氮化钛膜电极的制备及对多巴胺的检测

Cathodic arc deposition of nanocrystalline titanium nitride thin film on fluorine doped tin oxide coated glass substrate: Crystal structural, microstructural, mechanical, optical and electrical properties

Epitaxial titanium nitride (TiN) and titanium oxynitride (TiON) thin films have been grown on sapphire substrates using a pulsed laser deposition (PLD) method in high-vacuum conditions (base pressure <3 × 10-6 T). This vacuum contains enough residual oxygen to allow a time-independent gas phase oxidation of the ablated species as well as a time-dependent regulated surface oxidation of TiN to TiON films. The time-dependent surface oxidation is controlled by means of film deposition time that, in turn, is controlled by changing the number of laser pulses impinging on the polycrystalline TiN target at a constant repetition rate. By changing the number of laser pulses from 150 to 5000, unoxidized (or negligibly oxidized) and oxidized TiN films have been obtained with the thickness in the range of four unit cells to 70 unit cells of TiN/TiON. X-ray photoelectron spectroscopy (XPS) investigations reveal higher oxygen content in TiON films prepared with a larger number of laser pulses. The oxidation of TiN films is achieved by precisely controlling the time of deposition, which affects the surface diffusion of oxygen to the TiN film lattice. The lattice constants of the TiON films obtained by x-ray diffraction (XRD) increase with the oxygen content in the film, as predicted by molecular dynamics (MD) simulations. The lattice constant increase is explained based on a larger electrostatic repulsive force due to unbalanced local charges in the vicinity of Ti vacancies and substitutional O. The bandgap of TiN and TiON films, measured using UV-visible spectroscopy, has an asymmetric V-shaped variation as a function of the number of pulses. The bandgap variation following the lower number of laser pulses (150-750) of the V-shaped curve is explained using the quantum confinement effect, while the bandgap variation following the higher number of laser pulses (1000-5000) is associated with the modification in the band structure due to hybridization of O2p and N2p energy levels.

Properties of titanium nitride (TiN) films deposited by reactive sputtering and dc magnetron sputtering from composite target are studied. In the as-deposited films, a TiN (200) grain, which is the lowest energy grain and is dominant in bulk TiN, is grown in films from composite target. A resistivity of 44 µΩ-cm is attained. These results show that high quality TiN films can be deposited by dc magnetron sputtering employed TiN composite target. However, a TiN (111) grain is grown in TiN films by the nitridation of Ti. Nitridation of a reactively sputtered TiN film in ammonium is also studied. The TiN films deposited from composite target and formed by the nitridation of titanium show good barrier performance in Al-Si/TiN/Si Ohmic contact.

Reactive magnetron sputtering technique was used to gain titanium nitride (TiN) films on W18Cr4V high-speed steel and GCr15 bearing steel substrates at low temperature. The Surface chemical composition of the films was analyzed using energy dispersive X-ray spectroscopy (EDXS) and the surface morphology was examined using atomic force microscopy (AFM). Moreover, a series of experiments have been conducted to study the relationship between interfacial bonding strength and some major technological parameters, that is, substrate surface roughness, negative bias voltage, intermediate transition layer, substrate hardness, and ion etching before deposition. The experimental results have indicated that the TiN film with typical ratio of chemical metric can be deposited on substrates using reactive magnetron sputtering technique below 140°C. The AFM image has showed that the TiN film using magnetron sputtering technique was composed of densely distributed nano-grains with uniform structure. Its surface was flat and smooth. The indentation testing results have showed that the increase of surface roughness and substrate hardness improves the bonding strength of TiN / substrate significantly. Furthermore, the bonding strength of TiN / substrate can also be improved through the following methods: (1) choosing a proper intermediate transition layer; (2) adopting ion etching before deposition and (3) increasing negative bias voltage before deposition.

Characterization of titanium nitride (TiN) films on various substrates using spectrophotometry, beam profile reflectometry, beam profile ellipsometry and spectroscopic beam profile ellipsometry

This study investigates ultrathin titanium nitride (TiN) films in terms of their crystallographic structure, surface chemistry, sheet resistance and mechanical durability. These TiN ultrathin films were created by Atomic Layer Deposition (ALD) using TiCl4 and NH3 as precursors. The process consisted of 100, 200, 300 and 400 deposition cycles yielding ultrathin films 4.7, 9.4, 14.1 and 18.8 nm in thickness, respectively. Different planar substrates were employed, namely Si wafers, soda lime glasses and Ti foil. Based on image analyses, the deposition rate of 0.047 nm per cycle for ALD TiN (at 400 °C) was determined. A sheet resistance of 287 Ω/□ was achieved for the 18.8 nm film. X-ray diffraction (XRD) analysis confirmed the formation of cubic TiN with increasing crystallinity and texture with increased thickness. Sputter depth profiling in tandem with X-ray photoelectron spectroscopy (XPS) distinguished the uppermost oxidized surface from the stoichiometric TiN core in the films. Scratch tests demonstrated an enhanced adhesion and scratch resistance with ALD TiN films, aligned with the observed microstructural improvements. The comprehensive correlation between the film thickness, and their chemical composition, crystalline structure and mechanical performance highlights the vital role of ALD parameters in preparing TiN thin films for advanced technological applications.

Retention mechanism and conductivity corrosion resistance performance of Ag doped GLC and TiN films for metal bipolar plates

We have shown that titanium nitride (TiN) coating by activated reactive evaporation using the hollow cathode discharge method is a good surface treatment for stainless steel used in extremely high vacuum (XHV) applications. The TiN film blocks hydrogen diffusion because it has a much lower hydrogen permeation coefficient than stainless steel. By varying the coating and film parameters (e.g., thickness, composition, and substrate bias voltage Vb) the barrier effects on hydrogen permeation of the TiN films were evaluated using small membrane samples. The parameters were varied to optimize the properties of the TiN coating for vacuum materials. The structure of the TiN films was analyzed by an x-ray diffractometry and transmission electron microscopy to clarify the dependence of the barrier effect on the film structure. Stoichiometric TiN films with few defects were shown to have high barrier effects. To demonstrate the use of TiN coatings for XHV applications, the outgassing rates of a stainless steel chamber with and without a TiN film were measured by a modified throughput type apparatus that had a bakeable cryopump for obtaining XHV. The outgassing rates for the chambers were measured using a method which completely eliminated the outgassing contribution of the vacuum gauges. The nitrogen equivalent outgassing rates of the stainless steel chamber with and without a TiN film were 7×10−12 and 9.7×10−10 Pa m s−1, respectively.

A fabrication method for field emitter array of carbon nanotubes with improved carbon nanotube rooting

The interaction of a picosecond Nd:YAG laser (wavelength 532 nm, pulse duration 40 ps) with a polycrystalline titanium nitride (TiN) film was studied. The TiN thin film was deposited by physical vapour deposition on a silicon substrate. The titanium nitride/silicon system was modified with an energy fluence from 0.2 to 5.9 J cm−2. Multi-pulse irradiation was performed in air by a focused laser beam. Surface modifications were analysed after 1–100 successive laser pulses. Depending on the laser pulse energy and pulse count, the following phenomena were observed: (i) increased surface roughness, (ii) titanium nitride film cracking, (iii) silicon substrate modification, (iv) film exfoliation and (v) laser-induced periodical surface structures on nano- (NPSS) and micro-dimensions (MPSS).

Titanium nitride (TiN) films were deposited using tetrakis(dimethylamido)titanium (TDMAT) as a precursor. During film growth, N‐ and Ar‐ion beams with an energy of 120 eV were supplied in order to improve the film quality. The films deposited using a N‐ion beam showed a resistivity of about 320 μΩ cm and density of . The use of the N‐ion beam, however, drastically degraded the step coverage of the film (below 5% at the 0.5 × 1.5 μm contact). The films deposited using an Ar‐ion beam showed a resistivity of about 800 μΩ cm and density of . The step coverage measured at the same contact was around 30%. For comparison, the thermally decomposed film showed a resistivity of about 5800 μΩ cm and density of . Finally, the diffusion barrier properties of 50 nm thick TiN films for Cu were investigated by the etch‐pit test. The films deposited using N‐ and Ar‐ion beam failed after annealing at 600 and 650°C for 1 h, respectively, while thermally decomposed films failed at temperatures as low as 500°C. It is thought that the improvements of the diffusion barrier performance of the films deposited using a N‐ and Ar‐ion beam are the consequence of the film densification resulting from ion bombardment during film growth. © 2000 The Electrochemical Society. All rights reserved.

Effects of magnetic field strength and deposition pressure on the properties of TiN films produced by high power pulsed magnetron sputtering (HPPMS)

We propose a new chemical vapor deposition (CVD) process, the flow modulation chemical vapor deposition (FMCVD) process, to obtain high quality titanium nitride (TiN) films at low deposition temperature in a single CVD chamber. FMCVD uses sequential deposition and reduction processes, such as the deposition of TiN films followed by chlorine reduction. This cycle was repeated to achieve sufficient film thickness. By decreasing the thickness in one cycle, the residual chlorine concentration and the resistivity of the films decreased. Using FMCVD process, we could achieve low resistivity (250 µΩcm), low residual chlorine concentration (2 at.%) with uniform step coverage at low deposition temperature (380°C).

Dependence of diffusion barrier properties in microstructure of reactively sputtered TiN films in Al alloy/TiN/Ti/Si system

Hf0.5Zr0.5O2 (HZO), as a novel and outstanding ferroelectric material, exhibits an extremely high sensitivity, rendering it quite susceptible to electrode effect. Titanium nitride (TiN) is a commonly employed as electrode material in the complementary metal-oxide-semiconductor (CMOS) process. Adjusting the process parameters of preparing TiN film can alter matching degree with HZO, so as to find the optimal parameters of TiN process to improve ferroelectric property of HZO. In this study, the impact of key process parameters in atomic layer deposition (ALD) TiN, including cycle number, TiCl4 and NH3 pluse time, process temperature (Tp) on film thickness, crystalline phases of TiN, square resistivity (Rs), surface average roughness (Ra) and the root-mean-square roughness (Rq) of TiN film are comprehensively investigated. Through optimization, ~10nm ALD TiN film can achieve excellent uniformity of 0.43%, low Rs of 286.9Ω/sq, improved Ra and Rq of 1.82Å and 2.28Å. The results show that the maximum 2 times remnant polarization (2Pr) of the HZO ferroelectric capacitor with optimized TiN electrodes can reach 36.34µC/cm2, and the switching cycle endurance exceeds 1E7.&amp;#xD;