Method for growing single-layer two-dimensional material on any substrate

Abstract

The invention discloses a method for growing a single-layer two-dimensional material on any substrate. The method comprises the following steps: step 1, preparing and pretreating a substrate; 2, initializing an in-situ CVD (chemical vapor deposition) growth system; step 3, starting growth of the two-dimensional material; step 4, monitoring and analyzing in real time by the AI identification system; 5, the AI controls the femtosecond laser etching module to accurately remove the multi-layer area; step 6, dynamically adjusting growth and removal processes; 7, confirming the completion of growth of the single-layer two-dimensional material; step 8, taking out a sample and detecting; the in-situ CVD growth technology, the AI real-time identification technology and the femtosecond laser accurate etching technology are integrated, a systematic and automatic single-layer two-dimensional material growth scheme is formed, controllable preparation of the single-layer two-dimensional material on any substrate is achieved, and the dependence of a traditional method on a specific substrate is broken through.

Description

Technical Field

[0001] This invention relates to the field of controllable fabrication technology of two-dimensional materials, specifically a method for growing a single-layer two-dimensional material on any substrate. Background Technology

[0002] Currently, two-dimensional materials such as MoS2, WS2, and black phosphorus are showing broad application prospects in electronic devices, optoelectronic devices, and other fields due to their unique electrical and optical properties. However, the formation of multilayer regions is unavoidable during the growth of two-dimensional materials, which seriously affects the consistency and performance of devices and restricts their large-scale production and application.

[0003] Traditional methods such as chemical vapor deposition (CVD) or metal-organic chemical vapor deposition (MOCVD) face numerous challenges in the large-area fabrication of monolayer two-dimensional materials, making it difficult to achieve precise monolayer control. Existing methods for removing multilayer two-dimensional materials are mostly performed after material growth, which not only makes it difficult to accurately identify and locate multilayer regions, but also often requires manual intervention, resulting in complex operations, low efficiency, and the potential to damage the monolayer material and substrate, leading to reduced product yield.

[0004] Therefore, there is an urgent need for a method that can identify and remove multilayer regions in real time during the growth of two-dimensional materials, thereby enabling the controllable fabrication of single-crystal thin films of single-layer two-dimensional materials on any substrate. Summary of the Invention

[0005] The purpose of this invention is to provide a method for growing a single-layer two-dimensional material on any substrate, so as to solve the problems mentioned in the background art.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a method for growing a single-layer two-dimensional material on any substrate, comprising the following steps:

[0007] Step 1: Substrate preparation and pretreatment: Select any type of substrate, clean and pretreat the substrate to remove impurities, contaminants and oxide layers from the surface, and ensure the cleanliness and flatness of the substrate surface to provide a good foundation for the growth of two-dimensional materials.

[0008] Step 2: Initialization of the in-situ CVD growth system: Place the pretreated substrate into the reaction chamber of the in-situ CVD system, check the system's airtightness, and ensure that the reaction chamber is under vacuum or inert gas protection. Set the initial parameters of temperature, pressure, and gas flow rate required for growth according to the type of target two-dimensional material.

[0009] Step three, two-dimensional material growth initiation: according to the initial parameters set, the corresponding reaction gas is introduced into the reaction cavity, the heating device is started, and the growth process of the two-dimensional material is started. During the growth process, the growth of the material is observed in real time through the window of the in-situ CVD system;

[0010] Step four, real-time monitoring and analysis by AI recognition system: the AI recognition module captures the growth image of the two-dimensional material in real time through the image recognition camera, analyzes and processes the image using deep learning algorithm, distinguishes the single-layer region and multi-layer region based on optical contrast, spectral response and polarization characteristic information, and feeds back the recognition result to the control and feedback system in real time;

[0011] Step five, AI-controlled femtosecond laser etching module precisely removes the multi-layer region: based on the multi-layer region position information provided by the AI recognition module, the control and feedback system sends instructions to the femtosecond laser etching module in real time. The laser module then adjusts the laser wavelength and focusing parameters, precisely focuses the laser beam on the target multi-layer region, and realizes selective ablation removal. During the etching process, the system ensures effective removal of multi-layer materials while avoiding damage to single-layer regions and substrates through precise energy control and spatial positioning, achieving high selectivity and high fidelity laser processing;

[0012] Step six, dynamic adjustment of growth and removal process: during the growth of the two-dimensional material, the AI recognition system continuously monitors the growth state of the material. Once new multi-layer regions are formed, steps four and five are repeated to realize dynamic cooperation between growth and multi-layer removal;

[0013] Step seven, confirmation of single-layer two-dimensional material growth completion: when the AI recognition system monitors that the two-dimensional material has formed single-layer on the substrate and no new multi-layer region is generated, stop introducing the reaction gas, turn off the heating device, and let the reaction cavity cool down to room temperature naturally;

[0014] Step eight, sample removal and detection: after the reaction cavity cools down, the two-dimensional material sample grown on the substrate is taken out, and relevant detection means are used, including but not limited to atomic force microscope, scanning electron microscope, to detect the sample and confirm the quality and integrity of the single-layer two-dimensional material.

[0015] Preferably, the substrate material used in step one includes but is not limited to glass, sapphire, oxide, metal or semiconductor, etc.

[0016] Preferably, the cleaning and pretreatment method of the substrate in step one includes but is not limited to ultrasonic cleaning, chemical etching, plasma treatment, and the specific method is selected according to the material properties of the substrate.

[0017] Preferably, the window of the in-situ CVD system in step two is made of a high-temperature resistant and high-transmittance material to ensure that the AI ​​recognition system can clearly capture the growth image of the two-dimensional material.

[0018] Preferably, the deep learning algorithm of the AI ​​recognition module in step four needs to be trained with a large amount of single-layer and multi-layer two-dimensional material growth image data to improve the accuracy and efficiency of recognition.

[0019] Preferably, in step five, the wavelength of the femtosecond laser etching module can be adjusted within a certain range, and the focusing accuracy reaches the nanometer level. This allows for precise positioning and removal of multi-layer regions, with a small heat-affected zone that does not damage the surrounding single-layer material and substrate.

[0020] Preferably, the criterion for determining in step seven that the two-dimensional material has been completely formed into a single layer is: within a continuous period of time, the AI ​​recognition system does not detect the generation of new multi-layer regions, and all existing multi-layer regions have been removed.

[0021] Preferably, the testing of the sample in step eight also includes testing the crystal structure, electrical properties, and optical properties of the material to comprehensively evaluate the quality of the single-layer two-dimensional material.

[0022] Compared with the prior art, the beneficial effects of the present invention are:

[0023] This invention integrates three major technologies: in-situ CVD growth, AI real-time identification, and femtosecond laser precision etching, forming a systematic and automated single-layer two-dimensional material growth scheme. This enables controllable preparation of single-layer two-dimensional materials on any substrate, breaking through the dependence of traditional methods on specific substrates. Secondly, this invention identifies and removes multi-layer regions in real time during the two-dimensional material growth process, avoiding the tedious post-growth multi-layer removal operation, improving production efficiency and product yield, while reducing manual intervention and human error. The femtosecond laser etching module used in this invention features tunable wavelength, high focusing accuracy, and a small heat-affected zone, enabling precise removal of multi-layer regions without damaging the single-layer material or the substrate, ensuring the quality of the single-layer two-dimensional material. This invention is applicable to the growth of various two-dimensional materials, such as MoS2, WS2, and black phosphorus, and has broad applicability, providing strong technical support for the large-scale application of two-dimensional materials in electronics, optics, and other fields. Attached Figure Description

[0024] Figure 1 This is a flowchart of the method of the present invention. Detailed Implementation

[0025] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0026] Please see Figure 1 This invention provides a method for growing a single-layer two-dimensional material on any substrate, comprising the following steps:

[0027] Step 1: Substrate Preparation and Pretreatment: Select any type of substrate, clean and pretreatment the substrate to remove surface impurities, contaminants and oxide layers, ensuring the cleanliness and flatness of the substrate surface, providing a good foundation for the growth of two-dimensional materials; substrate materials include but are not limited to glass, sapphire, oxides, metals or semiconductors, etc., and the cleaning and pretreatment methods for the substrate include but are not limited to ultrasonic cleaning, chemical etching, and plasma treatment, and the specific method is selected according to the material characteristics of the substrate;

[0028] Step 2: Initialization of the in-situ CVD growth system: Place the pretreated substrate into the reaction chamber of the in-situ CVD system, check the system's airtightness, and ensure that the reaction chamber is under vacuum or inert gas protection. Set the initial parameters of temperature, pressure, and gas flow rate required for growth according to the type of target two-dimensional material. The window of the in-situ CVD system is made of a high-temperature resistant and high-transmittance material to ensure that the AI ​​recognition system can clearly capture the growth image of the two-dimensional material.

[0029] Step 3, Start-up of 2D material growth: According to the set initial parameters, the corresponding reaction gas is introduced into the reaction chamber, the heating device is started, and the 2D material growth process begins. During the growth process, the material growth is observed in real time through the window equipped with the in-situ CVD system.

[0030] Step 4: Real-time monitoring and analysis by the AI ​​recognition system: The AI ​​recognition module captures real-time images of the growth of two-dimensional materials through an image recognition camera, analyzes and processes the images using deep learning algorithms, and distinguishes between single-layer and multi-layer regions based on optical contrast, spectral response, and polarization feature information. The recognition results are then fed back to the control and feedback system in real time. The deep learning algorithm of the AI ​​recognition module needs to be trained with a large amount of single-layer and multi-layer two-dimensional material growth image data to improve the accuracy and efficiency of recognition.

[0031] Step 5: Femtosecond laser etching module precisely removes multi-layered areas: Based on the multi-layered area location information transmitted by the AI ​​recognition module, the control and feedback system sends instructions to the femtosecond laser etching module. The femtosecond laser etching module adjusts the wavelength and focusing precision to precisely focus the laser on the multi-layered areas, selectively ablating and removing them. During the removal process, the laser avoids damage to single-layered areas and the substrate. The wavelength of the femtosecond laser etching module can be adjusted within a certain range, and the focusing precision reaches the nanometer level. It can accurately locate and remove multi-layered areas with a small heat-affected zone, without damaging the surrounding single-layered materials and substrate.

[0032] Step Six: Dynamic Adjustment of Growth and Removal Processes: During the growth of two-dimensional materials, the AI ​​recognition system continuously monitors the growth status of the materials. Once a new multi-layer region is detected, the operations of Steps Four and Five are immediately repeated to achieve dynamic coordination between growth and multi-layer removal.

[0033] Step 7: Confirmation of completion of monolayer 2D material growth: When the AI ​​recognition system detects that the 2D material has been completely formed into a monolayer on the substrate and no new multilayer regions are generated, stop the flow of reaction gas, turn off the heating device, and allow the reaction chamber to cool naturally to room temperature; the standard for judging that the 2D material has been completely formed into a monolayer is: within a continuous period of time, the AI ​​recognition system does not detect the generation of new multilayer regions, and all existing multilayer regions have been removed.

[0034] Step 8, Sample Removal and Testing: After the reaction chamber has cooled, the two-dimensional material sample grown on the substrate is removed and tested using relevant testing methods, including but not limited to atomic force microscopy and scanning electron microscopy, to confirm the quality and integrity of the monolayer two-dimensional material. The testing of the sample also includes testing the crystal structure, electrical properties, and optical properties of the material to comprehensively evaluate the quality of the monolayer two-dimensional material.

[0035] Example: Growth of a monolayer of two-dimensional MoS2 material on a glass substrate

[0036] Step 1: Substrate preparation and pretreatment: Select a glass substrate and first place it in a container filled with ethanol for ultrasonic cleaning for 15 minutes to remove surface oil and other impurities. Then rinse it with deionized water and place it in a dilute hydrochloric acid solution for chemical etching for 5 minutes to remove the surface oxide layer. Finally, use a plasma treatment instrument to perform plasma treatment on the surface of the glass substrate to improve the activity of the substrate surface. After the treatment is completed, let the glass substrate dry for later use.

[0037] Step 2: Initialization of the in-situ CVD growth system: Place the pretreated glass substrate into the reaction chamber of the in-situ CVD system, close the reaction chamber, check its sealing to ensure there is no leakage, then evacuate the reaction chamber to a vacuum state, and then introduce argon gas as a protective gas. Set the growth temperature to 850℃, the reaction pressure to 50Pa, the argon gas flow rate to 50sccm, and the hydrogen sulfide gas flow rate to 5sccm.

[0038] Step 3, Start-up of two-dimensional material growth: According to the set parameters, start the heating device to gradually raise the temperature of the reaction chamber to 850°C. At the same time, argon and hydrogen sulfide gas are introduced. The molybdenum source (such as MoO3) is placed in the high-temperature zone of the reaction chamber, so that it volatilizes at high temperature and reacts with hydrogen sulfide gas to start the growth of MoS2 on the glass substrate.

[0039] Step 4: Real-time monitoring and analysis by the AI ​​recognition system: The image recognition camera of the AI ​​recognition module captures the growth images of MoS2 in real time through the window of the in-situ CVD system, capturing 10 frames per second. The deep learning algorithm analyzes these images in real time, accurately identifies the multi-layer regions based on the difference in optical contrast between single-layer and multi-layer regions of MoS2, and sends their position coordinates to the control and feedback system in real time.

[0040] Step 5: AI-controlled femtosecond laser etching module precisely removes multi-layered areas: Based on the multi-layered area location information provided by the AI ​​recognition module, the control and feedback system sends real-time commands to the femtosecond laser etching module. The laser module then adjusts the laser wavelength and focusing parameters to precisely focus the laser beam on the target multi-layered area, achieving selective ablation removal. During the etching process, the system ensures effective removal of multi-layered materials through precise energy control and spatial positioning, while avoiding damage to single-layered areas and the substrate, achieving highly selective and high-fidelity laser processing.

[0041] Step 6: Dynamic Adjustment of Growth and Removal Process: During the growth of MoS2, the AI ​​recognition system continuously monitors and performs a comprehensive analysis of the growth image every 30 seconds. When a new multi-layer region is found to be formed, the femtosecond laser etching module is notified in time to remove it, ensuring that the multi-layer region is removed in a timely manner during the growth process.

[0042] Step 7: Confirmation of completion of single-layer two-dimensional material growth: When the AI ​​recognition system does not detect the generation of new multi-layer MoS2 regions for 30 consecutive minutes, and all previously identified multi-layer regions have been removed, it is determined that the single-layer MoS2 growth is complete. Stop the introduction of hydrogen sulfide gas and argon gas, turn off the heating device, and allow the reaction chamber to cool naturally.

[0043] Step 8, Sample Removal and Testing: After the reaction chamber temperature drops to room temperature, the MoS2 sample on the glass substrate is removed and tested using an atomic force microscope. It is observed that the MoS2 has a uniform thickness and is a single-layer structure. Scanning electron microscopy shows that the sample surface is smooth and without obvious defects. Electrical performance tests show that it has good conductivity, and optical performance tests show that it has excellent optical properties.

[0044] Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for growing a single-layer two-dimensional material on any substrate, characterized in that: Includes the following steps: Step 1: Substrate preparation and pretreatment: Select any type of substrate, clean and pretreat the substrate to remove impurities, contaminants and oxide layers from the surface, and ensure the cleanliness and flatness of the substrate surface to provide a good foundation for the growth of two-dimensional materials. Step 2: Initialization of the in-situ CVD growth system: Place the pretreated substrate into the reaction chamber of the in-situ CVD system, check the system's airtightness, and ensure that the reaction chamber is under vacuum or inert gas protection. Set the initial parameters of temperature, pressure, and gas flow rate required for growth according to the type of target two-dimensional material. Step 3, Start-up of 2D material growth: According to the set initial parameters, the corresponding reaction gas is introduced into the reaction chamber, the heating device is started, and the 2D material growth process begins. During the growth process, the material growth is observed in real time through the window equipped with the in-situ CVD system. Step 4: Real-time monitoring and analysis of the AI ​​recognition system: The AI ​​recognition module captures the growth images of the two-dimensional material in real time through the image recognition camera, analyzes and processes the images using deep learning algorithms, and distinguishes between single-layer and multi-layer regions based on optical contrast, spectral response, and polarization feature information, and feeds the recognition results back to the control and feedback system in real time. Step 5: AI-controlled femtosecond laser etching module precisely removes multi-layered areas: Based on the multi-layered area location information provided by the AI ​​recognition module, the control and feedback system sends commands to the femtosecond laser etching module in real time; the laser module then adjusts the laser wavelength and focusing parameters to precisely focus the laser beam on the target multi-layered area, achieving selective ablation removal; during the etching process, the system ensures effective removal of multi-layered materials through precise energy control and spatial positioning, while avoiding damage to single-layered areas and the substrate, achieving high selectivity and high fidelity laser processing; Step Six: Dynamic Adjustment of Growth and Removal Processes: During the growth of two-dimensional materials, the AI ​​recognition system continuously monitors the growth status of the materials. Once a new multi-layer region is detected, the operations of Steps Four and Five are immediately repeated to achieve dynamic coordination between growth and multi-layer removal. Step 7: Confirmation of completion of single-layer two-dimensional material growth: When the AI ​​recognition system detects that the two-dimensional material has been completely formed into a single layer on the substrate and no new multi-layer regions are generated, stop the introduction of reaction gas, turn off the heating device, and allow the reaction chamber to cool naturally to room temperature. Step 8, Sample Removal and Testing: After the reaction chamber has cooled, the two-dimensional material sample grown on the substrate is removed and tested using relevant testing methods, including but not limited to atomic force microscopy and scanning electron microscopy, to confirm the quality and integrity of the single-layer two-dimensional material.

2. The method for growing a single-layer two-dimensional material on any substrate according to claim 1, characterized in that: The substrate materials used in step one include, but are not limited to, glass, sapphire, oxide, metal, or semiconductor.

3. The method for growing a single-layer two-dimensional material on any substrate according to claim 1, characterized in that: The cleaning and pretreatment methods for the substrate in step one include, but are not limited to, ultrasonic cleaning, chemical etching, and plasma treatment. The specific method is selected according to the material properties of the substrate.

4. The method for growing a single-layer two-dimensional material on any substrate according to claim 1, characterized in that: In step two, the window of the in-situ CVD system is made of a high-temperature resistant and high-transmittance material to ensure that the AI ​​recognition system can clearly capture the growth image of the two-dimensional material.

5. The method for growing a single-layer two-dimensional material on any substrate according to claim 1, characterized in that: In step four, the deep learning algorithm of the AI ​​recognition module needs to be trained with a large amount of single-layer and multi-layer two-dimensional material growth image data to improve the accuracy and efficiency of recognition.

6. The method for growing a single-layer two-dimensional material on any substrate according to claim 1, characterized in that: In step five, the wavelength of the femtosecond laser etching module can be adjusted within a certain range, and the focusing accuracy reaches the nanometer level. It can accurately locate and remove multi-layer areas, and the heat-affected zone is small, so it will not damage the surrounding single-layer materials and substrate.

7. The method for growing a single-layer two-dimensional material on any substrate according to claim 1, characterized in that: The criterion for determining in step seven that the two-dimensional material has been completely formed into a single layer is: within a continuous period of time, the AI ​​recognition system does not detect the generation of new multi-layer regions, and all existing multi-layer regions have been removed.

8. The method for growing a single-layer two-dimensional material on any substrate according to claim 1, characterized in that: The testing of the sample in step eight also includes testing the crystal structure, electrical properties, and optical properties of the material to comprehensively evaluate the quality of the single-layer two-dimensional material.

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