Titanium Nitride Thin Films Research Articles

Dataset for TiN Thin Films Prepared by Plasma-Enhanced Atomic Layer Deposition Using Tetrakis(dimethylamino)titanium (TDMAT) and Titanium Tetrachloride (TiCl4) Precursor.

A dataset in this report is regarding an article “Ultrathin Effective TiN Protective Films Prepared by Plasma-Enhanced Atomic Layer Deposition for High Performance Metallic Bipolar Plates of Polymer Electrolyte Membrane Fuel Cells” [1]. TiN (Titanium Nitride) thin films were deposited by Plasma-Enhanced Atomic Layer Deposition (PEALD) method using well known two types of precursor: using tetrakis(dimethylamino)titanium (TDMAT) and titanium tetrachloride (TiCl4), and plasma. Summarized reports, growth characteristics (growth rate as a function of each precursor pulse time, plasma power, precursor and plasma purge time, thickness depending on the number of PEALD cycles), each precursor structural information and the atomic force micrographs (AFM) data are herein demonstrated. For TDMAT-TiN, N2 plasma was used as a reactant whereas, H2+N2 plasma was used as TiCl4-TiN reactant. To apply the bipolar plate substrate, two types of TiN thin films were introduced into Stainless steel (SUS) 316L.

Transparent Microelectrode Arrays Fabricated by Ion Beam Assisted Deposition for Neuronal Cell in Vitro Recordings.

Microelectrode array (MEA) is a tool used for recording bioelectric signals from electrically active cells in vitro. In this paper, ion beam assisted electron beam deposition (IBAD) has been used for depositing indium tin oxide (ITO) and titanium nitride (TiN) thin films which are applied as transparent track and electrode materials in MEAs. In the first version, both tracks and electrodes were made of ITO to guarantee full transparency and thus optimal imaging capability. In the second version, very thin (20 nm) ITO electrodes were coated with a thin (40 nm) TiN layer to decrease the impedance of Ø30 µm electrodes to one third (1200 kΩ → 320 kΩ) while maintaining (partial) transparency. The third version was also composed of transparent ITO tracks, but the measurement properties were optimized by using thick (200 nm) opaque TiN electrodes. In addition to the impedance, the optical transmission and electric noise levels of all three versions were characterized and the functionality of the MEAs was successfully demonstrated using human pluripotent stem cell-derived neuronal cells. To understand more thoroughly the factors contributing to the impedance, MEAs with higher IBAD ITO thickness as well as commercial sputter-deposited and highly conductive ITO were fabricated for comparison. Even if the sheet-resistance of our IBAD ITO thin films is very high compared to the sputtered one, the impedances of the MEAs of each ITO grade were found to be practically equal (e.g., 300–370 kΩ for Ø30 µm electrodes with 40 nm TiN coating). This implies that the increased resistance of the tracks, either caused by lower thickness or lower conductivity, has hardly any contribution to the impedance of the MEA electrodes. The impedance is almost completely defined by the double-layer interface between the electrode top layer and the medium including cells.

THE EFFECT OF RATIO OF GAS MIXTURE FOR MECHANICAL PROPERTIES AND CRYSTAL STRUCTURES ON 316L STAINLESS STEEL BIOMATERIAL USING DC SPUTTERING TECHNIQUE

316L stainless steel is widely used as an orthopedic implant due to its high corrosion resistance and biocompatibility, but the weakness of these materials is low hardness and high wear. The surface must be modified to improve the material. For the purpose, a titanium nitride (TiN) thin film was deposited on the surface of SS 316L using DC sputtering technique. The sputtering process was carried out for various of a gas mixture of argon (Ar) and nitrogen (N2) such as 90 Ar: 10N2, 80 Ar: 20 N2, 70 Ar: N2, and 60 Ar: 40 N2, while the other parameters kept constant. The objective of the gas mixture variation is to find out the optimum condition of ratio Ar: N2 gas mixture with the highest hardness and lowest wear resistance. From experiment done it’s found that the highest hardness in order of 232.02 VHN, while before being coated the hardness is 133.61 VHN, or there is an increasing hardness by factor 1.73, while the wear resistance reduces from 11.6 × 10-8 mm2/kg to 1.17 × 10-8 mm2/kg or there is reducing in wear resistance by factor 9.9. The optimum conditions were achieved at Ar: N2 ratio = 70:30. From XRD analysis, it can be concluded that the crystal structure of TiN thin film is cubic with the peaks (111), (200), (202), (311) and (222). From cross-section microstructure analysis using Scanning Microscope Electron (SEM), it’s found the thickness of the thin film is 744 nm.

Imaging of surface plasmon polaritons in low-loss highly metallic titanium nitride thin films in visible and infrared regimes.

Titanium nitride (TiN) has been identified as a promising refractory material for high temperature plasmonic applications such as surface plasmon polaritons (SPPs) waveguides, lasers and light sources, and near field optics. Such SPPs are sensitive not only to the highly metallic nature of the TiN, but also to its low loss. We have formed highly metallic, low-loss TiN thin films on MgO substrates to create SPPs with resonances between 775-825 nm. Scanning near-field optical microscopy (SNOM) allowed imaging of the SPP fringes, the accurate determination of the effective wavelength of the SPP modes, and propagation lengths greater than 10 microns. Further, we show the engineering of the band structure of the plasmonic modes in TiN in the mid-IR regime and experimentally demonstrate, for the first time, the ability of TiN to support Spoof Surface Plasmon Polaritons in the mid-IR (6 microns wavelength).

Enhancement in corrosion resistance and vibration damping performance in titanium by titanium nitride coating

Titanium nitride (TiN) thin films are deposited on titanium (Ti) substrates by pulsed laser deposition and radio frequency magnetron sputtering. The main goal of this research is to improve the corrosion resistance and the vibration damping performance of the Ti substrates by surface modification of the substrates with TiN thin film coatings. Electrochemical results indicate that TiN films bring about a significant improvement in the corrosion resistance of the Ti disks in phosphate buffer saline solution. It is also observed that TiN deposited at room temperature has the best corrosion efficiency in terms of lower corrosion current density and more positive corrosion potential. From the damping measurements, it is observed that the damping ratios of the TiN-coated beams are one to two orders of magnitude greater than those of uncoated ones. Additionally, the damping amplitudes of the TiN coated beams have been observed to return to zero position faster than the uncoated beam. The energy dissipation due to internal friction at the beam-coating interface and inter-lamellae interface within TiN coatings can be the mechanism responsible for reducing vibration amplitudes of TiN-coated beams.

Grid-assisted magnetron sputtering deposition of nitrogen graded TiN thin films

Titanium Nitride (TiN) films were obtained using the grid-assisted magnetron sputtering deposition technique on Al substrates in two conditions: under constant and variable nitrogen concentration along the thin solid film thickness. The formation of a film with variable N concentration (herein referred as graded film) was confirmed using energy filtered transmission electron microscopy, X-ray photoelectron spectroscopy and grazing incidence X-ray diffraction. The TiN thin films microstructures were also analysed using scanning and transmission electron microscopies (SEM and TEM). The viability of synthesizing TiN thin films with variable N concentration is herein proposed as an alternative method for tailoring the properties of such functional coating materials.

Surface enhanced Raman scattering on ion-beam-deposited [formula omitted]/Si substrates

Titanium nitride (TiNx) thin films were fabricated on silicon substrates by ion beam deposition. The surface enhanced Raman scattering (SERS) effect of the TiNx/Si substrates was studied with Rhodamine 6G as probe molecule. The results show that TiNx thin films can enhance the Raman signal, and the film with suitable thickness can significantly improve the SERS performance. For the 30 nm thick TiNx thin films the enhancement factor is up to 6.6×104. The enhancement factor can be further improved several times by assisting ions. The main role of the assisting ions is to enhance the intensity and density of hot spots through the modification of surface morphology and plasmons. The study implies that high carrier concentration, and suitable size and high density of the grains and gaps are important for improving SERS performance. This work indicates the promising future of TiNx and assisting ions in the development of SERS active templates.

Implementation of the new minimum resultant error approach to extract elastic-plastic properties of titanium nitride thin film by nanoindentation, finite element analysis, and modified dimensional analysis

Obtaining the plastic properties of thin film coatings has been the main challenge for decades. Implementing the hybrid methods seems to be an applicable way to address this issue. Unfortunately, limitations of nonunique answers together with the need for enormous amount of calculations are counted as the main challenges. To overcome such difficulties, a modified dimensional analysis method is proposed, which is able to reduce the number of dimensionless parameters. Another novel algorithm named “minimum resultant error method” is developed to provide proper criteria to investigate the compliance of the analytical results with empirical data. With this algorithm, yield stress, strain hardening exponent, and strain hardening coefficient are extracted as unique values by using a single indenter nanoindentation results. The simulation results are processed with combined modified dimensional analysis method and minimum resultant error method algorithms. The effects of interlayer, friction coefficient, and indenter tip radius are investigated. Error analysis to the modulus of elasticity is undertaken and the results show less than 2% error for the infimum point, while the individual dimensionless functions errors are below 3.4%. According to the results, this new approach is well-coped with the earlier studies.

Structural properties of TiN thin films prepared by RF reactive magnetron sputtering

In this present work, thin films of Amorphous Titanium Nitride (TiN) were deposited on suitably cleaned oxidized p-type silicon (SiO2) substrates with few nanometers in thickness by Radio Frequency (R.F.) reactive magnetron sputtering at room temperature. The structural and morphological changes of amorphous TiN thin films was investigated at three different gas ratios such as R[Ar/N2 = 1:1, 1:2 and 1:5] and corresponding films thickness were measured at 14 to 18 nm using profilometer. X-ray diffraction technique (XRD) was used to investigate the crystal structure of the as-deposited films, which confirms that amorphous films have been formed during the deposition. Field emission scanning electron microscopy (FE-SEM) analysis was employed to examine the surface morphology of the films which reveals that sputter deposited particles forming globular aggregates of ∼20 nm diameter; typical of magnetron sputtering deposition. The structural variation, crystallinity and defects of the thin films were studied by Raman spectroscopy.

Plasmonic titanium nitride via atomic layer deposition: A low-temperature route

To integrate plasmonic devices into industry, it is essential to develop scalable and CMOS compatible plasmonic materials. In this work, we report high plasmonic quality titanium nitride (TiN) on c-plane sapphire grown by plasma-enhanced atomic layer deposition. TiN with low losses, high metallicity, and a plasma frequency below 500 nm was achieved at temperatures less than 500 °C by exploring the effects of chemisorption time, substrate temperature, and plasma exposure time on the material properties. A reduction in chemisorption time mitigates premature precursor decomposition at TS > 375 °C, and a trade-off between reduced impurity concentration and structural degradation caused by plasma bombardment is achieved for 25 s plasma exposure. 85 nm thick TiN films grown at a substrate temperature of 450 °C, compatible with CMOS processes, with 0.5 s chemisorption time and 25 s plasma exposure exhibited a high plasmonic figure of merit (|ε′/ε′′|) of 2.8 and resistivity of 31μΩcm. As a result of the improved quality, subwavelength apertures were fabricated in the TiN thin films and are shown to exhibit extraordinary transmission.

Narrow‐Band Thermal Emitter with Titanium Nitride Thin Film Demonstrating High Temperature Stability

AbstractA refractory wavelength selective thermal emitter is experimentally realized by the excitation of Tamm plasmon polaritons (TPPs) between a titanium nitride (TiN) thin film and a distributed Bragg reflector (DBR). The absorptance reaches nearly unity at ≈3.73 μm with the bandwidth of 0.36 μm in the experiment. High temperature stabilities are confirmed up to 500 and 1000 °C in ambient and in vacuum, respectively. When the TiN TPP structure is compared to the TiN–insulator–TiN (TiN‐metal–insulator–metal (MIM)) structure, the former shows higher Q‐factor, which indicates the advantage of choosing the TiN TTP structure against the MIM structure. The proposed refractory TiN TPP structure is lithography‐free and scalable, which paves a way for large scale thermal emitters in practical usage.

Investigation of strain and stoichiometry of epitaxial titanium nitride on sapphire

Titanium nitride (TiN) is a recent material of interest for plasmonics and electrodes due to its high-temperature stability, robustness, and CMOS-compatibility. Previously we found that optical plasmonic quality correlated with the microstructural quality of TiN, and both properties depended on deposition temperature: TiN grown at 550 °C resulted in favorable optical properties for plasmonic materials. The present work investigates strain and stoichiometry of TiN films as a result of varying deposition temperature. Six (111)-oriented TiN films were grown on c-sapphire with reactive magnetron sputtering; substrate temperatures ranged from 280 °C to 760 °C. The TiN films were analyzed with x-ray photoelectron spectroscopy, x-ray diffraction, and high-resolution transmission electron microscopy to examine composition, strain, lattice constants, unit cell angles, dislocation defects, mosaicity, and low-angle tilt boundaries. We found that lattice constants only remained a constant 4.242 Å at temperatures above 490 °C. Above this substrate temperature the deviation from a 90˚ unit cell angle remained at a minimum, indicating less strain. When combined with the previously-found plasmonic material properties of the films, this trend suggests that more relaxed films grow above 490 °C and yield lower relative optical loss, and favorable plasmonic material quality factors. Rocking curves suggested fewest dislocation defects and least mosaicity in the optically favorable 550 °C film. The results of this work indicate that microstructure, most significantly strain and defects, correlates with optical properties in TiN. This work emphasizes the importance of specific deposition conditions—in this case, substrate temperature—to minimize strain and defect density for achieving optimal plasmonic properties for TiN thin films.

Disordered Nonlinear Metalens for Raman Spectral Nanoimaging.

Over the past decades, considerable progress has been made toward far-field optical imaging beyond the diffraction limit. However, most working proof-of-concepts are based on either time-consuming scanning of a subdiffraction focal spot over a sample or postrecovery treatment using a priori information on a sought image. To our knowledge, none of these can be regarded as being close to a perfect far-field superlensing system capable of real-time color imaging with subwavelength resolution. In this paper, we suggest a proof-of-concept for far-field nonlinear metalens that is made of a disordered metal-dielectric nanocomposite. Postoxidation of a refractory titanium nitride (TiN) thin film, used as a nonlinear plasmonic material, results in the formation of a titanium oxynitride (TiON) film comprising a mixture of multiple phases of TiOxNy. Due to a double epsilon-near-zero behavior near the percolation threshold, the TiON favors supercoupling of the incident light to surface plasmon resonance within the visible and near-infrared range. Point spread function narrowing is achieved owing to the multiplicative nature of stimulated Raman scattering (SRS) and enhanced third-order optical nonlinearity in TiN and TiO2 particle chains through plasmon resonances and Anderson localization of light, respectively. Combined with a conventional confocal optical microscope, the multimode metalens shows subwavelength resolution of λ/6NA at different visible wavelengths (SRS overtones) using multiwalled carbon nanotubes as a test sample. We are confident that our finding will bring us one step closer to developing a robust and versatile far-field super-resolution color imaging system and, eventually, implementing "eye-on-a-chip" technology.

Bidirectional properties of TiC, TiN and TiNC thin films deposited by radio frequency magnetron sputtering.

Titanium nitride (TiN), titanium carbide (TiC) and titanium carbonitride (TiNC) thin films show promising practical applications due to their photoelectric properties and corrosion behaviour. In this work, we investigated the factors which may affect the optical properties and the corrosion behaviour of these coatings. The titanium coatings were carried out by sputtering using the target of Ti6Al4V (purity 99.96%) with different N2, CH4 and Ar partial pressures. XRD, FTIR, Raman and SEM with EDX studies show the formation of titanium nitride, titanium carbide coatings. Uv-vis spectroscopy was carried out to estimate the optical properties using the numerical Swanepoel method. Potentiodynamic polarization studies in Hank's solution show that the corrosion resistance is found to be in the order of C-TiN(2) > C-TiN(1) > TiN > TiC. A high protective efficiency was determined (60%) when comparing TiNC(2) and TiC corrosion current densities, which confirms the lower corrosion velocity and the higher passivation stability of the coatings composed with TiN and TiC phases. Electrochemical impedance spectroscopy studies show that the Rct increases in the following order: TiC < TiN < C-TiN(1) < C-TiN(2), highlighting the fact that C-TiN(2) coating has the higher corrosion resistance.

The microstructure and mechanical properties of Ti(CoCr)N films produced by DC magnetron sputtering

Titanium nitride (TiN) thin films have excellent physical and chemical properties, and are widely used as cutting tools, drills and die protective coatings. However, their limited hardness and corrosion resistance caused by the rough, loose, columnar structure will affect its application in extreme environments. TiN films with refined grains and nanostructure might solve this problem. In this paper, Co and Cr atoms were doped into TiN film to tailor its structure. The effects of Co and Cr content on the Ti(CoCr)N film structure, mechanical properties and corrosion resistance were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), atomic force microscopy (AFM), microhardness tester and electrochemical corrosion tester. The results show that Co and Cr doping can disturb the columnar growth of TiN films, and lead to refinement of TiN grains. Compared to TiN films without Co and Cr doping, the hardness of Ti(CoCr)N with 2.7 at.% Co and 1.9 at.% Cr increases by about 37% to 31.3 GPa. And Ti(CoCr)N films with 2.7 at.% Co and 1.9 at.% Cr have the best corrosion resistance.

Adhesion-Increased Carbon Nanowalls for the Electrodes of Energy Storage Systems

Carbon nanowalls (CNWs), which are used as electrodes for secondary batteries in energy storage systems (ESSs), have the widest reaction surface area among the carbon-based nanomaterials, but their application is rare due to their low adhesion with substrates. Indium tin oxide (ITO), a representative transparent conducting oxide (TCO) material, is widely used as the electrode for displays, solar cells, etc. Titanium nitride (TiN) is a well-used material as an interlayer for improving the adhesion between two materials. In this study, ITO or TiN thin films were used as an interlayer to improve the adhesion between a CNW and a substrate. The interlayer was deposited on the substrate using a radio frequency (RF) magnetron sputtering system with a four-inch TiN or ITO target. CNWs were grown on the interlayer-coated substrate using a microwave-plasma-enhanced chemical vapor deposition (MPECVD) system with a mixture of methane (CH4) and hydrogen (H2) gases. The adhesion of the CNW/interlayer/substrate structure was observed through ultrasonic cleaning.

DEVELOPMENT AND EXPERIMENTAL STUDIES OF METHODS FOR INCREASING THE STABILITY OF MATERIALS OF ACCELERATING STRUCTURES TO HIGH VACUUM ELECTRICAL DISCHARGES

The experimental technique is described and the results of a study of the resistance to high vacuum electrical breakdowns of copper samples coated with thin films of titanium nitride are presented. The studies were carried out in a two-electrode system having the so-called “plane-tip” configuration. Using the method of X-ray diffractometry, we studied the effect of the structure of titanium nitride films on their efficiency as a material that reduces the probability of breakdown.

Effect of frequency and pulse-on time of high power impulse magnetron sputtering on deposition rate and morphology of titanium nitride using response surface methodology

Abstract Titanium nitride thin films were deposited on silicon by high power impulse magnetron sputtering (HiPIMS) method at different frequencies (162−637 Hz) and pulse-on time (60−322 μs). Response surface methodology (RSM) was employed to study the simultaneous effect of frequency and pulse-on time on the current waveforms and the crystallographic orientation, microstructure, and in particular, the deposition rate of titanium nitride at constant time and average power equal to 250 W. The crystallographic structure and morphology of deposited films were analyzed using XRD and FESEM, respectively. It is found that the deposition rate of HiPIMS samples is tremendously dependent on pulse-on time and frequency of pulses where the deposition rate changes from 4.5 to 14.5 nm/min. The regression equations and analyses of variance (ANOVA) reveal that the maximum deposition rate (equal to (17±0.8) nm/min) occurs when the frequency is 537 Hz and pulse-on time is 212 μs. The experimental measurement of the deposition rate under this condition gives rise to the deposition rate of 16.7 nm/min that is in good agreement with the predicted value.

Highly Plasmonic Titanium Nitride by Room-Temperature Sputtering

Titanium nitride (TiN) has recently emerged as an attractive alternative material for plasmonics. However, the typical high-temperature deposition of plasmonic TiN using either sputtering or atomic layer deposition has greatly limited its potential applications and prevented its integration into existing CMOS device architectures. Here, we demonstrate highly plasmonic TiN thin films and nanostructures by a room-temperature, low-power, and bias-free reactive sputtering process. We investigate the optical properties of the TiN films and their dependence on the sputtering conditions and substrate materials. We find that our TiN possesses one of the largest negative values of the real part of the dielectric function as compared to all other plasmonic TiN films reported to date. Two-dimensional periodic arrays of TiN nanodisks are then fabricated, from which we validate that strong plasmonic resonances are supported. Our room-temperature deposition process can allow for fabricating complex plasmonic TiN nanostructures and be integrated into the fabrication of existing CMOS-based photonic devices to enhance their performance and functionalities.

Wrinkled titanium nitride nanocomposite for robust bendable electrodes

Electrical contacts and interconnections are critical components for all electronic devices. Bendable electrodes with enhanced electro-mechanical properties are highly desirable to develop innovative wearable electronic devices. Herein we report on a fabrication method for robust bendable coatings based on titanium nitride (TiN) thin films and silver nanowires (Ag NWs). TiN and TiN-AgNWs nanocomposites were deposited on polyethylene terephthalate (PET) substrates using a plasma enhanced pulsed laser deposition (PLD) technique. The resulting TiN coatings exhibit excellent adhesion to PET and their sheet resistance can be tuned using a dual frequency PLD process and further decreased by incorporating Ag NWs into the TiN layers. Sample sheet resistance was decreased down to values as low as corresponding to the formation of TiN-AgNWs nanocomposites. The electro-mechanical robustness of TiN based coatings were evaluated by four-probe resistance measurements in situ under cyclic bending tests. We show that the TiNAgNWs nanocomposites surpass both ITO and Ag NWs coatings in terms of mechanical robustness and electrical conductivity respectively. These nanocomposites withstand high strain fatigue loading up to ϵ = 2.6%, keeping RS below 5 Ω/□. The data demonstrates that the incorporation of Ag NWs in TiN coatings improve the mechanical robustness, limiting the crack growth and propagation, with low optical transmittance decrease (≈11%). These results indicate that Ag NWs based nanocomposites are attractive materials for flexible electronic devices.