热处理对Fe-O、Fe-N-O薄膜透射率的影响

采用二极溅射方法在玻璃基体上制备了Fe-O、Fe-N-O薄膜.在空气气氛下用不同温度对其进行了加热处理,并用紫外可见分光光度仪对热处理前后样品的透射率进行了研究.结果表明,热处理对薄膜的光学性能影响较大;N元素的存在对薄膜的光学性能有一定的影响;随着加热温度的增加透射率增加.XPS实验结果证明薄膜性能改变的原因是热处理后薄膜的成分与结构发生了明显的变化.     

溅射共沉积GaAs—SiO2复合薄膜的XPS研究

采用Ｘ射线光电子能谱（ＸＰＳ）研究了由ＧａＡｓ和ＳｉＯ２组成的复合靶共溅射沉积的ＧａＡｓ－ＳｉＯ２复合薄膜的Ｇａ、Ａｓ和Ｓｉ的化学结合状态及其沉积时的基片温度对其影响。结果表明：Ｇａ、Ａｓ和Ｓｉ分别主要是以ＧａＡｓ和ＳｉＯ２的化学组态存在于复合薄膜之中，但当沉积时基片温度上升到一定值后（我们实验中为４００℃），有部分的Ｇａ和Ａｓ被氧化，其氧化量随着基片温度的进一步升高而上升。沉积的ＳｉＯ２中存在着少量的缺氧缺位。     

溅射二氧化铈氧敏薄膜的XPS研究

本文用射频磁控溅射法制备了ＣｅＯ２－ｘ高温氧敏薄膜，利用Ｘ射线光电子能谱研究了不同处理条件对ＣｅＯ２－ｘ薄膜电子组态的影响，特别是对表面的价态和吸附性质的影响。通过对Ｃｅ３ｄＸＰＳ谱的高斯拟合，计算了Ｃｅ＾３＋浓度并给出了判定Ｃｅ＾４＋还原的标志。研究结果表明，在空气中经１１７３Ｋ高温退火后可得到结晶完好的多晶ＣｅＯ２薄膜，而薄膜的化学价态没有变化，退火前后薄膜表面总有少量Ｃｅ＾３＋存在（１５％）     

真空蒸发沉积CdZnTe纳米薄膜的结构与形貌

采用真空蒸发沉积技术在ITO玻璃上制备得到CdZnTe纳米晶薄膜,并利用台阶仪、X射线能谱仪(EDS)、X射线衍射仪(XRD)和原子力显微镜(AFM)研究了CdZnTe薄膜厚度、成分、结构和形貌特征。实验结果表明,薄膜在(111)面表现出明显的择优生长特性。在薄膜生长初期,纳米薄膜中存在一定程度的非晶态富集Te,但随着沉积时间延长,薄膜成分向化学计量比逼近,结构也向闪锌矿CdZnTe转变。薄膜表面形貌平整,粗糙度Ra约为2～5nm。随着沉积时间的延长,薄膜形貌由晶粒堆砌状向多晶层片连接状转变。在沉积时间分别为15、30和45min时,薄膜的厚度依次分别约为100、300和500nm,而薄膜的晶粒平均尺寸依次分别为43.15、30.81和71.94nm。     

反应溅射Si-C-N薄膜的结构分析

本文用射频反应磁控溅射制备了ＳｉＣＮ薄膜,对薄膜的化学成分、结构进行了研究。结果表明,反应气体Ｎ２、Ｓｉ、Ｃ三者之间形成了Ｓｉ－Ｃ,Ｓｉ－Ｎ和Ｃ－Ｎ键,构成了复杂的网络结构。成分分析表明薄膜的化学计量式近似为ＳｉＣＮ。对比分析了反应应溅射制备ＳｉＣＮ、ＣＮｘ、ＳｉＮｙ、ＳｉＣｘ薄膜的ＦＴＩＲ谱。     

多种基底上溅射沉积ZnO薄膜的结构

在玻璃基底和四种硅基底上用反应式直流磁控溅射法制备了ＺｎＯ薄膜。用ＡＥＳ和ＸＲＤ对薄膜结构和组分进行测试,结果表明,五种基底上生长的ＺｎＯ薄膜在不同程度上都具有优良的纵均匀性、明显的ｃ轴择优取向和较高的结晶度,而硅基底上薄膜的结构普遍优于玻璃基底上沉积的薄膜。     

掠射角溅射沉积纳米结构氧化钨薄膜

采用掠射角反应磁控溅射法在室温下沉积了纳米结构氧化钨(WO₃)薄膜, 并对薄膜进行热处理。利用场发射扫描电镜(FE-SEM)和X射线衍射仪(XRD)对氧化钨薄膜的形貌和结构进行了表征。当掠射角度为80°时, 采用直流电源沉积的氧化钨薄膜具有纳米斜柱状结构, 而采用脉冲直流电源沉积的薄膜呈现纳米孔结构。纳米薄膜经450℃热处理3 h后, 纳米斜柱彼此连接, 失去规整结构, 而纳米孔结构的孔尺寸变大。XRD分析表明室温沉积的氧化钨薄膜具有无定形结构, 经450℃热处理1 h后, 转变为单斜晶相。具有纳米斜柱状或纳米孔结构氧化钨薄膜的光学调制幅度在波长600 nm时达到60%, 且电致变色性能可逆。     

溅射沉积Ni-Mn-Ga薄膜的研究进展

以Ni-Mn-Ga为主要代表的铁磁形状记忆合金(FSMAs)不但具有传统形状记忆合金受温度控制的热弹性形状记忆效应,而且具有受磁场控制的铁磁形状记忆效应.微机电系统(MEMS)的应用要求Ni-Mn-Ga合金必须制备成薄膜的形式.对溅射沉积Ni-Mn-Ga薄膜的制备工艺进行了回顾与总结,对薄膜的各种性能特征和影响因素进行了详细的叙述,最后介绍了溅射沉积Ni-Mn-Ga薄膜的应用状况和应用趋势.     

非织造布表面反应溅射沉积ZnO薄膜及其结构与性能分析

实验采用低温直流磁控溅射技术，经O2和Zn在真空腔内反应、在涤纶纺粘非织造布表面沉积ZnO功能性纳米薄膜。运用能量散射X射线能谱仪（EDX）分析样品镀层前后元素组成的变化及其含量，并利用原子力显微镜（AFM）分析纳米结构表面镀层的形貌及其与直流溅射工艺参数的关系。分析表明：ZnO颗粒尺寸在一定范围内随氧氩比的增大而增大，氧氩比为20sccm：20sccm时较合适；溅射功率和镀膜厚度的增加均使ZnO颗粒尺寸增大，溅射功率过大会导致ZnO颗粒发生畸变；溅射压强增加颗粒直径则是先增大后减小，同时压强增大颗粒均匀性和取向性变差。利用织物感应式静电测试仪测试镀层前后织物的抗静电性能，发现经镀层后非织造布的抗静电性能得到了显著的改善，而且随着膜厚的增加抗静电性能提高也很明显。     

Growth, structure and properties of sputtered niobium oxide thin films

Niobium oxide (NbO_x) films were deposited by pulsed dc magnetron sputtering at different total gas pressures and oxygen flow rates. Various film properties were characterized by X-ray photoelectron spectroscopy, atomic force microscopy, variable angle spectroscopic ellipsometry and four point probe. It was found that oxygen flow rates required for preparing NbO, NbO₂ and Nb₂O₅ at a constant total pressure of 0.93 Pa were approximately 2, 4 and > 6 sccm, respectively. The results showed that the film properties, specifically composition can be significantly changed by the total gas pressure and the oxygen flow rate.     

The structure and composition of oxidized and reduced tungsten oxide thin films

The structure, morphology and composition of pure WO₃ thin films deposited onto vacuum-cleaved NaCl(001) single crystals have been studied at different substrate temperatures up to 580 K and under different oxidative and reductive treatments in the temperature range 373-873 K by Transmission Electron Microscopy, Selected-Area Electron Diffraction and X-ray Photoelectron Spectroscopy (XPS). A transition from an amorphous structure obtained after deposition at 298 K to a more porous structure with small crystallites at the highest substrate temperatures has been observed. XPS spectra reveal the presence of W⁶⁺ irrespective of the preparation procedure. Significant changes in the film structure were only observed after an oxidative treatment in 1 bar O₂ at 673 K, which induces crystallization of a monoclinic WO₃ structure. After raising the oxidation temperature to 773 K, the film shows additional reconstruction and a hexagonal WO₃ structure becomes predominant. This hexagonal structure persists at least up to 873 K oxidation temperature. However, these structural transformations observed upon oxidation were almost completely suppressed by mixing the WO₃ thin film with a second oxide, e.g. Ga₂O₃. Reduction of the WO₃ films in 1 bar H₂ at 723-773 K eventually induced the formation of the β-W metal structure, as evidenced by electron diffraction and XPS.     

Microstructure-mechanical and chemical behavior relationships in passive thin films

The passive films play an important role in corrosion and stress corrosion cracking of austenitic stainless steels. The current research investigates the relationship between alloy chemistry, microstructure, and mechanical behavior of passive films formed on 316, 304, and 904L stainless steels (SS). X-ray photoelectron spectroscopy and transmission electron microscopy were used to investigate the effect of alloy chemistry and microstructure constituents on the thin film fracture properties determined by nanoindentation tests. The analyses showed that fracture loads are directly related to the crystallography of the thin films. It was found that decreasing the ratio of iron to other metallic elements in the film led to an increase in the load required to fracture the film. It was also found that films grown on 304, 316, and 904L stainless steels were the cubic polymorph of Cr₂O₃, rather than the lower energy rhombohedral form. In the case of 904L SS the film formed as an epitaxial layer. In the other two cases it consisted of small crystalline islands in an amorphous matrix. A dichromate treatment of 316 SS decreased the iron content in the oxide film and increased the hardness. It also resulted in an epitaxial film.     

Structure and morphology of laser-ablated Pb thin films

The growth of polycrystalline Pb thin films on Si substrates at room temperature by near infrared laser ablation of pure Pb target is presented. Several diagnostic techniques were used to deduce the structure, the morphology and the thickness of the deposited films. We investigated the above properties as a function of laser fluence (1-8 J/cm²). Detailed morphological studies were also carried out on the irradiated target surface to deduce the laser ablation process. According to our results, the increase of laser fluence improves the crystallinity of the deposited films but not the deposition rate and the droplet density. The measured deposition rate was extremely low and varied between 0.04 and 0.09 Å per pulse. The final goal of this research activity is the realization of photocathodes based on Pb-thin-film to be used in superconducting Nb radio-frequency cavity.     

Correlation between resistivity and oxygen vacancy of hydrogen-doped indium tin oxide thin films

Thin films of indium tin oxide (ITO) sputter-deposited by dc-plasma containing deuterium on glass substrate without any heat treatments exhibited gradual lowering in electrical resistivity with increasing the deuterium content [D₂] in plasma gas by 1% and then demonstrated a jump in resistivity by further increase of [D₂] than 1%. X-ray photoelectron spectroscopy revealed that hydroxyl-bonded oxygen in ITO grew continuingly with [D₂]. Deuterium positioned at the interstitial site increased almost quantitatively with increasing [D₂]. Rutherford backscattering spectroscopy showed gradual reduction in the oxygen content of ITO with increasing [D₂] by 1% and then demonstrated an abrupt increase of the oxygen content with the increase of [D₂] than 1%. The films with [D₂] < 1% were oxygen deficient, but those with [D₂] > 1% were excess of oxygen. The most oxygen deficient film of [D₂] = 1% was the most conductive. Behavior in the resistivity with [D₂] looks parallel to that in the oxygen content. A lower resistivity of the films corresponded well to oxygen vacancy rather than hydrogen interstitial.     

Preparation and characterization of atomically flat and ordered silica films on a Pd(100) surface

Ultrathin silica films with different thicknesses have been grown on a Pd(100) surface by depositing silicon in the presence of O₂. The film composition and electronic properties were characterized by X-ray photoelectron spectroscopy (XPS), ultraviolet photoelectron spectroscopy (UPS), and high-resolution electron energy loss spectroscopy (HREELS). Scanning tunneling microscopy was applied to investigate the film morphology and lattice structure. The results show that the obtained films are atomically flat and highly ordered in a long range. UPS and HREELS measurements indicate that the silica film has the same electronic and vibrational properties as bulk silica. A 2.8 nm thick film exhibits low defects in the film and high thermal stability up to 800 K, as evidenced by ion scattering spectroscopy and XPS.     

Solvothermal approach for low temperature deposition of aluminium oxide thin films

At elevated pressure, stoichiometric and high quality Al₂O₃ thin films are fabricated at 65-105 °C. By using pre-organised single source precursor aluminium(III) diisopropylcarbamate, Al₂O₃ were deposited on the surface of a Si substrate in a single step in the liquid phase. Comprehensive removal of large carbamate ligands by proposed β-elimination during decomposition of precursor led to an effective delivery of enshrouded Al-O fragments. Scanning electron microscopy revealed dense and grainy surface morphology. The thicknesses of the films were measured to be 150-300 nm and independent to reaction temperatures or reaction times. Through the use of near edge X-ray absorption fine structure spectroscopy, Al absorption peaks suggest a short range crystalline formation in a film deposited at 105 °C.     

Sputter deposited LiPON thin films from powder target as electrolyte for thin film battery applications

Lithium phosphorus oxynitride (LiPON) thin films as solid electrolytes were prepared by reactive radio frequency (rf) magnetron sputtering from Li₃PO₄ powder compact target. High deposition rates and ease of manufacturing powder target compared with conventional ceramic Li₃PO₄ targets offer flexibility in handling and reduce the cost associated. Rf power density varied from 1.7 Wcm^− 2 to 3 Wcm^− 2 and N₂ flow from 10 to 30 sccm for a fixed substrate to target distance of 4 cm for best ionic conductivity. The surface chemical analysis done by X-ray photoelectron spectroscopy showed incorporation of nitrogen into the film as both triply, N_t and doubly, N_d coordinated form. With increased presence of N_t, ionic conductivity of LiPON was found to be increasing. The electrochemical impedance spectroscopy of LiPON films confirmed an ionic conductivity of 1.1 × 10^− 6 Scm^− 1 for optimum rf power and N₂ flow conditions.     

Effects of UV-ozone treatment on radio-frequency magnetron sputtered ZnO thin films

The effects of UV-ozone treatment on ZnO thin films prepared by using radio-frequency magnetron sputtering are investigated. Decrease in the density of oxygen vacancy as well as increase in the density of oxygen interstitial were inferred from the UV-ozone treated samples. It was also found that a considerable difference in the work function (0.25 eV) is induced by UV-ozone treatment implying a shift in Fermi level. This shift was confirmed by capacitance-voltage measurements, which demonstrated that the boundary between the inversion region and the depletion region of a ZnO-based metal-oxide-semiconductor (MOS) capacitor positively shifts when UV ozone treated. Our results clearly indicate that the threshold voltage of a thin film transistor can be adjusted by modifying the ZnO surface via UV ozone treatment. MOS capacitors fabricated with UV-ozone treated HfO₂ and/or ZnO also yielded a smaller leakage current (~ 73%-90% smaller) and a larger breakdown voltage (~ 8%-11% larger). The physical mechanism behind the effect of the UV ozone treatment is addressed in this study with the help of X-ray photoelectron spectroscopy and ultraviolet photoelectron spectroscopy.     

Magnetron sputtering of Zr-Si-C thin films

The phase composition and chemical bonding of ZrC and ZrSiC films deposited by magnetron sputtering has been studied. The results show that the binary Zr-C films at higher carbon contents form nanocrystallites of ZrC in an amorphous carbon matrix. The addition of Si induces a complete amorphization of the films above a critical concentration of about 15 at.%. X-ray diffraction and transmission electron microscopy confirm that the amorphous films contain no nanocrystallites and therefore can be described as truly amorphous carbides. The amorphous films are thermally stable but start to crystallize above 500 °C. Analysis of the chemical bonding with X-ray photoelectron spectroscopy suggests that the amorphous films exhibit a mixture of different chemical bonds such as ZrC, ZrSi and SiC and that the electrical and mechanical properties are dependent on the distribution of these bonds. For higher carbon contents, strong SiC bonds are formed in the amorphous Zr-Si-C films making them harder than the corresponding binary Zr-C films.