Study of TiN and ZrN thin films grown by cathodic arc technique

Thin films of TiN and ZrN were grown on stainless steel 316 substrate using the pulsed cathodic arc technique with different number of discharges (one to five discharges). The coatings were characterized in terms of crystalline structure, microstructure, elementary chemical composition and stoichiometric by X-ray diffraction (XRD), atomic force microscopy (AFM) and X-ray photoelectron spectroscopy for chemical analyses (XPS), respectively. The XRD results show that for TiN as for ZrN, the preferential direction occurs in the plane (2 0 0), and this result stays when increasing the number of discharges. The grain size is increased with the increase of the number of discharges for both nitrides, the roughness for the TiN film is greater than for the ZrN film; these results were determined by AFM. XPS analysis determined that there is a higher nitrogen presence in the ZrN film than in the TiN film.     

Deposition and characterization of low temperature silicon nitride films deposited by inductively coupled plasma CVD

Silicon nitride films have been deposited at a low temperature (70 °C) by inductively coupled plasma chemical vapor deposition (ICP-CVD) technique and their physical and chemical properties were studied. For a deposited SiN sample, β-phase was observed and refractive index of 2.1 at 13.18 nm/min deposition rate was obtained. The attained stress of 0.08 GPa is lower as compared to the reported value of 1.1 GPa for SiN thin films. To study the deposited film, characterization was performed using X-ray photoelectron spectra (XPS), X-ray diffraction (XRD), micro Raman spectroscopy, Fourier transfer infrared spectroscopy (FTIR), cross-section scanning electron microscopy (SEM) and atomic force microscopy (AFM).     

TiN growth on Si by hybrid radical beam PLD

High-quality (good crystallinity and stoichiometry) titanium nitride (TiN) thin films were grown on Si(100) substrates by pulsed laser deposition (PLD) using a high-purity titanium target (99.99%) and nitrogen radical beam. The crystallinity, chemical composition, and depth profiles of the grown films were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and Rutherford backscattering spectroscopy (RBS), respectively. The XRD pattern indicated that the preferred growth of TiN(200) with an orientation parallel to the Si(100) direction was obtained and the nitrogen radical drastically improved crystallinity compared with that grown in ambient nitrogen gas. RBS spectra indicated that the combination of PLD and the nitrogen radical beam suppressed silicidation at the interface between the Si substrate and TiN thin film during growth. The XPS analysis revealed that this method achieved the synthesis of stoichiometric TiN films.     

Synthesis and characterization of tantalum nitride films prepared by cathodic vacuum arc technique

Tantalum nitride films were deposited on silicon wafer and steel substrates by cathodic vacuum arc in N₂/Ar gas mixtures. The chemical composition, crystalline microstructure and morphology of the films were investigated by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM), respectively. According to the results, film composition and microstructure depends strongly on the N₂ partial pressure and the applied negative bias (V_s).     

PIIID复合强化处理轴承钢表面TiN膜层的XPS表征

用等离子体浸没离子注入与沉积(PIIID)复合强化新技术在AISI52100轴承钢基体表面成功合成了硬而耐磨的氮化钛薄膜。膜层表面的化学组成和相结构分别用X射线衍射(XRD)和X射线光电子能谱(XPS)表征;膜层表面的原子力显微镜(AFM)形貌显示出TiN膜结晶完整,结构致密均匀。XRD测试结果表明,TiN在(200)晶面衍射峰最强,具有择优取向。Ti(2p)的XPS谱峰泰勒拟合分析揭示出,Ti(2p_1/2)峰和Ti_2p3/2峰均有双峰出现,表明氮化物中的Ti至少存在不同的化学状态;N(1s)的XPS谱峰在396.51, 397.22和399.01 eV附近出现了三个分峰,分别对应于TiNO_y,TiN和N—N键中的氮原子。结合O(1s)的XPS结果,证实膜层中除生成有稳定的TiN相外,还有少量钛的氧化物和未参与反应的单质氮。整个膜层是由TiN,TiO₂,Ti—O—N化合物和少量单质氮组成的复合体系。     

Substrate-target distance dependence of structural and optical properties in case of Pb(Zr,Ti)O3 films obtained by pulsed laser deposition

The paper presents the influence of pulsed laser deposition (PLD) parameters on the structural and optical properties of PZT thin films grown on platinum substrate. X-ray diffraction (XRD), spectroscopic ellipsometry (SE) and X-ray photoelectron spectroscopy (XPS) are used to determine the thin film properties. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) are employed to get additional information. By changing the distance between target and substrate, different crystalline orientations of PZT are obtained. The thin film thickness and its roughness, as well as the refractive index are also influenced by the chosen distance.     

Formation of high quality gallium nitride thin films on Ga-diffused Si(1 1 1) substrate

High quality gallium nitride thin films have been successfully grown on the Ga-diffused Si(1 1 1) substrates through ammoniating Ga₂O₃ thin films deposited by r.f. magnetron sputtering. X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), atomic force microscope (AFM) and photoluminescence (PL) were used to characterize the synthesized samples. The analyses reveal that the formed films are high quality polycrystalline hexagonal gallium nitride. The as-formed GaN films show a flat surface topography with RMS roughness varied from 29 to 48 Å. The strong near-band-edge-emission peak around 368 nm was observed at room temperature. This is a novel method to fabricate GaN thin films based on the direct reaction between Ga₂O₃ and NH₃ on the Ga-diffused Si(1 1 1) substrates.     

Tribological properties of chemically bonded polyimide films on silicon with polyglycidyl methacrylate brush as adhesive layer

Polyimide thin films, which possess good stability and film uniformity, are successfully fabricated on single crystal silicon wafers coated with a thin polymer brush by suface-initiated polymerization (SIP) as an adhesive layer. The growth kinetic of polyglycidyl methacrylate (PGMA) brush was studied by the means of ellipsometry. The nano-scale morphology and chemical composition of PGMA brush and polyimide film were studied with atomic force microscopy (AFM), Fourier transform infrared spectrum (FT-IR), and X-ray photoelectron spectroscopy (XPS). The tribological behaviors of the thin films sliding against AISI-52100 steel ball were examined on a static-dynamic friction precision measurement apparatus and UMT-2MT tribometer. The worn surface of the polyimide thin films was investigated with scanning electron microscopy (SEM). The results indicated that the chemically bonded polyimide films exhibited better friction reduction and antiwear behavior compared to the polymide films on bare silicon surface. At a load of 0.5 N and sliding speed of 20 mm s⁻¹, the durability life of the polyimide thin films is over 25,000 sliding cycles and the friction coefficient is about 0.08.     

Synthesis and characterization of superhard Ti-Si-N films obtained in an inductively coupled plasma enhanced chemical vapor deposition (ICP-CVD) with magnetic confinement

Using a novel inductively coupled plasma enhanced chemical vapor deposition (ICP-CVD) with magnetic confinement system, Ti-Si-N films were prepared on single-crystal silicon wafer substrates by sputtering Ti and Si (5 at.%:1 at.%) alloyed target in argon/nitrogen plasma. High-resolution transmission electron microscopy (HRTEM), X-ray photoelectron spectroscopy (XPS), X-ray diffractometer (XRD), field emission scanning electron microscope (FESEM), atomic force microscopy (AFM) and Nano Indenter XP tester were employed to characterize nanostructure and performances of the films. These films were essentially composed of TiN nanocrystallites embedded in an amorphous Si₃N₄ matrix with maximum hardness value of 44 GPa. Experimental results showed that the film hardness was mainly dependent on the TiN crystallite size and preferred orientation, which could be tailored by the adjustment of the N₂/Ar ratio. When the N₂/Ar ratio was 3, the film possessed the minimum TiN size of 10.5 nm and the maximum hardness of 44 GPa.     

射频磁控溅射法制备氮化硅基ZnO薄膜的光致发光性能研究

氮化硅薄膜因其耐腐蚀性、高温稳定性和良好的机械强度等优点,被广泛用作透射电子显微镜(TEM)、扫描电子显微镜(SEM)、原子力显微镜(AFM)、X射线光电子能谱仪(XPS)、能量色散X射线光谱仪(EDX)等的表征实验承载体。特别是,SiN可作为SEM观察时的低扰背景。然而SiN薄膜较差的荧光性制约了其进一步在荧光器件中的广泛应用。为了进一步提高SiN薄膜窗口的荧光效率,实验研究中采用了射频磁控溅射技术在SiN_x薄膜衬底上成功制备出系列ZnO薄膜,并分别进行了氮气氛非原位退火和原位退火处理。然后利用原子力显微镜(AFM)、扫描电子显微镜(SEM)、拉曼光谱仪(Raman)对薄膜的微结构和光致发光(PL)性能进行了研究,并系统研究了所制备薄膜的发光情况。实验研究结果表明,镀膜后荧光强度普遍提升, 退火促进晶粒进一步熟化生长、结晶性能大幅提升、晶界减少,且退火方式对射频磁控溅射法制备的ZnO/SiN复合薄膜的微结构和发光性能有显著影响。与SiN_x薄膜相比,未退火的ZnO/SiN_x薄膜和N₂气氛非原位退火的ZnO/SiN_x薄膜在380 nm附近的带边本征发射强度分别提高了7.7倍和34.0倍以上。与非原位退火处理的薄膜相比,原位退火处理的ZnO/SiN_x薄膜具有更多的氧空位缺陷,因此表现出更强的可见光波段PL强度,在425～600 nm的可见光波段表现出更高的光致发光能力。这些结果有助于优化氮化硅基ZnO荧光薄膜的制备参数。     

立方氮化硼薄膜的生长特性与粘附性研究

用X射线衍射技术、红外吸收光谱、扫描电子显微镜、X射线光电子能谱对热丝辅助射频等离子体化学汽相沉积法制备的立方氮化硼(c-BN)薄膜的生长特性和粘附性进行了研究.改变生长条件，在Si、不锈钢和Ni衬底上沉积c-BN薄膜，进而研究了c-BN薄膜的质量和生长条件与衬底之间的关系.实验发现，Ni衬底上生长的薄膜c-BN含量较高，且粘附性好.当Si衬底上溅射一层Ni过渡层，再生长c-BN薄膜，薄膜中c-BN含量提高，与Si衬底的粘附性也显著增强. 关键词：     

Synthesis of silica supported titania nanocomposite in controllable phase content and morphology

The silica supported titania nanocomposite thin films with controllable particle size and phase content were successfully prepared by a convenient post annealing approach involving in solid-solid interfacial reaction. The effects of growth conditions, such as the annealing temperature and silicon concentration on the particle size and phase content, were systematically studied by using Atomic force microscopy (AFM), Raman spectroscopy, X-ray diffraction (XRD), and X-ray spectroscopy (XPS). The results indicate that the silicon concentration is a dominant factor in the morphology, crystallization and phase transformation of these nanocomposites. A mechanism for the high temperature phase transformation is also proposed based on the migration of the oxygen vacancies.     

Deposition of tungsten nitride thin films by plasma focus device at different axial and angular positions

Tungsten nitride thin films were deposited on stainless steel-304 substrates by using a low energy (2 kJ) Mather type plasma focus device. X-ray diffraction (XRD), scanning electron microscopy (SEM), atomic force microscopy (AFM) and microhardness are used to study the surface of treated samples. The XRD analysis shows that the degree of crystallinity of deposited thin films strongly depends on axial and angular positions of samples. The SEM micrographs of the deposited films at different angular positions (0°, 10° and 30°) and axial position of 8 cm show that the content of WN sub-micro crystalline structures on the surface of deposited films decreased with increasing the angle with respect to anode axis. From AFM results we observe that for the sample deposited at 8 cm and 0° axial and angular positions, respectively, the most uniform surface and the most homogenous distribution of grains are obtained. Also the hardness results show that the highest mechanical hardness is obtained when the film is deposited at 8 cm and 0° axial and angular positions, respectively.     

Carbon Nitride Thin Films Deposited by Plasma Assisted Nd∶YAG Laser Ablation of Graphite in N2+H2 Atmosphere

Carbon nitride thin films are deposited on silicon wafers by 532 nm Nd∶YAG laser ablation of graphite in the N2+H2 atmosphere assisted by a dc glow discharge plasma at a higher gas pressure of about 4.0 kPa. The properties of the thin films are investigated by scanning electron microscopy (SEM), energy-dispersive X-ray (EDX) and X-ray diffraction (XRD). The results show that the deposited films are composed of α-C3N4, β-C3N4 phase and have the N/C atomic ratio of 2.01. The optical emission spectroscopy (OES) studies indicate that the introduction of a dc glow discharge and the adoption of a higher gas pressure during the film deposition are favorable to the net generation of the atomic N, CN radicals and N+2 in B2Σ+u excited state in the plasma, which are considered to play a major role in the synthesis of carbon nitride.     

Carbon Nitride Thin Films Deposited by Plasma Assisted Nd:YAG Laser Ablation of Graphite in N2+H2 Atmosphere

Carbon nitride thin films are deposited on silicon wafers by 532 nm Nd:YAG laser ablation of graphite in the N2+H2 atmosphere assisted by a dc glow discharge plasma at a higher gas pressure of about 4.0 kPa. The properties of the thin films are investigated by scanning electron microscopy (SEM), energy-dispersive X-ray (EDX) and X-ray diffraction (XRD). The results show that the deposited films are composed of α-C3N4, β-C3N4 phase and have the N/C atomic ratio of 2.01. The optical emission spectroscopy (OES) studies indicate that the introduction of a dc glow discharge and the adoption of a higher gas pressure during the film deposition are favorable to the net generation of the atomic N, CN radicals and N+2 in B2Σ+u excited state in the plasma, which are considered to play a major role in the synthesis of carbon nitride.     

低压等离子体增强化学汽相沉积法制备立方氮化碳薄膜

用低压等离子体增强化学汽相沉积法和氮化硅中间过渡层的方法，在硅片和玻璃上，制备了立方氮化碳薄膜.用光电子能谱测试了其成分和结合能，薄膜含氮量为42.96%.C1s和N1s的结合能分别为285.01和398.60eV.透射电子显微镜研究表明，制备的氮化碳属于体心立方结构，根据衍射花样，计算的晶格常量a为0.536nm，这与理论预言的结果a为0.53973nm很接近.随着沉积的时间增长，还观测到了氮化碳薄膜的菊池花样.在玻璃上沉积的氮化碳薄膜在可见光和近红外区域是透明的，在400nm处有光吸收. 关键词：     

Multilayer films of cationic graphene-polyelectrolytes and anionic graphene-polyelectrolytes fabricated using layer-by-layer self-assembly

Extremely thin sheets of carbon atoms called graphene have been predicted to possess excellent thermal properties, electrical conductivity, and mechanical stiffness. To harness such properties in composite materials for multifunctional applications, one would require the incorporation of graphene. In this study, new thin film composites were created using layer-by-layer (LBL) assembly of polymer-coated graphitic nanoplatelets. The positive and negative polyelectrolytes used to cover graphene sheets were poly allylamine hydrochloride (PAH) and poly sodium 4-styrenesulfonate (PSS). The synthesized poly allylamine hydrochloride-graphene (PAH-G) and poly sodium 4-styrenesulfonate-gaphene (PSS-G) were characterized by X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), and thermo gravimetric analysis (TGA). The multilayer films created by spontaneous sequential adsorption of PAH-G and PSS-G were characterized by ultra violet spectroscopy (UV-vis), scanning electron microscopy (SEM), and AFM. The electrical conductivity of the graphene/polyelectrolyte multilayer film composites measured by the four-point probe method was 0.2 S cm⁻¹, which was sufficient for the construction of advanced electro-optical devices and sensors.     

辉光放电等离子体辅助XeCl准分子激光溅射沉积碳氮薄膜

利用直流辉光放电等离子体辅助的脉冲激光沉积技术在Si衬底上生长了碳氮薄膜.通过扫描电子显微镜、X射线衍射、X射线光电子能谱、俄歇电子能谱等多种手段,对薄膜的形貌、成分、晶体结构、价键状态等特性进行了分析和确定.结果表明,沉积薄膜为含有非晶SiN和晶态氮化碳颗粒结构,晶态成分呈多晶态,主要为α-C₃N₄相、β-C₃N₄相,晶粒大小为40—60nm.碳氮之间主要以C-N非极性共价键形式相结合. 关键词： 脉冲激光沉积 直流辉光放电 碳氮薄膜     

Characteristics of sculptured Cu thin films and their optical properties as a function of deposition rate

Sculptured copper thin films were deposited on glass substrates, using different deposition rates. The nano-structure and morphology of the films were obtained, using X-ray diffraction (XRD), atomic force microscopy (AFM) and scanning electron microscopy (SEM). Their optical properties were measured by spectrophotometry in the spectral range of 340-850 nm. The real and imaginary refractive indices, film thickness and fraction of metal inclusion in the film structure were obtained from optical fitting of the spectrophotometer data.     

Influence of oxygen partial pressure on the composition and orientation of strontium-doped lead zirconate titanate thin films

The influence of oxygen partial pressure during the deposition of piezoelectric strontium-doped lead zirconate titanate thin films is reported. The thin films have been deposited by RF magnetron sputtering in an atmosphere of high purity argon and oxygen (in the ratio of 9:1), on platinum-coated silicon substrates (heated to 650 degrees C). The influence of oxygen partial pressure is studied to understand the manner in which the stoichiometry of the thin films is modified, and to understand the influence of stoichiometry on the perovskite orientation. This article reports on the results obtained from films deposited at oxygen partial pressures of 1-5 mTorr. The thin films have been studied using a combination of X-ray photoelectron spectroscopy (XPS), glancing angle X-ray diffraction (GA-XRD), and atomic force microscopy (AFM). XPS analysis highlights the marked influence of variations in oxygen pressure during sputtering, observed by variations in oxygen concentration in the thin films, and in some cases by the undesirable decrease in lead concentration in the thin films. GA-XRD is used to study the relative variations in perovskite peak intensities, and has been used to determine the deposition conditions to attain the optimal combination of stoichiometry and orientation. AFM scans show the marked influence of the oxygen partial pressure on the film morphology.