GaAs-based laser epitaxial wafer of quantum well planting structure and preparation method of GaAs-based laser epitaxial wafer

Abstract

The invention discloses a GaAs-based laser epitaxial wafer of a quantum well planting structure and a preparation method thereof, the epitaxial wafer comprises a GaAs substrate, the GaAs substrate is provided with a GaAs buffer layer, an Al < x > 1 Ga < 1-x > 1 As N limiting layer, an Al < x > 2 Ga < 1-x > 2 As lower light field sealing layer, an Al < x > 3 Ga < 1-x > 3 As lower waveguide layer, an In < y > 1 Ga < 1-y > 1 As lower quantum well planting layer, an In < y > 2 Ga < 1-y > 2 As quantum well layer, an Al < x > 4 Ga < 1-x > 4 As upper waveguide layer A, an In < y > 3 Ga < 1-y > 3 As upper quantum well planting layer and an Al < x > 5 Ga < 1-x > 5 As upper waveguide layer B, an Al < x > < 6 > Ga < 1-x > < 6 > As upper light field sealing layer, an Al < x > < 7 > Ga < 1-x > < 7 > As P limiting layer and a GaAs ohmic contact layer; vertical structure quantum wells are planted in the upper and lower waveguide layers by adopting a three-time epitaxy mode, and a closed resonant cavity is realized on the upper and lower waveguide layers by using a light field closing layer meeting a preset refractive index; wherein the light parallel to the axis is not influenced and still realizes lasing output, and the light which is not parallel to the axis is reflected back to the resonant cavity through the light field sealing layer to become new laser which is lased by the seed source of the planted quantum well again.

Description

Technical Field

[0001] The present application relates to the field of optoelectronic technology, and in particular to a GaAs-based laser epitaxial wafer with a quantum well planting structure and a preparation method thereof. Background Art

[0002] Semiconductor lasers are lasers that use semiconductor materials as gain media and are widely used in modern communications, optical sensing, medical treatment, scientific research and other fields. Their working principle is based on the electroluminescence effect, that is, by applying current to the semiconductor material, electrons and holes recombine in the active region and generate photons. Photons continue to increase through the stimulated radiation process, thereby generating coherent light output. Edge-emitting semiconductor lasers have attracted widespread attention due to their low cost and simple production, and are currently mass-produced in the commercial field.

[0003] The density of monochromatic modes in edge-emitting semiconductor lasers is very high and there are many light wave modes. The average energy of each mode is very small, which is not conducive to light oscillation. In order to solve this problem, edge-emitting lasers use a resonant cavity to reduce the number of modes in the cavity, increase the energy density of the radiation field, and reduce the threshold current to achieve laser lasing. However, the problem is that the light beam that is not parallel to the cavity axis is reflected multiple times by the resonant cavity surface and overflows the cavity, resulting in most of the laser modes of the edge-emitting semiconductor laser being wasted and unable to achieve a high proportion of laser output. Summary of the invention

[0004] The present application provides a GaAs-based laser epitaxial wafer with a quantum well planting structure and a preparation method thereof, in order to solve the above-mentioned problems.

[0005] On the one hand, the present application provides a GaAs-based laser epitaxial wafer with a quantum well planting structure, wherein the laser epitaxial wafer comprises a GaAs substrate, on which are arranged in order from bottom to top a GaAs buffer layer (1), an Alx1Ga1-x1As N limiting layer (2), an Alx2Ga1-x2As lower optical field confinement layer (3), an Alx3Ga1-x3As lower waveguide layer (4), an Iny1Ga1-y1As lower quantum well planting layer (5), an Iny2Ga1-y2As quantum well layer (6), an Alx4Ga1-x4As upper waveguide layer A (7), an Iny3Ga1-y3As upper quantum well planting layer (8), an Alx5Ga1-x5As upper waveguide layer B (9), an Alx6Ga1-x6As upper optical field confinement layer (10), an Alx7Ga1-x7As P limiting layer (11), GaAs ohmic contact layer (12); the process of quantum well planting includes: planting vertical structure quantum wells in the upper and lower waveguide layers by three-dimensional epitaxy, and realizing closed resonant cavity by using light field confinement layer meeting preset low refractive index in the upper and lower waveguide layers; wherein light parallel to the axis is not affected and still realizes lasing output, and light not parallel to the axis is reflected back to the resonant cavity through the light field confinement layer, becoming the seed source of the planted quantum well to re-laser new laser.

[0006] On the other hand, the present application also provides a method for preparing a GaAs-based laser epitaxial wafer with a quantum well planting structure, comprising the following steps:

[0007] Step S1: placing a GaAs substrate in a growth chamber of an MOCVD device, heating the H2 environment to 710-740°C for 30-40 minutes, and then introducing AsH3 to perform a high-temperature heat treatment on the GaAs-based substrate to remove water and oxygen on the substrate surface;

[0008] Step S2: When the temperature of the reaction chamber drops to 680-710°C, TMGa and AsH3 are introduced to grow a GaAs buffer layer with a thickness of 100-300nm on the GaAs substrate;

[0009] Step S3: When the temperature of the reaction chamber drops to 640-680°C, TMAl, TMGa and AsH3 are introduced to grow an Alx1Ga1-x1As N confinement layer with a thickness of 1-4 um on the surface of step S2;

[0010] Step S4: maintaining the temperature at 640-680°C, after step S3 is completed, introducing TMAl, TMGa and AsH3 to grow the Alx2Ga1-x2As lower light field confinement layer with a thickness of 10-30nm;

[0011] Step S5: maintaining the temperature at 640-680°C, after step S4 is completed, introducing TMAl, TMGa and AsH3 to grow the Alx3Ga1-x3As lower waveguide layer with a thickness of 100-300nm;

[0012] Step S6: taking out the epitaxial wafer and etching a longitudinal deep groove with a depth of 3-10 nm on the Alx3Ga1-x3As lower waveguide layer by dry etching;

[0013] Step S7: maintaining the temperature at 540-580°C, after completing step S6, continue to grow an Iny1Ga1-y1As lower quantum well planting layer with a thickness of 3-10nm;

[0014] Step S8: maintaining the temperature at 540-580°C, after step S7 is completed, continuing to grow an Iny2Ga1-y2As quantum well layer with a thickness of 3-7nm;

[0015] Step S9: maintaining the temperature at 640-680°C, after step S8 is completed, introducing TMAl, TMGa and AsH3 to grow the Alx4Ga1-x4As upper waveguide layer A with a growth thickness of 3-10nm;

[0016] Step S10: Take out the epitaxial wafer and etch a longitudinal deep groove with a depth of 3-10 nm on the Alx4Ga1-x4As upper waveguide layer A through a dry etching process;

[0017] Step S11: maintaining the temperature at 540-580°C, after step 10 is completed, continuing to grow an Iny3Ga1-y3As upper quantum well planting layer with a thickness of 3-10nm;

[0018] Step S12: maintaining the temperature at 640-680°C, after step S11 is completed, introducing TMAl, TMGa and AsH3 to grow an Alx5Ga1-x5As upper waveguide layer B with a thickness of 600-900nm;

[0019] Step S13: maintaining the temperature at 640-680°C, after step S12 is completed, introducing TMAl, TMGa and AsH3 to grow an Alx6Ga1-x6As upper optical field confinement layer with a thickness of 10-30nm;

[0020] Step S14: maintaining the temperature at 640-680°C, after step S13 is completed, introducing TMAl, TMGa and AsH3 to grow an Alx7Ga1-x7As P confinement layer with a thickness of 0.4-0.8um;

[0021] Step S15: When the temperature of the reaction chamber drops to 540-560° C., TMGa and AsH 3 are introduced, and a GaAs ohmic contact layer with a thickness of 300-600 nm is grown on the Alx7Ga1-x7As P confinement layer.

[0022] The present application provides a GaAs-based laser epitaxial wafer with a quantum well planting structure and a preparation method thereof, which have the following beneficial effects: the quantum well planting structure adopts the technology of three-stage epitaxy to plant vertical structure quantum wells in the upper and lower waveguide layers, and uses a light field closure layer with a low refractive index in the upper and lower waveguide layers to realize a closed resonant cavity, and the light parallel to the axis is not affected and still realizes the laser output, and the light not parallel to the axis is reflected back to the resonant cavity through the light field closure layer, and becomes the seed source of the planted quantum well to re-laser a new laser, and since the planted quantum well is perpendicular to the resonant cavity, the new laser formed after being excited by the seed source will be guaranteed to be parallel to the axis direction of the resonant cavity, and the full output of the laser mode is realized, which improves the high-proportion laser output of the edge-emitting laser. And since the newly generated laser is still the laser generated by the same seed source exciting the quantum well, there will be no mode interference, and it is still a coherent light source to ensure the purity of the laser, avoiding the loss introduced by mode competition. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0024] Figure 1 A structural diagram of a GaAs-based laser epitaxial wafer with a quantum well planting structure provided in an embodiment of the present application;

[0025] Figure 2 This is an enlarged view of the upper and lower quantum well planting layers provided in an embodiment of the present application. DETAILED DESCRIPTION

[0026] In order to make the purpose, technical solution and advantages of the present application clearer, the technical solution of the present application will be clearly and completely described below in combination with the specific embodiments of the present application and the corresponding drawings. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present application.

[0027] The embodiment of the present application provides a GaAs-based laser epitaxial wafer with a quantum well planting structure and a method for preparing the same. The technical solution proposed in the embodiment of the present application is described in detail below with reference to the accompanying drawings.

[0028] Figure 1This is a structure diagram of a GaAs-based laser epitaxial wafer with a quantum well planting structure provided in an embodiment of the present application. Figure 1 As shown, it includes: a GaAs substrate, a GaAs buffer layer (1), an Alx1Ga1-x1As N limiting layer (2), an Alx2Ga1-x2As lower optical field confinement layer (3), an Alx3Ga1-x3As lower waveguide layer (4), an Iny1Ga1-y1As lower quantum well planting layer (5), an Iny2Ga1-y2As quantum well layer (6), an Alx4Ga1-x4As upper waveguide layer A (7), an Iny3Ga1-y3As upper quantum well planting layer (8), an Alx5Ga1-x5As upper waveguide layer B (9), an Alx6Ga1-x6As upper optical field confinement layer (10), an Alx7Ga1-x7As P limiting layer (11), and a GaAs ohmic contact layer (12).

[0029] Among them, the enlarged picture of the upper and lower quantum well planting layers is as follows Figure 2 As shown, quantum well planting is achieved by three-step epitaxy, and the planted quantum wells are used to convert the loss light into new parallel-axis lasable light. The new photons generated in this way will not produce mode competition, thus achieving internal light superposition amplification.

[0030] The above is a GaAs-based laser epitaxial wafer with a quantum well planting structure provided in an embodiment of the present application. The embodiment of the present application also provides a corresponding preparation method thereof, including:

[0031] Step S1: placing a GaAs substrate in a growth chamber of an MOCVD device, heating the H2 environment to 710-740°C and baking for 30-40 minutes, then introducing AsH3 to perform high-temperature heat treatment on the GaAs-based substrate to remove water and oxygen on the substrate surface; preferably, the high-temperature heat treatment temperature of step S1 is 720°C and the baking time is 35 minutes;

[0032] Step S2: When the temperature of the reaction chamber drops to 680-710°C, TMGa and AsH3 are introduced to grow a GaAs buffer layer with a thickness of 100-300nm on the GaAs substrate; preferably, the reaction chamber temperature of step S2 is 690°C, the growth thickness is 200nm, and the doping concentration is 1E18-3E18 atoms / cm3;

[0033] Step S3: When the temperature of the reaction chamber drops to 640-680°C, TMAl, TMGa and AsH3 are introduced to grow an Alx1Ga1-x1As N limiting layer on step S2 with a thickness of 1-4um; preferably, the reaction chamber temperature of step S3 is 650°C, the growth thickness is 2.5um, 0.2≤x1≤0.4, and the doping concentration is 5E17-2E18 atoms / cm3; particularly preferably, in step S3, x1=0.30, the doping concentration is 1E18 atoms / cm3, and Si2H6 is used as the doping source;

[0034] Step S4: maintaining the temperature at 640-680°C, after the completion of step S3, introducing TMAl, TMGa and AsH3 to grow the Alx2Ga1-x2As lower light field confinement layer with a thickness of 10-30nm; preferably, the reaction chamber temperature of step S4 is 650°C, the growth thickness is 20nm, 0.7≤x2≤0.9, and the doping concentration is 5E17-2E18 atoms / cm3; in a particularly preferred step S4, x2=0.8, the doping concentration is 5E17 atoms / cm3, and Si2H6 is used as the doping source;

[0035] Step S5: maintaining the temperature at 640-680°C, after step S4 is completed, introducing TMAl, TMGa and AsH3 to grow the Alx3Ga1-x3As lower waveguide layer with a thickness of 100-300nm; preferably, the reaction chamber temperature of step S5 is 650°C, the growth thickness is 200nm, 0.1≤x3≤0.4; particularly preferably, in step S5, x3=0.15;

[0036] Step S6: Take out the epitaxial wafer and etch a longitudinal deep groove with a depth of 3-10 nm on the Alx3Ga1-x3As lower waveguide layer through a dry etching process; preferably, the groove depth of step S6 is 5 nm;

[0037] Step S7: maintaining the temperature at 540-580°C, after step S6 is completed, continuing to grow a 3-10nm thick Iny1Ga1-y1As lower quantum well planting layer; preferably, the reaction chamber temperature of step S7 is 550°C, the growth thickness is 5nm, and the value of y1 in the Iny1Ga1-y1As quantum well is 0.5-0.6;

[0038] Step S8: maintaining the temperature at 540-580°C, after step S7 is completed, continuing to grow an Iny2Ga1-y2As quantum well layer with a thickness of 3-7nm; preferably, the reaction chamber temperature in step 8 is 550°C, the growth thickness is 5nm, and the value of y2 in the Iny2Ga1-y2As quantum well layer is 0.5-0.6; particularly preferably, the value of y2 in the Iny2Ga1-y2As quantum well layer in step 8 is 0.55;

[0039] Step S9: maintaining the temperature at 640-680°C, after step S8 is completed, introducing TMAl, TMGa and AsH3 to grow the waveguide layer A on Alx4Ga1-x4As, with a growth thickness of 3-10nm; preferably, the reaction chamber temperature of step S9 is 650°C, the growth thickness is 5nm, 0.1≤x4≤0.4; particularly preferably, in step S9, x4=0.15;

[0040] Step S10: Take out the epitaxial wafer and etch a longitudinal deep groove with a depth of 3-10 nm on the Alx4Ga1-x4As upper waveguide layer A through a dry etching process; preferably, the groove depth of step S10 is 5 nm;

[0041] Step S11: maintaining the temperature at 540-580°C, after step S10 is completed, continuing to grow a 3-10nm thick Iny3Ga1-y3As upper quantum well planting layer; preferably, the reaction chamber temperature of step S11 is 550°C, the growth thickness is 5nm, and the value of y3 in the Iny3Ga1-y3As upper quantum well planting layer is 0.5-0.6; particularly preferably, the value of y3 in the Iny3Ga1-y3As upper quantum well planting layer in step S11 is 0.55;

[0042] Step S12: maintaining the temperature at 640-680°C, after step S11 is completed, introducing TMAl, TMGa and AsH3 to grow an Alx5Ga1-x5As upper waveguide layer B with a thickness of 600-900nm; preferably, the reaction chamber temperature of step S12 is 650°C, the growth thickness is 800nm, 0.1≤x5≤0.4, and the doping concentration is 5E17-2E18 atoms / cm3; in a particularly preferred step S12, x5=0.15, the doping concentration is 5E17 atoms / cm3, and CBr4 is used as the doping source;

[0043] Step S13: maintaining the temperature at 640-680°C, after step S12 is completed, introducing TMAl, TMGa and AsH3 to grow an Alx6Ga1-x6As upper optical field confinement layer with a thickness of 10-30nm; preferably, the reaction chamber temperature of step S13 is 650°C, the growth thickness is 20nm, 0.7≤x6≤0.9, and the doping concentration is 5E17-2E18 atoms / cm3; in a particularly preferred step S13, x6=0.80, the doping concentration is 5E17 atoms / cm3, and CBr4 is used as the doping source;

[0044] Step S14: maintaining the temperature at 640-680°C, after step S13 is completed, introducing TMAl, TMGa and AsH3 to grow an Alx7Ga1-x7As P limiting layer with a thickness of 0.4-0.8um; preferably, the reaction chamber temperature of step S12 is 650°C, the growth thickness is 0.6um, 0.6≤x7≤0.9, and the doping concentration is 9E17-5E18 atoms / cm3; in a particularly preferred step S14, x7=0.7, the doping concentration is 1E18 atoms / cm3, and CBr4 is used as the doping source;

[0045] Step S15: When the temperature of the reaction chamber drops to 540-560°C, TMGa and AsH3 are introduced, and a GaAs ohmic contact layer with a thickness of 300-600nm is grown on the Alx7Ga1-x7As P confinement layer. Preferably, the reaction chamber temperature of step S15 is 550°C, the growth thickness is 500nm, and the doping concentration is 9E18-5E19 atoms / cm3; in a particularly preferred step S15, the doping concentration is 3E19 atoms / cm3, and CBr4 is used as the doping source.

[0046] In the present application, Si2H6 is selected for doping on the N side, and CBr4 is selected for doping on the P side. The role of N-side doping is to provide electrons, and the potential difference is achieved through the change of doping gradient, which is beneficial to the migration of electrons to the quantum well. The role of P-side doping is to provide holes, and the potential difference is achieved through the change of doping gradient, which is beneficial to the migration of holes to the quantum well, and finally the holes and electrons are recombinated in the quantum well.

[0047] The embodiment of the present application also sets up control groups 1-3, control group 1: on the basis of the present application, the Alx2Ga1-x2As lower light field confinement layer (3), the Iny1Ga1-y1As lower quantum well planting layer (5), the Iny3Ga1-y3As upper quantum well planting layer (8), and the Alx6Ga1-x6As upper light field confinement layer (10) are removed, and the remaining parameters are consistent with the present application; the purpose is to prove the difference between the quantum well planting structure proposed in the present application and the traditional structure.

[0048] Control group 2: The Alx2Ga1-x2As lower light field confinement layer (3) and the Alx6Ga1-x6As upper light field confinement layer (10) were removed and the remaining parameters were consistent with the present application; the purpose was to prove that the light field confinement layer can better play the role of the quantum well planting structure.

[0049] Control group 3: Iny1Ga1-y1As lower quantum well planting layer (5) and Iny3Ga1-y3As upper quantum well planting layer (8), and other parameters are removed to keep consistent with the present application; the purpose is to prove the effect of the quantum well planting structure.

[0050] The chips of this application and two control groups were packaged on a COS heat sink, and the samples were tested under the condition of 15A continuous working current at room temperature. Ten COS of each sample were selected for continuous aging test at 25A to monitor the number of failures. As shown in Table 1 below:

[0051] Table 1 Monitoring table of the number of failures in this application and the control group

[0052]

[0053] Compared with the test results of the present application, the GaAs-based high-power laser epitaxial wafer and its preparation method of a quantum well planting structure proposed in the present application can significantly reduce the threshold current, increase the output power and increase the chip reliability, which is consistent with the theoretical analysis; compared with the test results of the present application, the optical field confinement layer of the comparative example 2 can further improve the performance parameters of the quantum well planting structure. The parameters without the optical field confinement layer still have parameter performance advantages over the traditional structure (comparative example 1), but there is still a significant gap with the present application; compared with the test results of the present application, comparative example 3 further confirms that the quantum well planting structure can reflect the light that is not parallel to the axis through the optical field confinement layer back to the resonant cavity, and become the seed source of the planted quantum well to re-laser a new laser. Since the planted quantum well is perpendicular to the resonant cavity, the new laser formed after being excited by the seed source will be guaranteed to be parallel to the axis direction of the resonant cavity, realizing the full output of the laser mode and improving the high-proportion laser output of the edge-emitting laser. And since the newly generated laser is still the laser generated by the same seed source exciting the quantum well, there will be no mode interference, and it is still a coherent light source to ensure the purity of the laser, avoiding the loss introduced by mode competition. And this application helps to improve chip reliability.

[0054] Each embodiment in this application is described in a progressive manner, and the same or similar parts between the embodiments can be referred to each other, and each embodiment focuses on the differences from other embodiments. In particular, for the device embodiment, since it is basically similar to the method embodiment, the description is relatively simple, and the relevant parts can be referred to the partial description of the method embodiment.

[0055] It should also be noted that the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, commodity or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, commodity or device. In the absence of more restrictions, the elements defined by the sentence "comprises a ..." do not exclude the existence of other identical elements in the process, method, commodity or device including the elements.

[0056] The above is only an embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various changes and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included in the scope of the claims of the present application.

Claims

1. A GaAs-based laser epitaxial wafer with a quantum well planting structure, characterized in that: The laser epitaxial wafer comprises a GaAs substrate, on which a GaAs buffer layer (1), an Alx1Ga1-x1As N limiting layer (2), an Alx2Ga1-x2As lower optical field confinement layer (3), an Alx3Ga1-x3As lower waveguide layer (4), an Iny1Ga1-y1As lower quantum well planting layer (5), an Iny2Ga1-y2As quantum well layer (6), an Alx4Ga1-x4As upper waveguide layer A (7), and an Iny3Ga1-y3As upper quantum well planting layer (8) are sequentially arranged from bottom to top. Alx5Ga1-x5As upper waveguide layer B (9), Alx6Ga1-x6As upper optical field confinement layer (10), Alx7Ga1-x7As P restriction layer (11), GaAs ohmic contact layer (12); the process of quantum well planting includes: planting vertical structure quantum wells in the upper and lower waveguide layers by three-dimensional epitaxy, and realizing closed resonant cavity with optical field confinement layer meeting preset refractive index in the upper and lower waveguide layers; wherein, light parallel to the axis is not affected and still realizes lasing output, and light not parallel to the axis is reflected back to the resonant cavity through the optical field confinement layer, becoming the seed source of the planted quantum well to re-laser new laser.

2. A method for preparing a GaAs-based laser epitaxial wafer with a quantum well planting structure, characterized in that: The following steps are involved: Step S1: placing a GaAs substrate in a growth chamber of an MOCVD device, heating the H2 environment to 710-740°C for 30-40 minutes, and then introducing AsH3 to perform a high-temperature heat treatment on the GaAs-based substrate to remove water and oxygen on the substrate surface; Step S2: When the temperature of the reaction chamber drops to 680-710°C, TMGa and AsH3 are introduced to grow a GaAs buffer layer with a thickness of 100-300nm on the GaAs substrate; Step S3: When the temperature of the reaction chamber drops to 640-680°C, TMAl, TMGa and AsH3 are introduced to grow an Alx1Ga1-x1As N confinement layer with a thickness of 1-4 um on the surface of step S2; Step S4: maintaining the temperature at 640-680°C, after step S3 is completed, introducing TMAl, TMGa and AsH3 to grow the Alx2Ga1-x2As lower light field confinement layer with a thickness of 10-30nm; Step S5: maintaining the temperature at 640-680°C, after step S4 is completed, introducing TMAl, TMGa and AsH3 to grow the Alx3Ga1-x3As lower waveguide layer with a thickness of 100-300nm; Step S6: taking out the epitaxial wafer and etching a longitudinal deep groove with a depth of 3-10 nm on the Alx3Ga1-x3As lower waveguide layer by dry etching; Step S7: maintaining the temperature at 540-580°C, after completing step S6, continue to grow an Iny1Ga1-y1As lower quantum well planting layer with a thickness of 3-10nm; Step S8: maintaining the temperature at 540-580°C, after step S7 is completed, continuing to grow an Iny2Ga1-y2As quantum well layer with a thickness of 3-7nm; Step S9: maintaining the temperature at 640-680°C, after step S8 is completed, introducing TMAl, TMGa and AsH3 to grow the Alx4Ga1-x4As upper waveguide layer A with a growth thickness of 3-10nm; Step S10: Take out the epitaxial wafer and etch a longitudinal deep groove with a depth of 3-10 nm on the Alx4Ga1-x4As upper waveguide layer A through a dry etching process; Step S11: maintaining the temperature at 540-580°C, after step 10 is completed, continuing to grow an Iny3Ga1-y3As upper quantum well planting layer with a thickness of 3-10nm; Step S12: maintaining the temperature at 640-680°C, after step S11 is completed, introducing TMAl, TMGa and AsH3 to grow an Alx5Ga1-x5As upper waveguide layer B with a thickness of 600-900nm; Step S13: maintaining the temperature at 640-680°C, after step S12 is completed, introducing TMAl, TMGa and AsH3 to grow an Alx6Ga1-x6As upper optical field confinement layer with a thickness of 10-30nm; Step S14: maintaining the temperature at 640-680°C, after step S13 is completed, introducing TMAl, TMGa and AsH3 to grow an Alx7Ga1-x7As P confinement layer with a thickness of 0.4-0.8um; Step S15: When the temperature of the reaction chamber drops to 540-560° C., TMGa and AsH 3 are introduced, and a GaAs ohmic contact layer with a thickness of 300-600 nm is grown on the Alx7Ga1-x7As P confinement layer.

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