Molybdenum nitride film and preparation method thereof, and vacuum interconnection system

Abstract

The application discloses a molybdenum nitride film and a preparation method and a vacuum interconnection system thereof, and the preparation method comprises the following steps: providing a substrate; and growing a molybdenum nitride film on the substrate through an ultrahigh vacuum chemical vapor deposition process, wherein the crystal phase of the molybdenum nitride film is delta-MoN, and the vacuum degree in the growth process of the molybdenum nitride film is not higher than 3*10 ‑10 Mbar, and the substrate temperature is 850 DEG C to 1000 DEG C. The ultrahigh vacuum chemical vapor deposition process is adopted, and the growth parameters in the growth process of the molybdenum nitride film are controlled, so that the preparation of the molybdenum nitride film with a pure delta-MoN crystal phase is realized.

Description

Technical Field

[0001] This invention belongs to the field of semiconductor materials technology, specifically relating to a molybdenum nitride thin film and its preparation method, and a vacuum interconnect system. Background Technology

[0002] Transition metal nitride thin films are a class of inorganic compound films formed by the combination of transition metal elements and nitrogen atoms. They possess high hardness, excellent electrical conductivity, good chemical stability, and unique optoelectronic and magnetic properties, making them promising for applications in numerous fields. Currently, various techniques exist for preparing transition metal nitride thin films, including solution methods, sputtering, atomic layer deposition (ALD), and chemical vapor deposition (CVD). Among these, magnetron sputtering is one of the most commonly used methods, allowing the preparation of molybdenum nitride films on various substrates by adjusting parameters such as nitrogen flow rate and sputtering power. However, magnetron sputtering offers relatively limited control over crystal quality and stoichiometry, typically resulting in polycrystalline films, and lacks real-time monitoring of the growth process. Atomic layer deposition (ALD) and plasma-enhanced ALD can achieve precise control over nanometer-scale thickness and offer good step coverage, but their deposition rates are relatively low, and precursor costs are high. Chemical vapor deposition (CVD) offers high controllability, good uniformity, and high scalability, making it suitable for large-scale preparation and thus a crucial technology for synthesizing high-quality transition metal nitride thin films. Among them, ultra-high vacuum chemical vapor deposition (UHVCVD) further increases the background vacuum to 10. -9 ~10 -10 The mbar level technology can significantly reduce the contamination and damage to the thin film by residual impurity gases (H2O, O2, CO, etc.), and is an advanced technology for preparing ultra-high purity, atomically flat thin films.

[0003] Molybdenum nitride (MoNx) is a typical transition metal nitride with excellent electrical conductivity, mechanical properties, and electrochemical performance, making it promising for applications in catalysis, energy storage, integrated circuits, and protective coatings. Molybdenum nitride exists in various phases, including γ-Mo₂N, δ-MoN, and ε-MoN. While the crystal structures and properties of different phases vary, they all exhibit excellent chemical and thermal stability, making them irreplaceable in extreme environments. In catalysis, Molybdenum nitride, due to its noble metal-like electronic structure and surface active sites, demonstrates excellent catalytic activity in reactions such as hydrodesulfurization, hydronitrogenation, ammonia decomposition for hydrogen production, and electrocatalytic hydrogen evolution. In energy storage, Molybdenum nitride exhibits significant pseudocapacitive behavior as an electrode material for supercapacitors. Furthermore, Molybdenum nitride films, with their high hardness and oxidation resistance, also show great promise for applications in hard protective coatings and diffusion barrier layers for integrated circuits.

[0004] While existing technologies, such as UHVCVD, can significantly reduce the contamination and damage of molybdenum nitride films by impurity gases, still face a series of challenges. One primary difficulty is controlling the high-purity phase. Molybdenum nitride exists in multiple phases (such as δ-MoN and γ-Mo2N), and phase-selective growth remains difficult in traditional UHVCVD processes, often resulting in mixed-phase products that affect the characterization of the material's intrinsic properties. Furthermore, although UHVCVD reduces background impurities, the lack of real-time monitoring during growth makes it impossible to dynamically understand surface morphology evolution, chemical state changes, and three-dimensional composition distribution. Uniformity is another key issue, especially on large-size substrates. Due to the complexity of reaction conditions, the thickness and composition of the film may vary in different regions. Simultaneously, traditional UHVCVD methods typically lack the ability to monitor and adjust reaction conditions in real time, failing to correct problems immediately during film growth, which also limits a deeper understanding of the reaction mechanism. More importantly, traditional characterization methods usually require removing the sample after growth and exposing it to the atmosphere before performing characterization such as scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). This process introduces surface contamination and cannot obtain information on the dynamic evolution during the growth process. It is also difficult to achieve multi-dimensional correlation analysis from surface morphology, chemical valence state to three-dimensional elemental distribution.

[0005] Therefore, in order to address the above-mentioned technical problems, it is necessary to provide a molybdenum nitride thin film, its preparation method, and a vacuum interconnection system. Summary of the Invention

[0006] The purpose of this invention is to provide a molybdenum nitride thin film and its preparation method, as well as a vacuum interconnection system, which can prepare high-quality, uniform pure δ-MoN crystalline molybdenum nitride thin films.

[0007] To achieve the above objectives, an embodiment of the present invention provides the following technical solution:

[0008] A method for preparing a molybdenum nitride thin film, the method comprising the following steps: providing a substrate; growing a molybdenum nitride thin film on the substrate by ultra-high vacuum chemical vapor deposition, wherein the crystal phase of the molybdenum nitride thin film is δ-MoN, and the vacuum degree during the growth of the molybdenum nitride thin film is not higher than 3×10⁻⁶. -10 mbar, substrate temperature is 850℃~1000℃.

[0009] In one embodiment, the substrate is a Mo(110) substrate, and the step of growing a molybdenum nitride thin film on the substrate by ultra-high vacuum chemical vapor deposition is as follows: using ammonia as a nitrogen source, and controlling the nitrogen source partial pressure to be 1×10⁻⁶. -6 mbar~5×10 -6 mbar, molybdenum nitride thin films are grown on substrates using ultra-high vacuum chemical vapor deposition process.

[0010] In one embodiment, prior to the step of growing a molybdenum nitride thin film on the substrate using an ultra-high vacuum chemical vapor deposition process, the method further includes: pre-treating the substrate to remove surface impurities and form atomic-level steps.

[0011] In one embodiment, the pretreatment step of the substrate includes: surface treatment of the substrate by argon ion etching process; and surface treatment of the substrate by annealing process.

[0012] In one embodiment, the step of preparing a molybdenum nitride thin film on a substrate by ultra-high vacuum chemical vapor deposition further includes: using photoemission electron microscopy to perform in-situ dynamic monitoring of the growth process of the molybdenum nitride thin film in order to dynamically optimize the process parameters.

[0013] In one embodiment, after the step of preparing a molybdenum nitride thin film on a substrate by ultra-high vacuum chemical vapor deposition, the method further includes: performing high-resolution spectroscopic analysis on the molybdenum nitride thin film using X-ray photoelectron spectroscopy to obtain the XPS spectrum of the molybdenum nitride thin film, and determining the valence state of the transition metal elements and the form in which nitrogen exists in the molybdenum nitride thin film.

[0014] In one embodiment, after the step of preparing a molybdenum nitride thin film on a substrate by ultra-high vacuum chemical vapor deposition, the method further includes: performing three-dimensional compositional analysis using a time-of-flight secondary ion mass spectrometer to obtain a three-dimensional reconstructed image of the transition metal nitride thin film.

[0015] Another embodiment of the present invention provides the following technical solution:

[0016] A molybdenum nitride thin film, which is prepared according to the preparation method described above.

[0017] Another embodiment of the present invention provides the following technical solution:

[0018] A vacuum interconnection system for preparing the aforementioned molybdenum nitride thin film, the vacuum interconnection system comprising an ultra-high vacuum chemical vapor deposition apparatus, a photoemission electron microscope, an X-ray photoemission spectrometer, and a time-of-flight secondary ion mass spectrometer, wherein the imaging chamber of the photoemission electron microscope is integrated with the growth chamber of the ultra-high vacuum chemical vapor deposition apparatus, and the growth chamber, the X-ray photoemission spectrometer, and the time-of-flight secondary ion mass spectrometer are connected by a vacuum interconnection pipe.

[0019] In one embodiment, the vacuum level of the growth chamber is no higher than 3 × 10⁻⁶. -10 mbar.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] This invention employs an ultra-high vacuum chemical vapor deposition process to achieve the preparation of pure δ-MoN crystalline molybdenum nitride thin films by controlling the growth parameters during the growth process of molybdenum nitride thin films.

[0022] This invention integrates the growth chamber of an ultra-high vacuum chemical vapor deposition (UCVD) apparatus with the imaging chamber of a photoemission electron microscope (PEEEM), enabling in-situ dynamic monitoring of the molybdenum nitride (MoN) film growth process and achieving dynamic optimization of the MoN film growth process.

[0023] This invention connects the growth chamber, X-ray photoelectron spectrometer, and time-of-flight secondary ion mass spectrometer via a vacuum interconnection pipeline, avoiding contact between the grown molybdenum nitride film and the atmospheric phase, thus improving the accuracy of the characterization results. Attached Figure Description

[0024] 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.

[0025] Figure 1 This is a schematic diagram of the vacuum interconnection system in Embodiment 1 of the present invention;

[0026] Figure 2 This is a schematic flowchart of the molybdenum nitride thin film preparation method in Embodiment 1 of the present invention;

[0027] Figure 3 This is a PEEM characterization image of the pretreated substrate in Embodiment 1 of the present invention;

[0028] Figure 4 These are PEEM characterization images of the molybdenum nitride thin film at different time points during growth in Example 1 of this invention;

[0029] Figure 5 XPS pattern of the molybdenum nitride thin film grown in Example 1 of this invention;

[0030] Figure 6 This is a three-dimensional reconstructed image of the molybdenum nitride thin film grown in Example 1 of the present 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 will be clearly and completely described below with reference to the accompanying drawings. 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] In this invention, unless otherwise expressly specified and limited, the disclosed "range" is defined in the form of a lower limit and / or an upper limit. A given range is defined by selecting a lower limit and / or an upper limit, which defines the boundary of the particular range. Ranges defined in this way include endpoints and can be arbitrarily combined; that is, any lower limit can be combined with any upper limit to form an unspecified range, and any lower limit can be combined with other lower limits to form an unspecified range. Similarly, any upper limit can be combined with any other upper limit to form an unspecified range. Furthermore, each individually disclosed point or single value can itself serve as a lower limit or upper limit and can be combined with any other point or single value or with other lower limits or upper limits to form an unspecified range.

[0033] This invention discloses a method for preparing a molybdenum nitride thin film, comprising the following steps: providing a substrate; growing a molybdenum nitride thin film on the substrate using an ultra-high vacuum chemical vapor deposition process, wherein the crystal phase of the molybdenum nitride thin film is δ-MoN, and the vacuum degree during the growth of the molybdenum nitride thin film is not higher than 3 × 10⁻⁶. -10 mbar, substrate temperature is 850℃~1000℃.

[0034] The present invention also discloses a molybdenum nitride thin film, which is prepared according to the above-described preparation method.

[0035] The present invention also discloses a vacuum interconnection system for preparing the above molybdenum nitride film. The vacuum interconnection system comprises an ultra-high vacuum chemical vapor deposition apparatus, a photoemission electron microscope, an X-ray photoelectron spectrometer and a time-of-flight secondary ion mass spectrometer. An imaging chamber of the photoemission electron microscope is integrated with a growth chamber of the ultra-high vacuum chemical vapor deposition apparatus, and the growth chamber, the X-ray photoelectron spectrometer and the time-of-flight secondary ion mass spectrometer are communicated with each other via vacuum interconnection pipes

[0036] The present invention is further described below with reference to specific examples.

[0037] Example 1:

[0038] Reference Figure 1 As shown in the figure, the vacuum interconnection system in this example comprises an ultra-high vacuum chemical vapor deposition apparatus, a photoemission electron microscope (Photoemission Electron Microscopy, PEEM), an X-ray photoelectron spectrometer and a time-of-flight secondary ion mass spectrometer (Time-of-Flight Secondary Ion Mass Spectrometry, TOF-SIMS), wherein an imaging chamber of the photoemission electron microscope is integrated with a growth chamber of the ultra-high vacuum chemical vapor deposition apparatus, and the growth chamber, the X-ray photoelectron spectrometer and the time-of-flight secondary ion mass spectrometer are communicated with each other via vacuum interconnection pipes.

[0039] Wherein, the vacuum degree of the growth chamber is not higher than 3×10 -10 mbar, so as to provide an atomically clean growth environment for the molybdenum nitride film. Meanwhile, in this example, the growth chamber of the UHVCVD apparatus is integrated with the imaging chamber of the PEEM, which enables in-situ, real-time and high spatial resolution imaging of the surface of the molybdenum nitride film by photoelectron emission during the growth process, and realizes dynamic monitoring of morphology evolution, grain nucleation and growth process, surface uniformity and work function change of the molybdenum nitride film during the growth process of the molybdenum nitride film, thereby enabling real-time optimization of process parameters during the growth process of the molybdenum nitride film, improving the preparation efficiency and the quality of the prepared molybdenum nitride film, and providing intuitive experimental evidence for the research on the growth mechanism of the molybdenum nitride film.

[0040] Furthermore, XPS can acquire high-resolution XPS spectra of the prepared molybdenum nitride film surface using a monochromatic X-ray source, obtaining high-resolution surface chemical information, including the different chemical states and electronic structures of elements in the molybdenum nitride film, achieving (quasi)in-situ determination of valence states. By determining the different chemical valence states of molybdenum and the presence of nitrogen in the molybdenum nitride film, it is possible to determine whether there are oxide or impurity phases in the prepared molybdenum nitride film, and whether a pure δ-MoN crystalline phase molybdenum nitride film has been successfully prepared. Simultaneously, if the grown molybdenum nitride film contains other crystalline phases besides the target δ-MoN crystalline phase, quantitative analysis of the XPS spectra can obtain the atomic ratio of molybdenum to nitrogen, allowing for further control of the stoichiometric ratio of molybdenum to nitrogen during the molybdenum nitride growth process, thus enabling the growth of a pure δ-MoN crystalline phase molybdenum nitride film.

[0041] TOF-SIMS can use Bi3 + Or Ar + A cluster ion gun was used as the primary ion source to acquire secondary ion mass spectra of the grown molybdenum nitride (MoN) films in both positive and negative ion modes. Three-dimensional compositional analysis of the grown MoN films was performed using a depth profiling mode (alternating between sputtering and analytical ion guns) to obtain the MoN... - Related functional groups and possible impurity ions (such as O) - OH - By varying the signal intensity with sputtering depth, a three-dimensional elemental distribution map of the molybdenum nitride (MoN) thin film is constructed, providing information on the distribution of elements and molecular fragments in the lateral and longitudinal directions. In this embodiment, the uniformity of molybdenum and nitrogen elements, interdiffusion at the interface, and the distribution of trace impurities in the grown MoN film can be obtained without damaging the film. This is significant for evaluating the quality of the grown MoN film, optimizing the growth process, and understanding the growth mechanism of MoN films.

[0042] In addition, the vacuum interconnect system in this embodiment also includes a pretreatment chamber (not shown), which is also connected to the growth chamber through a vacuum interconnect pipe. The substrate is surface treated in the pretreatment chamber by argon ion etching and annealing processes.

[0043] In this embodiment, by integrating the growth chamber of UHVCVD with the imaging chamber of PEEM, in-situ dynamic monitoring of the growth process of molybdenum nitride thin films can be realized, so that process parameters can be dynamically optimized during the growth process. Meanwhile, in this embodiment, the growth chamber, XPS and TOF-SIMS are connected to each other through vacuum interconnection pipelines, so that non-destructive transfer of molybdenum nitride thin films between different chambers is realized, which ensures that the characterization of molybdenum nitride thin films is carried out without exposure to atmospheric environment, fundamentally eliminates the pollution of moisture, oxygen and impurities in air to the surface and interface of molybdenum nitride thin films, ensures the intrinsic state of the surface and interface of molybdenum nitride thin films, and makes the characterization results authentic and reliable. In addition, with the vacuum interconnection system in this embodiment, comprehensive, multi-scale in-situ characterization from the growth process to the final product, from the surface to the bulk, from morphology to valence state and then to three-dimensional composition can be realized. Combined with the characterization results of PEEM, XPS and TOF-SIMS, the evolution law of molybdenum nitride thin films with process parameters can be obtained, the optimal parameters for growing high-quality, uniform pure-phase molybdenum nitride thin films can be obtained more accurately, conveniently and quickly, and the preparation process can be optimized through rapid iteration with high repeatability.

[0044] Refer Figure 2 as shown, the preparation method of the molybdenum nitride thin film in this embodiment comprises the following steps: S1, providing a substrate; S2, growing a molybdenum nitride thin film on the substrate by an ultra-high vacuum chemical vapor deposition process, wherein the crystal phase of the molybdenum nitride thin film is δ-MoN, and the vacuum degree during the growth of the molybdenum nitride thin film is not higher than 3×10 -10 mbar, and the substrate temperature is 850°C to 1000°C.

[0045] Wherein, the substrate in this embodiment is a Mo(110) substrate.

[0046] Specifically, before growing the molybdenum nitride thin film on the substrate by the UHVCVD process, this embodiment further comprises pre-treating the substrate to remove impurities on the substrate surface and form atomic-level steps.

[0047] More specifically, in the pre-treatment chamber of the vacuum interconnection system in this embodiment, argon ion etching is firstly performed on the substrate with argon ions with an energy of 1.5 keV to clean the substrate surface and remove the oxide layer and other contaminants on its surface; then annealing treatment is performed on the substrate at a temperature of 1200°C to improve the cleanliness of the surface of the Mo(110) substrate and remove microscopic surface irregular defects such as grain boundaries and dislocations.

[0048] Refer Figure 3 as shown, after completing the pre-treatment of the substrate, the substrate is transferred to the imaging chamber through the vacuum interconnection pipeline, and PEEM is used to characterize the surface morphology of the substrate. The characterization results show that the surface of the pre-treated substrate in this embodiment is clean, flat, and has atomic-level steps.

[0049] Specifically, step S2 in this embodiment includes using high-purity ammonia gas (NH3) as the nitrogen source, and controlling the partial pressure to 1×10 - 6 mbar to 5×10 -6 within the range of mbar, heating the substrate to 850°C to 1000°C, and growing a molybdenum nitride thin film of pure δ-MoN phase on the substrate by means of UHVCVD equipment. Preferably, the partial pressure of ammonia gas is 2×10 -6 mbar, the substrate temperature is set to 900°C, and the vacuum in the growth chamber is 3×10 -10 mbar.

[0050] It is worth noting that the growth parameter range of the molybdenum nitride thin film with pure δ-MoN crystal phase in this embodiment is obtained through multiple experiments using the above-mentioned vacuum interconnected system and combining with the characterization results of PEEM, XPS and TOF-SIMS analysis.

[0051] Specifically, growing a molybdenum nitride thin film by the UHVCVD process under a vacuum degree of no more than 3×10 -10 mbar can control the concentration of residual gases such as H2O, O2, CO, and hydrocarbons within an extremely low range, avoid the incorporation of impurities during the growth process to the greatest extent from the source, ensure the high purity of the molybdenum nitride thin film, and is conducive to obtaining the intrinsic phase and a good molybdenum nitride thin film. Meanwhile, controlling the substrate temperature within the range of 850°C to 1000°C is conducive to obtaining the molybdenum nitride thin film with pure δ-MoN crystal phase. When the temperature is lower than 850°C, the cracking efficiency of the nitrogen source is low and the concentration of active nitrogen atoms is low, which easily leads to the formation of a under-nitrided phase and affects the stability of the δ-MoN crystal phase. When the temperature is higher than 1000°C, the cracking of the nitrogen source is too intense, resulting in an excessively high concentration of nitrogen atoms, which easily leads to the formation of molybdenum nitride of other crystal phases and reverse etching of the grown molybdenum nitride thin film, leading to a decreased growth rate and high surface roughness. In addition, controlling the partial pressure of the nitrogen source within the range of 1×10 -6 mbar to 5×10 -6 mbar can regulate the stoichiometric ratio of molybdenum element to nitrogen element and ensure the preparation of the molybdenum nitride thin film with pure δ-MoN crystal phase.

[0052] Further, in this embodiment, the imaging chamber of PEEM is integrated with the growth chamber of UHVCVD, so that PEEM can be used to conduct in-situ dynamic monitoring on the growth process of the molybdenum nitride thin film. When abnormal morphologies such as three-dimensional island structures or cracks are monitored in the molybdenum nitride thin film, process parameters such as nitrogen source partial pressure, substrate temperature and growth time can be dynamically optimized within a specified range, so that the surface coverage of the grown molybdenum nitride thin film meets expectations and has good uniformity.

[0053] Ref Figure 4As shown, in this example, PEEM is used to characterize the molybdenum nitride films at different time points, achieving in-situ dynamic monitoring of the growth process of the molybdenum nitride films. Meanwhile, the characterization results show that the molybdenum nitride film prepared in this example has good growth quality.

[0054] Further, after completing the growth of the molybdenum nitride film in this example, the method further comprises transferring the substrate with the grown molybdenum nitride film to XPS for high-resolution spectroscopic analysis through a vacuum interconnected pipeline, obtaining the XPS pattern of the molybdenum nitride film, and determining the valence state of molybdenum element and the existing form of nitrogen element in the molybdenum nitride film. Meanwhile, XPS can also detect whether there is surface contamination on the grown molybdenum nitride film.

[0055] Refer to Figure 5 As shown, the XPS pattern of the molybdenum nitride film grown in this example shows that the binding energy of the N1s spectrum is located at 396.7 eV, and the binding energy of Mo3p is located at 394.0 eV, which corresponds to the δ-MoN phase. No contamination peaks such as carbon and oxygen are detected, proving that the molybdenum nitride film with pure δ-MoN crystal phase is successfully prepared in this example.

[0056] Further, after completing the preparation of the molybdenum nitride film in this example, the method further comprises transferring the substrate with the prepared molybdenum nitride film to TOF-SIMS for three-dimensional composition analysis through the vacuum interconnected pipeline.

[0057] Refer to Figure 6 As shown, the molybdenum nitride film with pure δ-MoN crystal phase grown in this example has good uniformity.

[0058] Example 2:

[0059] In this example, the preparation method of the molybdenum nitride film is substantially the same as that in Example 1, with the difference that in the process of growing the molybdenum nitride film on the substrate by using the ultra-high vacuum chemical vapor deposition process in this example, the temperature of the substrate is 850°C.

[0060] Example 3:

[0061] In this example, the preparation method of the molybdenum nitride film is substantially the same as that in Example 1, with the difference that in the process of growing the molybdenum nitride film on the substrate by using the ultra-high vacuum chemical vapor deposition process in this example, the temperature of the substrate is 1000°C.

[0062] It can be seen from the above technical solutions that the present invention has the following beneficial effects:

[0063] The present invention adopts an ultra-high vacuum chemical vapor deposition process, and realizes the preparation of the molybdenum nitride film with pure δ-MoN crystal phase by controlling the growth parameters during the growth process of the molybdenum nitride film;

[0064] This invention integrates the growth chamber of an ultra-high vacuum chemical vapor deposition (UCVD) apparatus with the imaging chamber of a photoemission electron microscope (PEEEM), enabling in-situ dynamic monitoring of the molybdenum nitride (MoN) film growth process and achieving dynamic optimization of the MoN film growth process.

[0065] This invention connects the growth chamber, X-ray photoelectron spectrometer, and time-of-flight secondary ion mass spectrometer via a vacuum interconnection pipeline, avoiding contact between the grown molybdenum nitride film and the atmospheric phase, thus improving the accuracy of the characterization results.

[0066] 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 its spirit or essential characteristics. 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, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within this disclosure. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0067] 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 a molybdenum nitride thin film, characterized in that, The preparation method includes the following steps: Provide substrate; Molybdenum nitride (MoN) films were grown on substrates using ultra-high vacuum chemical vapor deposition (UCVD). The crystal phase of the MoN film was δ-MoN, and the vacuum level during the growth process did not exceed 3 × 10⁻⁶. -10 mbar, substrate temperature is 850℃~1000℃.

2. The method for preparing molybdenum nitride thin films according to claim 1, characterized in that, The substrate is a Mo(110) substrate, and the steps for growing a molybdenum nitride thin film on the substrate by ultra-high vacuum chemical vapor deposition are as follows: Using ammonia as the nitrogen source, the partial pressure of the nitrogen source is controlled at 1×10⁻⁶. -6 mbar~5×10 -6 mbar, molybdenum nitride thin films are grown on substrates using ultra-high vacuum chemical vapor deposition process.

3. The method for preparing molybdenum nitride thin films according to claim 1, characterized in that, Prior to the step of growing a molybdenum nitride thin film on the substrate using an ultra-high vacuum chemical vapor deposition process, the following steps are also included: The substrate is pretreated to remove surface impurities and form atomic-level steps.

4. The method for preparing molybdenum nitride thin film according to claim 3, characterized in that, The steps for pretreating the substrate include: The substrate is surface-treated using argon ion etching. The substrate is surface treated by annealing.

5. The method for preparing a molybdenum nitride thin film according to claim 1, characterized in that, The step of preparing molybdenum nitride thin films on a substrate using ultra-high vacuum chemical vapor deposition also includes: In-situ dynamic monitoring of the growth process of molybdenum nitride thin films was carried out using photoemission electron microscopy to dynamically optimize process parameters.

6. The method for preparing a molybdenum nitride thin film according to claim 1, characterized in that, The process includes, after the step of preparing a molybdenum nitride thin film on the substrate using ultra-high vacuum chemical vapor deposition, the following steps: High-resolution spectroscopic analysis of molybdenum nitride thin films was performed using X-ray photoelectron spectroscopy to obtain XPS spectra of the molybdenum nitride thin films, and to determine the valence states of transition metal elements and the form in which nitrogen exists in the molybdenum nitride thin films.

7. The method for preparing a molybdenum nitride thin film according to claim 1, characterized in that, The process includes, after the step of preparing a molybdenum nitride thin film on the substrate using ultra-high vacuum chemical vapor deposition, the following steps: Three-dimensional compositional analysis was performed using time-of-flight secondary ion mass spectrometry to obtain three-dimensional reconstructed images of transition metal nitride thin films.

8. A molybdenum nitride thin film, characterized in that, The molybdenum nitride thin film is prepared by the preparation method according to any one of claims 1 to 7.

9. A vacuum interconnection system for preparing the molybdenum nitride thin film as described in claim 8, characterized in that, The vacuum interconnection system includes an ultra-high vacuum chemical vapor deposition (CVD) device, a photoemission electron microscope (PEE) device, an X-ray photoemission spectrometer (XPS) device, and a time-of-flight secondary ion mass spectrometer (TOF-MS / MS). The imaging chamber of the PPE device is integrated with the growth chamber of the CVD device. The growth chamber, the XPS device, and the TOF-MS / MS device are connected by a vacuum interconnection pipe.

10. The vacuum interconnection system according to claim 9, characterized in that, The vacuum level of the growth chamber is no higher than 3 × 10⁻⁶. -10 mbar.

Images