Effects of substrate temperature on the surface of polymer thin films prepared by R.F. sputtering with a polyimide target

In this study, we characterized polymer thin films deposited by a conventional radio frequency sputtering apparatus introduced into argon and nitrogen gases with a polyimide target onto copper substrates.Heating effects due to heating the copper substrate at 250 °C in the sputtering on tribological and adhesion properties of thin films were investigated with measuring friction coefficient, wear durability and pull strength. Surface roughness of the nitrogen sputtered thin film decreased by the heating. Friction coefficient of argon and nitrogen sputtered thin films prepared at 250 °C was almost the same level as that prepared at room temperature, respectively. Wear durability of these thin films and adhesion strength between these thin films and copper substrate decreased by the heating.     

Cubic PbS thin films on TCO glass substrate by galvanic technique

We report an electrochemical deposition of PbS thin films on SnO₂:F coated Transparent Conducting Oxide (TCO) glass substrates from a solution of EDTA, Pb(OAc)₂ and Na₂S₂O₃. A Pb strip acted as a sacrificial anode, while the TCO glass was the cathode. No external bias was applied. The deposition of PbS thin films was pH sensitive and a pH around 3 was found to be optimum for film deposition. The deposition was carried out at 80 °C, with stirring of the solution. X-ray diffraction studies revealed that the PbS films were of cubic phase. Scanning electron microscope image analysis showed a highly compact surface morphology. IR spectrum yielded an energy band gap around 0.4 eV. A.C. current–voltage (I–V) measurements were carried out using gold as one of the contacts. It was found that the PbS film formed an ohmic contact when the other electrode was also gold, however, a Schottky junction resulted, when the second contact was TCO.     

基体偏压对中频磁控溅射沉积DLC膜结构的影响

利用中频非平衡磁控溅射技术,以氩气和甲烷混合气体为工作气体,在载玻片和单品硅片上沉积含氢的类金刚石簿膜.改变加载在基体上的负偏压,在0～400 V范围内,制备5种偏压值下的薄膜,研究偏压对薄膜结构的影响.用光学显微镜和AFM考察薄膜的光学形貌;激光Raman谱定性分析膜的化学组分;VFIR分析其C-H键合类型;纳米压痕法测量膜的硬度.结果表明:当基体上施加偏压-100 V时,可以有效地提高沉积粒子与基体结合力以及溥膜的致密性,薄膜中正四面体的sp3结构和sp3CHn含最增加,纳米硬度提高.     

Deposition of ZnO thin films on Si by RF magnetron sputtering with various substrate temperatures

Undoped ZnO thin films were successfully deposited on Si substrates by RF magnetron sputtering with different substrate temperatures. The dependence was systematically investigated the structural, morphology, chemical state and optical properties of ZnO thin films. Crystal quality, growth orientation and optical properties of ZnO thin films were improved at proper substrate temperature (450 °C) whereas were deteriorated at higher temperature (600 °C). X-ray photoelectron spectroscopy showed that proper substrate temperature promoted the formation of Zn–O bonding, resulting in an improvement of film quality, while higher temperature decreased the formation of the Zn–O bonding and increased the oxygen vacancy due to formation of an amorphous SiO₂ layer at the interface of ZnO and Si, resulting in a degradation of film quality. Moreover, the amorphous SiO₂ layer is formed by oxygen related to the Zn–O bonding, mainly. Therefore, the experimental results indicate that the substrate temperature plays an important role in the deposition of ZnO film on Si substrate and needs to be carefully selected to suppress a formation of an amorphous SiO₂ layer.     

Low-temperature deposited Titanium-doped zinc oxide thin films on the flexible PET substrate by DC magnetron sputtering

Transparent conducting Titanium-doped zinc oxide thin films (TZO) with high transparency and relatively low resistivity were firstly deposited on water-cooled polyethylene terephthalate (PET) substrates at room temperature by DC magnetron sputtering. The microstructure, optical and electrical properties of the deposited films were investigated and discussed. The XRD patterns show that all the deposited films are polycrystalline with a hexagonal structure and have a preferred orientation along the c-axis perpendicular to the substrate. The electrical resistivity decreases when the sputtering power increases from 45 W to 60 W. However, as the puttering power continue increases from 60 W to 90 W, the electrical resistivity increases rapidly. When the puttering power is 60 W, the films deposited on PET substrate have the lowest resistivity of 4.72 × 10⁻⁴ Ω cm and a relatively high transmittance of above 92% in the visible range.     

Low-temperature deposited Titanium-doped zinc oxide thin films on the flexible PET substrate by DC magnetron sputtering

Transparent conducting Titanium-doped zinc oxide thin films (TZO) with high transparency and relatively low resistivity were firstly deposited on water-cooled polyethylene terephthalate (PET) substrates at room temperature by DC magnetron sputtering. The microstructure, optical and electrical properties of the deposited films were investigated and discussed. The XRD patterns show that all the deposited films are polycrystalline with a hexagonal structure and have a preferred orientation along the c-axis perpendicular to the substrate. The electrical resistivity decreases when the sputtering power increases from 45 W to 60 W. However, as the puttering power continue increases from 60 W to 90 W, the electrical resistivity increases rapidly. When the puttering power is 60 W, the films deposited on PET substrate have the lowest resistivity of 4.72 × 10⁻⁴ Ω cm and a relatively high transmittance of above 92% in the visible range.     

Residual stresses of sputtering titanium thin films at various substrate temperatures

This work seeks to characterize the residual stresses of titanium thin films as they are affected by various substrate temperatures during the sputtering process. The titanium thin films are deposited on silicon wafers by a RF magnetron sputter while different substrate temperatures are considered. The residual stresses are measured by both X-ray diffraction and a substrate curvature method, and consistent results are obtained by both methods. The results show that the residual stress decreases as the substrate temperature increases, in which the stress changes from tensile to compressive when the substrate temperature increases from 25 to 50 degrees C. Furthermore, the elastic modulus and hardness of the titanium thin films are tested with a nanoindenter using a standard Berkovich probe. Correlations between the residual stresses and mechanical properties measured by nanoindentation are also discussed.     

Effect of the substrate temperature on zirconium oxynitride thin films deposited by water vapour-nitrogen radiofrequency magnetron sputtering

ZrN_x films were deposited by radiofrequency reactive magnetron sputtering technique in nitrogen and water vapour atmosphere varying the working temperature from room temperature to 600 °C. The films' physical properties were investigated using X-ray diffraction, Secondary Ion Mass Spectroscopy, Atomic Force Microscopy and Transmission Electron Microscopy. It was found that the increase of temperature caused a decrease in the oxygen incorporation and a transition from cubic phase of Zr₂ON₂ to ZrN one. The formation of nanosized crystalline particles dispersed in the amorphous matrix was observed.     

Characterization of aluminum-doped zinc oxide thin films by RF magnetron sputtering at different substrate temperature and sputtering power

In this study, transparent conductive Al doped zinc oxide (ZnO: Al, AZO) thin films with a thickness of 40 nm were prepared on the Corning glass substrate by radio frequency magnetron sputtering. The properties of the AZO thin films are investigated at different substrate temperatures (from 27 to 150 °C) and sputtering power (from 150 to 250 W). The structural, optical and electrical properties of the AZO thin films were investigated. The optical transmittance of about 78 % (at 415 nm)–92.5 % (at 630 nm) in the visible range and the electrical resistivity of 7 × 10^?4 Ω-cm (175.2 Ω/sq) were obtained at sputtering power of 250 W and substrate temperature of 70 °C. The observed property of the AZO thin films is suitable for transparent conductive electrode applications.     

直流反应磁控溅射在3003铝箔表面制备薄膜的研究

为有效提高3003铝箔表面光泽度、比面积及强硬度,采用直流反应磁控溅射的方法.在一定溅射参数条件下,选用高纯钼靶和钛靶对3003铝箔进行溅射实验,分别在铝箔表面主要沉积出AlMo3、Al3Mo薄膜和TiAl、(Ti,Al)N薄膜,利用X射线衍射、扫描电镜分析相组成及微观组织结构,并测试了显微硬度和薄膜厚度,实验结果表明:制备出的AlMo3、Al3Mo薄膜和TiAl薄膜结晶良好,与基底结合良好,铝箔表面美观漂亮、硬度增高及比表面积得到一定提高.     

Influence of sputtering parameters and nitrogen on the microstructure of chromium nitride thin films deposited on steel substrate by direct-current reactive magnetron sputtering

Chromium nitride thin films were deposited on SA-304 stainless steel substrates by using direct-current reactive magnetron sputtering. The influence of process conditions such as nitrogen content in the fed gas, substrate temperature, and different sputtering gases on microstructural characteristics of the films was investigated. The films showed (200) preferred orientation at low nitrogen content (< 30%) in the fed gas. The formation of Cr₂N and CrN phases was observed when 30% and 40% N₂ were used, with a balance of Ar, respectively. Field emission scanning electron microscopy and atomic force microscopy were used to characterize the morphology and surface topography of the thin films, respectively. Microhardness tests showed a maximum hardness of 16.95 GPa for the 30% nitrogen content.     

Improved ITO thin films with a thin ZnO buffer layer by sputtering

In this paper, we report a buffering method of improving the quality of ITO thin films on glass by r.f. magnetron sputtering. By applying a ZnO buffer before the ITO deposition in the same run of sputtering, ITO films showed single (111)-oriented highly textured structure, while ITO films showed mixed-oriented polycrystalline structure on bare glass. A design of experiment was taken out to minimize the resistivity of ITO films in the deposition parameter space (oxygen ratio, total gas pressure, and temperature). Resistance measurements showed that the ITO films with ZnO buffers had a remarkable 50% decrease of resistivity comparing to those without ZnO buffers at optimized deposition condition. Room-temperature Hall effect measurements showed that the decrease in resistivity comes from a large increase of mobility and a slight increase of carrier density after forming gas annealing. The ZnO/glass may be a good alternative substrate to bare glass for producing high quality ITO films for advanced electro-optic applications.     

Al-Mg-B thin films prepared by magnetron sputtering

Hard, nanocomposite aluminum magnesium boride thin films were prepared on Si (100) substrates with a three target magnetron sputtering system. The films were characterized by X-ray diffraction, atomic force microscope, electron micro-probe, Fourier transform infrared spectroscopy and nanoindentation. The results show that the maximum hardness of the as-deposited films is about 30.7 GPa and these films are all X-ray amorphous with smooth surfaces. The influences of substrate temperature and boron sputtering power on the quality of the films are discussed. From the results of this work, magnetron sputtering is a promising method to deposit Al-Mg-B thin films.     

Effects of substrate temperatures on the thermal stability of Al-doped ZnO thin films grown by DC magnetron sputtering

In this work, Al-doped (4 at%) ZnO(AZO) thin films were prepared by DC magnetron sputtering using a home-made ceramic target at different substrate temperatures. The microstructure, optical, electrical and thermal stability properties of these thin films were characterized systematically using scanning electron microscopy, UV–Vis-NIR spectrometry, X-ray diffraction, and Hall measurements. It was observed that the AZO thin films deposited at 350 °C exhibited the lowest resistivity of 5.76 × 10⁻⁴ Ω cm, high average visible transmittance (400–800 nm) of 92%, and the best thermal stability. Comparing with the AZO thin films deposited at low substrate temperatures, the AZO thin films deposited at 350 °C had the highest compact surface morphology which could hinder the chemisorbed and diffused oxygen. This was considered to be the main mechanism which was responsible for the thermal degradation of AZO thin films.     

Highly conductive, undoped ZnO thin films deposited by electron-cyclotron-resonance plasma sputtering on silica glass substrate

The electrical and optical properties of undoped ZnO films deposited by electron cyclotron resonance (ECR) plasma sputtering at room temperature were characterized. The lowest resistivity we achieved was 2.6 × 10^− 3 Ωcm with optical transmittance at visible wavelengths higher than 85%. The X-ray diffraction (002) peak was weak and the rocking curve was asymmetrical, indicating that oxygen vacancies prevented large crystalline domains from forming. At low argon-sputtering-gas pressure, carrier concentration and Hall mobility increased with increasing argon pressure. When the optimum pressure (40 mPa) was exceeded, however, Hall mobility and optical transmittance were severely reduced, which indicated that excess Zn atoms were populated at the interstitials of the network. Admitting only 0.67 mPa of O₂ gas during deposition deteriorated resistivity over 1 MΩcm due to high excitation efficiency in the ECR plasma. Deposition under a higher magnetic field produced lower resistivities.     

The properties of Al doped ZnO thin films deposited on various substrate materials by RF magnetron sputtering

Transparent conductive Al-doped ZnO (AZO) thin films were deposited on various substrates including glass, polyimide film (PI) and stainless steel, using radio frequency magnetron sputtering method. The structural, electrical and optical properties of AZO thin films grown on various substrates were systematically investigated. We observe that substrate materials play important roles in film crystallization and resistivity but little on optical transmittance. X-ray diffractometer study shows that all obtained AZO thin films have wurtzite phase with highly c-axis preferred orientation, and films on glass present the strongest (002) diffraction peaks. The presence of compression stress plays critical role in determining the crystalline structure of AZO films, which tends to stretch the lattice constant c and enlarge the (002) diffraction angle. Although the films on the glass present the finest electrical properties and the resistivity reaches 12.52 × 10-4 Ωm, AFM study manifests that films on flexible substrates, especially stainless steel, bestrew similar inverted pyramid structure which are suitable for window material and electrode of solar cells. The average optical transmittance of AZO thin films deposited on glass and PI are both around 85% in the visible light range (400–800 nm).     

Influence of substrate temperature on phase formation in Al-Cr thin films

Thin films (of the order of nm) of Al-Cr alloys were prepared by successive depositions by an electron gun in a vacuum chamber. Three Al and two Cr layers, of thicknesses as to yield the final composition, were deposited on both hot (350 °C and 440 °C) and cold (70 °C and 108 °C) substrates and the phases formed were characterized in each case by X-ray diffraction and TEM observations, both in bright and in dark field conditions. The results show that on the hot substrates, Bragg peaks that do not correspond to any reported crystalline or quasi-crystalline phase appear. Both the samples on cold substrates and those heated afterwards showed an amorphous structure by X-ray diffractomery but TEM demonstrated the presence of tiny faulted crystallites, with the same Bragg reflections than those deposited on hot substrates. The results show that, for the composition range studied, a new phase not reported before appears and the substrate temperature only produces crystallite growth, not the formation of new phases. Received: 26 May 2000 / Reviewed and accepted: 31 May 2000     

The influence of substrate temperature on the properties of aluminum-doped zinc oxide thin films deposited by DC magnetron sputtering

Transparent, conducting, aluminum-doped zinc oxide (AZO) thin films were deposited on Corning 1737 glass by a DC magnetron sputter. The structural, electrical, and optical properties of the films, deposited using various substrate temperatures, were investigated. The AZO thin films were fabricated with an AZO ceramic target (Al₂O₃:2 wt%). The obtained films were polycrystalline with a hexagonal wurtzite structure and preferentially oriented in the (002) crystallographic direction. The lowest resistivity was 6.0 × 10⁻⁴Ω cm, with a carrier concentration of 2.7 × 10²⁰ cm⁻³ and a Hall mobility of 20.4 cm²/Vs. The average transmittance in the visible range was above 90%.     

The effect of substrate temperature on the physical properties of tantalum oxide thin films grown by reactive radio-frequency sputtering

Thin films of TaO_x were deposited on Si(1 0 0) by radio-frequency magnetron sputtering at substrate temperatures of 25, 100, 200, 300, 400, and 500 °C. The properties of TaO_x thin films deposited with different oxygen-to-argon gas ratios and substrate temperatures were evaluated. The results show that the films with lowest leakage current density were obtained at ambient temperature with an oxygen mixture ratio (OMR) of 60% and the oxygen-to-tantalum ratio has a minimum with increasing deposition substrate temperature. From the current–voltage (I–V) characteristics of the TaO_x thin films as a function of deposition substrate temperature, we found that the leakage current density in the TaO_x thin films increases with increasing deposition substrate temperature. The higher leakage current density in the TaO_x films is correlated to the oxygen deficiency in TaO_x films and crystallization at higher deposition temperature.