Patterned boron nitride nanotubes, methods of making and using same
By combining boron-nitrogen single-source precursors and catalyst patterning, the problems of directional gas transport and corrosive gases in the CVD method were solved, enabling localized patterned growth of BNNTs on silicon substrates and improving process compatibility and purity.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- NANJING UNIV
- Filing Date
- 2026-05-18
- Publication Date
- 2026-06-19
AI Technical Summary
In existing CVD methods for preparing boron nitride nanotubes, the directional transport of gas flow makes it difficult to achieve controllable growth on silicon substrates, and the high corrosiveness of nitrogen-containing gases affects device compatibility and purity.
By employing a combination of boron-nitrogen single-source precursors and catalyst patterning, localized patterned growth of BNNTs on a substrate is achieved through localized reactant supply and restricted gas flow orientation.
This method enables localized patterned growth of BNNTs on silicon substrates, reduces the impact of airflow orientation, avoids the use of corrosive gases, and improves process compatibility and purity.
Smart Images
Figure CN122233337A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of boron nitride nanotube technology, specifically relating to a patterned boron nitride nanotube, its preparation method, and its application. Background Technology
[0002] Boron nitride nanotubes (BNNTs) are one-dimensional hollow tubular materials with a structure similar to carbon nanotubes, consisting of boron and nitrogen atoms separated by sp... 2 The alternating hybrid arrangement forms a hexagonal lattice structure. Due to the strong polar covalent characteristics of BN bonds, BNNT not only possesses excellent mechanical properties and high thermal conductivity, with a theoretical elastic modulus exceeding 1 TPa, but also exhibits typical electrical insulation properties with a band gap of approximately 5.5 eV. Furthermore, BNNT also demonstrates good chemical stability, high-temperature resistance, and oxidation resistance, making it a promising candidate for applications in thermal management materials, insulating layers for microelectronic devices, high-temperature structural materials, and functional coatings. As microelectronic devices evolve towards higher integration and miniaturization, the problem of localized heat accumulation is becoming increasingly prominent, necessitating the development of high thermal conductivity insulating materials capable of spatially controllable integration on silicon substrates. BNNT has thus become a crucial candidate material.
[0003] Currently, the main methods for preparing boron nitride nanotubes (BNNTs) include laser ablation, thermal plasma, arc discharge, and chemical vapor deposition (CVD). While laser ablation, thermal plasma, and arc discharge methods can yield high-quality BNNTs, they typically require ultra-high temperature environments above 2000℃, involve complex equipment, and struggle to achieve ordered or localized deposition of nanotubes on substrates, thus failing to meet device integration requirements. In contrast, CVD methods, due to their relatively simple process and better controllability, have become the main technical route for achieving BNNT growth on substrates. Existing CVD methods typically use boron-containing precursors and nitrogen-containing gases as reactants to achieve BNNT growth at temperatures above 1100℃, and achieve a certain degree of regioselectivity through pre-deposited catalysts or boron sources.
[0004] In existing chemical vapor deposition (CVD) processes for preparing boron nitride nanotubes (BNNTs), boron-containing precursors and nitrogen-containing gases are typically used as reactants. Under high-temperature conditions, boron and nitrogen-containing active species are generated, and BNNTs are grown under the action of a catalyst. During this process, the nitrogen-containing gas flows axially within the furnace tube, exerting a significant directional transport effect on the gaseous reactants. This causes the generated BNNTs to easily migrate with the gas flow and deposit in downstream regions, making it difficult to achieve controllable growth at specific locations on the substrate. Simultaneously, the ammonia gas in the nitrogen-containing gas is highly corrosive, easily damaging the silicon substrate and the constructed device structure, reducing process compatibility. Furthermore, unreacted boron sources in traditional methods tend to remain on the substrate surface, introducing impurities and affecting subsequent device fabrication and performance stability. Therefore, gas flow transport, the involvement of corrosive gases, and interface contamination collectively limit the controllable integration of BNNTs on silicon substrates. Summary of the Invention
[0005] The purpose of this invention is to provide a patterned boron nitride nanotube, its preparation method and application. The preparation method does not require corrosive ammonia gas, can reduce the influence of airflow orientation and realize the localized patterned growth of BNNTs on silicon substrates.
[0006] To achieve the above objectives, a specific embodiment of the present invention provides the following technical solution:
[0007] A method for preparing patterned boron nitride nanotubes, the method comprising the following steps:
[0008] A substrate is provided, and a catalyst is deposited on the substrate surface to form a patterned catalyst region;
[0009] Take a boron-nitrogen precursor and place it in a container, then place the substrate above the container with the catalyst region facing the container;
[0010] Heating under an inert atmosphere causes the boron-nitrogen precursor to decompose and generate a gaseous intermediate, which then reacts with the catalyst in the catalyst region to generate boron nitride nanotubes.
[0011] In one or more embodiments of the present invention, the boron-nitrogen precursor is at least one selected from ammonia borane, polyborazine, borazine, and decaborane.
[0012] In one or more embodiments of the present invention, the catalyst is at least one selected from iron tetroxide, aluminum oxide, silicon oxide, lithium oxide, and magnesium oxide.
[0013] In one or more embodiments of the present invention, the catalyst and solvent are mixed to form a dispersion, the dispersion is coated on the surface of a substrate, and after drying, a patterned catalyst region is formed.
[0014] The solvent is at least one of ethanol, deionized water, acetone, and ethyl acetate;
[0015] The concentration of the dispersion is 0.1 mg / mL to 10 mg / mL.
[0016] In one or more embodiments of the present invention, the reaction temperature is 1000℃-1400℃ and the reaction time is 10min-600min.
[0017] In one or more embodiments of the present invention, the heating rate in the heating step is 1°C / min to 30°C / min.
[0018] In one or more embodiments of the present invention, the inert gas is at least one of nitrogen and argon, and the gas flow rate is less than or equal to 200 sccm.
[0019] In one or more embodiments of the present invention, the distance between the substrate and the container is 5mm-20mm.
[0020] Another specific embodiment of the present invention provides the following technical solution:
[0021] A patterned boron nitride nanotube was prepared by the above-described method.
[0022] Another specific embodiment of the present invention provides the following technical solution:
[0023] Application of patterned boron nitride nanotubes in thermal management of microelectronic devices, electronic packaging, functional surface engineering, high-temperature protective materials, and advanced electronic devices.
[0024] Compared with the prior art, the present invention has the following beneficial effects:
[0025] 1. This invention combines a single-source precursor containing both nitrogen and boron with catalyst patterning. Without the need to introduce gaseous boron-nitrogen sources or carrier gas, localized patterned growth of BNNTs on a substrate is achieved by locally supplying reactants and restricting the direction of gas flow.
[0026] 2. The patterned BNNTs structure prepared by this invention can be applied to the thermal management of microelectronic devices, achieving directional heat dissipation by constructing local heat conduction channels on the surface of heat sources such as chips; it can also be applied in the field of electronic packaging as a thermal interface material with both thermal conductivity and electrical insulation; in addition, it also has potential application value in functional surface engineering, high-temperature protection materials and advanced electronic devices. Attached Figure Description
[0027] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0028] Figure 1 The images shown are SEM images and energy dispersive spectroscopy images of the patterned boron nitride nanotubes in Example 1 of this invention.
[0029] Figure 2 Optical photographs, infrared thermal images, and surface temperature-time curves of BNNTs@Si and Si wafers in Example 1 of this invention are shown.
[0030] Figure 3 Comparison of SEM images of patterned boron nitride nanotubes in Examples 1-4 of this invention. Detailed Implementation
[0031] To enable those skilled in the art to better understand the technical solutions in this disclosure, the technical solutions in the embodiments of this disclosure are described clearly and completely below. Obviously, the described embodiments are only some embodiments of this disclosure, and not all embodiments. Based on the embodiments in this disclosure, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of this disclosure.
[0032] A specific embodiment of the present invention provides a method for preparing patterned boron nitride nanotubes, which specifically includes the following steps:
[0033] Step 1, catalyst pattern preparation.
[0034] Specifically, the substrate is selected from silicon-based substrates, sapphire substrates, or silicon carbide substrates, and the catalyst is selected from oxides, specifically at least one of iron oxide, aluminum oxide, silicon oxide, lithium oxide, and magnesium oxide, with magnesium oxide being preferred. The catalyst is dispersed in a solvent to form a uniform dispersion, and the solvent is selected from at least one of ethanol, deionized water, acetone, and ethyl acetate, with a dispersion concentration of 0.1 mg / mL-10 mg / mL, preferably 2 mg / mL-5 mg / mL.
[0035] The dispersion is coated onto the substrate surface using methods such as masking or direct writing (e.g., using a needle, syringe, or soft brush). The coating thickness can be set according to actual needs, such as 1μm-100μm, specifically 1μm, 10μm, 30μm, 40μm, 60μm, or 90μm. After natural drying, a catalyst region with a preset pattern is formed on the substrate surface. The size of the resulting catalyst pattern ranges from millimeters to micrometers.
[0036] Step 2, Precursor Arrangement.
[0037] Specifically, a boron-nitrogen precursor is used, which is at least one selected from ammonia borane, polyborazine, borazine, and decaborane, with ammonia borane being preferred. The boron-nitrogen precursor is placed in a container, such as a crucible, and the substrate is placed upside down above the container so that the substrate is in the transport path of the decomposition products of the boron-nitrogen precursor, i.e., the catalyst region faces the container. The distance between the substrate and the container is 5 mm to 20 mm, specifically 5 mm, 10 mm, 15 mm, or 20 mm.
[0038] Regarding dosage, 250mg of catalyst can be used in conjunction with 10mg-1000mg of boron-nitrogen precursor, preferably 100mg-200mg of boron-nitrogen precursor.
[0039] Step 3, CVD growth.
[0040] Specifically, following the placement method in step 2, the substrate and container are placed in the heating zone of the tube furnace. During the heating phase, an inert gas is introduced. The inert gas is a gas that does not react with the boron-nitrogen precursor, such as nitrogen or argon, preferably argon. The gas flow rate is less than or equal to 200 sccm, preferably 20 sccm. The furnace temperature is raised to the reaction temperature of 1000℃-1400℃, preferably 1200℃-1250℃, at a heating rate of 1℃ / min-30℃ / min, preferably 20℃ / min.
[0041] After the furnace temperature reaches the reaction temperature, it is maintained at a constant temperature for 10-600 minutes, preferably 120 minutes. At the reaction temperature, the boron-nitrogen precursor decomposes to generate boron- or nitrogen-containing gaseous intermediates. These gaseous intermediates diffuse within the local space and preferentially accumulate in the catalyst region, reacting under the action of the catalyst to generate BNNTs, thereby achieving localized growth in the catalyst region. In this process, since boron-nitrogen precursor powder is used as a single-source precursor, its decomposition can simultaneously provide boron and nitrogen sources within the local space, eliminating the need for additional gaseous boron-nitrogen sources or carrier gas, thus effectively reducing the directional transport effect of the gas flow in the horizontal direction. Simultaneously, the catalyst is pre-fixed on the substrate surface, allowing BNNTs to preferentially grow in the catalyst distribution area and restricting their deposition in non-target areas, thereby achieving the patterned growth of millimeter-scale BNNTs on the silicon substrate.
[0042] Step 4: After the reaction is complete, cool to room temperature under inert gas protection and remove the sample.
[0043] Another specific embodiment of the present invention provides patterned boron nitride nanotubes, which are prepared by the above-described preparation method.
[0044] Another specific embodiment of the present invention provides the application of patterned boron nitride nanotubes in thermal management of microelectronic devices, electronic packaging, functional surface engineering, high-temperature protective materials, and advanced electronic devices.
[0045] The present invention will be further described in detail below with reference to specific embodiments.
[0046] Example 1
[0047] The method for preparing patterned boron nitride nanotubes in this embodiment is as follows:
[0048] (1) Catalyst pattern preparation
[0049] 250 mg of magnesium oxide (MgO) powder was dispersed in 50 mL of anhydrous ethanol to prepare a catalyst dispersion with a concentration of 5 mg / mL. The dispersion was then sonicated for 30 min to obtain a uniform suspension. Subsequently, a mask was used to cover the surface of a clean 20 mm × 20 mm silicon wafer, and the catalyst dispersion was deposited onto the open areas of the mask by spraying to a thickness of 1 μm. After natural drying, the mask was removed to obtain catalyst regions with a regular pattern.
[0050] (2) Precursor arrangement
[0051] Weigh 200 mg of ammonia borane (NH3BH3) powder and place it at the bottom of the crucible; place the patterned silicon substrate upside down about 5 mm above the crucible so that it is located in the rising transport path of the precursor pyrolysis products.
[0052] (3) CVD growth process
[0053] The above apparatus was placed in the isothermal zone of a tube furnace, and the reaction was carried out under the protection of high-purity argon (Ar). The argon flow rate was 20 sccm, and the temperature was increased to 1250℃ at a rate of 20℃ / min, and held at this temperature for 120 min. After the reaction was completed, the heating system was turned off and the sample was allowed to cool naturally to room temperature under an argon atmosphere to obtain a sample containing patterned boron nitride nanotubes, denoted as BNNTs@Si.
[0054] The scanning electron microscope images and energy dispersive spectroscopy characterization of the obtained samples are as follows: Figure 1 As shown, from Figure 1 (a) The SEM image shows BNNTs with clearly patterned boundary regions in the sample, combined with Figure 1 (b) Distribution of boron and Figure 1 The nitrogen distribution in (c) indicates that the present invention has successfully generated patterned BNNTs on the substrate surface.
[0055] Thermal conductivity tests were conducted on BNNTs@Si and Si wafers. Specifically, an infrared thermal imager was used to monitor and record the surface temperature distribution of the samples in real time during the heating process. Figure 2 (a) shows the optical photograph and infrared thermal image. Figure 2 (b) shows the surface temperature of BNNTs@Si and Si wafers over time. Figure 2 As can be seen, patterned boron nitride nanotubes possess excellent thermal conductivity.
[0056] Example 2
[0057] The preparation method of patterned boron nitride nanotubes in this embodiment is the same as that in Example 1. The difference is that in step (3) CVD growth, the temperature is increased to 1200℃ at a rate of 20℃ / min.
[0058] The SEM image of the sample obtained in this embodiment is as follows: Figure 3 As shown in (a).
[0059] Example 3
[0060] The preparation method of patterned boron nitride nanotubes in this embodiment is the same as that in Example 1. The difference is that in step (3) during CVD growth, the temperature is increased to 1300℃ at a rate of 20℃ / min.
[0061] The SEM image of the sample obtained in this embodiment is as follows: Figure 3 As shown in (c).
[0062] Example 4
[0063] The preparation method of patterned boron nitride nanotubes in this embodiment is the same as that in Example 1. The difference is that in step (3) during CVD growth, the temperature is increased to 1350℃ at a rate of 20℃ / min.
[0064] The SEM image of the sample obtained in this embodiment is as follows: Figure 3 As shown in (d).
[0065] Compare the scanning electron microscope images of the samples obtained in Examples 1-4, as follows: Figure 3 As shown, boron nitride nanotubes can grow normally on the substrate at different reaction temperatures.
[0066] In addition, by changing the amount of ammonia borane, such as using 100 mg ammonia borane, 150 mg ammonia borane, and 300 mg ammonia borane, the present invention shows that boron nitride nanotubes can also grow normally on the substrate.
[0067] In summary, this invention prepares patterned BNNTs in a tube furnace using chemical vapor deposition technology, eliminating the need for corrosive ammonia gas, reducing the influence of gas flow orientation, and achieving localized patterned growth of BNNTs on a substrate.
[0068] It will be apparent to those skilled in the art that this disclosure is not limited to the details of the exemplary embodiments described above, and that this disclosure can be implemented in other specific forms without departing from the spirit or essential characteristics of this disclosure. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of this disclosure is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within this disclosure.
[0069] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.
Claims
1. A method for preparing patterned boron nitride nanotubes, characterized in that, The preparation method includes the following steps: A substrate is provided, and a catalyst is deposited on the substrate surface to form a patterned catalyst region; Take a boron-nitrogen precursor and place it in a container, then place the substrate above the container with the catalyst region facing the container; Heating under an inert atmosphere causes the boron-nitrogen precursor to decompose and generate a gaseous intermediate, which then reacts with the catalyst in the catalyst region to generate boron nitride nanotubes.
2. The patterned boron nitride nanotubes according to claim 1, characterized in that, The boron-nitrogen precursor is at least one of ammonia borane, polyborazine, borazine, and decaborane.
3. The patterned boron nitride nanotubes according to claim 1, characterized in that, The catalyst is at least one of iron(II,III) oxide, aluminum oxide, silicon oxide, lithium oxide, and magnesium oxide.
4. The patterned boron nitride nanotubes according to claim 1, characterized in that, The catalyst and solvent are mixed to form a dispersion, which is then coated onto the surface of a substrate and dried to form a patterned catalyst region. The solvent is at least one of ethanol, deionized water, acetone, and ethyl acetate; The concentration of the dispersion is 0.1 mg / mL to 10 mg / mL.
5. The patterned boron nitride nanotubes according to claim 1, characterized in that, The reaction temperature is 1000℃-1400℃, and the reaction time is 10min-600min.
6. The patterned boron nitride nanotubes according to claim 5, characterized in that, The heating rate in the heating step is 1℃ / min-30℃ / min.
7. The patterned boron nitride nanotubes according to claim 1, characterized in that, The inert gas is at least one of nitrogen and argon, and the gas flow rate is less than or equal to 200 sccm.
8. The patterned boron nitride nanotubes according to claim 1, characterized in that, The distance between the substrate and the container is 5mm-20mm.
9. A patterned boron nitride nanotube, characterized in that, It is prepared by the preparation method according to any one of claims 1-8.
10. The application of the patterned boron nitride nanotubes of claim 9 in thermal management of microelectronic devices, electronic packaging, functional surface engineering, high-temperature protective materials, and advanced electronic devices.