Method for preparing boron nitride film and boron nitride film

Abstract

The present invention provides a method for preparing a boron nitride film and a boron nitride film, the method mainly comprising providing a precursor comprising boron atoms and nitrogen atoms to an energy control mechanism, forming an excited state of the precursor in the energy control mechanism, and finally forming a material layer comprising boron nitride on a substrate. The method is characterized in that an energy control mechanism is used, and the energy control mechanism comprises a first electromagnetic wave source emitting a specific wavelength range. The method has the advantages that the operation can be performed at a lower temperature, the risk of thermal damage to the substrate is reduced, and the energy consumption is also reduced. In addition, the method also comprises some optional steps, and the steps can further enhance the formation of the boron nitride film.

Description

Technical Field

[0001] The present invention relates to a film deposition method and a film, in particular to a method for preparing a boron nitride film and a boron nitride film. The present invention belongs to the field of films, in particular to a method for preparing a boron nitride film. Background Art

[0002] Boron nitride thin films have attracted widespread attention due to their unique mechanical, thermal, chemical and electrical properties. These properties make boron nitride thin films very suitable for a variety of high temperature and high pressure applications, such as cutting tools, electronic devices and protective coatings. Synthesis of boron nitride thin films usually involves chemical vapor deposition or physical vapor deposition techniques using precursors such as boron urea and ammonia borane.

[0003] However, the synthesis of high-quality BN films remains challenging due to the difficulty in controlling the stoichiometry, phase state, and microstructure of the film. For example, conventional chemical vapor deposition techniques need to be performed at high temperatures, which may cause thermal damage to the substrate and increase energy consumption. In addition, although physical vapor deposition techniques can be performed at lower temperatures, their ability to control the stoichiometry and phase state of the film is limited.

[0004] Therefore, although boron nitride thin films have many excellent properties, the challenges in their preparation process still limit their use in practical applications. How to solve the above problems is something that people with ordinary knowledge in the field should consider. Summary of the invention

[0005] In order to solve the above problems, the object of the present invention is to provide a method for preparing a boron nitride film and a boron nitride film.

[0006] Based on the above and other purposes, the present invention provides a method for preparing a boron nitride film, which comprises the following steps. First, a precursor containing boron and nitrogen atoms is provided to an energy control mechanism. Then, an excited state of the precursor is formed in the energy control mechanism. The excited state contains boron and nitrogen atoms, or some or all of the ligands are in a broken bond state. Next, a material layer is formed on a substrate, wherein the material layer contains boron nitride. In this process, the energy control mechanism includes a first electromagnetic wave source, which emits electromagnetic waves in a specific wavelength range.

[0007] In some embodiments, the precursor is selected from compounds with a molecular percentage of boron and nitrogen of 1:1. Moreover, the precursor is selected from compounds with a molecular percentage of boron and nitrogen of 1:1 including cycloborane (B3H6N3), trimethylamine borane (TDMAB, C3H12BN), tetramethylamine borane, borourea, ammonia borane (BH6N), tri(ethylmethylamine) borane (TEMAB), etc.

[0008] In some embodiments, the method further includes forming a substrate bias on the substrate to reduce particles from falling onto the surface of the substrate.

[0009] In order to achieve the above and other purposes, the present invention adopts technical means, components and their effects, and a preferred embodiment is described below with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 A flow chart of an embodiment of the present invention for preparing a boron nitride layer on a substrate is shown.

[0011] Figure 2A Shown is an embodiment of the energy control mechanism of the present invention.

[0012] Figure 2B Another embodiment of the energy control mechanism of the present invention is shown.

[0013] Figure 3 Shown is a substrate with a boron nitride thin film formed thereon.

[0014] Figure 4 Shown is a schematic diagram of the interior of the reaction chamber. DETAILED DESCRIPTION

[0015] Please refer to Figure 1The present invention provides a method for depositing a boron nitride layer on a substrate, as described in the process described in step S110. The method first provides a precursor containing boron atoms and nitrogen atoms to an energy control mechanism, as shown in step S110. The precursor is a compound selected from a molecular percentage of boron and nitrogen of 1:1. These compounds include Boron-Nitrogen Cycloalkanes (B3H6N3), Trimethylamine Borane (TDMAB, C3H12BN), Tetramethylammonium Borohydride, Boron Nitride, Ammonia Borane (BH6N), and Triethylmethylamine Borane (TEMAB). Cycloalkanes are colorless liquids at room temperature and are often used as precursors for depositing boron nitride films due to their high thermal stability. Trimethylamine borane is a compound known for its high reactivity and volatility, making it suitable for chemical vapor deposition processes. Tetramethylamine borane is a compound that is stable in air and can be used as a single source precursor for boron nitride films. Boron urea is a compound that is stable under normal conditions and can be used as a precursor for synthesizing boron nitride nanotubes. Ammonia borane is a compound that is solid at room temperature and can be used as a precursor for synthesizing boron nitride nanotubes and nanosheets. Tri(ethylmethylamine)borane is a compound that is stable under normal conditions and can be used as a precursor for synthesizing boron nitride films. In the present invention, these compounds can be used alone or in combination.

[0016] Please also refer to Figure 1 and Figure 2A, which depicts an embodiment of the energy control mechanism of the present invention. The energy control mechanism 100 includes a power supply 101, a first electromagnetic wave source 102, and a propagation device 103 for emitting electromagnetic waves, the propagation device 103 being, for example, a waveguide or an antenna. The power supply 101 will provide energy to the first electromagnetic wave source 102 to generate electromagnetic waves, the first electromagnetic wave source 102 may be a device that generates electromagnetic waves at a specified wavelength and energy level, and the propagation device 103 will guide the electromagnetic waves to the precursor. In addition, the energy control mechanism 100 may also include a control system 104 for adjusting the wavelength and energy of the electromagnetic waves. In this embodiment, the control system 104 includes a microprocessor 104a or other type of controller, and a sensor 104b for monitoring the wavelength and energy of the electromagnetic waves. The microprocessor 104a can adjust the operation of the first electromagnetic wave source 102 according to the reading of the sensor 104b to maintain the desired wavelength and energy level. In addition, the energy control mechanism 100 may include a cooling system 105 and a safety system 106. The cooling system 105 may prevent the energy control mechanism 100 from overheating during operation, and the safety system 106 may shut down the energy control mechanism 100 when a failure occurs in the energy control mechanism 100. In addition, the energy control mechanism 100 also has a channel (not shown) for introducing and taking out precursors.

[0017] In one embodiment of the method, the precursor is introduced into the energy control mechanism 100 under specific temperature conditions. In this embodiment, the temperature is maintained in the range of 25 to 400 degrees Celsius. The introduction of the precursor into the energy control mechanism 100 is carried out by an inert carrier gas, which can be argon, helium, nitrogen or a combination of these gases. The selection of the inert carrier gas depends on its ability to maintain the precursor in a stable state and its compatibility with the precursor and the energy control mechanism 100. In this process, the flow rate of the inert carrier gas can be adjusted to optimize the formation of the excited state of the precursor. A higher flow rate may be used to quickly introduce the precursor into the energy control mechanism, while a lower flow rate may be used to ensure sufficient interaction between the precursor and the electromagnetic wave. The flow rate can also be adjusted according to changes in temperature or pressure in the energy control mechanism. This allows dynamic control of the process to ensure that a high-quality boron nitride layer is formed on the substrate. In one embodiment, the molecular mole concentration of the precursor containing boron atoms and nitrogen atoms in the inert carrier gas is between 0.5% and 10%. The flow rate of the inert carrier gas entering the energy control mechanism 100 is set to 20-40 sccm, the vapor pressure in the energy control mechanism 100 is set to 20-60 torr, and the average residence time of the inert carrier gas is 10-100 seconds.

[0018] Please continue to refer to Figure 1 and Figure 2AIn step S120, a higher energy state, or "excited state", is generated in the precursor by the energy control mechanism 100. This excited state includes making the boron atoms and nitrogen atoms in an excited state, or including some or all ligands in a broken bond state. In one embodiment, the wavelength of the electromagnetic wave sent by the first electromagnetic wave source 102 of the energy control mechanism 100 is controlled to be between 180-500nm, and the energy is between 100W-600W. In another specific implementation, as Figure 2B As shown, except Figure 2A In addition to the components shown, the energy control mechanism 100' also includes a second electromagnetic wave source 107. The wavelength of the second electromagnetic wave source 107 ranges from 0.5nm to 180nm, and the energy ranges from 100 to 600W. The wavelength of the second electromagnetic wave source 107 is shorter than that of the first electromagnetic wave source 102, because shorter wavelengths correspond to higher energy photons, which can more effectively excite precursors, resulting in more efficient formation of excited states. By adjusting the first electromagnetic wave source 102 and the second electromagnetic wave source 107, the formation of the excited state of the precursor can be optimized.

[0019] Next, please also refer to Figure 1 and Figure 3 , Figure 3 The substrate is shown as a substrate formed with a boron nitride film. In step S130, we guide the precursor in an excited state onto at least one surface of the substrate 20. The key to this step is that the precursor is in an excited state. In this excited state, the boron and nitrogen atoms of the precursor or part or all of the ligands are in a broken bond state. This broken bond state means that the boron and nitrogen atoms have been excited and are ready to react chemically with other atoms or molecules. The formation of this state is achieved by exposing the precursor to specific energy conditions, which are provided by our energy control mechanism. When the precursor is guided onto the substrate 20, the boron and nitrogen atoms in the excited state begin to form a new material layer 21 on the substrate (as shown in step S140). This new material layer 21 contains boron nitride, that is, a boron nitride film. In this process, the arrangement of the boron and nitrogen atoms on the substrate determines the specific properties of the boron nitride layer formed. In short, step S130 is mainly to guide the precursor in an excited state onto the substrate and form a material layer containing boron nitride on the substrate. During this process, the temperature of the substrate 20 is maintained at less than or about 400°C.

[0020] The material layer 21 may include hexagonal boron nitride (h-BN), tetragonal boron nitride (c-BN) or amorphous boron nitride (a-BN). Different types of boron nitride in the material layer, such as hexagonal boron nitride (h-BN), tetragonal boron nitride (c-BN) or amorphous boron nitride (a-BN), are due to different structural arrangements of boron and nitrogen atoms in the material. These different structures lead to different physical and chemical properties, which may be advantageous for different applications. For example, h-BN has a layered structure similar to graphite, making it very useful as a lubricant. On the other hand, c-BN has a structure similar to diamond, making it extremely hard and very useful for cutting tools. Amorphous boron nitride has a unique irregular structure that gives it some distinctive physical and chemical properties. These properties cannot be found in other materials with regular structures. Therefore, amorphous boron nitride can exhibit superior performance in certain specific professional applications, such as in high temperature or high pressure environments, or when high wear resistance or corrosion resistance is required. In addition, due to its irregular structure, amorphous boron nitride also has excellent thermal and chemical stability, which allows it to maintain its structure and performance unchanged in many high-temperature or chemically harsh environments. Therefore, amorphous boron nitride is widely used in many industrial applications, such as high-performance lubricants, wear-resistant materials, anti-corrosion coatings, etc.

[0021] In this embodiment, the material of the substrate 20 is selected from the group of metal, metal alloy, ceramic, polymer or a combination thereof. In detail, the material of the metal substrate can be selected from the group including aluminum, copper, steel or a combination thereof. The material of the metal alloy substrate can be selected from the group including stainless steel, brass, bronze or a combination thereof. The ceramic substrate can be selected from the group including aluminum oxide, zirconium oxide, silicon carbide or a combination thereof. The material of the polymer substrate can be selected from the group including polyethylene, polypropylene, polystyrene or a combination thereof. The selection of the substrate material can depend on various factors, such as the desired properties of the boron nitride layer, the intended application of the product, and the conditions under which the product will be used. For example, a person with ordinary knowledge in the art may select a metal or metal alloy substrate because it has high thermal conductivity. In addition, a person with ordinary knowledge in the art may also select a ceramic substrate because it has high temperature resistance. And, a person with ordinary knowledge in the art may also select a polymer substrate because it is low in cost and easy to manufacture. In addition, the substrate can be a combination of these materials. For example, the material of the substrate 20 can be a metal-ceramic composite material, a metal-polymer composite material, a ceramic-polymer composite material, or a metal-ceramic-polymer composite material. A balance of properties, such as strength, toughness, thermal conductivity, and cost, can be achieved through the combination of materials.

[0022] It is worth noting that the substrate 20 can be treated or coated before depositing the boron nitride film to enhance the adhesion between the material layer 21 and the substrate 20. For example, the substrate can be cleaned, roughened, or coated with a primer or an adhesion promoter. In addition, in one embodiment, an electric field called a substrate bias can be set on the substrate 20 to reduce the deposition of charged particles on the surface of the substrate 20. The substrate bias can be a positive bias or a negative bias, depending on the charge polarity of the charged particles. For example, if the charged particles are mainly positively charged, a positive bias is set, and vice versa. The substrate bias is set mainly to repel charged particles that may interfere with the deposition process, thereby improving the quality of the deposited boron nitride. When a bias is set on the substrate, this electric field affects the movement of the charged particles, making it more difficult for the charged particles to fall directly on the substrate surface. This can reduce the random deposition of charged particles on the substrate surface, thereby making the formed material layer 21 smoother and more uniform. Therefore, the setting of the substrate bias helps to improve the quality of the boron nitride film.

[0023] Please also refer to Figure 4 , Figure 4The internal schematic diagram of the reaction chamber is shown. In one embodiment, step S130 is implemented in a reaction chamber 200 equipped with a plasma source 210, and this design is to increase the formation rate of boron nitride. In this process, the plasma source 210 in the reaction chamber 200 plays a key role. The main function of the plasma source 210 is to generate plasma, which is a gas containing plasma. Plasma is a state of matter with unbalanced charge, containing equal numbers of positive and negative charges. In this state, the atoms or molecules of the gas are ionized by the energy of the plasma source 210 to form charged particles. These charged particles have high energy and can further react chemically with the precursor. In this chemical reaction process, the charged particles combine with the boron atoms and nitrogen atoms in the precursor to form boron nitride. This chemical reaction process is carried out in the reaction chamber 200 and is carried out under the action of the plasma source 210. In addition, the plasma source 210 can have a variety of forms, such as direct current plasma (DC plasma), radio frequency plasma (RF plasma), electron cyclotron resonance plasma (ECR plasma) or a combination thereof. These different types of plasma sources have their specific operating conditions and advantages. For example, a DC plasma source is the most common type of plasma source, which uses a DC voltage to generate plasma. An RF plasma source uses an RF voltage to generate plasma, which can operate at a lower pressure and can produce a higher density of plasma. An electron cyclotron resonance plasma source uses a magnetic field to generate plasma, which can operate at an extremely low pressure and can produce an extremely high density of plasma. In this embodiment, the energy output of the plasma source 210 is set to more than 300W. This energy setting is to ensure that the plasma source can effectively generate plasma and can transfer enough energy to the atoms or molecules of the gas to ionize it and form charged particles. This energy setting can also be adjusted according to specific application requirements. In addition, the plasma is composed of at least one gas selected from argon, helium, nitrogen, hydrogen, ammonia or a combination thereof. The choice of these gases depends on their ability to effectively generate plasma and their compatibility with the precursors and reaction chamber. For example, argon and helium are the most commonly used plasma gases because they have high ionization energies and can produce high-density plasmas. Nitrogen and hydrogen can be used for specific applications, such as when specific chemical reactions need to be generated in the plasma. Ammonia can be used when nitrogen-containing chemical reactions need to be generated in the plasma.

[0024] In summary, the method for preparing a boron nitride film of the present invention has several significant advantages over the existing boron nitride film deposition method. First, the method operates at a relatively low temperature, which greatly reduces the risk of thermal damage to the substrate and also reduces energy consumption. This low-temperature operation method not only improves efficiency, but also makes the method more environmentally friendly. In addition, the method of the present invention also includes some optional steps that can further enhance the formation of the boron nitride layer. For example, the method can form a substrate bias on the substrate, which helps to reduce the deposition of charged particles on the surface of the substrate, thereby improving the quality of the boron nitride layer. In addition, the method can also include a plasma source in the reaction chamber, which helps to increase the formation rate of boron nitride, thereby improving production efficiency. These optional steps make the method more flexible in the process of preparing a boron nitride film and can be adjusted according to specific needs.

[0025] The invention is described above, but it is not intended to limit the scope of the patent rights claimed by the invention. Any changes or modifications made by those skilled in the art without departing from the spirit or scope of this patent shall be considered as equivalent changes or designs completed under the spirit disclosed by the invention and shall be included in the claims of the invention.

Claims

1. A method for preparing a boron nitride film, characterized in that: The method includes: (a) providing a precursor comprising boron atoms and nitrogen atoms to an energy control mechanism; (b) forming an excited state of the precursor in the energy control mechanism, wherein the excited state comprises boron and nitrogen atoms, or some or all of the ligands are in a bond-broken state; and (c) forming a material layer on the substrate, wherein the material layer comprises boron nitride; The energy control mechanism includes a first electromagnetic wave source, which emits electromagnetic waves within a specific wavelength range.

2. The method for preparing a boron nitride thin film according to claim 1, characterized in that: The precursor is selected from a compound in which boron and nitrogen have a molecular percentage of 1:

1.

3. The method for preparing a boron nitride thin film according to claim 2, characterized in that: The precursor is selected from compounds including cycloborane (B3H6N3), trimethylamine borane (TDMAB, C3H12BN), tetramethylamine borane, boron urea, ammonia borane (BH6N), tri(ethylmethylamine) borane (TEMAB) and the like, wherein the molecular ratio of boron to nitrogen is 1:

1.

4. The method for preparing a boron nitride thin film according to claim 1, characterized in that: The material of the substrate is selected from metal, metal alloy, ceramic, polymer or a combination thereof.

5. The method for preparing a boron nitride thin film according to claim 1, characterized in that: The material layer includes hexagonal boron nitride (h-BN), tetragonal boron nitride (c-BN) or amorphous boron nitride (a-BN).

6. The method for preparing a boron nitride thin film according to claim 1, characterized in that: Step (a) further comprises introducing the precursor into the energy control mechanism at a temperature between 25-400°C.

7. The method for preparing a boron nitride thin film according to claim 6, characterized in that: The introduction of the precursor into the energy control mechanism is performed by an inert carrier gas.

8. The method for preparing a boron nitride thin film according to claim 7, characterized in that: The inert carrier gas is selected from argon, helium, nitrogen or a combination thereof.

9. The method for preparing a boron nitride thin film according to claim 7, characterized in that: The precursor has a molecular mole concentration in an inert carrier gas ranging from 0.5% to 10%.

10. The method for preparing a boron nitride thin film according to claim 7, characterized in that: The flow rate of the inert carrier gas entering the energy control mechanism is set at 20-40 sccm.

11. The method for preparing a boron nitride thin film according to claim 7, characterized in that: The gas pressure in the energy control mechanism is set to 20-60 torr.

12. The method for preparing a boron nitride thin film according to claim 7, characterized in that: The average residence time of the inert carrier gas in the energy control mechanism is 10-100 seconds.

13. The method for preparing a boron nitride thin film according to claim 1, characterized in that: The wavelength of the electromagnetic wave emitted by the first electromagnetic wave source is between 180-500nm, and the energy is between 100W-600W.

14. The method for preparing a boron nitride thin film according to claim 13, characterized in that: The energy control mechanism comprises a second electromagnetic wave source. The wavelength of the electromagnetic wave emitted by the second electromagnetic wave source is between 0.5nm and 180nm, and the energy is between 100W and 600W.

15. The method for preparing a boron nitride thin film according to claim 1, characterized in that: Step (c) further includes forming a substrate bias on the substrate to reduce particles from falling onto the substrate surface.

16. The method for preparing a boron nitride thin film according to claim 1, characterized in that: Step (c) further includes maintaining the temperature of the substrate at less than or about 400°C.

17. The method for preparing a boron nitride thin film according to claim 1, characterized in that: Step (c) further provides a reaction chamber, wherein the reaction chamber includes a plasma source to increase the formation rate of boron nitride.

18. The method for preparing a boron nitride thin film according to claim 17, characterized in that: The plasma source is direct current plasma (DC plasma), radio frequency plasma (RF plasma), electron cyclotron resonance plasma (ECR plasma) or a combination thereof, and the energy of the plasma is greater than 300W.

19. The method for preparing a boron nitride thin film according to claim 14, characterized in that: The plasma comprises at least one gas selected from argon, helium, nitrogen, hydrogen, ammonia or a combination thereof.

20. A boron nitride film formed on a substrate, characterized in that: The boron nitride film is prepared by the method for preparing a boron nitride film according to any one of claims 1 to 19.

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