wherein the lattice constants of the quantum barrier layer and the growth preparation layer satisfy (b-c)/c greater than 0.01%.

4. The epitaxial wafer of claim 1, wherein the quantum well layer is an InGaN material or an InGaAlN material, wherein the In component content In the quantum well layer is not less than 20 mol%, and the thickness of the quantum barrier layer is not less than 10nm.

5. The epitaxial wafer of claim 1, wherein the quantum well layer is InGaN material or InGaAlN material, wherein the molar percentage content of In component In the quantum well layer is not less than 32%, and the thickness of the quantum barrier layer is not less than 20nm.

6. The epitaxial wafer of claim 4 or 5, wherein the quantum barrier layer is a GaN material or an InGaAlN material.

7. The epitaxial wafer of claim 6 wherein the growth preparation layer is a GaN material or an InGaAlN material.

8. The epitaxial wafer of claim 1, wherein the epitaxial wafer comprises a plurality of the quantum barrier layers and a plurality of the quantum well layers, and the number of the quantum well layers and the quantum barrier layers which are alternately stacked is 2-1000 cycles.

9. An epitaxial wafer manufacturing method, characterized by comprising:

acquiring a preset average stress characterization coefficient;

acquiring preset parameters of the epitaxial wafer, wherein the preset parameters comprise a lattice constant of a growth preparation layer, a lattice constant of a quantum barrier layer, and a lattice constant and a thickness of a quantum well layer;

calculating the thickness of the quantum barrier layer based on the preset average stress characterization coefficient and the preset parameter;

and manufacturing the epitaxial wafer based on the thickness of the quantum barrier layer.

10. The epitaxial wafer manufacturing method according to claim 9, wherein a specific calculation formula for calculating the thickness of the quantum barrier layer based on the preset average stress characterization coefficient and the preset parameter is as follows:

Sc＝{[(c-b)/c]×Lb+[(c-a)/c]×La}/(Lb+La)；

and the Sc is the preset average stress characterization coefficient, a is the lattice constant of the quantum well layer, b is the lattice constant of the quantum barrier layer, c is the lattice constant of the growth preparation layer, la is the thickness of the quantum well layer, and Lb is the thickness of the quantum barrier layer.

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