Effect of amorphous C films deposited by RF magnetron sputtering on smoothing K9 glass substrate

Soft X-ray multilayer reflectors must be deposited on super-smooth surface such as super-polished silicon wafers or glasses, which are complicate, time-consuming and expensive to produce. To overcome this shortage, C films deposited by RF magnetron sputtering were considered to smooth the K9 glass substrates’ surface in the present paper. The structure of C films was systematically studied by XRD and Raman spectrum. The surface morphology and rms-roughness were obtained by AFM. Then, we calculated the impact of the C layers on the reflectivity curve of Mo/Si soft X-ray multilayer reflector around 13.5 nm. The C films exhibit typical amorphous state. With the increasing of power and thickness, the content of sp3 hybrid bonding decreases while the amount or size of well-organized graphite clusters increases. The surface rms-roughness decreases from 2.4 nm to 0.62 nm after smoothed by an 80 nm thick C layer deposited in 500 W, which is the smoothest C layer surface we have obtained. The calculation results show that the theoretical normal incidence reflectivity of Mo/Si multilayer at 13.5 nm increases from 7% to 63%.     

Cu-In-O composite thin films deposited by reactive DC magnetron sputtering

Cu-In-O composite thin films were deposited by reactive DC magnetron sputtering at room temperature. The samples were characterized by scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), UV/vis spectrophotometer, four-probe measurement and Seebeck effect measurement, etc. The samples contain Cu, In and O. The ratios of Cu to In and O to In increase with increase in O₂ flow rates. The ratio of Cu to In is over 1 and this suggests that Cu is in excess. The obtained Cu-In-O thin films are very possibly made of rhombohedral In₂O₃ and monoclinic CuO. Transmittance of the films decreases with increase in O₂ flow rate. The decrease in transmittance results from increase in Cu content in the films. The optical band gap of all the samples is estimated to be 4.1-4.4 eV, which is larger than those of In₂O₃ and CuO. The sheet resistance of the films decreases with increase in O₂ flow rate. Conductivity of the films is a little low, due to the addition of Cu and the poor crystalline quality of the film. The conduction behavior of the films is similar to that of In₂O₃ and the conduction mechanism of Cu-In-O thin films is through O vacancy.     

The effects of substrate temperatures on the electrical properties of CaZrO3 thin films prepared by RF magnetron sputtering

The radio frequency magnetron sputtering technology (RFMS) was employed to deposit perovskite structure orthogonal phase CaZrO₃ thin films on Pt/Ti/SiO₂/Si substrates. The effects of substrate temperatures on structure and electrical properties of these films were investigated in detail. The CaZrO₃ thin films were systematically characterized by means of X-ray diffraction (XRD), Scanning electron microscope (SEM), Multi-frequency LCR meter (HP4294A) and Radiant Precision Workstation to study the phase structure, cross-section morphology, dielectric and ferroelectric properties at different substrate temperatures. The result indicates that these films can withstand 80 V DC Bias voltage and have excellent stability of frequency, voltage and temperature. The CaZrO₃ thin film prepared at 550 °C turned out to be mainly orthorhombic CaZrO₃ phase with high permittivity, low dielectric loss, extremely low leakage current (at 1 MHz, the dielectric constant is 39.42, the dielectric loss is 0.00455, the quality factor is 220 and the leakage current density is 9.11 × 10⁻⁷A/cm² at 80 V applied voltage.). This work demonstrates that higher substrate temperature can boost the formation of orthorhombic CaZrO₃ phase and the CaZrO₃ thin film prepared by RF magnetron sputtering is a very promising paraelectric material in the application of thin film capacitor.     

Crystal orientation control of polycrystalline TiN thin films using ZnO under layers deposited by magnetron sputtering

The effect of ZnO under layers on crystal growth of TiN thin films was investigated. TiN single layers and double-layered ZnO/TiN thin films were deposited on soda-lime-silicate glass substrates by magnetron sputtering. XRD analysis indicated that TiN single layers exhibited {1 1 1} preferred orientation on glass substrates; on the other hand, the TiN thin films with {1 0 0} preferred orientation were obtained using ZnO under layers and crystallized better than the TiN single layers. This crystal orientation change of TiN thin films should come from heteroepitaxial-like growth because the TiN{1 0 0} and ZnO{0 0 1} crystal lattice planes have similar atomic arrangements. Besides, the possible mismatch between TiN and ZnO atomic arrangements was estimated to be 7.8%. Furthermore, the resistivity and optical absorbance of TiN thin films decreased when they were deposited on ZnO under layers. It can be considered that electrical and optical properties should be improved due to the well-crystallization of TiN thin films using ZnO under layers.     

The effect of hydrogen on copper nitride thin films deposited by magnetron sputtering

Copper nitride thin films were deposited on Si (1 0 0) wafers by reactive magnetron sputtering at various H₂/N₂ ratios. X-ray diffraction measurements show that the films are composed of Cu₃N crystallites with anti-ReO₃ structure and exhibit preferred orientation of [1 0 0] direction. Although the relative composition of the films has obviously changes with the H₂/N₂ ratios, the orientations of the films keep almost no changes. However, the grain size, lattice parameter and composition of the films are strongly dependent on the H₂/N₂ ratios. The copper nitride films prepared at 10% H₂/N₂ ratios show poor stability and large weight gain compared to the copper nitride films prepared at 0% H₂/N₂ ratios.     

Tuning stress-induced magnetic anisotropy and high frequency properties of FeCo films deposited on different curvature substrates

It is important to control magnetic anisotropy of ferromagnetic materials. In this work, FeCo thin films are deposited on the curving substrates by electrochemical deposition to adjust the stress-induced magnetic anisotropy. The compressive stress is produced in the as-deposited films after the substrates are flattened. A simplified theoretical model of ferromagnetic resonance is utilized to measure the intrinsic magnetic anisotropy field and saturation magnetization. The results show that the stress-induced magnetic anisotropy and the resonance frequency increase with the increase of substrate curvature. The induced easy axis is perpendicular to the compressive stress direction.     

Indium zinc oxide thin films deposited by sputtering at room temperature

The deposition of amorphous indium zinc oxide (IZO) thin films on glass substrates with n-type carrier concentrations between 10¹⁴ and 3 × 10²⁰ cm⁻³ by sputtering from single targets near room temperature was investigated as a function of power and process pressure. The resistivity of the films with In/Zn of ∼0.7 could be controlled between 5 × 10⁻³ and 10⁴ Ω cm by varying the power during deposition. The corresponding electron mobilities were 4-18 cm² V⁻¹ s⁻¹.The surface root-mean-square roughness was <1 nm under all conditions for film thicknesses of 200 nm. Thin film transistors with 1 μm gate length were fabricated on these IZO layers, showing enhancement mode operation with good pitch-off characteristics, threshold voltage 2.5 V and a maximum transconductance of 6 mS/mm. These films look promising for transparent thin film transistor applications.     

A torque magnetometer for thin films applications

We describe the development of an automatic torque magnetometer based on a torsion pendulum. The instrument uses the capacitive arrange developed by Randall D. Peters, Rev. Sci. Instr. 60 (8), 2789 (1989), as sample's angular position sensor. The instrument performance is illustrated by measuring the in plane magnetic anisotropy of Co thin films and systems with exchange-bias. It possesses a sensitivity of 10^?10 Nm and is capable to determine anisotropy constants in magnetic films as thin as 3 nm. The instrument design and the measurement procedures are presented.     

Physical and electrochemical study of platinum thin films deposited by sputtering and electrochemical methods

In this work platinum thin films deposited by sputtering and electrochemical methods were characterized through physical and electrochemical analysis. The as-grown platinum thin films were characterized through X-ray diffraction (XRD), atomic force microscopy (AFM); scanning electronic microscopy (SEM) and through electrochemical impedance spectroscopy (EIS) measurements. Structural studies indicated that platinum thin films were polycrystalline. Morphological characteristics were significantly affected by the substrate type and synthesis method. Finally the EIS analysis indicated that platinum films were electrochemically stable and present both low resistance of charge transfer and low series resistance; the equivalent circuit of platinum interface has been proposed.     

Properties of Eu-doped zinc oxide thin films grown on glass substrates by radio-frequency magnetron sputtering

Eu-doped ZnO (EZO) thin films were prepared on glass substrates at various growth temperatures by radio-frequency magnetron sputtering. The properties of deposited thin films showed a significant dependence on the growth temperature. The preferential growth orientation of all the thin films was occurred along the ZnO (002) plane. The maximum crystallite size and the minimum average transmittance in the wavelength range of 450–1100 nm were observed for the EZO thin film deposited at 25 °C. A red shift of the optical band gap was observed in the growth temperature range of 25–300 °C. The highest figure of merit, an index for evaluating the performance of transparent conducting thin films, was obtained at 200 °C of growth temperature. These results indicated that the high-quality EZO film was obtained at a growth temperature of 200 °C.     

Growth, structural, and magnetic properties of iron nitride thin films deposited by dc magnetron sputtering

FeN thin films were deposited on glass substrates by dc magnetron sputtering at different Ar/N₂ discharges. The composition, structure and the surface morphology of the films were characterized using X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), and atomic force microscopy (AFM). Films deposited at different nitrogen pressures exhibited different structures with different nitrogen contents, and the surface roughness depended on the mechanism of the film growth. Saturation magnetization and coercivity of all films were determined using superconducting quantum interference device, which showed that if N₂/(Ar+N₂) flow ratio was equal to or larger than 30% the nonmagnetic single-phase γ″-FeN appeared. If N₂/(Ar+N₂) flow ratio was less than 10%, the films consisted of the mixed phases of FeN_0.056 and γ′-Fe₁₆N₂, whose saturation magnetizations were larger than that of -Fe. If N₂/(Ar+N₂) flow ratio was 10%, the phases of γ′-Fe₄N and -Fe₃N appeared, whose saturation magnetizations were lower than that of -Fe.     

溅射功率对直流磁控溅射Ti膜结构的影响

 采用直流磁控溅射方法制备了纯Ti膜,研究了不同功率下Ti膜的沉积速率、表面形貌及晶型结构,并对其应力进行了研究。研究表明：薄膜的沉积速率随溅射功率的增加而增加,当溅射功率为20 W时,原子力显微镜(AFM)图像显示Ti膜光洁、致密,均方根粗糙度最小可达0.9 nm。X射线衍射(XRD)分析表明薄膜的晶体结构为六方晶型,Ti膜应力先随溅射功率增大而增大,在60 W时达到最大值（为945.1 MPa）,之后随溅射功率的增大有所减小。     

溅射功率对直流磁控溅射Ti膜结构的影响

采用直流磁控溅射方法制备了纯Ti膜,研究了不同功率下Ti膜的沉积速率、表面形貌及晶型结构,并对其应力进行了研究。研究表明：薄膜的沉积速率随溅射功率的增加而增加,当溅射功率为20 W时,原子力显微镜(AFM)图像显示Ti膜光洁、致密,均方根粗糙度最小可达0.9 nm。X射线衍射(XRD)分析表明薄膜的晶体结构为六方晶型,Ti膜应力先随溅射功率增大而增大,在60 W时达到最大值（为945.1 MPa）,之后随溅射功率的增大有所减小。     

Structural,luminescent, and morphological properties of Eu3+-doped NaTaO3 thin films grown by magnetron sputtering

Radio-frequency (RF)-sputtered Eu³⁺-doped NaTaO₃ thin films were grown at different deposition temperatures. The X-ray diffraction patterns revealed that all thin films contained two mixed phases of NaTaO₃ and Na₂Ta₈O₂₁. The photoluminescence spectra of the thin films consisted of a strong orange emission (592 nm) and two weak red bands (616 nm and 689 nm), suggesting that more Eu³⁺ ions in the NaTaO₃ host crystal were located at inversion symmetry sites. The maximum intensities of all emission peaks were achieved for the sample grown at 100 °C, in which the gravel-shaped crystallites evolved with a band gap energy of 4.61 eV, chromaticity coordinates of (0.554, 0.434), and average transmittance of 92.4%. These results indicate that the photoluminescence intensity, band gap energy, and color tunability can be achieved for RF-sputtered Eu³⁺-doped NaTaO₃ thin films by varying the growth temperature.     

Influence of substrate temperature on the optical and piezoelectric properties of ZnO thin films deposited by rf magnetron sputtering

In this study, ZnO thin films were fabricated using the rf magnetron sputtering method and their piezoelectrical and optical characteristics were investigated for various substrate temperatures. The ZnO thin film has the largest crystallization orientation for the (0 0 2) peak and the smallest FWHM value of 0.56° at a substrate temperature of 200 °C. The surface morphology shows a relatively dense surface structure at 200 °C compared to the other substrate temperatures. The surface roughness shows the smallest of 1.6 nm at a substrate temperature of 200 °C. The piezoelectric constant of the ZnO thin film measured using the pneumatic loading method (PLM) has a maximum value of 11.9 pC/N at a substrate temperature of 200 °C. The transmittance of the ZnO thin film measured using spectrophotometry with various substrate temperatures ranged from 75 to 93% in the visible light region. By fitting the refractive index from the transmittance to the Sellmeir dispersion relation, we can predict the refractive index of the ZnO thin film according to the wavelength. In the visible light range, the refraction index of the ZnO thin film deposited at a substrate temperature of 200 °C is the range of 1.88-2.08.     

GeC薄膜的射频磁控反应溅射制备及性质

用射频磁控反应溅射法在ZnS衬底上制备了GeC薄膜,研究了工艺参数对Ge靶溅射及GeC薄膜红外透射性能的影响.衬底温度较低时GeC薄膜中含有H,形成了CH₂,CH₃,Ge-CH₃等,使薄膜产生红外吸收;随衬底温度升高,薄膜红外吸收明显减小.靶基距、射频功率、Ar:CH₄气体流量比、总气压对靶面中毒及溅射影响较大,但对GeC薄膜红外吸收影响较小.靶面中毒严重时,所制备无氢GeC薄膜附着性能差,随靶中毒减弱薄膜附着性能变好.优化工艺后,在ZnS衬底上制备了附着性能良好的无氢GeC薄膜,其折射率约为1.78,薄膜中C的含量比Ge的大,二者主要形成了C—Ge键.所制备的GeC/GaP红外增透保护膜系对ZnS衬底有良好的增透效果. 关键词： GeC薄膜 红外透射光谱 射频磁控溅射 XPS     

Low-temperature deposited ZnO thin films on the flexible substrate by cathodic vacuum arc technology

In this paper, un-doped zinc oxide (ZnO) films with various thicknesses (150, 250, 350, 450 and 550 nm) were successfully prepared onto PET substrates using cathodic vacuum arc technique at low-temperature (<40 °C). Their microstructure, optical and electrical properties were investigated and discussed. The films showed (0 0 2) peaks, an average transmittance over 80% in the visible region. Calculated values of the band gap are around 3.29-3.33 eV when the film thickness increased, indicating a slight blue shift of optical transmission spectra. The lowest resistivity about 5.26 × 10⁻³ Ω cm could be achieved for the un-doped ZnO film with thickness of 550 nm.     

Nanocrystalline titanium carbide thin films deposited by reactive magnetron sputtering

We investigated the structure and composition of titanium carbide thin films deposited by the reactive magnetron sputter ion plating process as a function of deposition parameters. The films were sputtered onto unheated glass substrates by means of an unbalanced planar d.c. magnetron equipped with a titanium target using a mixture of argon and methane. The deposition parameters ranged from 0.05 Pa to 2 Pa for total working gas pressurep _T, from 10% to 60% (volume) for relative methane concentration in the working gas mixture, from 45 mm to 85 mm for the substrate-to-target distanced _s-t and from −50V to −800V for the substrate biasU _S. It was found that the crystallinity of the thin films strongly decreases with increasingp _T,d _s-t andU _S. The experiments described show the conditions necessary to obtain sputter-deposited nanocrystalline titanium carbide films. This work has been partially supported by the Grant Agency of the Czech Republic under Grant No. 106/96/K245 and by the Ministry of Education of the Czech Republic under Grant No. VS96 059.     

Co-based nanogranular thin films on flexible substrate for gigahertz applications

The Co-based granular thin films were deposited on the flexible substrate (Kapton) by magnetron sputtering. The films comprise of Co nanocrystallites and small amount of amorphous (Al,O)-rich inter-granular phase and have the electric resistivities in the range 50–120 μΩ cm, depending on the composition and thickness. The as-deposited films with thickness <80 nm have low coercivity (<20 Oe along hard direction), high permeability (up to 500) and resonance frequency up to 2.5 GHz. Compared to the rigid films, the flexible films have relatively higher coercivity and lower resonance frequency. A comparison between Co-based granular films and FeTaN continuous films has also been discussed.