Mo电极形貌对AIN薄膜择优取向生长的影响

采用射频磁控溅射方法在不同形貌的Mo电极上制备了(002)择优取向的AlN薄膜。采用XRD、FESEM表征了Mo电极及AlN薄膜的结构、表面形貌及择优取向。结果表明,Mo电极的形貌影响AlN薄膜的择优取向生长,在较高溅射气压下沉积的Mo电极晶粒细小、分布均匀,有助于AlN薄膜(002)择优取向生长。     

A study on the plasma polymer thin film surface modification for DNA alignment by using high energy electron beam irradiation

The plasma polymer thin films were deposited on Si(100) substrate by PECVD (plasma enhanced chemical vapor deposition) method. Liquid cyclohexene was used as single organic precursor. It was heated up to 60 °C and bubbled up by hydrogen gas, which flow rate was 50 sccm (standard cubic centimeters per min). Deposition temperature was room temperature. Plasma was ignited by a radio frequency (RF; 13.56 MHz) of 10 W.As-deposited plasma polymer thin films were treated by e-beam of 300 keV with various adsorption radiation doses. The plasma polymer films, which were treated by high energy e-beam (HEEB), were investigated by FT-IR (Fourier Transform Infrared), XPS (X-ray Photoelectron Spectroscopy), AFM (Atomic Force Microscopy), and the water contact angles.From IR spectra, the intensity of OH functional group is increased by increasing electron dose rate. XPS results also show that the intensity of O_1s peak is increased by increasing electron dose rate. C_1s peak shows that oxygen bonded at carbon site. The water contact angles are decreased by increasing electron dose rate. From the AFM analysis, we observed the formation of λ-DNA (deoxyribonucleic acid) array on plasma polymer film, which was treated by HEEB with 14 kGy of adsorption radiation dose.     

Preparation of diamond-like carbon films by cathodic micro-arc discharge in aqueous solutions

Diamond-like carbon films (DLC) and silicon doped diamond-like carbon films were deposited on Ni substrate by cathodic micro-arc discharge at room temperature in aqueous solutions. The deposit potential was 130 V. The structure of the films was characterized by a scanning electron microscope (SEM), X-ray photoelectron spectroscopy (XPS) and Raman spectroscopy. Raman spectra and XPS analysis demonstrated that the films were diamond-like carbon clearly. SEM observation showed that the DLC films were uniform and the thickness was about 200 nm. Potentiodynamic polarization curve indicated the corrosion resistance of the Ni substrate was markedly improved by DLC films.     

热退火对射频反应溅射氮化铝薄膜场电子发射的影响

以氮气为反应气体;用射频反应溅射方法制备了ＡＩＮ薄膜,结合ＸＰＳ和ＸＲＤ表征考察了热退火后处理对样品场电子发射性能的影响．实验表明,热退火是改善样品场发射稳定性的有效途径,样品经７００℃退火后,发射电流的涨落从未退火前的１３５μＡ下降到２０μＡ;并且发射的开启电压、发射电流的涨落和滞后等对退火温度表现出强烈的依赖性．文中认为,退火处理造成了薄膜结构的变化,引起表面电子亲和势特性以及电导特性的改变,进而影响了其发射特性     

Characteristics and mechanical properties of titanium-containing diamond like carbon films deposited by cathodic arc evaporation

Depositions of titanium-containing diamond-like carbon (Ti-DLC) films were conducted by mixing C+ and Ti+ plasma streams originated from cathodic arc plasma sources in argon (Ar). The deposition was processed at Ti target current ranging from 20 Amp to 70 Amp. Film characteristics were investigated using Raman spectroscopy, X-ray photoelectron spectroscopy (XPS). Film microstructures were evaluated using field emission scanning electron microscopy (FEGSEM), an atomic force microscope (AFM), X-ray diffractometry (XRD) and high-resolution transmission electron microscopy (HRTEM). Mechanical properties were investigated by using a nanoindentation tester and ball on disc wear test. Results shows that surface roughness (Ra) of the films ranged between 2.4 and 7.2 nm and roughness increased relative to the increase in Ti target current. The FESEM studies showed that the surface micrographs of Ti-DLC films revealed a cauliflower-like microstructure and the cross-sectional micrograph revealed a snake-skin like structure. HRTEM studies showed that the Ti-DLC films consisted of nano scale TiC particles which were comparable with low angle XRD and XPS results. XPS analysis established that the Ti2p spectrum is present when the Ti target current reaches 30 Amp or higher. Ti concentration increased as the Ti target current was increased. An extremely thin TiO2 layer exists on the top of the Ti-DLC films which was comparable with the AES results. The film thickness which could be deposited for Ti-DLC is much higher than that of conventional DLC films. Nanoindentation tests show that the nanohardness of the films ranging 15-22 GPa, with Er values ranging from 145 to 175 GPa. The wear test demonstrates the friction coefficient of the 420SS substrate, DLC and Ti-DLC films were about 0.8, 0.3 and 0.2, respectively. Obviously, the friction coefficients of the Ti-DLC films were lower than that of the DLC films.     

电化学沉积DLC膜及其表征

采用电化学沉积方法，甲醇有机溶剂作碳源，在直流电源作用下在单晶硅表面沉积得到碳薄膜。薄膜不溶于苯、丙酮等有机溶剂，具有较高的硬度(16GPa左右)，用AFM、Raman和FTIR分析手段对该薄膜表面形貌和结构进行表征，Raman和FTIR结果表明电化学沉积得到的是含氢的类金刚石碳薄膜。通过研究样品薄膜的XPS和XAES谱图特征，进一步证实薄膜是DLC薄膜，并用线性插入法估算出样品薄膜中SP^3的相对含量为60％，同时推测了电化学沉积DLC薄膜的生长机理。     

Pulsed Laser Deposition of Superhard Nitride Coatings

Nitrides coatings have a large number of applications in high-technology industries due to many unique physical, chemical, and mechanical properties. Thin films of aluminum nitride (AIN), silicon nitride (Si₃N₄), and carbon nitride (CN_x) were deposited on Si (100) substrates using the pulsed laser deposition (PLD) method. The seeding of titanium nitride (TiN) before the CN_x deposition has promoted the growth of the predominantly crystalline CN_x films. The laser deposition parameters and substrate temperature play an important role in fabricating high quality films. The structural and microstructural properties of these films have been characterized using x-ray diffraction, and scanning electron microscope techniques. The Fourier Transform Infrared (FTIR) and x-ray photoelectron spectroscopy (XPS) have been used to investigate the bonding properties in CN_x films. The mechanical properties of the films were evaluated to correlate with the processing parameters of the deposited films. It has been shown that the films with crystalline quality structure have higher hardness and modulus values.     

Synthesis of nanostructured zirconia electrodeposited films on AISI 316L stainless steel and its behaviour in corrosion resistance assessment

This work deals with the study of AISI 316L stainless steel samples coated with nanostructured zirconia thin films, using electrodeposition methods. The chemical composition and compounds formed were determined by X-ray photoelectron spectroscopy (XPS). The morphology of zirconia films was analysed by scanning electron microscopy (SEM) and atomic force microscopy (AFM).Corrosion resistance of the coated steel was tested in a chloride environment. XPS analysis results show zirconium element on the metal surface, bound to oxygen-forming zirconia. The anodic polarization curves obtained in Hank's solution show that zirconia coating can be used as protective coating against pitting corrosion of AISI 316L stainless steels.     

Characterization of cathodically deposited carbonaceous films on a silicon substrate

Carbon-based deposits were electrochemically formed on silicon substrates in ethanol at room temperature. This work was based on the work reported by Namba, who described the electrochemical deposition of diamond from organic solutions. The deposits were analysed using a scanning electron microscope, energy dispersive spectroscopy (EDS), X-ray photoelectron spectroscopy (XPS), Raman spectroscopy and electrochemical impedance spectroscopy. Scanning electron micrographs showed some crystalline deposits on the silicon. EDS was unable to identify carbon in the film, but did reveal impurities such as sodium, potassium, calcium and zinc. It was later established that the impurities most likely came from impurities in the graphite used for a counter electrode. XPS showed the presence of carbon species, and subsequently Raman spectroscopy was used to classify further the carbon deposits. Raman spectroscopy showed the presence of amorphous carbon in some films, but no diamond peak was observed for any of the films. EIS revealed that the impedance of the deposited films was nearly identical to that of the uncoated silicon, and did not resemble the impedance of diamond. Thus, in this work, carbon–based films were formed electrochemically, but these films were not diamond.     

Controlling of the electrical resistivity of GaN layer using AIN nucleation layer

The sheet resistance (Rs) of undoped GaN films on AIN/c-plane sapphire substrate was investigated. The Rs was strongly dependent on the AIN layer thickness and semi-insulating behavior was observed. To clarify the effect of crystalline property on Rs, the crystal structure of the GaN films has been studied using X-ray scattering and transmission electron microscopy. A compressive strain was introduced by the presence of AIN nucleation layer (NL) and was gradually relaxed as increasing AIN NL thickness. This relaxation produced more threading dislocations (TD) of edge-type. Moreover, the surface morphology of the GaN film was changed at thicker AIN layer condition, which was originated by the crossover from planar to island grains of AIN. Thus, rough surface might produce more dislocations. The edge and mixed dislocations propagating from the interface between the GaN film and the AIN buffer layer affected the electric resistance of GaN film.     

Modification of fullerene nanocolumn structure by accelerated C60 ions

Crystalline C60 and amorphous graphite-like films of nanocolumn arrays fabricated by glancing angle deposition of C60 fullerene at substrate temperatures of -425 K were studied by transmission electron microscopy (TEM) and atomic-force microscopy (AFM). Characteristic dimension of columns is 200-400 nm. We used co-deposition of C60 molecules and accelerated C60 ions to modify the structure and properties of nanocolumn arrays. Influence of incidence angle for C60 ions on formation of film morphology was revealed. Raman spectrum analysis showed that amorphous carbon nanocolumns consist of nanographite areas with average size of -1.5 nm. The films have high conductivity (close to graphite) and have no mechanical stresses. The carbon films were applied in all-solid-state rechargeable thin-film battery as an anode layer. The nanocolumn amorphous carbon film as anode electrode showed the discharge capacity of about 50 microAh cm(-2)microm(-1) and good cycling ability over 100 times in full cell system.     

Friction force microscopy study of annealed diamond-like carbon film

In this paper we introduce mechanical and structural characteristics of diamond-like carbon (DLC) films which were prepared on silicon substrates by radio frequency (RF) plasma enhanced chemical vapor deposition (PECVD) method using methane (CH₄) and hydrogen (H₂) gas. The films were annealed at various temperatures ranging from 300 to 900 °C in steps of 200 °C using rapid thermal processor (RTP) in nitrogen ambient. Tribological properties of the DLC films were investigated by atomic force microscopy (AFM) in friction force microscopy (FFM) mode. The structural properties of the films were obtained by high resolution transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS). The wettability of the films was obtained using contact angle measurement. XPS analysis showed that the sp³ content is decreased from 75.2% to 24.1% while the sp² content is increased from 24.8% to 75.9% when the temperature is changed from 300 to 900 °C. The contact angles of DLC films were higher than 70°. The FFM measurement results show that the highest friction coefficient value was achieved at 900 °C annealing temperature.     

AlN薄膜的成分,相结构和氧化性能

用Ｘ射线光电子能谱（ＸＰＳ）剥层分析方法，研究ＡｌＮ薄膜在大气中加热时的氧化性能，结果表明，常温时ＡｌＮ薄膜稳定；在７００℃加热时，Ａｌ２Ｏ３膜开发增厚，ＡｌＮ被氧化，加热温度愈高ＡｌＮ被氧化得愈剧烈。     

Structural characteristics of phosphorus-doped C60 thin film prepared by radio frequency-plasma assisted thermal evaporation technique

Phosphorus doped C60 (P:C60) thin films were prepared by a radio frequency plasma assisted thermal evaporation technique using C60 powder as a carbon source and a mixture of argon and phosphine (PH3) gas as a dopant precursor. The effects of the plasma power on the structural characteristics of the as-prepared films were then studied using Raman spectroscopy, Auger electron spectroscopy (AES) and X-ray photo-electrons spectroscopy (XPS). XPS and Auger analysis indicated that the films were mainly composed of C and P and that the concentration of P was proportional to the plasma power. The Raman results implied that the doped films contained a more disordered carbon structure than the un-doped samples. The P:C60 films were then used as a coating layer for the Si anodes of lithium ion secondary batteries. The cyclic voltammetry (CV) analysis of the P:C60 coated Si electrodes demonstrated that the P:C60 coating layer might be used to improve the transport of Li-ions at the electrode/electrolyte interface.     

XPS,AFM研究沥青基碳纤维电化学表面处理过程的机制

对各向同性沥青基碳纤维进行电化学氧化表面处理,用XPS,AFM分析了碳纤维表面含氧官能团和表面微观形貌的变化过程。实验结果表明:电化学氧化处理是表面碳及其含氧官能团逐步被氧化成羧基和CO₂的过程。氧化处理首先是使碳纤维表面变得更光滑,持续氧化后才会出现沟槽,SEM的分辨率不足以表征碳纤维电化学氧化前后的表面形貌变化,而采用AFM可在纳米尺度上表征碳纤维在电化学氧化过程中的表面形貌变化。AFM和XPS的结合可表征碳纤维电化学氧化表面处理的进程。     

Surface and nanoindentation studies on nanocrystalline titanium diboride thin film deposited by magnetron sputtering

A detailed study on the mechanical, structural and surface characteristics of nanocrystalline TiB₂ films deposited on Si-100 substrates by direct current (DC) magnetron sputtering was carried out. X-ray photoelectron spectroscopy (XPS), atomic force microscope (AFM), nanoindentaion and X-ray diffraction (XRD) studies on these films were performed. Magnetron sputtered titanium diboride coatings had a maximum hardness of 36 GPa and elastic modulus of 360 GPa. From the XRD analyses, the films were found to grow in (00l) direction-oriented perpendicular to the substrate. The AFM analysis of the films showed the variation of grain size between 30 and 50 nm. The high-resolution AFM images revealed arrangements of atoms resembling lattice and the interplanar spacings measured on the image also showed the orientation of grains in the (001) direction. Nanoindentation studies at very shallow depths showed a continuous increase of hardness and modulus with indentation depth up to 40 nm due to tip blunting and presence of oxides on the film surface (confirmed from the XPS study). The elastic recovery was approximately 69% for 100 nm depth whereas it was 52% for 1000 nm depth.     

Effects of oxygen flow rate on microstructure and optical properties of aluminum oxide films deposited by electron beam evaporation technique

Reactive evaporation technique has been used to deposit thin films of alumina (Al₂O₃) on crystalline Si substrates at ambient temperatures in an electron beam (e-beam) evaporation system using alumina granules as evaporant material. The loss of oxygen due to dissociation of alumina has been compensated by bleeding high purity oxygen gas into the system during evaporation. A set of samples were prepared at different flow rates of oxygen and the films have been characterized by Spectroscopic Ellipsometry (SE), Atomic Force Microscopy (AFM), Grazing Incidence X-ray Reflectivity (GIXR) and X-ray Photoelectron Spectroscopy (XPS) measurements. The density and optical properties of the films showed interesting variation with oxygen flow rates.     

Photocatalytic TiO2 films deposited on cenosphere particles by pulse magnetron sputtering method

In the present study, TiO₂ films were deposited on the surface of cenosphere particles using the modified magnetron sputtering equipment under different working conditions. The resulting films were characterized by field emission scanning electron microscopy (FE-SEM), Atomic Force Microscopy (AFM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The FE-SEM and AFM results show that the grain sizes and root-mean-square (RMS) roughness values of the TiO₂ films increase with the increase in deposition time and film thickness. The XRD results indicate that the film was TiO₂ film and sputtering time is an importance condition to influence the films crystal. With the increasing of sputtering time, the crystallization of the TiO₂ film was increased. The XPS results show that only TiO₂ films existed on the surface of cenosphere particles. In addition, the photocatalytic activities of these films were investigated by degrading methyl orange under UV irradiation. The results suggest that the photocatalytic activity of cenosphere particles with anatase TiO₂ films is remarkable and this catalyst can be applicable for the photocatalytic degradation of other organic compounds under UV lights.     

Corrosion behavior of aluminum doped diamond-like carbon thin films in NaCl aqueous solution

Aluminum doped diamond-like carbon (DLC:Al) thin films were deposited on n-Si(100) substrates by co-sputtering a graphite target under a fixed DC power (650 W) and an aluminum target under varying DC power (10-90 W) at room temperature. The structure, adhesion strength and surface morphology of the DLC:Al films were characterized by X-ray photoelectron spectroscopy (XPS), micro-scratch testing and atomic force microscopy (AFM), respectively. The corrosion performance of the DLC:Al films was investigated by means of potentiodynamic polarization testing in a 0.6 M NaCl aqueous solution. The results showed that the polarization resistance of the DLC:Al films increased from about 18 to 30.7 k(omega) though the corrosion potentials of the films shifted to more negative values with increased Al content in the films.     

辅助气体组成对类金刚石薄膜结构和性能的影响

分别以氩气-甲烷、氩气-乙炔为辅助气体,高纯石墨为靶材,利用中频脉冲非平衡磁控溅射技术制备了类金刚石薄膜.采用Raman光谱、X射线光电子能谱、纳米压痕测试仪、原子力显微镜对所制备类金刚石薄膜的键结构、机械性能、表面形貌进行了分析.Raman光谱和X射线光电子能谱测试结果表明,以氩气-甲烷为辅助气体制备的类金刚石薄膜中sp3杂化键的含量比以氩气-乙炔为辅助气体制备的类金刚石薄膜的高.纳米压痕测试结果表明,以氩气-甲烷为辅助气体制备的类金刚石薄膜的纳米硬度比以氩气-乙炔为辅助气体的高.原子力显微镜测试结果表明,以氩气-甲烷为辅助气体制备的类金刚石薄膜的RMS表面粗糙度比以氩气-乙炔为辅助气体的低.以上结果说明辅助气体组成对类金刚石薄膜的键结构、机械性能、表面形貌有较大的影响.