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Nickel-Titanium (Ni-Ti) thin films have gained a lot of attention due to their unique features, such as the shape memory effect. Micro-actuators, micro-valve, micro-fluid pumps, bio-medical applications, and electronic applications have a lot of interest in these smart thin films. Sputter-deposited NiTi thin films have shown the potential to be very useful as a powerful actuator in micro-electro-mechanical systems (MEMS) because of their large recovery forces and high recoverable strains. Despite the advancement of improved deposition methods for the NiTi thin films, there are still certain unsolved challenges that impede accurate composition control throughout the deposition process. Many applications, spanning from the aerospace industries to a range of nanotechnologies, require knowledge of the sputtering characteristics of the materials that are subjected to bombardment, ejection, and deposition of ions. In recent decades, atomic scale modeling has been given a high emphasis in ion sputtering research, providing an adequate and precise description of collision cascades in solids using the Stopping and Range of Ions in Matter (SRIM) and Transport of Ions in Matter (TRIM). In this paper, SRIM is used to address how the heavy ions interact with the target materials. A variety of ion-solid interaction characteristics, including the sputter yield, have been determined by simulating collision cascades in the solids. On the other hand, TRIM was used to describe the range of ions that enter into the matter and cause damage to the target throughout the process. The simulation was carried out to compare the sputtering yield of Ni and Ti by varying the energy input (from 300V to 1300V). SRIM simulation was conducted by varying the thickness of the film, the angle of incidence of ions, and the energy involved in the sputtering process. The characterization of the films has been carried out using Field Emission Scanning Electron Microscopy (FESEM) to comprehend the surface and interface morphologies of the films and to validate the simulated results. With an increase in energy input (target voltage), the sputtering yield increased. The sputtering yield of the Ni target was higher than the Ti target indicating that Ni can be removed relatively easier than Ti.

Recently [M. Kunat et al., Surf. Sci.474, 114 (2001)] a quenching of adsorbate-assisted adsorption ("autocatalytic adsorption") by defects has been observed for the system CO/Cu(110). A conceptually similar effect for CO adsorption on O–Ir(110) had additionally been reported before [U. Burghaus et al., Surf. Sci.384, L869 (1997)]. Presented is a simple Monte Carlo simulation (MCS) scheme which includes basically one free fit parameter and can reproduce both effects consistently.

A characteristic wedge-shaped iron (Fe) film system, deposited on glass substrate by a DC-magnetron sputtering method and quenched by silicone oil during deposition, has been successfully fabricated. The mechanical behaviors of the quenched and non-quenched Fe films have been compared and analyzed. The internal stress is found to transform from tension to compression in nature after quenching, which results in the formation of buckling pattern in the quenched Fe film while crack pattern in the non-quenched film. It is proposed that the origin of the compressive stress is mainly due to freezing of the Fe atoms (or clusters) with high kinetic energy and doping of the oil molecules into the Fe film defects.

Single-phase CuInSe₂ films were grown by high vapor selenization of CuIn alloy precursors within a partially closed graphite box. The CuIn precursors were prepared using Cu_xIn_y alloy targets with different composition rates under low vacuum level by a homemade sputtering system. The Cu and In composition rates of the used targets are 11:9, 10:10, and 9:11, respectively. The metallic precursor films were selenized using a two-step temperature profile, i.e. at 250°C and 400–500°C, respectively. The influence of the temperature at the second selenization step on the quality of the CIS absorbing layers was investigated. The CIS films were characterized by X-ray diffractometry, scanning electron microscopy, energy dispersive X-ray analysis, and Raman spectroscopy. The deposited CIS absorbers selenized at a high temperature of 500°C for 30 min exhibited a single-phase chalcopyrite structure with a preferential orientation in the (112) direction. These layers display uniform, large, and densely packed crystals with a grain size of about 3–5 μm. Cadmium sulfide buffer layer was manufactured by chemical bath deposition method. Bilayers ZnO/ZnO:Al were prepared by RF magnetron sputtering deposition. CIS solar cells with an efficiency of about 6.5% were produced without antireflective films. The method to fabricate CIS solar cells by a combination of the low vacuum sputtering deposition and the graphite box selenization process has provided a simple control process and shown a promising potential for developing high efficient and low-cost CuInSe₂ solar cells.

Tantalum (Ta) films deposited on glass substrates have been prepared by a direct current magnetron sputtering method, and buckling patterns induced by residual compressive stress are investigated in detail. When the film thickness increases, the buckling morphologies evolve from straight-sided buckle network to wavy or wormlike wrinkles gradually, and finally change into telephone cord buckles. The geometrical parameters of the buckling patterns are found to increase linearly with the film thickness. Based on the geometrical parameters of the buckling patterns, the mechanical properties of the Ta films are also discussed in the frame of continuum elastic theory.

InN film with an AlInN/AlN bilayer buffer was deposited on Si(111) substrate by radio frequency (RF) magnetron sputtering. X-ray diffraction and Raman spectroscopy measurements reveal that the InN film is of hexagonal wurtzite crystal structure with highly (0002) preferred orientation. An Al_0.24In_0.76N interface layer of about ~50 nm was confirmed by transmission electron microscopy (TEM) and further analyzed by X-ray photoelectron spectroscopy (XPS). The quality of this film is remarkably better than InN films grown directly on Si substrate or with only an AlN buffer, due to the effective accommodation of mismatch between the film and substrate. Our results will be very useful in the fabrication of applicable nitride microelectronic materials.

A wedge-shaped iron (Fe) film system, quenched by silicone oil during deposition, has been prepared on glass substrates by direct current magnetron sputtering, and the influence of external disturbance on buckling patterns is investigated. The experiment shows that the wedge-shaped Fe film possesses a high compressive stress, which is relieved by spontaneous formation of telephone cord buckles in the atmosphere condition. The growth process can last several days to more than a month. When the film is disturbed by an external force, the stored stress energy will release drastically to form straight-sided buckles within several seconds. The morphological characteristics, edge effect and formation mechanism of the straight-sided buckles are discussed in detail.

HfN and VN thin films were deposited onto silicon and 4140 steel substrates with r.f. reactive magnetron sputtering by using Hf and V metallic targets with 4-inch diameter and 99.9% purity in argon/nitrogen atmosphere, applying a substrate temperature of 250°C and a pressure of 1.2 × 10^-3 mbar. In order to evaluate the structural, chemical, morphological, mechanical and tribological properties, we used X-ray diffraction (XRD), transmission electron microscopy (TEM), energy dispersive X-ray analysis (EDX), atomic force microscopy (AFM), scanning electron microscopy (SEM), nanoindentation, pin-on-disc and scratch tests. Film structure determined by XRD showed that FCC (NaCl-type) films are formed in both the cases by δ-HfN and δ-VN phases. Hardness and elastic modulus values obtained for both the films were 21 and 224 GPa for the HfN film and 19 and 205 GPa for the VN film, respectively. Additionally, the films showed low friction coefficient of 0.44 for HfN and 0.62 for VN when these films were evaluated against 100 Cr6 steel, and finally the critical load was found at 41 N for the HfN film and 34 N for the VN film.

Molybdenum thin films were sputter deposited under different conditions of DC power and chamber pressure. The structure and topography of the films were investigated using AFM, SEM and XRD techniques. Van der Pauw method and tape test were employed to determine electrical resistivity and interfacial strength to the substrate, respectively. All the films are of sub-micron thickness with maximum growth rate of 78 nm/min and crystallite size in the range of 4 to 21 nm. The films produced at high power and low pressure exhibit compressive residual strains, low electrical resistivity and poor adhesion to the glass substrate, whereas the converse is true for films produced at high pressure.

Structure evolution and electric properties of tantalum nitride (TaN) films deposited on Al₂O₃-based ceramic and glass substrates by magnetron reactive sputtering were carried out as a function of the N₂-to-Ar flow ratio. The TaN thin films on Al₂O₃-based ceramic substrates grow with micronclusters composed of numerous nanocrystallites, contains from single-phase of Ta₂N grains to TaN, and exhibits high defect density, sheet resistance and negative TCR as the N₂-to-Ar flow ratio continuously increases. However, the films on the glass substrates grow in the way of sandwich close-stack, contains from single-phase of Ta₂N grains to TaN and Ta₃N₅ phases with the increase of N₂-to-Ar flow ratio. These results indicate that the N₂-to-Ar flow ratio and surface characteristic difference of substrates play a dominant effect on the structure and composition of the TaN films, resulting in different electrical properties for the films on Al₂O₃-based ceramic and the samples on glass substrates.

Ta (3.3 nm)/Ni–Al (3.3 nm) integrated films deposited on Si substrates by magnetron sputtering, annealed at various temperatures in a ultra-high vacuum, have been studied as diffusion barrier layers between Cu and Si for application in Cu interconnection. The images of transmission electron microscopy (TEM) prove that the cross-sectional interfaces of Cu/Ta/Ni–Al/Si sample annealed at 600°C are clear and sharp. No Cu–silicide peaks can be found from the X-ray diffraction (XRD) patterns of the 850°C annealed sample, but the sheet resistance of the sample increases abruptly. Moreover, large grooves are found from the image of atomic force microscopy (AFM) for the 850°C annealed sample, implying the failure of the diffusion barrier. The integrated Ta/Ni–Al barrier layer retains thermally stable nature up to at least 800°C, indicating that the Ta/Ni–Al integrated film is an excellent diffusion barrier between Cu and Si.

Aluminum oxide (Al₂O₃) thin films with Al₂O₃ buffer layer were deposited on Si (100) and Si (111) substrates using RF magnetron sputtering of Al₂O₃ target in Ar atmosphere. The synthesized films were then annealed at the temperature of 400${}^{\circ }$C, 600${}^{\circ }$C and 800${}^{\circ }$C in nitrogen (N₂) environment for 6h. Structural properties and surface morphology are examined by using X-Ray Diffraction (XRD), Field Emission Scanning Electron Microscope (FESEM) and Atomic Force Microscope (AFM). XRD analysis indicated that different orientation of Al₂O₃ were formed with different intensities due to increase in the annealing temperature. From FESEM cross-section analysis results, it is observed that the thickness of films were increased as the annealing temperature increased. EDX analysis shows that the concentration of aluminum and oxygen on both the Si substrates increased with the increase in annealing temperature. The surface roughness of the films were found to be decreased first when the annealing temperature is increased to 400${}^{\circ }$C, yet the roughness increased when the annealing temperature is further increased to 800${}^{\circ }$C.

In this study, surface-enhanced Raman spectroscopic (SERS) substrates with reusability were carefully fabricated and investigated. Based on a simple and cost-effective hydrothermal process, zinc sheets were used as a base for growing zinc oxide nanorods (ZnO NRs) with hexagonal structures as templates for the SERS substrates. In the experimentation, the authors explored a variation of the physical NR structures based on precursors of zinc nitrate (Zn(NO${}_3{)}_2)$: hexamethylenetetramine (HMTA) at 1:1 ratio, in aqueous solution with DI water at a concentration of 2.5–20mM. The prepared zinc oxide templates were finally decorated with gold nanoparticles (Au NPs) with the sputtering deposition for 90s in order to promote the SERS-active surface. From physical observations, the scanning electron microscopic (SEM) results showed that the ZnO NRs exhibited an increase in size from 56.4nm to 244.06nm as the solution concentration was increased. Further investigations also demonstrated that the Au-decorated SERS-active samples had the gold nanoparticles covering the top of the ZnO NRs. The prepared SERS substrates were finally measured for the Raman enhancement with methylene blue (MB) as the test molecules. The results showed that the SERS substrates could detect the Raman peaks of the MB at the limit of detection of $1\times 10^{-6}$M. In addition, the SERS substrates were tested for reusability with the UV exposure, up to at least nine cycles. This work therefore reported the progress of the fabrications of the SERS-active materials with the reusable potentials in several SERS applications.

Copper aluminium oxide (Cu–Al₂O₃) films were synthesized on Si(111) substrates through RF magnetron sputtering by using the layer stacking technique. Cu and Al₂O₃ targets were used to deposit Cu and Al₂O₃ thin films under Ar atmosphere, respectively and the deposited films were then annealed under N₂ environment at 350${}^{\circ }$C, 450${}^{\circ }$C and 550${}^{\circ }$C for 6h. The structural properties of the films were investigated by using X-ray diffraction (XRD) while the surface morphology and topography of the deposited films were examined through Field Emission Scanning Electron Microscopy (FESEM), Energy Dispersive X-ray (EDX) and Atomic Force Microscopy (AFM). XRD analysis revealed the existence of multiple phases of CuO, Al₂O₃ and CuAl₂O₄ in the deposited films on Si(111) substrates. As a result of the annealing effect, the peak intensities of CuO, Al₂O₃ and CuAl₂O₄ were found to be increased along with the shifting of peak positions. Williamson–Hall (WH) analysis was also implemented to analyze the structural properties such as crystallite size, stress, strain, and energy density. Based on the three models used in WH analysis, the changes in the crystallite size and strain of the films were indicated to be anomalous with the changes in the annealing temperature. Moreover, the strain of films was also showed to be changed from compressive strain into tensile strain. The FESEM results also indicated the formation of various surface morphologies under various annealing temperatures whereas EDX analysis showed an increased atomic percentage of Cu, Al, and O due to the effect of increase in annealing temperature. The AFM analysis showed that the surface roughness of the deposited films increased with the increase in the annealing temperature.

Silicon carbon nitride (SiCN) films were prepared on silicon substrate by reactive magnetron sputtering of a sintered silicon carbide target in a mixture of argon, nitrogen and acetylene. Detailed studies including energy dispersive spectrometer, atomic force microscope, X-ray diffraction, Fourier transformed infrared spectrometry and $C$–$V$ measuring instrument were performed. The as-deposited SiCN films do not exhibit obvious crystalline phase, and the SiCN films annealed at 600${}^{\circ }$C show SiC crystal and graphite carbon. The SiCN films mainly consist of Si–N, Si–C, Si–O, C–C, C$\equiv$N, Si–H_n and N–H_n bonds, and increasing C₂H₂ flow rate promotes the formation of C–C, N–H_n and Si–N bonds. The SiCN film with low dielectric constant of 3.8 and compact structure was successfully prepared.

In this work, various silver-based thin films were prepared by sputtering method with inclined substrates in the presence of shadowing object. The morphology and structural and optical properties of the prepared thin films were investigated by means of scanning electron microscopy (SEM) and X-ray diffraction (XRD) and diffuse reflectance spectroscopy (DRS), respectively. The wettability of films was investigated by measuring contact angles of the films. The obtained results show that by increasing shadowing effect, a decrease in contact angle of the prepared samples is observed. Bruggeman homogenization simulation method was applied to describe the film structures. The theoretical part and simulation using Bruggeman homogenization confirm the experimental findings and show the best possible agreements. Finally, an increase in contact angle of the prepared thin films with high porosity and high surface roughness was observed. In films with silver–silver oxide compositions, the higher contribution of oxide part in the structure of the films leads to the hydrophilicity of the surface.

Wrinkling patterns are beneficial for a wide range of engineering applications including flexible electronics, tuned optics, sensoring, energy harvesting, surface wetting and biomedicine. Here we report on controllable multimode wrinkling patterns of metal (iron) films sputter deposited on flexible substrates with gradient modulus. It is found that disordered wrinkles (G1 wrinkling) form in the weakly crosslinking region at the early stage of film deposition. Disordered labyrinth wrinkles with larger wavelengths and ordered stripe wrinkles localized by cracks (both G2 wrinkling) appear in the strongly crosslinking region for the samples with small film thickness and large thickness, respectively. The coexistence of the labyrinth G1 wrinkling and labyrinth G2 wrinkling (or stripe G2 wrinkling) can be obtained by tuning the substrate modulus and film thickness. The morphologies, evolutions and mechanisms of such wrinkles are discussed in detail based on the stress theory. This study can promote better understanding of the substrate effect on the complex wrinkling patterns.

Thermal oxidation and annealing of zinc nitride sputtered films are described in this paper. Zinc nitride films were produced by the sputtering a zinc target (99.999%) in the plasma, ignited in a mixture of Ar:N₂ (20:10 sccm) gas at 60 W and working pressure of $8\times 10^{-5}$mbar. The films were initially micro-annealed in H₂O₂ solution (35vol.%) at room temperature and subsequently in ambient air in the low temperature range of 100–$200^{\circ }$C. The as-sputtered and annealed films were examined using X-ray diffraction (XRD), spectrophotometer, Raman and photoluminescence spectroscopies. Annealing oxidation leads to the transformation of the cubic crystal structure of zinc nitride into wurtzite ZnO through the oxygen diffusion process. The XRD peak of (002) plane and the principal $E_2$ (high) phonon mode, detected for the annealed film, are clear signature on the conversion of zinc nitride film into crystalline ZnO. The sputtered annealed film showed optical transmittance of 85% and average bandgap energy of 3.28eV due to the formation of ZnO. The presented method is appealing since it provides an easy two-step route to the conversion of zinc nitride film into ZnO with p-type behavior and tunable characteristics for various optoelectronic applications.