TaN Films Research Articles

Enhancing electrical and thermal property of diamond-based Ta2N films through introducing a Ta transition layer

Diamond, renowned for its exceptional heat dissipation properties, stands out as an optimal substrate for tantalum nitride (Ta2N) film resistors. To fully exploit the high thermal conductivity of diamond, we introduce a thin tantalum (Ta) interlayer between the TaN thin film and the polished diamond substrate, aiming to strengthen their bond and enhance the interfacial thermal conductance. Comprehensive morphological and structural analyses, utilizing advanced techniques such as grazing incident X-ray diffraction (GI-XRD), transmission electron microscopy (TEM), and energy-dispersive X-ray spectroscopy (EDS), were employed. Electrical properties were measured using a four-point probe, and thermal boundary conductance (TBC) between Ta2N and diamond was assessed through time-domain thermoreflection (TDTR), comparing scenarios with and without the Ta interlayer. Results demonstrate that the Ta interlayer facilitates tantalum carbide (TaxC) formation, improving adhesion and resulting in a remarkable 70 % increase in overall interface TBC. Moreover, the thin Ta interlayer positively influences the overall temperature coefficient of resistance (TCR) of the Ta2N film. Our strategic approach showcases enhanced adhesion and thermal performance, opening promising avenues for elevated functionality and reliability of Ta2N film resistors in high-temperature applications.

Stable Oxygen Incorporation in Superconducting TaN: An Experimental and Theoretical Assessment.

Oxide formation in superconducting TaN thin films is analyzed through experimental measurements and computational simulations. TaN was synthesized in an ultrahigh vacuum (UHV) system by reactive pulsed laser deposition and characterized in situ by X-ray photoelectron spectroscopy; it was also characterized ex situ by X-ray diffraction, transmission electron microscopy, and the four-point probe method. Despite being grown in an UHV chamber with a base pressure of 5 × 10-9 Torr, TaN contains a significant amount of oxygen (up to 20 at. %) attributed to residual gases containing O atoms. Several TaN1-x O x models, with different amounts of O atoms incorporated into N sites, were simulated using ab initio calculations to assess the feasibility of oxide formation. Thermodynamic stability analysis reveals that TaN1-x O x stability increases with oxygen addition, indicating that its incorporation is thermodynamically favorable. The oxygen-impurified TaN exhibits a face-centered cubic structure and is a superconductor (R = 0 Ω) at 2.99 K. The results discussed here highlight the importance of considering stable oxygen impurities when studying superconductivity in TaN films. The formation of TaN1-x O x regions in the compound may be key to understanding the variation in critical temperature reported in the literature.

First principles calculations of interfacial adhesion energy between Fe substrate and transition layer of films

Transition metal nitride films have high hardness and low wear rate, but the film substrate bonding strength between the film and the Fe substrate determines whether the film is useable. Adding transition layer materials is an effective way to improve the bonding strength of the membrane substrate. This article selects Ti, Zr, Hf, V, Cr, Ta, and TiN as transition layer materials, and uses first principles to calculate the interface bonding energies of ten interface models: Fe/TaN, Fe/Cr, Fe/V, Fe/Ti, Fe/Zr, Fe/Hf, Fe/Ta, Fe/TiN, Ti/TiN, and TiN/TaN. The model with higher bonding energy is selected to calculate the atomic population, electron gain and loss, and partial wave density of states of atoms, and further study the bonding situation at the interface. By comparing the bonding energy, the interfacial bonding energy between Fe and transition layer materials Ti, V, Cr, Ta, and TiN is higher than that of Fe and TaN films. And the interfacial binding energy of Fe/Ti, Ti/TiN and TiN/TaN are 0.3041eV/Å2, 0.4217eV/Å2 and 0.3687eV/Å2, respectively, which are higher than that of Fe and TaN film. Therefore, when preparing TaN thin films on Fe substrates, adding a double transition layer material Ti/TiN between the Fe substrate and TaN thin films, forming an interface model with a four layer structure of Fe/Ti/TiN/TaN, can optimize the bonding force between the substrate and the film to the greatest extent.

Study on TaN Thin Film Transducer Fabricated on the AlN Surface

In order to develop a new type of transducer for insensitive explosive devices, the problems in the film forming process of AlN ceramic surface were studied and the solutions were given. By comparison of ignition experiments, the surface roughness and average ignition current of the TaN film energy commutator prepared on the surface of polished AlN ceramics were smaller and higher. It met the technical requirements of insensitive explosive devices, which provided a new way for insensitive explosives.

Effect of nitrogen content on the mechanical and biological properties of tantalum nitride coatings

In this article, the effect of nitrogen content on the mechanical and biological properties of Tantalum Nitride coatings has been studied. TaN coatings with different N concentrations were deposited on glass slides and medical metals by magnetron sputtering in Ar + N2 atmosphere to improve the adhesion strength and biocompatibility of PVD coatings. The morphology, composition, mechanical properties, and biology of the TaN films were characterized at varying N levels, which were obtained by adjusting the flow rate of N2 at 5, 10, and 15 sccm. Results showed that hardness of the coating increased when N2 was added. The film transitioned from γ-Ta2N to ε-TaN and δ-TaN when N2 gas flow rate increased. The γ-Ta2N coating had the highest hardness (37.30 GPa). The adhesion strength of the coatings was increased with N2 flow rate and then decreased, the ε-TaN film deposited at a N2 flow rate of 10 sccm had the highest adhesion strength (18.12 N). TaN coating deposited at a N2 flow rate of 10 sccm showed the highest cell growth rate (151.77 %) and number of cells on the surface. The friction curve of the δ-TaN coating subjected to 15 sccm N2 flow rate exhibited excellent wear resistance with minimum fluctuation. According to the aforementioned findings, TaN coatings deposited under various nitrogen flow rates have significantly improved in adhesion strength, wear resistance, hardness, and biocompatibility, which offers a good reference value for research on the surface modification of medical metal and a good replacement material for the field of medical implantation.

Investigation into the effect of a PECVD-deposited SiOx chamber coating on the selective, radical-based NF3 etching of TaN with respect to BEOL low-k

This paper explores the use of a low temperature inductively coupled plasma discharge containing an NF3/Ar mixture for the isotropic, dry etching of TaN with selectivity to low-k dielectric; relying on radically based etch, without nonselective ion bombardment. With a clean chamber condition, no etch selectivity is found between TaN and the low-k dielectric, but when the chamber condition is manipulated by the addition of a plasma-deposited SiOx coating to the chamber wall, selectivity between TaN and the low-k dielectric is achieved. Deposition occurred on the low-k dielectric when the coating was applied to the chamber walls before etch, and while the TaN film etch rate did decrease with a coating applied, an etching regime was still observed. The coating was found to add significant atomic oxygen to the etch processes and decreased etching of the low-k dielectric. The deposition regime apparent for the low-k dielectric was made possible by the inability of the fluorine radicals to volatize silicon oxyfluoride compounds, causing deposition of a silicon oxyfluoride film on the low-k surface. The same etching inhibition was not observed on TaN, allowing selective etching.

A Full-Band Isolated In-Phase Power Divider via Waveguide-to-Microstrip Transition

A 3-dB waveguide-to-microstrip isolated power divider with a full bandwidth of rectangular TE10 mode has been presented in this study. A TaN film resistor is designed between the tips of the dual microstrip probes suspended in the waveguide to improve isolation. The measured results show above 19.6-dB minimum isolation in full Ka-band (26.5–40 GHz). The return loss is higher than 15.8 dB at all ports, with an average loss of 0.35 dB.

Achieving high toughness and wear resistance for hard TaN-Ag films actuated by Ag

Ceramic-Ag films with enhanced mechanical and tribological properties have been widely researched. Transition metal nitrides (TMNs) films as hard ceramic material with doping Ag atoms commonly show a nano-composite structure and possess the combination of high hardness and toughness. Herein, the TaN film with incorporating few Ag atoms (1.2 at.%) presents FCC solid solution structure according to the HRTEM and XPS results, accompanied by grain refinement. From the XPS valence band and HRTEM, the increased metallic characters in electronic structure of TM-N bonds and the decreased grain size results in the enhanced mechanical properties. The TaN-Ag film with solid-solution structure possesses higher hardness (36.1 GPa) and toughness (KIC = 1.48 MPa*m1/2), combined with an improved wear resistance (wear rate: ∼1.9 × 10−6 mm3/N*m). In addition, a relatively lower coefficient of friction (0.18–0.23) is achieved for TaN-Ag films from the lubrication of AgTaO3 activated by Ag atoms.

(Invited, Digital Presentation) Investigation of Polarization Behavior of HfO2 Thin Films Via Piezoelectric Characterization

Nonvolatile memory based on field-effect transistors with ferroelectric gate dielectrics (FeFET) was first proposed in the 1960s[1]. Later, in the 1990s, FeFETs were proposed to operate as neuromorphic devices and were actively studied[2]. However, it has not been realized due to the difficulty of forming ferroelectric thin films on Si and obtaining a good Si/ferroelectric interface. This situation was greatly changed by the discovery of ferroelectricity in hafnium oxides [3]. Now, FeFETs have attracted attention again due to the high CMOS process compatibility of hafnium oxides as well as their good ferroelectricity even in ultra-thin films. FeFETs have many potential applications, including steep switching transistors and reservoir computing as well as nonvolatile memory. In addition, the understanding of the ferroelectric properties of HfO2-based thin films has been deepened. On the other hand, reliability issues such as robustness, switching endurance, fatigue characteristics, wake-up effects, and imprinting still remain to be addressed for practical applications. These are problems common to ferroelectric thin films, but because HfO2 is an ultra-thin film, they are not easy to analyze. Therefore, in this study, we focused on the evaluation of ferroelectricity by the direct piezoelectric effect. In contrast to the inverse piezoelectric response, the direct piezoelectric response is, in principle, independent of the film thickness, so we expect that the direct piezoelectric response could be analyzed even for HfO2-based thin films.TaN/Hf0.5Zr0.5O2 (HZO)/TaN capacitor was prepared on a Si wafer. TaN electrodes were deposited by DC sputtering method. The thickness of the TaN films was 10 nm. The HZO film was then deposited by the RF magnetron sputtering method using HfO2 and ZrO2 targets. The fabricated capacitor was annealed in a rapid thermal annealing system at 700 °C. The details of the deposition are described in Ref. 4. The direct piezoelectric response of the HZO film was measured using the wafer flexure technique [5]. The strain was applied periodically to the sample, and the charge induced via the direct piezoelectric response wasmeasured using a lock-in amplifier. While the conventional ferroelectric characterization, including the P-E measurement, might be influenced by the space charge, leakage current so on, the direct piezoelectric response only depends on the remaanenrt polarization because there are no other physical phenomena similar to the direct piezoelectric response. We investigated the state of polarization during the retention and wake-up process. The film showed a time-dependent imprint at room temperature during polarization retention. The internal electric field that generated the imprint gradually increased from 0.05 to 0.6 MV/cm. In contrast, the magnitude of the direct piezoelectric response did not change during the polarization retention. Similar analyses were also carried out for the wake-up process. Based on the obtained results, we concluded that the non-ferroelectric layer exists at the interface between the HZO film and TaN electrode and gradually transitions to ferroelectric phases through the electric field cycle[6]. The presentation will also cover the domain observation of HZO films by the direct piezoeelectric response.[1] J. L. Moll and Y. tarui, IEEE trans. Elect. Dev., ED-10, 338 (1963)[2] H. Ishiwara, Jpn. J. Appl. Phys., 32, 442 (1993)[3] T. S. Boscke, J. Muller, D. Brauhaus, U. Schroder, and U. Bottger, Appl. Phys. Lett. 99, 102903 (2011).[4] S. Migita, H. Ota, H. Yamada, K. Shibuya, A. Sawa, and A. Toriumi, Jpn. J. Appl. Phys., Part 1 57, 04FB01 (2018).[5] J. F. Shepard, P. J. Moses, and S. Trolier-McKinstry, Sens. Actuators, A 71, 133 (1998).[6] K. Takada, M. Murase, S. Migita, Y. Morita, H. Ota, N. Fujimura, and T. Yoshimura, Appl. Phys. Lett. 119, 032902 (2021)

Effect of processing conditions on residual stress in sputtered transition metal nitrides (TiN, ZrN and TaN): Experiments and modeling

Stress evolution during reactive DC magnetron sputtering deposition in TiN, ZrN and TaN films at different growth rates, pressures and relative gas flow rates was measured by a wafer curvature technique. The results indicate that, for a given growth rate, the stress in each material is tensile at higher pressures and becomes more compressive with lower pressures. At lower pressures, the stress tends to become more compressive with increasing growth rate. Increasing the gas flow rate of N2 relative to Ar is observed to enhance compressive stress generation in TaN but has a weaker effect on TiN and ZrN. At lower pressure, the compressive stress magnitude scales with TiN < ZrN < TaN. The stress at different processing conditions was analyzed in terms of a kinetic model that includes the effects of growth kinetics and energetic bombardment. The resulting parameters are compared with calculations from binary collision Monte-Carlo simulation codes.

Growth Mechanisms of TaN Thin Films Produced by DC Magnetron Sputtering on 304 Steel Substrates and Their Influence on the Corrosion Resistance

In this work, thin films of TaN were synthesized on 304 steel substrates using the reactive DC sputtering technique from a tantalum target in a nitrogen/argon atmosphere. All synthesis parameters such as gas ratio, pressure, gas flow, and substrate distance, among others, were fixed except the applied power of the source for different deposited coatings. The effect of the target power on the formation of the resulting phases and the microstructural and morphological characteristics was studied using XRD and AFM techniques, respectively, in order to understand the growth mechanisms. Phase, line profile, texture, and residual stress analysis were carried out from the X-ray diffraction patterns obtained. Atomic force microscopy analysis allowed us to obtain values for surface grain size and roughness which were related to growth mechanisms in accordance with XRD results. Results obtained showed a strong correlation between the growth energy with the crystallinity of the samples and the formation of the possible phases since the increase in the growth power caused the samples to evolve from an amorphous structure to a cubic monocrystalline structure. For all produced samples, the δ-TaN phase was observed despite the low N2 content used in the process (since for low N2 content it was expected to be possible to obtain films with α-Ta or hexagonal ε-TaN crystalline structure). In order to determine the corrosion resistance of the coatings, electrochemical impedance spectroscopy and polarization resistance were employed in the Tafel region. The results obtained through this evaluation showed a direct relationship between the power used and the improvement of the properties against corrosion for specific grain size values.

Reactive sputtering deposition and characterization of Ta-N thin films

Reactive sputtering deposition and characterization of Ta-N thin films

Design of Chopsticks-Shaped Heating Resistors for a Thermal Inkjet: Based on TaN Film

Efficient printing frequency is critical for thermal bubble inkjet printing, while the difficulty lies in the structural design and material selection of the heating resistors. In this paper, a TaN film was used as the main material of the heating resistors, and two TaN films were placed in parallel to form the chopsticks-shaped structure. The heating time was divided into two sections, in which 0–0.1 μs was the preheating and 1.2–1.8 μs was the primary heating. At 1.8 μs, the maximum temperature of the Si3N4 film could reach about 1100 °C. At the same time, the SiO2 film was added between the TaN film and Si3N4 film as a buffer layer, which effectively avoided the rupture of the Si3N4 film due to excessive thermal stress. Inside the inkjet print head, the maximum temperature of the chamber reached about 680 °C at 2.5 μs. Due to the high power of the heating resistors, the working time was greatly reduced and the frequency of the inkjet printing was effectively increased. At the interface between the back of the chip and the cartridge, the SiO2 film was used to connect to ensure a timely ink supply. Under the condition of 12 V at 40 kHz, the inkjet chip could print efficiently with 10 nozzles at the same time. The inkjet chip proposed in this paper is not limited to only office printing, but also provides a new reference for 3D printing, cell printing, and vegetable and fruit printing.

Control of the Cu morphology on Ru-passivated and Ru-doped TaN surfaces - promoting growth of 2D conducting copper for CMOS interconnects.

Prolonging the lifetime of Cu as a level 1 and level 2 interconnect metal in future nanoelectronic devices is a significant challenge as device dimensions continue to shrink and device structures become more complex. At nanoscale dimensions Cu exhibits high resistivity which prevents its functioning as a conducting wire and prefers to form non-conducting 3D islands. Given that changing from Cu to an alternative metal is challenging, we are investigating new materials that combine properties of diffusion barriers and seed liners to reduce the thickness of this layer and to promote successful electroplating of Cu to facilitate the coating of high-aspect ratio interconnect vias and to allow for optimal electrical conductance. In this study we propose new combined barrier/liner materials based on modifying the surface layer of the TaN barrier through Ru incorporation. Simulating a model Cu29 structure at 0 K and through finite temperature ab initio molecular dynamics on these surfaces allows us to demonstrate how the Ru content can control copper wetting, adhesion and thermal stability properties. Activation energies for atom migrations onto a nucleating copper island allow insight into the growth mechanism of a Cu thin-film. Using this understanding allows us to tailor the Ru content on TaN to control the final morphology of the Cu film. These Ru-modified TaN films can be deposited by atomic layer deposition, allowing for fine control over the film thickness and composition.

Postcolonial Hangups in Southeast Asian Cinema: Poetics of Space, Sound, and Stability by Gerald Sim (review)

Reviewed by: Postcolonial Hangups in Southeast Asian Cinema: Poetics of Space, Sound, and Stability by Gerald Sim Nadine Chan Postcolonial Hangups in Southeast Asian Cinema: Poetics of Space, Sound, and Stability. By Gerald Sim. Amsterdam: Amsterdam University Press, 2020. 254 pp. ISBN 9048551161. Postcolonial Hangups in Southeast Asian Cinema begins with the premise that not every postcolonial society harbours a relationship of antagonism or disavowal for its colonial past. The author recounts a remark that a taxi driver in George Town, Malaysia, once made to two of the author's British colleagues. After pointing out that Malaysia was once a Crown colony, the cab driver assuaged them of their guilt by saying 'Oh don't worry. […] You [the British] were not as bad as the Japanese.' (p. 23) This is one of the examples that Sim uses to introduce us to the phenomenon of 'postcolonial nostalgia' (p. 24)—a bizarre condition (or affliction?) 'of unconflicted warmth with which some independent Southeast Asian countries remember colonialism' (p. 25). Postcolonial Hangups in Southeast Asian Cinema takes issue with what the author understands to be postcolonial theory's fixation on a politics of resistance. Instead, and contentiously, Sim calls for a new framework for the cinemas of formerly colonized Southeast Asian nations that makes room for ambivalence, and even nostalgia, around colonized pasts. This book, in the author's words, is meant to be read as 'a supplementary and corrective effort to vary and renew postcolonial film studies' (p. 33). Sim explores how the psychic, spatial, and political resonances of Singapore, Malaysia, and Indonesia's colonialization extends into the cinemas of recent decades and articulates with the emergent pressures of global capitalism. The poetics of 'space', 'sound', and 'stability' are the three key ideas around which Sim structures the book—and they are indeed rich and appropriate frameworks. Each of the four chapters showcases Sim's conceptual interventions via illuminating analysis, an extensive filmography, and gripping writing. Despite what the title may suggest, the book's chapters focus on a few countries within maritime Southeast Asia, namely Singapore, Malaysia, and Indonesia. Chapters 1 and 2 look at Singapore film from the Golden Age to the New Wave. In Chapter 1, 'Postcolonial Spatiality', aerial cartography, affective maps, colonial atlases, and their topographical imaginaries trace a fascinating postcolonial poetics of space, power, and history through Singapore film. Chapter 2, 'Reorienting Film History Spatially' extends Sim's generative ideas around postcolonial spatial epistemology to consider a politics of ambivalence and uncertainty in Tan Pin Pin's films which he reads as a symptom of the manufactured 'ahistoricality' of Singapore's late capitalist identity. Chapter 3, 'Postcolonial Cacophonies: Malaysia Senses the World' takes on the soundscape of Yasmin Ahmad's Orked trilogy as telling of Malaysia's postcolonial-global nexus. Chapter 4, 'Postcolonial Myths: Indonesia Americanizes Stability', looks at the psychic resonances of the reformasi era through the fiction of predictability in what the author identifies as the country's 'genre-dominated' cinema. Each of these chapters, particularly Chapter 1, offer thought-provoking analysis that couple critical theory with an intimate appreciation for cinema in the region that comes across clearly in the writing. Left slightly wanting in the introduction however is a stronger explication of how these poetics of 'space', 'sound', and 'stability' offer us a theoretical framework [End Page 224] that fulfils the author's promise for a renewed framework for postcolonial cinema in any definitive way. The book's critique of postcolonial criticism, while well taken, does appear somewhat unforgiving toward a field that has since evolved beyond the polarizing politics of the likes of Solanas and Gettino's 'Third Cinema' (which the author cites as a point of departure). Recent thinking in the larger field of empire/imperial studies has entwined the politics of late capitalism, globalization, and neoliberalism in ways that the author, building on Michael Hardt and Antonio Negri's Empire, seems not to give sufficient credit. Surely it is of little debate that the pressures of our global neoliberal present are extensions of, rather than ruptures from, colonial pasts. Relatedly, certain important premises of the book leave room for doubt; for example, the statement that the sovereignties of Malaysia and...

Development of a 0.15 μm GaAs pHEMT Process Design Kit for Low-Noise Applications

This work presents a process design kit (PDK) for a 0.15 μm GaAs pHEMT process for low-noise MMIC applications developed for AWR Microwave Office (MWO). A complete set of basic elements is proposed, such as TaN thin film resistors and mesa-resistors, capacitors, inductors, and transistors. The developed PDK can be used in technology transfer or education.

Growth optimization of TaN for superconducting spintronics

We have optimized the growth of superconducting TaN thin films on SiO2 substrates via dc magnetron sputtering and extract a maximum superconducting transition temperature of T c = 5 K as well as a maximum critical field μ 0 H c2 = (13.8 ± 0.1) T. This material is of interest for both different fields of quantum technology and superconducting spintronics as it represents a magnetic field-robust superconductor with strong spin–orbit interaction (SOI). After presenting the results of the growth optimization, we investigate in the second part the impact of the strong SOI in TaN on superconductor/ferromagnet heterostructures. To this end, we analyze the magnetization dynamics of both normal state and superconducting TaN/Ni80Fe20 (permalloy, Py)-bilayers as a function of temperature using broadband ferromagnetic resonance spectroscopy. In particular, we quantify the inverse current-induced torques of the bilayers and compare these results to NbN/Py-bilayers. In the normal state of TaN, we detect a positive damping-like current-induced torque σ d from the inverse spin Hall effect and a small field-like torque σ f attributed to the inverse Rashba–Edelstein effect at the TaN/Py-interface. In the superconducting state of TaN, we detect a negative σ d attributed to the quasiparticle mediated inverse spin Hall effect (QMiSHE) and the unexpected manifestation of a large positive field-like σ f of unknown origin matching our previous results for NbN/Py-bilayers. The QMiSHE can be used to probe spin currents in emergent quantum materials.

Stoichiometry tuning of TaN films through ion treatment: Molecular dynamics study

Ion treatment of face-centered cubic and amorphous TaN films is studied using classical molecular dynamics simulations. We investigated the effect of ion type (Ne, Ar, Kr, and Xe) and its energy (50, 100, 150, and 200 eV) on the sputtering yield of Ta and N, surface stoichiometry modification (Ta/N ratio), damage cascade development and ion penetration depths in the films at 598 K temperature. We observed that the N sputtering yield is much higher than Ta in both amorphous (a-TaN) and crystalline fcc-TaN (c-TaN) films; hence, the Ta/N ratio strongly depends on the N sputtering yield. Over the energy range studied, significant surface Ta/N modification is observed when TaN films, both amorphous and crystalline, are treated with Ne and Ar rather than Kr and Xe, mainly because of comparable sizes of Ne and Ar ions to N atoms. The Ta/N ratio is found to increase monotonically with the ion energy irrespective of the ion type and crystalline nature of the film. The average penetration depth of the Ne and Ar is ∼1.0 nm, whereas for Kr and Xe, it is ∼0.5 nm. The penetration depth distribution shows that the collision cascade penetrates deep into the film for Ne and Ar than for Kr and Xe. The collision cascade causes surface erosion, which sputters out Ta and N from the film via secondary ion sputtering. The methodology of ion treatment employed in the present study preserves the bulk properties of the TaN film while obtaining desired stoichiometry close to the film surface.

Sputter-deposited TaCuN films: Structure, tribological and biomedical properties

Stainless steel is a material that is commonly used in brackets and arch wires during orthodontic treatment. However, the high frictional resistance that occurs between stainless steel/stainless steel can reduce the efficiency of orthodontics. Developing protective films is a simple and effective method that can produce low friction in saliva environment. In this study, we investigated the respective mechanical and tribological behaviors of pure TaN film, TaCuN solid solution film and TaN/Cu nanocomposite film. Hardness tests showed that the hardness of TaN and TaN/Cu are approximately 15.6 and 7.3 GPa, respectively. However, TaCuN film has a higher hardness of about 17.6 GPa, which contributes to its excellent wear resistance. The hydrolysis reaction of TaCuN film during friction process turns the saliva environment into a solution containing oxide colloid particles. Moreover, during friction, a Cu2O-induced hydrophobic surface appears. As a result of the colloidal solution with double electric layer repulsion generated by this process and the saliva-lubricating film absorption of the hydrophobic surface, the TaCuN film achieves outstanding tribological properties, with a friction coefficient and wear rate of 0.045 and 1.18 × 10-9 mm3/Nm, respectively. In addition, biological experiments confirm that the TaCuN film is a material with non-toxic and good biocompatibility and that it demonstrates stronger antibacterial ability than stainless steel. Depositing the TaCuN solid-solution film on the arch wires represents an effective approach for the surface modification of orthodontic appliances. Furthermore, TaCuN film could potentially be applied as a protective film in the field of dental treatment.

Study on the Ignition Performance of TaN Transducer by Heat Treatment

In order to obtain good TaN film transducer and reduce its ignition voltage, the influence of the setting position and cooling method of the heat treatment process on the TaN film transducer were compared and analyzed. By measuring the square resistivity, SEM and XRD, the performance of the film before and after heat treatment were characterized. The ignition voltage of the TaN film transducer was tested, and the results showed that the ignition voltage of the heat-treated TaN film transducer could be reduced a lot. It provided a technical way for the micro-energy of MEMS pyrotechnics.