Method for fabricating active region of indium arsenide / indium phosphide quantum dot laser

Abstract

The present invention discloses a method for fabricating an active region of an indium arsenide / indium phosphide quantum dot laser. An indium phosphide substrate is selected; a layer of indium aluminum arsenide is epitaxially grown on the substrate; then a layer of indium aluminum gallium arsenide is grown; and then a multi-period indium arsenide quantum dot active layer is epitaxially grown, including growing indium arsenide quantum dots, growing an indium aluminum gallium arsenide layer lattice-matched with indium phosphide on the indium arsenide quantum dots, growing a stress adjustment layer on the indium aluminum gallium arsenide layer, and growing a spacer layer lattice-matched with indium phosphide on the stress adjustment layer; or: growing indium arsenide quantum dots, growing one or two stress adjustment layers on the indium arsenide quantum dots, and growing a spacer layer on the stress adjustment layer; epitaxially growing indium aluminum gallium arsenide on the quantum dot active layer; then epitaxially growing indium aluminum arsenide; and then epitaxially growing a layer of indium phosphide as an optical confinement layer; finally, epitaxially growing indium gallium arsenide as a contact layer to complete the preparation of the active region of the quantum dot laser. While adjusting the wavelength, the optical properties of the quantum dots are ensured.

Description

Technical Field

[0001] The present invention belongs to the technical field of semiconductor manufacturing, and particularly relates to a method for fabricating an active region of an indium arsenide / indium phosphide quantum dot laser. Background Art

[0002] Optical fiber communication has gradually replaced copper interconnection due to its larger channel density, higher data transmission speed, longer transmission distance, and lower cost to meet the rapidly expanding data transmission requirements. The 1.55-μm wavelength band is the lowest transmission loss window for optical fiber communication. Therefore, semiconductor lasers in this band have received extensive attention due to their potential applications in medium- and long-distance (10 - 80 km and above) optical fiber communication systems. The indium phosphide-based material system is the most widely used light source for 1.55-μm optical communication at present. Secondly, indium phosphide-based sensors have better safety. The light wave emitted by the device with a wavelength near 1.55 μm avoids the wavelength band that can cause harm to the human eye (less than 1400 nm), and can better protect the eye safety than gallium arsenide-based sensors. Therefore, it has natural advantages in wearable devices, face and gesture recognition, industrial sensors and controllers, etc. The 1.55-μm lidar can safely emit higher energy and transmit farther distances, and has key advantages in autonomous driving, robotics, etc.

[0003] Self-organized quantum dot systems have become a current research hotspot due to their superior optoelectronic properties and insensitivity to defects. According to theoretical research and experimental verification, zero-dimensional quantum dot lasers have higher temperature stability, greater gain, and lower threshold current compared to traditional quantum well lasers. In addition, the property of quantum dots being insensitive to material defects makes them a decisive factor for growing and fabricating lasers on silicon for silicon-based optoelectronic integration. Compared with the well-developed gallium arsenide-based indium arsenide quantum dots in terms of growth technology, the difficulty in growing indium arsenide quantum dots based on indium phosphide lies in their small lattice mismatch, the non-uniform stress field on the surface of the commonly used indium aluminum gallium arsenide or indium gallium arsenide phosphide quaternary compound barriers in the indium phosphide material system, and indium atom diffusion, which makes it difficult to form a uniform quantum dot morphology. Quantum dots based on indium phosphide are very likely to form quantum wires rather than quantum dots during growth. Such quantum wires will result in a relatively large full width at half maximum of the photoluminescence spectrum in the active region due to the anisotropy of their morphology, which is basically around 70 meV at room temperature and rarely less than 60 meV. In addition, controlling the emission wavelength at 1.55 microns at room temperature is also a major focus in the growth of indium phosphide quantum dots. Currently, the methods used internationally to fabricate high-density and highly uniform indium phosphide-based quantum dots emitting at 1.55 microns include growing on indium phosphide substrates, adjusting the growth interruption time, adjusting the way of arsenic-phosphorus exchange, adjusting growth parameters including the V / III ratio, growth rate, growth temperature, selection of As4 / As2, etc., and adjusting the capping layer method for growth optimization. High-density, quantum dot morphology, and quantum dots emitting at 1.55 microns in terms of emission wavelength have all been fabricated separately, but the research results that meet the above conditions simultaneously are still very limited.

[0004] In order to improve the luminescence efficiency and adjust the emission wavelength, the two-step growth method, which is derived from indium arsenide / gallium arsenide quantum dots, is applied to the growth of 1.55-μm indium phosphide-based quantum dots. The specific operation method is generally to grow a thin layer of indium gallium arsenide phosphide or indium gallium arsenide lattice-matched with indium phosphide at the same temperature after growing the quantum dot layer, so that some quantum dots are completely covered and the large dots are exposed. Then, by raising the substrate temperature, indium is evaporated to increase the uniformity of the dots. Subsequently, at a high temperature, the second capping layer (usually indium gallium arsenide phosphide or indium gallium arsenide) will be continuously grown to the thickness of the spacer layer to realize the growth of multi-layer quantum dots. Alternatively, the first capping layer can also be an indium phosphide capping layer to adjust the dot size through arsenic / phosphorus exchange, thereby adjusting the emission wavelength. However, for this method, the emission wavelength depends to a large extent on the thickness of the first capping layer. Moreover, if the thickness of the first capping layer is very thin, a lot of the volume of the luminescent quantum dots will be lost, and the luminescence efficiency will decrease. For the method of adjusting the emission wavelength by arsenic / phosphorus exchange, it is easy to cause the blurring of the quantum dot boundaries and reduce the carrier confinement ability of the quantum dots. Against this research background, the present invention proposes a method for growing the active region of an indium arsenide / indium phosphide quantum dot laser, which combines a stress layer (also a bandgap adjustment layer) and a two-step capping layer growth method, and can achieve the adjustment of the emission wavelength in a larger range while better ensuring the optical performance. Summary of the Invention

[0005] In view of the above technical problems, the present invention provides a method for fabricating the active region of an indium arsenide / indium phosphide quantum dot laser.

[0006] The technical solution adopted by the present invention to solve its technical problems is as follows:

[0007] A method for fabricating the active region of an indium arsenide / indium phosphide quantum dot laser, the method comprising the following steps:

[0008] S100: Select an indium phosphide substrate;

[0009] S200: Epitaxially grow a layer of indium aluminum arsenide lattice-matched with indium phosphide on the indium phosphide substrate;

[0010] S300: Grow a layer of indium aluminum gallium arsenide lattice-matched with indium phosphide on the indium aluminum arsenide layer;

[0011] S400: Epitaxially grow multiple periods of indium arsenide quantum dot active layers on the indium aluminum gallium arsenide layer; the indium arsenide quantum dot active layer includes growing indium arsenide quantum dots, growing a layer of indium aluminum gallium arsenide lattice-matched with indium phosphide on the indium arsenide quantum dots, growing a stress adjustment layer on the indium aluminum gallium arsenide layer, and growing a spacer layer lattice-matched with indium phosphide on the stress adjustment layer; or: growing indium arsenide quantum dots, growing one or two stress adjustment layers on the indium arsenide quantum dots, and growing a spacer layer lattice-matched with indium phosphide on the stress adjustment layer;

[0012] S500: Epitaxially grow indium aluminum gallium arsenide on the quantum dot active layer;

[0013] S600: Epitaxially grow indium aluminum arsenide on the indium aluminum gallium arsenide layer;

[0014] S700: Epitaxially grow a layer of indium phosphide as the optical confinement layer on the indium aluminum arsenide layer;

[0015] S800: Epitaxially grow indium gallium arsenide on the indium phosphide as the contact layer to complete the preparation of the active region of the quantum dot laser.

[0016] Preferably, S100 is specifically:

[0017] Select an indium phosphide substrate, which is an n+-type indium phosphide single crystal wafer with a doping concentration of 1×10 18 cm -3 -2×10 19 cm -3 , with a crystal orientation of 100, perform high-temperature annealing to remove the oxide layer at 480°C - 530°C for 1 to 3 minutes. The high-temperature annealing process can be protected by phosphorus-rich or arsenic-rich environment.

[0018] Preferably, S200 is specifically:

[0019] Use molecular beam epitaxy (MBE) to grow a lattice-matched n+-indium aluminum arsenide layer with a thickness of 100 nm - 600 nm on the indium phosphide substrate at a temperature between 470°C and 530°C, with a doping concentration of 5×10 17 cm -3 -2×10 19 cm -3 , where the ratio of group V to group III is greater than 25.

[0020] Preferably, S300 is specifically:

[0021] Deposit a lattice-matched n-type indium aluminum gallium arsenide layer on the indium aluminum arsenide layer, with a doping concentration of 1×10 16 cm -3 -5×10 18 cm -3 , the growth temperature of the indium aluminum gallium arsenide layer is between 470°C and 530°C, and the thickness is 100 nm to 400 nm, where the ratio of group V to group III is greater than 25.

[0022] Preferably, the growth structure of the indium arsenide quantum dot active layer in S400 is specifically:

[0023] Grow indium arsenide quantum dots at a temperature between 450°C and 520°C, with a growth rate of 0.1 ML / s - 0.7 ML / s, and the ratio of group V to group III is 1 - 30;

[0024] Subsequently, a layer of indium aluminum gallium arsenide lattice-matched to indium phosphide is grown, with a thickness of 1 nm - 10 nm and a growth temperature the same as that for quantum dot growth, to partially cover the quantum dots;

[0025] Then, a stress adjustment layer is grown. The stress adjustment layer is gallium arsenide, indium gallium arsenide, indium aluminum arsenide, or indium aluminum gallium arsenide or indium gallium arsenide phosphide with a lattice constant mismatched to indium phosphide. The growth temperature of the stress adjustment layer is the same as that for quantum dot growth, and the thickness is 0.5 - 20 monolayers, to control the height of the quantum dots and adjust the emission wavelength of the quantum dots by the bandgap width of the stress adjustment layer and the stress applied to the quantum dots; Subsequently, the substrate temperature is increased to 500 °C - 570 °C to evaporate indium, and the quantum dots with a height higher than the thicknesses of the indium aluminum gallium arsenide layer and the stress adjustment layer are disintegrated to improve the uniformity of the quantum dots;

[0026] Subsequently, the remaining indium phosphide lattice-matched spacer layer is grown on the stress adjustment layer to eliminate stress accumulation for multi-layer quantum dot growth.

[0027] Preferably, the growth structure of the indium arsenide quantum dot active layer in S400 is specifically:

[0028] Grow indium arsenide quantum dots between 450 °C and 520 °C, with a growth rate of 0.1 ML / s - 0.7 ML / s, and the ratio of group V to group III is 1 - 30;

[0029] Then, one or two stress adjustment layers are grown. The stress adjustment layer is gallium arsenide, indium gallium arsenide, indium aluminum arsenide, or indium aluminum gallium arsenide or indium gallium arsenide phosphide with a lattice constant mismatched to indium phosphide. The growth temperature of the stress adjustment layer is the same as the growth temperature of the quantum dots or directly heated to 500 °C - 540 °C for growth to achieve dual regulation of wavelength and emission intensity; Subsequently, the substrate temperature is increased to 500 °C - 570 °C to evaporate indium;

[0030] Subsequently, a spacer layer lattice-matched to indium phosphide is grown on the stress adjustment layer.

[0031] Preferably, S500 is specifically:

[0032] Grow a lattice-matched p-type indium aluminum gallium arsenide layer on the multi-layer quantum dots, with a doping concentration of 1×10 16 cm -3 -5×10 18 cm -3 , the growth temperature of the indium aluminum gallium arsenide layer is between 470 °C and 530 °C, and the thickness is 100 nm to 400 nm, where the ratio of group V to group III is greater than 25.

[0033] Preferably, S600 is specifically:

[0034] On the p-type indium aluminum gallium arsenide layer, a lattice-matched p+-indium aluminum arsenide layer is grown between 470 °C and 530 °C, with a doping concentration of 5×10 17 cm -3 -2×10 19 cm -3 , with a thickness of 100 nm – 600 nm, where the ratio of group V to group III is greater than 25.

[0035] Preferably, S700 is specifically:

[0036] A p+-indium phosphide optical confinement layer of 1000 nm–2000 nm is grown on the p+-indium aluminum arsenide layer, with a doping concentration of 1×10 18 cm -3 -2×10 19 cm -3 , and the growth temperature is between 470 °C and 530 °C, where the ratio of group V to group III is greater than 25.

[0037] Preferably, S800 is specifically:

[0038] A p+-indium gallium arsenide contact layer is grown on the p+-indium phosphide layer between 470 °C and 530 °C, with a thickness of 100 nm-400 nm and a doping concentration of 1×10 18 cm -3 -2×10 19 cm -3 , where the ratio of group V to group III is greater than 25.

[0039] The above method for fabricating the active region of an indium arsenide / indium phosphide quantum dot laser optimizes the growth method of the active region of an indium arsenide / indium phosphide quantum dot laser by using a stress adjustment layer (bandgap adjustment layer) as the second capping layer (or the first capping layer or two capping layers) in the two-step capping layer growth method, which can solve the problem of reducing the volume of luminescent quantum dots caused by reducing the capping layer thickness in the ordinary two-step capping layer growth method, and ensure the optical properties of the quantum dots while adjusting the wavelength. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 is a flowchart of the method for fabricating the active region of an indium arsenide / indium phosphide quantum dot laser according to an embodiment of the present invention;

[0041] Figure 2 is a schematic diagram of the growth structure of the active region of an indium arsenide / indium phosphide quantum dot laser according to an embodiment of the present invention;

[0042] Figure 3 is a schematic diagram of a partial structure of quantum dot growth according to an embodiment of the present invention;

[0043] Figure 4 is a schematic diagram of a partial structure of quantum dot growth according to another embodiment of the present invention;

[0044] Figure 5 This is a schematic diagram of the quantum dot growth part structure in another embodiment of the present invention. Detailed implementation manners

[0045] In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings.

[0046] In one embodiment, as Figure 1 and Figure 2 shown, a method for fabricating an active region of an indium arsenide / indium phosphide quantum dot laser, the method comprising the following steps:

[0047] S100: Select an indium phosphide substrate;

[0048] S200: Epitaxially grow a layer of indium aluminum arsenide lattice-matched to indium phosphide on the indium phosphide substrate;

[0049] S300: Grow a layer of indium aluminum gallium arsenide lattice-matched to indium phosphide on the indium aluminum arsenide layer;

[0050] S400: Epitaxially grow a multi-period indium arsenide quantum dot active layer on the indium aluminum gallium arsenide layer; the indium arsenide quantum dot active layer includes growing indium arsenide quantum dots, growing a layer of indium aluminum gallium arsenide lattice-matched to indium phosphide on the indium arsenide quantum dots, growing a stress adjustment layer on the indium aluminum gallium arsenide layer, and growing a separation layer lattice-matched to indium phosphide on the stress adjustment layer; or: growing indium arsenide quantum dots, growing one or two stress adjustment layers on the indium arsenide quantum dots, and growing a separation layer lattice-matched to indium phosphide on the stress adjustment layer;

[0051] S500: Epitaxially grow indium aluminum gallium arsenide on the quantum dot active layer;

[0052] S600: Epitaxially grow indium aluminum arsenide on the indium aluminum gallium arsenide layer;

[0053] S700: Epitaxially grow a layer of indium phosphide as an optical confinement layer on the indium aluminum arsenide layer;

[0054] S800: Epitaxially grow indium gallium arsenide on the indium phosphide as a contact layer to complete the preparation of the active region of the quantum dot laser.

[0055] The above method for fabricating an active region of an indium arsenide / indium phosphide quantum dot laser optimizes the growth method of the active region of the indium arsenide / indium phosphide quantum dot laser by using a stress adjustment layer (bandgap adjustment layer) as the second capping layer (or the first capping layer or two capping layers) in the two-step capping layer growth method, which can solve the problem of reducing the volume of luminescent quantum dots caused by reducing the capping layer thickness in the ordinary two-step capping layer growth method, and ensure the optical properties of the quantum dots while adjusting the wavelength.

[0056] In one embodiment, S100 specifically includes:

[0057] Select an indium phosphide substrate, which is an n+-type indium phosphide single crystal wafer with a doping concentration of 1×10 18 cm -3 -2×10 19 cm -3 , with a crystal orientation of 100. Perform high-temperature annealing to remove the oxide layer at 480°C - 530°C for 1 to 3 minutes. The high-temperature annealing process can be protected by phosphorus-rich or arsenic-rich environment.

[0058] In one embodiment, S200 specifically includes:

[0059] Use molecular beam epitaxy (MBE) to grow a lattice-matched n+-indium aluminum arsenide layer with a thickness of 100 nm - 600 nm on the indium phosphide substrate at a temperature between 470°C - 530°C, with a doping concentration of 5×10 17 cm -3 -2×10 19 cm -3 , where the ratio of group V to group III is greater than 25.

[0060] In one embodiment, S300 specifically includes:

[0061] Deposit a lattice-matched n-type indium aluminum gallium arsenide layer on the indium aluminum arsenide layer, with a doping concentration of 1×10 16 cm -3 -5×10 18 cm -3 , the growth temperature of the indium aluminum gallium arsenide layer is between 470°C - 530°C, and the thickness is 100 nm to 400 nm, where the ratio of group V to group III is greater than 25.

[0062] In one embodiment, as Figure 3 shown, the growth structure of the indium arsenide quantum dot active layer in S400 specifically includes:

[0063] Grow indium arsenide quantum dots at a temperature between 450°C - 520°C, with a growth rate of 0.1 ML / s - 0.7 ML / s, and the ratio of group V to group III is 1 - 30;

[0064] Subsequently, grow a layer of indium aluminum gallium arsenide layer lattice-matched with indium phosphide, with a thickness of 1 nm - 10 nm, and the growth temperature is the same as that of the quantum dot growth, used to partially cover the quantum dots;

[0065] Next, a stress adjustment layer (bandgap adjustment layer) is grown. The stress adjustment layer is gallium arsenide, indium gallium arsenide, indium aluminum arsenide, or indium aluminum gallium arsenide, indium gallium arsenide phosphide, etc. whose lattice constant does not match that of indium phosphide. The growth temperature of the stress adjustment layer is the same as the growth temperature of the quantum dots, and the thickness is 0.5 - 20 monolayers to control the height of the quantum dots and adjust the emission wavelength of the quantum dots by the bandgap of the stress adjustment layer and the stress applied to the quantum dots; Subsequently, the substrate temperature is increased to 500°C - 570°C to evaporate indium, and the quantum dots with a height higher than the thickness of the indium aluminum gallium arsenide layer and the stress adjustment layer are disintegrated to improve the uniformity of the quantum dots;

[0066] Subsequently, the remaining indium phosphide lattice-matched spacer layer is grown on the stress adjustment layer to eliminate stress accumulation for the growth of multiple layers of quantum dots.

[0067] Specifically, the above structure can be repeated multiple times to realize the growth of the active region of a multi-layer quantum dot laser.

[0068] In one embodiment, as Figure 4 and Figure 5 shown, the growth structure of the indium arsenide quantum dot active layer in S400 is specifically:

[0069] Indium arsenide quantum dots are grown between 450°C - 520°C, the growth rate is 0.1 ML / s - 0.7 ML / s, and the ratio of group V to group III is 1 - 30;

[0070] Next, one or two stress adjustment layers are grown. The stress adjustment layer is gallium arsenide, indium gallium arsenide, indium aluminum arsenide, or indium aluminum gallium arsenide, indium gallium arsenide phosphide, etc. whose lattice constant does not match that of indium phosphide. The growth temperature of the stress adjustment layer is the same as the growth temperature of the quantum dots or directly heated to 500°C - 540°C for growth to achieve dual regulation of wavelength and emission intensity; Subsequently, the substrate temperature is increased to 500°C - 570°C to evaporate indium;

[0071] Subsequently, an indium phosphide lattice-matched spacer layer is grown on the stress adjustment layer.

[0072] Specifically, a stress adjustment layer (bandgap adjustment layer), such as gallium arsenide, high-indium-content indium gallium arsenide, or indium gallium arsenide phosphide, etc., can also be directly grown on the indium arsenide quantum dots. Or, two stress adjustment layers can be directly grown on the indium arsenide quantum dots. For example, indium gallium arsenide is used as the original indium aluminum gallium arsenide layer, and gallium arsenide is used as the original stress adjustment layer to gradually apply stress and change the bandgap of the quantum dot active region to adjust the emission wavelength.

[0073] In one embodiment, S500 is specifically:

[0074] A lattice-matched p-type indium aluminum gallium arsenide layer is grown on the multi-layer quantum dots, and the doping concentration is 1×10 16 cm -3-5×10 18 cm -3 , the growth temperature of the indium aluminum gallium arsenide layer is between 470°C and 530°C, the thickness is from 100 nm to 400 nm, and the ratio of group V to group III is greater than 25.

[0075] In one embodiment, S600 specifically is:

[0076] On the p-type indium aluminum gallium arsenide layer, a lattice-matched p+-indium aluminum arsenide layer is grown between 470°C and 530°C, and the doping concentration is 5×10 17 cm -3 -2×10 19 cm -3 , the thickness is 100 nm – 600 nm, and the ratio of group V to group III is greater than 25.

[0077] In one embodiment, S700 specifically is:

[0078] A p+-indium phosphide optical confinement layer of 1000 nm–2000 nm is grown on the p+-indium aluminum arsenide layer, and the doping concentration is 1×10 18 cm -3 -2×10 19 cm -3 , the growth temperature is between 470°C and 530°C, and the ratio of group V to group III is greater than 25.

[0079] In one embodiment, S800 specifically is:

[0080] A p+-indium gallium arsenide contact layer is grown on the p+-indium phosphide layer between 470°C and 530°C, the thickness is 100 nm - 400 nm, and the doping concentration is 1×10 18 cm -3 -2×10 19 cm -3 , and the ratio of group V to group III is greater than 25.

[0081] The above method for fabricating the active region of an indium arsenide / indium phosphide quantum dot laser uses gallium arsenide, which has a large lattice mismatch with the indium phosphide-based material system, as the second capping layer (or the first capping layer or the two-step capping layer) for the two-step growth of indium arsenide / indium phosphide quantum dots to apply compressive stress to the quantum dots and introduce gallium arsenide with a wider bandgap. Combining with the indium evaporation technique to change the size of the dots, the emission wavelength of the quantum dots can be adjusted while ensuring good optical performance. This method can be extended to use materials with a larger lattice than the indium phosphide material system, such as indium gallium arsenide with a high indium composition, to apply tensile stress to the quantum dots and introduce a material with a narrower bandgap as the second capping layer (or the first capping layer or the two-step capping layer) in the two-step growth capping layer technique to shift the emission wavelength of the quantum dots to a longer wavelength. This method can achieve controllable adjustment of the emission wavelength of indium arsenide / indium phosphide quantum dots within a large range (1.3 - 2 microns or even longer).

[0082] The above method for fabricating the active region of an indium arsenide / indium phosphide quantum dot laser provided by the present invention has been introduced in detail. Specific examples are used in this article to elaborate on the principle and implementation mode of the present invention. The description of the above embodiments is only used to help understand the core idea of the present invention. It should be noted that for those of ordinary skill in the art in this technical field, without departing from the principle of the present invention, several improvements and modifications can still be made to the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention.

Claims

1. A method for making an indium arsenide / indium phosphide quantum dot laser active region, characterized in that: The method comprises the following steps: S100: selecting an indium phosphide substrate; S100 specifically includes: An indium phosphide substrate is selected, which is an n+ type indium phosphide single crystal with a doping concentration of 1×10 18 cm -3 -2×10 19 cm -3 , the crystal orientation is 100, and the high temperature deoxidation layer is carried out at 480℃-530℃ for 1 to 3 minutes. The high temperature deoxidation process can be protected by a phosphorus-rich or arsenic-rich environment; S200: epitaxially growing a layer of indium aluminum arsenide lattice matching with indium phosphide on the indium phosphide substrate; S300: growing a layer of indium aluminum gallium arsenide lattice-matched with indium phosphide on the indium aluminum arsenide layer; S400: epitaxially growing a multi-period indium arsenide quantum dot active layer on the indium aluminum gallium arsenide layer; the indium arsenide quantum dot active layer includes growing indium arsenide quantum dots, growing an indium aluminum gallium arsenide layer lattice-matched with indium phosphide on the indium arsenide quantum dots, growing a stress adjustment layer on the indium aluminum gallium arsenide layer, and growing a separation layer lattice-matched with indium phosphide on the stress adjustment layer; or: growing indium arsenide quantum dots, growing one or two stress adjustment layers on the indium arsenide quantum dots, and growing a separation layer lattice-matched with indium phosphide on the stress adjustment layer; S500: epitaxial growth of InAlGaAs on the quantum dot active layer; S600: epitaxially growing indium aluminum arsenide on the indium aluminum gallium arsenide layer; S700: epitaxially growing a layer of indium phosphide on the indium aluminum arsenide layer as a light confinement layer; S800: Epitaxially grow InGaAs on InP as a contact layer to complete the preparation of the active region of the quantum dot laser.

2. The method according to claim 1, characterized in that: S200 is specifically: The lattice-matched n+ InAlAs layer of 100 nm–600 nm was grown on the InP substrate by molecular beam epitaxy (MBE) at 470°C–530°C with a doping concentration of 5×10 17 cm -3 -2×10 19 cm -3 , among which the ratio of five ethnic groups to three ethnic groups is greater than 25.

3. The method according to claim 2, characterized in that S300 is specifically: A lattice-matched n-type InAlGaAs layer is deposited on the InAlAs layer with a doping concentration of 1×10 16 cm -3 -5×10 18 cm -3 The growth temperature of the InAlGaAs layer is between 470°C and 530°C, the thickness is between 100nm and 400nm, and the ratio of Group V to Group III is greater than 25.

4. The method according to claim 3, characterized in that The growth structure of the indium arsenide quantum dot active layer in S400 is as follows: InAs quantum dots were grown between 450°C and 520°C, with a growth rate of 0.1 ML / s to 0.7 ML / s, and a ratio of group V to group III of 1 to 30; Then grow a layer of indium aluminum gallium arsenide that matches the indium phosphide lattice with a thickness of 1nm-10nm, and the growth temperature is the same as the growth temperature of the quantum dots to partially cover the quantum dots; Then, a stress adjustment layer is grown. The stress adjustment layer is made of gallium arsenide, indium gallium arsenide, indium aluminum arsenide, or indium aluminum gallium arsenide or indium gallium arsenide phosphide whose lattice constant does not match that of indium phosphide. The growth temperature of the stress adjustment layer is the same as that of the quantum dots. The thickness is 0.5-20 monoatomic layers. The height of the quantum dots is controlled and the wavelength of the quantum dots is adjusted by the band gap width of the stress adjustment layer and the stress applied to the quantum dots. Then, the substrate temperature is increased to 500°C-570°C to evaporate indium. The quantum dots whose exposed height is higher than the thickness of the indium aluminum gallium arsenide layer and the stress adjustment layer are disintegrated, thereby improving the uniformity of the quantum dots. The remaining spacer layer lattice-matched to indium phosphide is then grown on the stress-modulating layer to eliminate stress accumulation and facilitate multi-layer quantum dot growth.

5. The method according to claim 3, characterized in that: The growth structure of the indium arsenide quantum dot active layer in S400 is as follows: InAs quantum dots were grown between 450°C and 520°C, with a growth rate of 0.1 ML / s to 0.7 ML / s, and a ratio of group V to group III of 1 to 30; Then, one or two stress adjustment layers are grown. The stress adjustment layers are made of gallium arsenide, indium gallium arsenide, indium aluminum arsenide, or indium aluminum gallium arsenide and indium gallium arsenide phosphide whose lattice constant does not match that of indium phosphide. The growth temperature of the stress adjustment layer is the same as that of the quantum dots or is directly increased to 500°C-540°C for growth, so as to achieve dual regulation of wavelength and luminous intensity. Then the substrate temperature is increased to 500°C-570°C to evaporate the indium; A spacer layer lattice-matched to InP is then grown on the stress-modulating layer.

6. The method according to claim 4 or 5, characterized in that: S500 is specifically: A lattice-matched p-type InAlGaAs layer was grown on the multilayer quantum dots with a doping concentration of 1×10 16 cm -3 -5×10 18 cm -3 The growth temperature of the InAlGaAs layer is between 470°C and 530°C, the thickness is between 100nm and 400nm, and the ratio of Group V to Group III is greater than 25.

7. The method according to claim 6, characterized in that S600 is specifically: On the p-type InAlGaAs layer, a lattice-matched p+ InAlAs layer is grown at 470°C-530°C with a doping concentration of 5×10 17 cm -3 -2×10 19 cm -3 , thickness is 100nm – 600nm, and the ratio of group V to group III is greater than 25.

8. The method according to claim 7, characterized in that S700 is specifically: A p+ InP light confinement layer of 1000nm–2000nm is grown on the p+ InAlAs layer with a doping concentration of 1×10 18 cm -3 -2×10 19 cm -3 The growth temperature is between 470℃-530℃, and the ratio of group V to group III is greater than 25.

9. The method according to claim 8, characterized in that S800 is specifically: A p+ InGaAs contact layer is grown on the p+ InP layer at 470°C-530°C with a thickness of 100nm-400nm and a doping concentration of 1×10 18 cm -3 -2×10 19 cm -3 , among which the ratio of five ethnic groups to three ethnic groups is greater than 25.

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