A method for preparing patterned two-dimensional sulfides / selenides by array and its application

Abstract

This invention belongs to the field of materials preparation technology, specifically relating to a method for the arrayed preparation of patterned two-dimensional sulfides / selenides and its applications. This invention provides an effective method for synthesizing arrayed two-dimensional materials by separating nucleation and growth. This method utilizes photolithography to pattern and array the material, and precisely controls the nucleation sites through coating technology, providing an induction source for the subsequent growth of the arrayed two-dimensional material, thereby obtaining high-quality patterned two-dimensional material array growth. This method is not only simple to operate but also yields pollution-free and damage-free arrayed two-dimensional materials, showing broad application prospects in the integration or miniaturization of electronic devices.

Description

Technical Field

[0001] This invention belongs to the field of materials preparation technology. More specifically, it relates to a method for the array preparation of patterned two-dimensional sulfides / selenides and its application. Background Technology

[0002] Two-dimensional layered van der Waals materials (or simply two-dimensional materials) are a new type of two-dimensional material composed of layers bonded by van der Waals bonds. They possess unique physicochemical properties, such as tunable band gaps, extremely high carrier mobility, and significant quantum confinement effects, leading to their wide applications in optoelectronics, biomedicine, photothermal conversion, fiber lasers, and nanotherapy. In particular, the unique optoelectronic properties, ease of integration, and CMOS process compatibility of two-dimensional materials hold promise for addressing the miniaturization, high energy efficiency, and high cost challenges faced by traditional semiconductor materials as device sizes shrink to sub-10nm scales. This could enable significant technological applications such as high-performance and integrated micro / nanoelectronic and optoelectronic devices.

[0003] Transition metal compounds, especially sulfides and selenides, have become the most promising two-dimensional semiconductor materials after graphene due to their unique electronic structures and excellent optoelectronic properties. Taking WS2 as an example, it has a wide tunable bandgap range, transitioning from 1.95 eV to 2.50 eV, and possesses extremely high carrier mobility, excellent light absorption, and good thermal stability, meeting many requirements of electronic and optoelectronic devices. For these devices, miniaturization and integration are the ultimate goals for practical applications. For instance, Chinese patent application CN102358954A discloses a novel method for synthesizing patterned single-crystal tungsten oxide nanowire arrays using catalyst localization technology. This method uses tungsten thin films as the source material and metal nanoparticle films as catalysts to obtain patterned tungsten oxide nanowire arrays with different growth densities. However, this tungsten oxide nanoarray requires noble metal nanoparticles as catalysts to achieve low-temperature localization of patterned tungsten oxide nanostructure films at relatively low temperatures (<800℃), and the expensive noble metal nanoparticle catalysts increase the fabrication cost of device arraying. For example, Chinese patent application CN107910249A discloses a method for preparing two-dimensional in-plane heterostructures. This method uses silicon dioxide as a protective sacrificial layer and selectively sulfides and selenizes transition metals or their oxides. It can form large-area two-dimensional in-plane heterostructures on any substrate without the need for secondary overlay and alignment. However, this method can only prepare large-area two-dimensional heterostructures and cannot achieve the array preparation of two-dimensional materials.

[0004] Furthermore, photolithography and dry etching of two-dimensional thin film materials to form arrayed two-dimensional materials has proven to be an effective approach. However, dry etching equipment is expensive, and residual etching gases can easily cause environmental pollution, thus increasing the cost of preparing arrayed two-dimensional materials. In addition, due to their atomic-level thickness and high specific surface area, with all atoms located on the surface, two-dimensional materials are highly sensitive to surface adsorption and the external environment. During the processing and trimming steps of reactive ion dry etching, the two-dimensional materials need to come into contact with solvents and high-energy ions, which can lead to surface contamination and boundary passivation, affecting the optical and electrical properties of the two-dimensional materials and reducing their application in devices. Vapor deposition can synthesize two-dimensional layered materials with high crystallinity. However, in the traditional vapor deposition synthesis process, the nucleation sites of the material are randomly distributed, and nucleation can occur at random locations and times on the substrate, resulting in polydispersity in the size and position of the sample and making it impossible to form regular patterned materials. This makes the arrayed fabrication of two-dimensional materials difficult, which is hard to meet the requirements of device arraying and integration.

[0005] Therefore, it is essential to develop an array fabrication method that requires no catalyst, is simple to operate, and causes no pollution or damage to the materials, in order to promote the integrated application of two-dimensional material devices. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to overcome the high difficulty of array preparation of two-dimensional materials in the prior art. For example, it is necessary to add noble metal nanoparticles as catalysts, or the nucleation site distribution of the material is disordered and random, and nucleation can occur at random positions and times on the substrate, resulting in polydispersity of sample size and position, and the inability to form regular patterned materials, which makes it difficult to meet the requirements of the final array and integration of devices. The present invention provides a method for array preparation of patterned two-dimensional sulfides / selenides.

[0007] The purpose of this invention is to provide the application of patterned two-dimensional sulfides / selenides prepared by the arraying method in the integration or miniaturization of electronic devices.

[0008] The above-mentioned objective of this invention is achieved through the following technical solution:

[0009] This invention protects a method for preparing patterned two-dimensional sulfides / selenides in an array, comprising the following steps:

[0010] S1. Perform array photolithography on the pretreated substrate to form an arrayed photolithography pattern, and deposit a film to obtain an arrayed thin film substrate with a thickness of 3-100 nm;

[0011] S2. The arrayed thin film substrate obtained in step S1 is subjected to a gas-phase growth process with a sulfur source or a selenium source under the protection of an inert gas, with a heating rate of 2 to 12 °C / min, and the temperature is raised to 400 to 1000 °C to carry out a sulfurization or selenization reaction, so as to obtain an arrayed two-dimensional sulfide or selenide.

[0012] In step S2, the sulfur or selenium source is placed at both ends of the arrayed thin film substrate to promote a full sulfidation or selenization reaction during the vapor-phase growth process, achieving high-quality sulfidation or selenization growth. The inert gas flow rate is 40–120 sccm. Excessive flow rate can lead to the removal of transition metal atoms during vapor-phase growth, preventing subsequent in-situ growth from inducing the formation of two-dimensional materials and hindering array formation, which is detrimental to the later miniaturization and integrated device fabrication. However, before this, the inert gas should be introduced at a flow rate of 150–250 sccm to ensure complete air removal.

[0013] Preferably, in step S2, the inert gas includes nitrogen, helium, argon, or neon.

[0014] Preferably, in step S1, the thin film is a transition metal thin film, a transition metal sulfide thin film, a transition metal selenide thin film, or a transition metal oxide thin film.

[0015] Specifically, the thin film includes tungsten sulfide thin film, tungsten selenide thin film, molybdenum thin film, molybdenum oxide thin film, molybdenum sulfide thin film, molybdenum selenide thin film, platinum thin film, platinum sulfide thin film, platinum selenide thin film, palladium thin film, palladium sulfide thin film, or palladium selenide thin film.

[0016] More preferably, the film is a tungsten sulfide film and a tungsten selenide film.

[0017] In detail, in step S2, the vapor phase growth process is carried out in a tube furnace. Specifically, the arrayed thin film substrate is placed at the center of the heating zone in the tube furnace, and the sulfur source or selenium source is not directly heated. The heat is diffused through the heating zone to raise the temperature and make it gaseous to participate in the reaction.

[0018] Furthermore, the sulfur source or selenium source is placed at a distance of 10 to 30 cm from the center of the heating zone.

[0019] Preferably, the time for the vapor phase growth treatment is 1 to 3 hours.

[0020] Further, in step S1, the pretreatment of the substrate is as follows: the substrate is ultrasonically washed with organic solvent and deionized water, dried, and then cleaned with plasma at a power of 30-60W for 0.5-2 minutes.

[0021] Furthermore, in step S1, the arrayed photolithography pattern is obtained by array photolithography using a photolithography machine, and the arrayed photolithography pattern can be patterned.

[0022] Preferably, in step S1, the shape of the arrayed photolithography pattern is an arbitrary polygon or circle.

[0023] Preferably, the substrate is any one of SiO2 / S1, Si, quartz, sapphire, and mica.

[0024] Preferably, in step S1, the coating technology includes magnetron sputtering, thermal evaporation, electron beam evaporation, or vacuum arc evaporation.

[0025] More preferably, in step S1, the coating technique is magnetron sputtering. The coating process involves sputtering a target material onto a substrate using magnetron sputtering to obtain a uniform thin film, followed by using an organic solvent to peel off the thin film from the photoresist to obtain a uniform arrayed thin film substrate.

[0026] Furthermore, the organic solvent removed by the photoresist is acetone, 1-methyl-2-pyrrolidone (NMP), or N-ethylpyrrolidone (NEP).

[0027] Furthermore, in step S1, the temperature at which the film grows into a nucleated film is room temperature.

[0028] Preferably, the sulfur source is sulfur powder, disodium trioxide, disodium disulfide, sodium sulfide, or hydrogen sulfide.

[0029] Preferably, the selenium source is selenium powder or hydrogen selenide. The selenium source can also be sodium selenide with a high melting point. When sodium selenide is used as the selenium source, the selenium source needs to be directly heated to increase the temperature at the selenium source so that it can be fully vaporized and sublimated.

[0030] Further, in step S2, the mass of the sulfur source or selenium source is 0.5 to 1 g.

[0031] This invention also protects the application of the patterned two-dimensional sulfides / selenides prepared by the arraying method in the integration or miniaturization of electronic devices.

[0032] This invention has the following beneficial effects: It provides an effective method for synthesizing arrayed two-dimensional materials by separating nucleation and growth. This method utilizes photolithography to pattern and array the material, and precisely controls the nucleation sites of the material through coating technology, providing an induction source for the subsequent growth of arrayed two-dimensional materials, thereby obtaining high-quality patterned two-dimensional material array growth. This method is not only simple to operate, but also can obtain pollution-free and damage-free arrayed two-dimensional materials, and has broad application prospects in the integration or miniaturization of electronic devices. Attached Figure Description

[0033] Figure 1 This is an optical microscope image of the patterned array W seed layer in Example 1.

[0034] Figure 2 This is a schematic diagram of vapor phase deposition preparation.

[0035] Figure 3 This is a two-dimensional WS2 optical microscope image from Example 1.

[0036] Figure 4 The image shows the two-dimensional Raman spectrum of WS2 in Example 1.

[0037] Figure 5 This is an optical microscope image of the two-dimensional WS2 array device in Example 1.

[0038] Figure 6 This is a two-dimensional WSe2 optical microscope image from Example 2.

[0039] Figure 7 The image shows the two-dimensional WSe2 Raman spectrum in Example 2.

[0040] Figure 8 The image shows the two-dimensional Raman spectrum of WS2 with poor crystallinity in Comparative Example 1.

[0041] Figure 9 This is an optical microscope image of the arrayed two-dimensional WS2 collapse growth in Comparative Example 2.

[0042] Figure 10 This is a two-dimensional optical microscope image of WS2 without arraying in Comparative Example 3.

[0043] Figure 11 This is an optical microscope image of the unevenly grown two-dimensional WSe2 in Comparative Example 4. Detailed Implementation

[0044] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, but the embodiments do not limit the present invention in any way. Unless otherwise specified, the reagents, methods and equipment used in the present invention are conventional reagents, methods and equipment in this technical field.

[0045] Unless otherwise specified, all reagents and materials used in the following examples are commercially available.

[0046] Example 1: A method for preparing patterned two-dimensional tungsten sulfide arrays

[0047] A method for preparing two-dimensional tungsten sulfide arrays includes the following steps:

[0048] S1. The S1O2 / S1 substrate is immersed in electronic grade acetone solution and sonicated for 20 min, then sonicated in electronic grade isopropanol solution for 20 min, then sonicated three times with deionized water, then dried with high-purity nitrogen, and finally cleaned with plasma at a power of 50W for 1 min before use.

[0049] S2. Using a photolithography machine, a rectangular pattern array is formed on the S1O2 / S1 substrate obtained after step S1. Then, the arrayed photolithography pattern is developed and then cleaned with plasma at a power of 60W for 0.5 minutes to remove the photoresist that has not been developed cleanly on the pattern.

[0050] S3. The substrate obtained after step S2 is subjected to magnetron sputtering to deposit a uniform tungsten film. The vacuum voltage is 3e-6 Torr, the RF power is 100W, the sputtering pressure is 3mTorr, the sputtering time is 1 minute, the seed layer thickness is 5nm, and the growth temperature is room temperature. The sputtered substrate is then subjected to resist removal treatment with electronic-grade acetone to obtain a substrate with an arrayed tungsten film, such as... Figure 1 As shown;

[0051] S4. Place the substrate with the arrayed tungsten film obtained in step S3 at the heating center of the tube furnace. Place 0.8g of sulfur powder in an alumina boat and place it at the air inlet and outlet, 25cm away from the heating center. Figure 2 As shown;

[0052] S5. First, the air in the tube furnace is removed. The inert gas flow rate is 200 sccm and maintained for 20 min to ensure that the air in the tube furnace is completely removed. Then, the tube furnace is heated. The argon gas flow rate is adjusted to 80 sccm and the temperature is increased to 650℃ at 5℃ / min. After holding at this temperature for 2 hours, the temperature is allowed to cool naturally to room temperature. Finally, high-quality arrayed two-dimensional tungsten sulfide is obtained on the S1O2 / S1 substrate.

[0053] The optical micrographs of the obtained arrayed two-dimensional tungsten sulfide were measured, and the results are as follows: Figure 3 As shown, arrayed two-dimensional tungsten sulfide was obtained using this method. The image shows that the prepared tungsten sulfide has a uniform color, indicating the preparation of a high-quality arrayed sample. This is because a seed layer—a tungsten film—was pre-deposited at specific sites, which is beneficial for subsequent arrayed vapor deposition growth.

[0054] The Raman spectra of the obtained arrayed two-dimensional tungsten sulfide were measured, and the results are as follows: Figure 4 As shown, Figure 4 The characteristic Raman peaks can be seen at 354.5 cm. -1 and 420.4cm -1 , respectively corresponding to the E of two-dimensional tungsten sulfide 12g and A 1g This confirmed that the vapor-phase sulfidation material was two-dimensional tungsten sulfide. The obtained arrayed two-dimensional tungsten sulfide was further fabricated into corresponding array devices using the L1ft-Off process (i.e., peel-off process) in integrated circuit manufacturing. The results are as follows: Figure 5 As shown.

[0055] Example 2: A method for preparing patterned two-dimensional tungsten selenide arrays

[0056] A method for preparing two-dimensional tungsten selenide arrays includes the following steps:

[0057] S1. The S1O2 / S1 substrate is immersed in electronic grade acetone solution and sonicated for 20 min, then sonicated in electronic grade isopropanol solution for 20 min, then sonicated three times with deionized water, then dried with high-purity nitrogen, and finally cleaned with plasma at a power of 30W for 2 min before use.

[0058] S2. Using a photolithography machine, perform triangular pattern arraying photolithography on the S1O2 / S1 substrate obtained after step S1, then develop to obtain the arrayed photolithography pattern, and then use plasma cleaning at a power of 50W for 1 minute to remove the photoresist that has not been developed cleanly on the pattern.

[0059] S3. The substrate obtained after step S2 is subjected to magnetron sputtering to deposit a uniform tungsten film. The vacuum voltage is 3e-6 Torr, the radio frequency power is 100W, the sputtering pressure is 3mTorr, the sputtering time is 1m1n, the thickness of the sputtered seed layer is 5nm, and the growth temperature is room temperature. Then the sputtered substrate is subjected to electronic grade acetone to remove the adhesive, resulting in a substrate with an arrayed tungsten film.

[0060] S4. Place the substrate with arrayed tungsten film obtained in step S3 in the heating center of the tube furnace, and place 1g of selenium powder in the corundum boat and place it at the air inlet and outlet, 12cm away from the heating center.

[0061] S5. First, the air in the tube furnace is removed. The argon inert gas flow rate is 200 sccm and maintained for 20 min to ensure that the air in the tube furnace is completely removed. Then, the tube furnace is heated. The argon gas flow rate is adjusted to 50 sccm and the temperature is increased to 450℃ at 10℃ / min. After holding at this temperature for 1 hour, the temperature is allowed to cool naturally to room temperature. Finally, high-quality arrayed two-dimensional tungsten selenide is obtained on the S1O2 / S1 substrate.

[0062] The optical micrographs of the obtained arrayed two-dimensional tungsten selenide were measured, and the results are as follows: Figure 6As shown, arrayed two-dimensional tungsten selenide was obtained using this method. The image shows that the prepared tungsten selenide has a uniform color, indicating the preparation of a high-quality arrayed sample. This is because a seed layer-tungsten film has been deposited at specific sites, which induces growth and facilitates subsequent arrayed vapor deposition growth. Additionally, it should be noted that incomplete removal of the photoresist stripping film... Figure 6 Some thin film remaining outside the pattern ( Figure 6 The third pattern in the last row does not affect the subsequent sulfidation or selenization of the thin film after the adhesive removal process. The yellowish triangle in the lower right corner is because the film is superimposed on the patterned film in reverse. Due to the increased thickness, the tungsten selenide sample appears to have a different color, but none of these factors affect the fact that it is a high-quality arrayed sample.

[0063] The Raman spectra of the obtained samples were measured, and the results are as follows: Figure 7 As shown, Figure 7 The characteristic Raman peaks can be seen at 250.2 cm. -1 and 262.4cm -1 , respectively corresponding to the E of two-dimensional tungsten selenide 1 2g and A 1g This confirms that the gas-phase selenized material is two-dimensional tungsten selenide.

[0064] Example 3: A method for preparing patterned two-dimensional tungsten sulfide arrays

[0065] A method for preparing two-dimensional tungsten sulfide arrays includes the following steps:

[0066] S1. The S1O2 / S1 substrate is immersed in electronic grade acetone solution and sonicated for 20 min, then sonicated in electronic grade isopropanol solution for 20 min, then sonicated three times with deionized water, then dried with high-purity nitrogen, and finally sonicated with plasma at a power of 60W for 0.5 min before use.

[0067] S2. Using a photolithography machine, a rectangular pattern array is formed on the S1O2 / S1 substrate obtained after step S1. Then, the arrayed photolithography pattern is developed and then cleaned with plasma at a power of 40W for 1.5 minutes to remove the photoresist that has not been developed cleanly on the pattern.

[0068] S3. The substrate obtained after step S2 is subjected to magnetron sputtering to deposit a uniform tungsten sulfide film. The vacuum voltage is 3e-6 Torr, the radio frequency power is 60W, the sputtering pressure is 3mTorr, the sputtering time is 10m1n, the thickness of the sputtered seed layer is 20nm, and the growth temperature is room temperature. Then the sputtered substrate is subjected to electronic grade acetone to remove the adhesive, resulting in a substrate with an arrayed tungsten sulfide film.

[0069] S4. Place the substrate with arrayed tungsten film obtained in step S3 in the heating center of the tube furnace, and place 0.5g of sulfur powder in the corundum boat at the air inlet and outlet, 30cm away from the heating center.

[0070] S5. First, the air in the tube furnace is removed. The inert gas flow rate is 180 sccm and maintained for 25 min to ensure that the air in the tube furnace is completely removed. Then, the tube furnace is heated. The argon gas flow rate is adjusted to 40 sccm and the temperature is increased to 800℃ at 3℃ / min. After holding at this temperature for 3 hours, the temperature is allowed to cool naturally to room temperature. Finally, high-quality arrayed two-dimensional tungsten sulfide is obtained on the S1O2 / S1 substrate.

[0071] The Raman spectra of the obtained samples were consistent with those in Example 1, confirming that the vapor-phase sulfidation material was two-dimensional tungsten sulfide. This demonstrated that two-dimensional tungsten sulfide array sputtering could be achieved at room temperature using photolithography, and then the amorphous tungsten sulfide deposited at room temperature could be recrystallized using a high-temperature vapor-phase growth method to achieve high-quality two-dimensional tungsten sulfide array growth.

[0072] Comparative Example 1: A method for preparing patterned two-dimensional tungsten sulfide by arraying

[0073] A method for fabricating patterned two-dimensional tungsten sulfide arrays includes the following steps:

[0074] S1. The S1O2 / S1 substrate is immersed in electronic grade acetone solution and sonicated for 20 min, then sonicated in electronic grade isopropanol solution for 20 min, then sonicated three times with deionized water, then dried with high-purity nitrogen, and finally cleaned with plasma at a power of 50W for 1 min before use.

[0075] S2. Using a photolithography machine, a rectangular pattern array is formed on the S1O2 / S1 substrate obtained after step S1. Then, the arrayed photolithography pattern is developed and then cleaned with plasma at a power of 60W for 0.5 minutes to remove the photoresist that has not been developed cleanly on the pattern.

[0076] S3. The substrate obtained after step S2 is subjected to magnetron sputtering to deposit a uniform tungsten film. The vacuum voltage is 3e-6 Torr, the radio frequency power is 100W, the sputtering pressure is 3mTorr, the sputtering time is 1m1n, the sputtering thickness is 5nm, and the growth temperature is room temperature. Then the sputtered substrate is subjected to electronic grade acetone to remove the adhesive, resulting in a substrate with an arrayed tungsten film.

[0077] S4. Place the substrate with arrayed tungsten film obtained in step S3 in the heating center of the tube furnace, and place 0.8g of sulfur powder in the corundum boat and place it at the air inlet and outlet, 25cm away from the heating center.

[0078] S5. First, remove the air from the tube furnace. The inert gas flow rate is 200 sccm and maintained for 20 min to ensure that the air in the tube furnace is completely removed. Then, start heating the tube furnace. Adjust the argon gas flow rate to 80 sccm and heat to 650℃ at 15℃ / min. Hold the temperature for 2 hours and let it cool naturally to room temperature to obtain arrayed two-dimensional tungsten sulfide.

[0079] The main difference between Comparative Example 1 and Example 1 is that the gas phase heating rate is 15°C / min.

[0080] The Raman spectrum of the arrayed two-dimensional tungsten sulfide obtained by measurement is as follows: Figure 8 As shown, the peaks are Raman peaks corresponding to tungsten sulfide, but the peak intensity is low and the peak value is unclear and sharp. This indicates that the rapid heating promotes poor crystallinity of tungsten sulfide grown in the gas phase. This is because the rapid heating prevents the tungsten nucleation sites from growing sufficiently, thus affecting the quality of gas phase sulfidation.

[0081] Comparative Example 2: An array preparation method for patterned two-dimensional tungsten sulfide

[0082] A method for fabricating patterned two-dimensional tungsten sulfide arrays includes the following steps:

[0083] S1. The S1O2 / S1 substrate is immersed in electronic grade acetone solution and sonicated for 20 min, then sonicated in electronic grade isopropanol solution for 20 min, then sonicated three times with deionized water, then dried with high-purity nitrogen, and finally cleaned with plasma at a power of 50W for 1 min before use.

[0084] S2. Using a photolithography machine, a rectangular pattern array is formed on the S1O2 / S1 substrate obtained after step S1. Then, the arrayed photolithography pattern is developed and then cleaned with plasma at a power of 60W for 0.5 minutes to remove the photoresist that has not been developed cleanly on the pattern.

[0085] S3. The substrate obtained after step S2 is subjected to magnetron sputtering to deposit a uniform tungsten film. The vacuum voltage is 3e-6 Torr, the radio frequency power is 80W, the sputtering pressure is 3mTorr, the sputtering time is 0.5m1n, the sputtering thickness is 1nm, and the growth temperature is room temperature. Then the sputtered substrate is subjected to resist removal treatment with electronic grade acetone.

[0086] S4. Place the substrate with arrayed tungsten film obtained in step S3 in the heating center of the tube furnace, and place 0.8g of sulfur powder in the corundum boat and place it at the air inlet and outlet, 25cm away from the heating center.

[0087] S5. First, remove the air from the tube furnace. The inert gas flow rate is 200 sccm and maintained for 20 min to ensure that the air in the tube furnace is completely removed. Then, start heating the tube furnace. Adjust the argon gas flow rate to 80 sccm and heat to 650℃ at 5℃ / min. Hold the temperature for 2 hours and let it cool naturally to room temperature to obtain arrayed two-dimensional tungsten sulfide.

[0088] The main difference between Comparative Example 2 and Example 1 is that the tungsten seed layer sputtering thickness is 1 nm.

[0089] The Raman spectra of the arrayed two-dimensional tungsten sulfide obtained by measurement show the Raman peaks corresponding to tungsten sulfide, but the tungsten seed layer on each pattern collapses into individual nucleation sites (e.g., Figure 9 As shown in the figure, the vapor phase grows into multiple two-dimensional tungsten sulfide sheets, which are arranged irregularly and cannot be arrayed, which is not conducive to the subsequent miniaturization and integration of devices.

[0090] Comparative Example 3: An array preparation method for patterned two-dimensional tungsten sulfide

[0091] A method for preparing patterned two-dimensional tungsten sulfide arrays includes the following steps:

[0092] S1. The S1O2 / S1 substrate is immersed in electronic grade acetone solution and sonicated for 20 min, then sonicated in electronic grade isopropanol solution for 20 min, then sonicated three times with deionized water, then dried with high-purity nitrogen, and finally cleaned with plasma at a power of 50W for 1 min before use.

[0093] S2. Using a photolithography machine, a rectangular pattern array is formed on the S1O2 / S1 substrate obtained after step S1. Then, the arrayed photolithography pattern is developed and then cleaned with plasma at a power of 60W for 0.5 minutes to remove the photoresist that has not been developed cleanly on the pattern.

[0094] S3. The substrate obtained after step S2 is subjected to magnetron sputtering to deposit a uniform tungsten film. The vacuum voltage is 3e-6 Torr, the radio frequency power is 100W, the sputtering pressure is 3mTorr, the sputtering time is 1m1n, the thickness of the sputtered seed layer is 5nm, and the growth temperature is room temperature. Then the sputtered substrate is subjected to electronic grade acetone to remove the adhesive, resulting in a substrate with an arrayed tungsten film.

[0095] S4. Place the substrate with arrayed tungsten film obtained in step S3 in the heating center of the tube furnace, and place 0.8g of sulfur powder in the corundum boat and place it at the air inlet and outlet, 25cm away from the heating center.

[0096] S5. First, the air in the tube furnace is removed. The inert gas flow rate is 200 sccm and maintained for 20 min to ensure that the air in the tube furnace is completely removed. Then, the tube furnace is heated. The argon gas flow rate is adjusted to 150 sccm and the temperature is increased to 650℃ at 5℃ / min. After holding at this temperature for 2 hours, the temperature is allowed to cool naturally to room temperature. Finally, arrayed two-dimensional tungsten sulfide is obtained on the S1O2 / S1 substrate.

[0097] The main difference between Comparative Example 3 and Example 1 is that the gas flow rate during the gas phase growth process is too high, exceeding 120 sccm.

[0098] The Raman spectra of the arrayed two-dimensional tungsten sulfide obtained by measurement show the Raman peaks corresponding to tungsten sulfide, but most two-dimensional tungsten sulfides are not on the array (e.g. Figure 10 As shown in the figure, this is because if the gas flow rate is too high, tungsten atoms are easily carried away during the gas phase growth process, which causes the subsequent in-situ growth to lack the induction of tungsten atoms, and thus cannot grow into two-dimensional tungsten sulfide, cannot be arrayed, and is not conducive to the later miniaturization and integrated device construction.

[0099] Comparative Example 4: An array preparation method for patterned two-dimensional tungsten selenide

[0100] A method for fabricating patterned two-dimensional tungsten selenide arrays includes the following steps:

[0101] S1. The S1O2 / S1 substrate is immersed in electronic grade acetone solution and sonicated for 20 min, then sonicated in electronic grade isopropanol solution for 20 min, then sonicated three times with deionized water, then dried with high-purity nitrogen, and finally cleaned with plasma at a power of 30W for 2 min before use.

[0102] S2. Using a photolithography machine, perform triangular pattern arraying photolithography on the S1O2 / S1 substrate obtained after step S1, then develop to obtain the arrayed photolithography pattern, and then clean it with plasma at a power of 50W for 1 minute to remove the photoresist that has not been developed cleanly on the pattern.

[0103] S3. The substrate obtained after step S2 is subjected to magnetron sputtering to deposit a uniform tungsten film. The vacuum voltage is 3e-6 Torr, the radio frequency power is 100W, the sputtering pressure is 3mTorr, the sputtering time is 1m1n, the thickness of the sputtered seed layer is 5nm, and the growth temperature is room temperature. Then the sputtered substrate is subjected to resist removal treatment with electronic grade acetone.

[0104] S4. Place the substrate with arrayed tungsten film obtained in step S3 in the heating center of the tube furnace, and place 1g of selenium powder in the corundum boat at the air inlet, 12cm away from the heating center.

[0105] S5. First, the air in the tube furnace is removed. The argon inert gas flow rate is 200 sccm and maintained for 20 min to ensure that the air in the tube furnace is completely removed. Then, the tube furnace is heated. The argon gas flow rate is adjusted to 80 sccm and the temperature is increased to 450℃ at 10℃ / min. The temperature is held for 1 hour and then allowed to cool naturally to room temperature. Finally, arrayed two-dimensional tungsten selenide is obtained on the S1O2 / S1 substrate.

[0106] The difference between Comparative Example 3 and Example 2: Selenium powder was only placed at the air inlet, while other raw materials and steps were the same as in Example 2.

[0107] The obtained optical micrographs of the arrayed two-dimensional tungsten sulfide showed uneven color distribution, such as... Figure 11 As shown, this demonstrates the inhomogeneity and low crystallinity of the prepared arrayed two-dimensional tungsten sulfide.

[0108] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present invention shall be considered equivalent substitutions and shall be included within the protection scope of the present invention.

Claims

1. A method for the arrayed fabrication of patterned two-dimensional sulfide / selenide, characterized by, The method comprises the following steps: S1. Forming an arrayed lithography layout on a pretreated substrate by array lithography, and coating a film to obtain an arrayed film substrate with a thickness of 3-100 nm; S2. Performing a vapor phase growth treatment on the arrayed film substrate obtained in step S1 and a sulfur source or a selenium source under the protection of an inert gas, setting a temperature rising rate of 2-12 ℃ / min, and rising the temperature to 400-1000 ℃ to perform a sulfurization or selenization reaction, to obtain an arrayed two-dimensional sulfide or selenide; In step S2, the sulfur source or the selenium source is placed at both ends of the arrayed film substrate; and the flow rate of the inert gas is 40-120 sccm; In step S1, the film is a transition metal film, a transition metal sulfide film, a transition metal selenide film, or a transition metal oxide film; In step S2, the vapor phase growth treatment is performed in a tube furnace, specifically, the arrayed film substrate is placed at the center of a heating zone in the tube furnace; and the sulfur source or the selenium source is not directly heated; The distance between the sulfur source or the selenium source and the center of the heating zone is 10-30 cm.

2. The arrayed manufacturing method of claim 1, wherein, The film comprises a tungsten film, a tungsten oxide film, a tungsten sulfide film, a tungsten selenide film, a molybdenum film, a molybdenum oxide film, a molybdenum sulfide film, a molybdenum selenide film, a platinum film, a platinum sulfide film, a platinum selenide film, a palladium film, a palladium sulfide film, or a palladium selenide film.

3. The arrayed manufacturing method of claim 1, wherein, The sulfur source is sulfur powder, disodium trisulfide, disodium disulfide, sodium sulfide, or hydrogen sulfide.

4. The arrayed manufacturing method of claim 1, wherein, The selenium source is selenium powder or hydrogen selenide.

5. The arrayed manufacturing method of claim 1, wherein, In step S1, the shape of the arrayed lithography layout is an arbitrary polygon or a circle.

6. The arrayed manufacturing method of claim 1, wherein, The substrate is any one of SiO2 / Si, Si, quartz, sapphire, and mica.

7. The arrayed manufacturing method of claim 1, wherein, The time of the vapor phase growth treatment is 1-3 h.

8. The arrayed manufacturing method of claim 1, wherein, In step S1, the coating technology comprises a magnetron sputtering technology, a thermal evaporation technology, an electron beam evaporation technology, or a vacuum arc evaporation technology.

9. The application of the patterned two-dimensional sulfide / selenide prepared by the arrayed preparation method of any one of claims 1-8 in the integration or miniaturization of electronic devices.

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