Microstructure Of TiN Research Articles

Microstructure and Electrochemical Properties of PVD TiN, (Ti, Al) N-Coated Ti-Based Bulk Metallic Glasses

In this study, the microstructure and electrochemical properties of PVD TiN and (Ti, Al) N coatings on Ti40Zr10Cu36Pd14 bulk metallic glass were investigated. The microstructure of TiN or (Ti, Al) N coatings, the BMG substrate and the interface was investigated by highresolution transmission electron microscopy. The electrochemical behavior of PVD coatings on the Ti-based BMG was studied by measuring potentiodynamic polarization curves in Hanks’ solution. HREM observation revealed that the sputtering TiN ((Ti, Al) N) coating consisted of cubic TiN ((Ti, Al) N) phase with a lattice parameter of 0.426 (0.422) nm in nanoscale. The polarization curves showed that the open circuit potential shifted to a more positive potential and the passive current density decreased due to the protective TiN or (Ti, Al) N coating. [doi:10.2320/matertrans.ME200820]

Fabrication and characterization of TiN–Ag nano-dice

TiN–Ag nanocomposite was synthesized by dc arc-plasma method. Microstructures of TiN–Ag nanocomposite were carefully characterized by powder X-ray diffraction method and transmission electron microscopy, and nano-morphologies by three-dimensional electron tomography. It was found that the surface of nanocrystalline TiN matrix was densely covered by finely dispersed Ag nanoparticles, and it was found that they were physically attached but not chemically bonded from their orientation relationships.

Contact Failure Analysis of Nitrided 32Cr2MoV Coated with TiN by Multi-Arc Ion Plating

In this paper, TiN coating was deposited onto the nitrided 32Cr2MoVA by multi arc ion plating and proceeded line contact fatigue experiment to investigate the influence of hard coatings on the contact failure properties of nitriding steel. The results of experiment show that pitting is primary type of contact fatigue failure for TiN coated 32Cr2MoV and the pits on the TiN coated surface are shallower and smaller than that of the nitrided 32Cr2MoV. After TiN coating produce crisping and desquamation under higher contact fatigue loads, the exposed matrix surface begin to bear the contact load. The superficial microstructure of TiN coated 32Cr2MoV was more fine, and content of nitrides were higher than that of the nitrided, which insured the distribution of hardness gradient of subsurface was more rational than that of nitrided 32Cr2MoV. The contact fatigue strength of TiN coated 32Cr2MoV is greater about 200MPa than that of the nitrided 32Cr2MoV.

Experimental studies on epitaxially grown TiN and VN films

TiN and VN single-layers were grown on (100) and (111) MgO substrates as model systems for future studies of V diffusion and understanding the evolution of the lubricous V 2O 5 phase on coating surfaces. The present study aims at elucidating the epitaxial quality and microstructure of TiN and VN films grown by unbalanced d.c. magnetron sputtering from Ti and V targets in Ar + N 2 on (100) and (111) MgO substrates. X-ray diffraction and electron back-scatter diffraction give evidence for epitaxial growth of the films on both MgO substrate orientations. Transmission electron microscopy studies reveal a cube-on-cube orientation for all film/substrate combinations. The higher dislocation density and larger fraction of misoriented grains for VN films on MgO is explained by the higher growth rate and lattice mismatch compared to TiN. Nanoindentation measurements of the (100) oriented single-crystal films reveal hardness values of ∼35 GPa for TiN and ∼23 GPa for VN.

Incremental recrystallization/grain growth driven by elastic strain energy release in a thermomechanically fatigued lead-free solder joint

A single shear lap solder joint specimen with lead-free eutectic Sn–Ag solder on copper substrates was exposed to 1500 thermomechanical fatigue (TMF) cycles between −15° (3.5 h) and 150 °C (20 min) to generate intrinsic thermal strains. The 0.15-mm-thick solder joint had a cross-sectional area of 1 mm 2. Orientation imaging microscopy was used to examine changes in the tin microstructure as a function of the number of TMF cycles. The tin phase consisted of embedded minority orientations within an initial dominant orientation, which varied by about 25° from one end of the joint to the other, by means of lattice curvature and low angle boundaries. Between about 150 and 750 cycles, an incremental recrystallization/grain growth process occurred where a minority solidification twin orientation grew and consumed the dominant initial orientation. An elastic FEM analysis incorporating anisotropic thermal expansion and elastic constants indicated that the final orientation had an internal stress state that was 20–100% smaller than the initial orientation, when subjected to a temperature change. The release of elastic strain energy provided the thermodynamic driving force for recrystallization/grain growth.

The Texture Effect on Diffusion Barrier Property on TiN Films between Copper and Si Wafer

TiN thin films are widely used as a coating material due to their good mechanical and conductivity properties, high thermal properties, strong erosion and corrosion resistance. Also TiN has been used in Si devices as a diffusion barrier material for Al and Cu-based metallization. The uniform and dense structure of thin films is influenced by the texture of films. It was good to have uniform and dense structure and bad to have an open columnar structure in TiN thin films. Therefore, the property of diffusion barrier of the TiN films in semiconductor also is related to the texture and microstructure of TiN coated layer. In this study, the relationship between the texture and microstructure and the best diffusion barrier propertiy of TiN coated films (by PVD and MOCVD) on semiconductor devices (Cu/TiN/SiO2/Si layer) were investigated under different processing conditions and textures. The property of diffusion barrier for Cu of physical vapor deposited TiN thin films is better than that of metal organic chemical vapor deposited TiN thin films. Also the property of diffusion barrier for Cu of (111) textured TiN thin films is better than that of (200) textured TiN thin films.

Preparation and Characterization of Tin Doped Tetra-Pod Shaped Zinc Oxide

Tin doped tetra-pod shaped ZnO (T-ZnO) were fabricated by equilibrant airflow reaction method. The microstructure of tin doped T-ZnO was characterized by X-ray Diffraction analysis and Scanning Electron Microscope. The results demonstrated that most of tin acted as a catalyst during the ZnO crystal growth process and the others reacted with ZnO to generate Zn2SnO4. Tin had catalytic influences on the morphology of T-ZnO, which promoted predominant growth on the c axis of ZnO crystal at the addition of 15% in weight and advanced the growth on the a axis at higher weight proportion.

The Texture and Property of Diffusion Barrier of TiN Thin Films

The uniform and dense structure of thin films is influenced by the texture of films. It was good to have uniform and dense structure and bad to have an open columnar structure in TiN thin films. Therefore, the property of diffusion barrier of the TiN films in semiconductor also is related to the texture and microstructure of TiN coated layers. In this study, the relationships between the textures and microstructures and the properties of TiN films on semiconductor were investigated under different processing methods (PVD and MOCVD). The property of diffusion barrier of RF sputtered (PVD) TiN is better than that of metal organic chemical vapor deposited (MOCVD) TiN thin films. Also the property of diffusion barrier of PVD (111) textured TiN is better than that of PVD (100) textured TiN thin films on oxidized Si wafer.

Self-Lubrication of Chlorine-Implanted Titanium Nitride Coating

Chlorine implantation into TiN coatings decreases the wear loss and the friction coefficient. Even by low-dose chlorine implantation, the wear volume is decreased by three orders of magnitude or more, and the friction coefficient becomes <0.1. This self-lubrication mechanism is related to the presence and mobility of implanted chlorine atoms inside the columnar TiN microstructure. According to observations of chlorine-implanted TiN coatings using high-resolution transmission electron microscopy, the chlorine atoms are present in the damaged region, where TiN is composed of nanosized grains. From these data, a self-lubrication mechanism is proposed with chlorine catalyzing the oxidation of titanium and leading to the formation of some tribological reaction product.

X-Ray photoelectron spectroscopy characterization of reactively sputtered Ti–B–N thin films

Sputter-deposited thin films of Ti–B–N with different B contents were studied using X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and nanoindentation measurements in order to investigate the microstructure transformation process upon increasing B content and to find the optimal microstructure corresponding to the highest hardness. The results indicated that part or all of the four phases, TiB, TiB 2, TiN and BN, existing in the reactively sputtered Ti–B–N thin films, depending on the B content. The films with a small amount of B addition were essentially cubic B1–NaCl TiN with (111) preferred orientation to the substrate surface, plus small amounts of TiB and BN phases. As the B content increased, the TiB phase gradually transformed to the TiB 2 phase. After TiB vanished, the BN phase increased sharply at the expense of the TiN phase. The maximum hardness was achieved by the formation of a multiphase microstructure comprising of a mixture of three phases with the following mole fractions ∼73 mol.% TiN, 17 mol.% TiB 2, 10 mol.% BN. The effect of B on stabilizing the multiphase microstructure of TiN, TiB 2 and BN was elucidated and explained on the basis of structural and thermodynamic stability.

The study on the microstructure of TiN and Ti1-xSixNy coatings

The microstructure of TiN coatings and Ti1-xSixNy nanocomposite coatings was studied by means of x-ray diffrection, x-ray photoelection spectroscopy, high resolution transmission electron microscopy and atomic force microscopy. The results showed that the Ti1-xSixNy coatings consisted of TiN nanocrystallites with grain size of 3-5nm and amorphous Si3N4 phase. The roughness of Ti1-xSixNy coatings was less than that of TiN coatings prepared under the same conditions. The orientation of TiN crystals in the Ti1-xSixNy coatings was discussed on the basis of interface energy.

Effect of microstructure on diffusion of copper in TiN films

We investigated the effect of the microstructure of TiN films on the diffusion behavior of Cu. Cu/TiN films were synthesized on Si(100) substrate by the pulsed laser deposition (PLD) technique. Three different microstructures of TiN were achieved by growing the films at different substrate temperatures, where higher deposition temperatures (∼650 °C) led to epitaxial growth by the mechanism of domain matching epitaxy and lower temperature depositions resulted in polycrystalline and nanocrystalline TiN films. These structures were characterized using x-ray diffraction and high-resolution transmission electron microscopy. Cu was deposited in situ on the samples with three different microstructures of TiN films on Si(100) by PLD. All three samples were simultaneously annealed at 500 °C for 30 min in high vacuum to study the effect of diffusion characteristics of Cu as a function of microstructure of the TiN films. Secondary ion mass spectroscopy, Z-contrast imaging and electron energy-loss spectroscopy were used to understand the diffusion mechanisms and rationalize results in different microstructures.

Superconducting transition of single-crystal tin microstructures

Single-crystal superconducting microstructures have been fabricated. The resistances of tin whiskers were measured in a multiprobe configuration. Contacts were made of copper, gold, or niobium films using e-beam lithography followed by a lift-off process. Structures with normal metal probes showed unusual behavior: below the critical temperature of bulk tin, the resistance decreases in distinct steps and does not reach zero even when cooled down to 1 K. The origin of these phenomena is not clear but is likely related to a proximity effect.

Diffusion Characteristics of Cu in TiN Thin Films

AbstractWe have investigated the diffusion characteristics of Cu in nanocrystalline, polycrystalline and single crystal TiN thin films, which are being used as a diffusion barrier for sub-quarter-micron metallization. These films were synthesized on Si (100) substrate by first ablating TiN and then ablating Cu targets using Pulse Laser Deposition technique. The three different microstructures of TiN were achieved by growing the films at different substrate temperatures, where higher temperatures (650 °C) leads to epitaxy. Then a uniform thin layer of Cu was deposited on TiN/Si substrate at room temperature for all the three depositions above. These structures were characterized using X-Ray diffraction technique and high-resolution transmission electron microscopy. Each sample is then annealed at 500 °C for 30min to study the diffusion barrier characteristics as a function of microstructure of TiN. Study of diffusion profile and Cu concentration measurement were performed using Scanning Transmission Electron Microscopy-Z contrast Imaging (0.12nm resolution), Electron Energy Loss Spectroscopy and Secondary Ion Mass Spectroscopy. From the results obtained the effect of microstructure of TiN thin films on the diffusion characteristics of Cu after annealing was analyzed. Four points probe resistivity measurements were made to establish structure property correlations.

Study on the characteristics of TiN thin film deposited by the atomic layer chemical vapor deposition method

TiN film was deposited on Si substrate by using an atomic layer chemical vapor deposition (CVD) system. In this system, the TiCl4 and NH3 gases were supplied, separately and Ar purge gas was added between the source and reactant gases to suppress the direct reaction. The microstructure of TiN was observed to be the columnar grain structure. The chemical species was analized by Auger electron spectroscopy (AES) and the Cl content in TiN film was detected below the detection limit of AES which was below 0.5%. The density of film grown at 450 °C measured by Rutherford backscattering spectroscopy was 4.85 g/cm3 and decreased as the process temperature decreased. The resistivity of this TiN was about 75 μΩ cm, which was very low compared to TiN film grown by other CVD methods. The step coverage of TiN film showed almost 100% conformality at 450 °C.

Thermal reactions and micro-structure of TiN–AlN layered nano-composites

Bilayer and multilayer structures of TiN and AlN thin films were synthesized using pulsed laser deposition technique in a substrate temperature range 300–700°C. The chemical reactions at TiN–AlN interfaces and the formation of different alloy phases were studied using X-ray diffraction (XRD) and transmission electron microscopy (TEM). It was observed that TiN–AlN interface remains sharp and stable for deposition temperatures up to ∼650°C. At higher deposition temperatures, however, substantial chemical reactions were found to occur. The ternary alloy phases such as Ti 3Al 2N 2 and Ti 3AlN have been observed, for the first time. The composites synthesized at temperatures lower than 650°C and subsequently annealed at higher temperature were found to exhibit very limited or no interfacial chemical reactions. The effect of layer thickness on the microstructure is also studied. The studies revealed that by controlling the thickness of individual layers and substrate temperatures, it was possible to control microstructure and obtain composite coatings consisting of ternary Ti–Al–N alloy phases. The results are discussed in terms of characteristic features of pulsed laser ablation process in which evaporated flux contains energetic ions, electrons and neutral particles. Preliminary nano-indentation measurements and oxidation measurements reveal that these composites possess desirable mechanical properties at high temperatures.

Structural and electrical properties of chemical vapor deposition tungsten overgrowth on physical vapor deposited and metalorganic chemical vapor deposited TiN adhesion layers

The structure and electrical properties of chemical vapor deposited W (CVD-W) films on various physical vapor deposited or metalorganic chemical vapor deposited TiN films have been investigated. The growth orientations of the TiN adhesion layers were controlled by deposition method and film thickness. The growth orientations of CVD-W films were found to depend strongly on the microstructures of TiN. The grain sizes and electrical resistivity of CVD-W were found to increase and decrease, respectively, with the grain sizes of underlying TiN layers.

Microstructure of TiN/ carbon steel functionally gradient materials processed by high-energy electron beam irradiation

This article presents a microstructural study of TiN/carbon steel functionally gradient materials (FGM) processed by of high-energy electron beam irradiation. The mixtures of TiN powders and flux were deposited on a plain carbon steel substrate, and were irradiated using an electron beam accelerator. The microstructures of the irradiated surface layer consisted of surface region, melted region, interface, coarse-grained heat-affected zone (HAZ), fine-grained HAZ, and unaltered matrix. Residual pores and TiN powder agglomerates were found in the sample processed without flux, whereas these defects were hardly observed in the samples processed with a considerable amount of flux. As a result of irradiation, the Ti content decreased along the depth from the irradiated surface, thereby yielding the characteristics of FGM. Owing to the dissolved Ti and the formation of fine cuboidal Ti(C,N) particles, the hardness of the irradiated surface layer was greatly improved, reaching as much as twice or three times that of the original matrix, but the hardening effect was reduced along the depth from the surface.

Effect of TiN Microstructure on Diffusion Barrier Properties in Cu Metallization

The relationship between TiN microstructures and diffusion barrier properties of TiN against Cu was investigated. TiN deposited by a chemical vapor deposition (CVD) method is composed of columnar grains grow normal to the sidewall on the side of the trench. On the other hand, the grain boundaries of sputter‐deposited TiN tilt upward from the normal direction to the sidewall, and the tilt angle depends on the sputtering conditions. Voids between TiN grains are observed on the side of the trench and the size of the voids depends on the deposition conditions. In the Cu/CVD‐TiN (the upper/lower layer) and Cu/conventional sputtered TiN system, no Cu is detected in surrounding films, either outside the sidewall or underneath the bottom of the trench after annealing at 400°C for 3 min. However, in the Cu/long‐throw sputtered TiN system where TiN is composed of columnar grains with void regions between grains, and the tilt angle of the grain boundaries from the normal direction to the sidewall is 27°, some Cu is detected outside the sidewall, even when the TiN thickness on the side of trench is equal to or thicker than that of CVD‐TiN or conventionally sputtered TiN. The diffusion barrier property of TiN in Cu metallization depends on the TiN grain structures rather than on the TiN thickness on the side of the trench.

Improved TiN film as a diffusion barrier between copper and silicon

Reactively-sputtered TiN films were studied as a copper diffusion barrier in the Cu/TiN/Ti/Si and Cu/TiN/Ti/SiO 2/Si multi-layer structures. From the viewpoint of the microstructure of TiN, the diffusion barrier property of TiN against copper improved when the grain boundary of TiN (as the diffusion path of copper) was extended and densified, which was confirmed by the increase of the breakdown temperature of the TiN diffusion barrier detected by various characterization methods. The 40-nm thick TiN with double deposition (extension of the grain boundary of TiN) and stuffing (the densification of the grain boundary of TiN) by RTP treatment (NH 3, 600°C, 1 min) was found to be stable up to 575°C for 2 h by the C– V method.