Ion Beam Sputtering Method Research Articles

Nanosecond laser-induced damage at different initial temperatures of Ta2O5 films prepared by dual ion beam sputtering

Ta2O5 films were deposited by dual ion beam sputtering method. The nanosecond laser-induced damage threshold (LIDT) at different initial temperatures and time of the films was investigated by an in situ high temperature laser-induced damage testing platform. It was shown that, when the initial temperature increased from 298 K to 383 K, the LIDT at 1064 nm and 12 ns significantly decreased by nearly 14%. Then the LIDT at 1064 nm and 12 ns decreased slower with the same temperature increment. Different damage morphologies were found at different initial temperatures. At low initial temperatures, it was the defects-isolated damage while at high initial temperatures it was the defects-combined damage. The theoretical calculations based on the defect-induced damage model revealed that both the significant increase of the highest temperature and the duration contributed to the different damage morphologies. With the initial temperature being increased, the thermal-stress coupling damage mechanism transformed gradually to the thermal dominant damage mechanism.

Magnetoelectric properties of magnetic/ferroelectric multilayer thin films

Magnetic/ferroelectric multilayer thin films using PbZr0.52Ti0.48O3 (PZT) and two different magnetic materials, i.e., Terfenol-D and CuFe2O4 (CuFO) layers, were fabricated, and their magnetoelectric (ME) coupling behavior was investigated. The PZT layer was first coated onto Pt/Ti/SiO2/Si substrate by sol-gel spin coating method. Pt layer, which served as an electrode and a diffusion barrier, was grown on the PZT layer by using the ion-beam sputtering method. The ME voltage coefficients were calculated from the ME voltage data measured utilizing a magnetoelectric test system. The Terfenol-D/Pt/PZT films were found to show a higher in-plane ME voltage coefficient than that the CuFO/Pt/PZT films due primarily to the higher magnetostriction coefficient of Terfenol-D.

Magnetoelectric Coupling Effect in Ferroelectric and Ferromagnetic Hybrid Thin Films

Magnetoelectric (ME) effect in multiferroic or ferroelectric/ferromagnetic composite thin films occurs through the elastic coupling between the piezoelectric properties of ferroelectric and magnetostrictive properties of ferromagnetic component. To obtain high elastic coupling and ME effect, we introduced PZT [Pb(Zr0.52, Ti0.48)O3] as a ferroelectric materials and CuFO (CuFe2O4) as ferromagnetic materials because of their high piezoelectric coefficient and magnetostrictive properties among various metal-oxide materials. To evaluate ME effect, we prepared CuFO/Pt/PZT/Pt hybrid thin films directly on Pt/TiO2/SiO2/Si substrate by using ion beam sputtering and spin-coating method. We investigated the microstructures and morphologies of hybrid thin films by XRD and SEM, the ferroelectric and ferromagnetic behaviors of hybrid films were examined by measuring polarization and magnetization hysteresis loops vs. electric and magnetic field. Magnetoelectric coefficients were calculated by measured magnetoelectric voltages using magnetoelectric measurement system. In this research, we’ll discuss the relations between annealing temperatures and multiferroic properties.

Magnetoelectric Coupling of CuFe2O4/Pt/Pb(Zr0.52Ti0.48)O3 Multilayer Thin Films

CuFe2O4/Pt/Pb(Zr0.52Ti0.48)O3 (PZT) multilayer thin films were grown on (111)-oriented Pt/TiO2/SiO2/Si<100> substrate. PZT layer was fabricated by the sol-gel method. Afterwards, Pt layer was deposited by ion beam sputtering method. Finally, CuFe2O4 layer were deposited using pulsed laser deposition method (PLD). The film structure is tri-layered type, where the bottom PZT layer covered the whole substrate, while Pt and CuFe2O4 layers were deposited through circular shadow masks to measure ferroelectric and magnetoelectric properties. Film microstructure was observed using XRD and FE-SEM. Magnetoelectric coefficients were calculated by measured magnetoelectric voltages using magnetoelectric measurement system.

Study and Fabrication of Filter Film in Tactical Optical Fiber Communication System

The development of optical fiber transmission technology provides a broad application prospect for the communication of real-time battlefield information. The information could be communicated between the front and headquarters through the cable by using tactical optical fiber communication system, which ensures the missions of military intelligence communicated and tactical real-time arrangement are completed successfully. According to the requirements of multiplexer for military tactical optical fiber communication system, the filters with low-loss have been developed. Filters are prepared by the depositing method of dual ion beam sputtering, Nb2O5 and SiO2 have been chosen as deposition materials, and the filter film is designed and optimized with the help of TFCalc software. In order to broaden the shortwave cutoff region of the filter, the long-wave pass film have been added behind the initial film, and the thickness of the matching layers have been optimized, which based on the concept of equivalent refractive index, the insertion loss of the pass-band of the filter has been reduced. The optical extreme value method and average time method have been used to control layers thickness, and the problem of the layers thickness accuracy controlling have been solved by using the method of real-time calibration of the deposition rate and the repeatability of parameters accurately control. The transmission spectrum of the filter has been tested, which demonstration that the center wavelength of the filter is 1511.2nm, the width of the filters pass band is 17.1nm and 23.5nm in the region of-0.5dB and-35dB respectively, the worst insertion loss within pass band region is-0.1dB, the ripple of the pass band is 0.06dB. The results show that the preparation of the filter meets the using requirements of military tactical fiber optic communication system well.

Corrosion behaviors of Mo coating on stainless steel 316 substrates implanted by different nitrogen ion fluences

The molybdenum nitride coating was produced by nitrogen ion implantation of the molybdenum layer deposited on the stainless steel 316 (SS) substrates. At first, molybdenum layers were deposited on the substrates by ion beam sputtering method, then nitrogen ions with an energy of 30 keV and a fluence between 1×10 17 and 12×10 17 N + cm −2 were implanted in Mo/SS system. Crystal structure and topography of the surface are investigated by grazing incidence X-ray diffraction (GIXRD) and atomic force microscopy (AFM) image respectively. XRD patterns showed the formation of molybdenum nitride phases in all implanted samples. Corrosion tests showed that the corrosion resistance of the samples strongly depends on the nitrogen applied fluences. A considerable improvement of corrosion performance by increasing ions fluences was observed. The lowest corrosion current density with amount of 0.1 μ A/cm 2 was obtained at 12×10 17 ions/cm 2 fluence in our case.

Properties of CuInGaSe2 Thin-Film Prepared from Multiple Layers via Ion Beam Sputtering Method

Properties of CuInGaSe2 Thin-Film Prepared from Multiple Layers via Ion Beam Sputtering Method

Conductive, magnetic and structural properties of multilayer films

Composite-semiconductor and composite-dielectric multilayer films were obtained by the ion beam sputtering method in the argon and hydrogen atmospheres with compositions: {[(Co45-Fe45-Zr10)x(Al2O3)y]-[α-Si]}120, {[(Co45-Ta45-Nb10)x(SiO2)y]-[SiO2]}56, {[(Co45-Fe45-Zr10)x(Al2O3)y]-[α-Si:H]}120. The images of surface relief and distribution of the dc current on composite layer surface were obtained with using of atomic force microscopy (AFM). The dependencies of specific electric resistance, ferromagnetic resonance (FMR) fields and width of line on metal (magnetic) phase concentration x and nanolayers thickness of multilayer films were obtained. The characteristics of FMR depend on magnetic interaction among magnetic granules in the composite layers and between the layers. These characteristics depend on the thickness of composite and dielectric or semiconductor nanolayers. The dependences of electric microwave losses on the x and alternating field frequency were investigated.

Stannic oxide thin film growth via ion-beam-sputtering

Stannic oxide (SnO2) is of great technological interest as a member of the important family of oxide materials that combine low electrical resistance with high optical transparency in the visible range of the electromagnetic spectrum.Tin oxide thin films are grown on sapphire substrates by ion beam sputtering method with varying heater temperature from 100 to 750°C at constant gas flux. Enhancement of crystallinity of thin films with temperature is observed from X-ray diffraction and Raman spectroscopy studies. Morphological studies by atomic force microscopy reveal changes in grain size with variation in substrate temperature.

Adhesion, microstrain, and corrosion behavior of ZrN-coated AZ91 alloy as a function of temperature

Abstract

Electrical properties and local domain structure of LiNbO3 thin film grown by ion beam sputtering method

The nanocrystalline ferroelectric LiNbO3 films on (001) Si substrates with the random orientation of polycrystalline grains and the predominance of the grains with lateral orientation of the polar axis were grown using the ion beam sputtering method. The remanent polarization and the coercive field are 12 µC/cm2 and 29 kV/cm, respectively. The thermal annealing leads to the coarsening of the grains. The appearance of the “local texture,” which gives rise to the unipolarity of the heterostructures caused by the predominance of the one direction in the vertical component of the spontaneous polarization, is investigated.

Ferromagnetic Schottky junctions using half-metallic Co2MnSi/diamond heterostructures

We demonstrate half-metallic Heusler Co2MnSi films epitaxially grown on diamond semiconductors using the ion-beam assisted sputtering method. Lower temperature growth below ∼400 °C is key for obtaining abrupt Co2MnSi/diamond interfaces. The Co2MnSi films on diamond showed a negative anisotropic magnetoresistance of ∼0.2% at 10 K, suggesting the half-metallic nature of the Co2MnSi films. Schottky junctions formed using the Co2MnSi/diamond heterostructures at 400 °C showed clear rectification properties with a rectification ratio of ∼103. The Schottky barrier heights of the Co2MnSi/diamond interfaces were estimated to be ∼0.8 eV. These results indicate that Co2MnSi is a promising spin source for spin injection into diamond.

Preparation and tunable optical properties of ion beam sputtered SiAlON thin films

One kind of quaternary thin films of SiAlON were deposited by ion beam sputtering method at ambient temperature, through a sintered SiAlON ceramic target. Ultraviolet, visible and near infrared (UV–VIS–NIR) Spectrophotometer, Fourier transformed infrared spectroscopy (FTIR), glancing incidence X-ray diffraction (GIXRD) and X-ray photoelectron spectroscopy (XPS) were employed to characterize the optical, crystalline and chemical composition properties. The optical properties of the deposited amorphous films could be tailored by changing the relative content of O or N in the films, through introducing different working gas and gas flux adjusting (oxygen, nitrogen or their mixtures). By this way, the refractive index at 850 nm can be tailored from 1.53 to 1.83, and the chemical composition data from XPS analysis supplied strong evidences. Reasonably, the SiAlON films were thought to be one kind of candidate films either as a buffer layer benefit from their high temperature stability, or a mid infrared antireflective layer for silicon and other infrared window materials.

Hard antireflective films of SiAlON for zinc sulfide in 3–5 μm regions

SiAlON films with antireflective and protective functionality for zinc sulfide were prepared by an ion beam sputtering method. A great transmittance improvement (at 3.8μm) of 25.1% has been realized for zinc sulfide substrate. At the same time, the in situ high temperature transmittance was also recorded and it was proven that the SiAlON films on zinc sulfide window materials can keep thermal stability well at temperature as high as 250°C in the region of 3–5μm. The micro hardness of the zinc sulfide was improved by 75% in average after being coated with SiAlON films, and the SiAlON films possess good behaviors in harsh environmental tests including adhesion, abrasion, moisture, and thermal shock circle.

Preferential growth and enhanced dielectric properties of Ba0.7Sr0.3TiO3 thin films with preannealed Pt bottom electrode

Ba0.7Sr0.3TiO3 (BST) thin films, about 100 nm in thickness, were prepared on unannealed and 700 °C-preannealed Pt bottom electrodes by the ion beam sputtering and post-deposition annealing method. It was found that the preannealed Pt layer has a more compact structure, making it not only a bottom electrode but also a good template for high-quality BST thin film growth. The BST films deposited on preannealed Pt bottom electrodes showed (0 0 l)-preferred orientation, dense and uniform microstructure with no intermediate phase formed at the film/electrode interface, and thus enhanced dielectric properties. As a result, the typical relative dielectric constant and tunability (under a dc electric field of 1 MV cm−1) reach 180 and 50.1%, respectively, for the BST thin films with preannealed Pt bottom electrodes, which are significantly higher than those (166 and 41.3%, respectively) for the BST thin films deposited on unannealed Pt bottom electrodes.

Nanostructured vanadium oxide thin film with high TCR at room temperature for microbolometer

In order to obtain high quality of thermal sensitive material, VOx thin film of high temperature coefficient of resistance (TCR) of 6.5%/K at room temperature has been deposited by reactive ion beam sputtering and post annealing method. AFM and XRD measurements indicate that the VOx thin film with nanostructured crystalline is composed of VO2 and V2O3. The nanostructured VOx microbolometer has been designed and fabricated. The measurement of the film system with TiN absorbing layer indicates that it has about 92% infrared absorption in the range of 8–14μm. The performance of this bolometer, comparing with that of bolometer with common VOx, has a better result. At 20Hz frequency and 10μA bias current, the bolometer with high TCR has reached detectivity of 1.0×109cmHz1/2/W. It also indicates that this nanostructured VOx thin film has not only a higher TCR but also a lower noise than common VOx thin film without annealing.

Conduction mechanisms in Si-LiNbO3 heterostructures grown by ion-beam sputtering method

The polycrystalline films LiNbO3 on the substrates (001) Si with the spontaneous orientation of grains are developed by the ion-beam sputtering method. The mechanisms of conductivity in the interval of temperatures T = 90–400 K are investigated by the method of the current–voltage characteristics. The initial site of the current–voltage characteristics is defined by the properties of contact Si-LiNbO3 and is described within the framework of Fowler–Nordheim tunneling and Richardson–Schottky emission. At the high voltage, the conductivity is defined by the volume of the film LiNbO3 and is described by the thermo-assisted tunneling of the electrons through the intercrystalline barriers with the height φb = 0.7 eV. The parameters of the traps presented in the band gap of LiNbO3 are defined.

Microstructure evolution of copper doped beryllium thin films

Copper (Cu) doped beryllium (Be) thin films were deposited on silicon substrates by using a simple ion beam sputtering method, which can also realize the varying of Cu doping concentration. Detailed morphological and structural characterizations of the samples clearly disclose a microstructure evolution of films upon doping Cu. Doping Cu can effectively suppress film grain growth, causing a small grain size as well as uniform size distribution. Furthermore, doping Cu affects the crystallographic texture of film, which leads to the formation of more compact film structure. In particular, the surface smoothness of the doped films is significantly improved, which makes them promising candidates for various applications.

Effect of negative substrate bias on the microstructure and mechanical properties of Ti–Si–N films deposited by a hybrid filtered cathodic arc and ion beam sputtering technique

A hybrid cathodic arc and ion beam sputtering method was employed to synthesize Ti–Si–N films. The influence of negative substrate bias on the structure and mechanical properties was investigated by using XRD, XPS, HRTEM, nanoindentor and so on. With the increasing of negative bias there is a decrease in the TiN crystallite size from 36nm to 10nm. Negative substrate bias promoted the conformation of nc–TiN/a–Si3N4 nanocomposite structure with complete phase separation and uniform crystallite size. Superhard TiSiN films with a maximum hardness of 46GPa were successfully synthesized under 100V negative bias. Severe oxidation occurred in films deposited under 200V and 300V negative substrate bias due to the decreasing of deposition rate, which led to the hardness of films reduced to the value of 26GPa and 22GPa respectively.

Optimization in fabricating bismuth telluride thin films by ion beam sputtering deposition

N-type bismuth telluride (Bi2Te3) thermoelectric thin films were deposited on BK7 glass substrates by ion beam sputtering method. Various substrate temperatures were tried to obtain optimal thermoelectric performance. The influence of deposition temperature on microstructure, surface morphology and thermoelectric properties was investigated. X-ray diffraction shows that the films are rhombohedral with c-axis as the preferred crystal orientation when the deposition temperature is above 250°C. All the films with single Bi2Te3 phase are obtained by comparing X-ray diffraction and Raman spectroscopy. Scanning electron microscopy result reveals that the average grain size of the film is larger than 500nm when the deposition temperature is above 300°C. Thermoelectric properties including Seebeck coefficient and electrical conductivities were measured at room temperature, respectively. It is found that Seebeck coefficients increase from −28μVk−1 to −146μVk−1 and the electrical conductivities increase from 1.87×103Scm−1 to 3.94×103Scm−1 when the deposition temperature rose to 250°C and 300°C, respectively. An optimal power factor of 6.45×10−3Wm−1K−2 is gained when the deposition temperature is 300°C. The thermoelectric properties of bismuth telluride thin films have been found to be strongly enhanced by increasing the deposition temperature.