Three-dimensional monte-carlo simulation of grain growth in Pt-Co thin film

Grain growth is an important phenomenon in various thin films that comprise integrated circuits and magnetic disks. This paper demonstrates a three-dimensional Monte-Carlo (MC) simulation model to study grain growth in a binary Pt-Co system. In the formation of this system, a disordered phase is obtained, but later, it is transformed to an ordered phase through heat treatment. Using two methods, random nucleation and film growth, the grain growth of the single disordered phase was simulated. In simulating the order/disorder transition, the film-growth technique was employed, and the effect of surface energy, grain-boundary energy (GBE), and stability of the disordered and ordered phases was examined. The results show that the number and distribution of the nuclei of the ordered phase play an important role in grain size and grain morphology. It was also found that the formation of the columnar structure retarded grain growth and that the anisotropic GBE led to larger grain size.     

多晶硅薄膜的新型激光晶体制备方法

采用两步激光晶化方法制备了多晶硅薄膜,其晶粒尺寸为１．１μｍ,比用传统单步晶化制备的薄膜晶粒尺寸大,表明该方法法对扩大晶粒尺寸很有效。拉曼光谱分析表明０．３０Ｊ／ｃｍ＾２晶化的薄膜结晶程度已很高。     

MIM结构力敏薄膜应变栅的高温稳定性

运用薄膜技术在镍基弹性体上制备金属 -绝缘层 -金属 (MIM)结构的薄膜应变栅 ,测试了应变栅在 2 0 0～ 30 0℃的高温区内的稳定性 ,并分析了应变栅薄膜的结构、薄膜的应力以及热处理工艺等因素对力敏薄膜在高温下的稳定性的影响。     

多晶硅薄膜的新型激光晶化制备方法

采用两步激光晶化方法制备了多晶硅薄膜 ,其晶粒尺寸为 1.1μm,比用传统单步晶化制备的薄膜晶粒尺寸大 ,表明该方法对扩大晶粒尺寸很有效。拉曼光谱分析表明 0 .30 J/ cm2晶化的薄膜结晶程度已很高     

Interfacial reactions of cobalt thin films on (001) GaAs

Interfacial reactions between cobalt thin films and (001) GaAs have been studied by transmission electron microscopy, energy-dispersive analysis of x-rays in a scanningTEM, Auger electron spectroscopy and x-ray photoelectron spectroscopy. The completely reacted layer was found to be “β-Ga₂0₃/(CoGa, CoAs)/GaAs.” The formation of a surface layer ofβ-Ga₂O₃ and the use of encapsulated samples minimized As loss from the reacted layer. Both CoGa and CoAs were found to grow epitaxially on (001) GaAs. The orientation relationships between CoGa and GaAs were determined to be [001] CoGa//[001] GaAs and (220) CoGa//(220) GaAs. The Burgers vectors of interfacial dislocations were identified as 1/2 〈101〉 and 1/2 〈011〉 which are inclined to the (001) GaAs surface. Almost all of the CoGa films were found to be epitaxially related to the surface. No interfacial dislocations were observed in most of the epitaxial CoAs films which are considered to be pseudomorphic with respect to GaAs. The orientation relationships between CoAs and GaAs were determined to be [101] CoAs//[011] GaAs and (020) CoAs//(220) GaAs. Two-step annealing was found to be effective in promoting epitaxial growth.     

Crystallographic evolution of microstructure in thin film processing: Part I. grain size distribution

Processing parameters and the resulting properties of a material are linked by the relationship between processing and microstructure. Characterizing the effect of processing variations on microstructure and determining its origin are essential to advanced material development. In this and a companion article, some readily applied techniques for producing quantitative data on grain size and shape, as well as grain and boundary crystallography, are described. The method described in Part I utilizes transmission electron microscopy and image analysis to measure grain size in large quantities (2000 to 3000 grains per sample), differentiated into orientation class subpopulation distributions. On application to Ni thin films produced by ion assisted deposition, the results have identified an orientation subpopulation that is predominantly responsible for the larger grain sizes observed in films grown under high ion flux. Larger grain size and the development of a preferred orientation have both been associated with increasing ion flux during growth, however, these results give the first experimental evidence connecting grain size and texture in these films.     

唯一性检测在椭圆偏振光谱薄膜拟合中的应用

利用椭圆偏振光谱进行薄膜样品的测量数据分析拟合时,薄膜厚度与介电常数具有很强的关联性。不同色散模型的选取也会对拟合结果产生明显的影响,引起较大误差。介绍了唯一性检测在椭偏拟合中的实现方法。并以二氧化钛样品为例,利用唯一性检测对比了不同色散模型、不同厚度、不同测量波段、不同入射角度时的唯一性检测结果。结果表明,唯一性检测能够有效标定出椭偏测量和拟合过程中所产生的误差,同时能够对不同色散模型进行量化对比,提升拟合精度。     

Effects of barrier layer and processing conditions on thin film Cu microstructure

The crystallographic texture and grain size of sputtered Cu films were characterized as a function of deposition temperature, barrier layer material, and vacuum conditions. For Cu deposited in a HV chamber, (111) Cu texture was found to weaken with increasing deposition temperatures on W, amorphous C and Ta barrier layers, each deposited at 30°C. Conversely, under identical Cu deposition conditions, texture was found to strengthen with increasing deposition temperature on Ta deposited at 100°C. Median Cu grain size varied parabolically with deposition temperature on all barrier layers and was slightly higher on the 100°C Ta at a given Cu deposition temperature, relative to the other underlayers. For depositions in an UHV chamber, Cu texture was found to strengthen with increasing Cu deposition temperature, independent of Ta deposition temperature. Median Cu grain size, however, was still higher on 100°C Ta than on 30°C Ta. The observed differences between the two different chambers suggest that the trend of weak texture at elevated deposition temperatures may be related to contamination. Characterization of the Ta underlayers revealed that the strengthened texture of Cu films deposited on 100°C Ta is likely related to textural inheritance.     

Nanoporous characteristics of sol-gel-derived ZnO thin film

Sol-gel-derived nanoporous ZnO film has been successfully deposited on glass substrate at 200℃ and subsequently annealed at different temperatures of 300, 400 and 600℃. Atomic force micrographs demonstrated that the film was crack-free, and that granular nanoparticles were homogenously distributed on the film surface. The average grain size of the nanoparticles and RMS roughness of the scanned surface area was 10 nm and 13.6 nm, respectively, which is due to the high porosity of the film. Photoluminescence (PL) spectra of the nanoporous ZnO film at room temperature show a diffused band, which might be due to an increased amount of oxygen vacancies on the lattice surface. The observed results of the nanoporous ZnO film indicates a promising application in the development of electrochemical biosensors due to the porosity of film enhancing the higher loading of bio-macromolecules (enzyme and proteins).     

旋磁基片DC-10GHz微波功率电阻器设计制作

基于旋磁基片设计并通过光刻工艺制作DC-10 GHz微波电阻器。通过HFSS仿真设计制作DC-10 GHz电阻器,采用磁控反应溅射制作TaN薄膜,电压驻波比VSWR均小于1.25。旋磁基片微波电阻器相对于应用广泛的氧化铝基片微波电阻器,可直接集成于同样以旋磁为基片的结环行器中,从而能制作出更加小型化的微波隔离器,有效减小器件体积,符合现代通信产品小型化、集成化的发展要求。     

薄膜红外探测器的研究

介绍了薄膜热电偶探测器的研究,讨论了薄膜热电偶探测器的结构对探测器响应特性的影响.     

快速热退火制备多晶硅薄膜的研究

采用等离子体增强化学气相沉积法(PECVD)沉积非晶硅薄膜,然后在快速热退火炉中进行退火。研究了升温速率、降温速率对晶化的影响。结果表明:退火中,升温速率越大,越不利于晶核的形成;降温速率较小时(100℃/60s),形成的晶粒尺寸较小,晶化情况较好,晶化率估算达64.56%。     

NiTi形状记忆薄膜的显微结构和力学性能

NiTi形状记忆合金薄膜具有形状记忆效应，极有希望用于制造高技术领域微电子机械系统中的微型激发器。NiTi形状记忆合金薄膜在制备和使用过程中需要高品质（衬）底材。本文利用高分辨电子显微学和高分辨分析电子显微学详细研究了硅底材NiTi形状记忆合金薄膜的NiTi／Si和NiTi／SiO2微结构体系，包括薄膜精细结构和界面反应。也研究了其显微结构和力学性能的关系。特别给出了NiTi形状记忆合金薄膜产生疲劳过程的微观过程的起因，通过高达十万个使用热循环前后样品显微结构变化的比较，发现纳米尺度上的TiNi3新相的形成导致疲劳过程的发生。如何抑制TiNi3新相形成的研究正在进行之中，这将为进一步提高NiTi形状记忆合金的使用寿命指出方向。     

Highly transparent polyimide/nanocrystalline-zirconium dioxide hybrid materials for organic thin film transistor applications

A solution-processable high k dielectric materials based on polyimide/zirconium dioxide (PI-ZrO₂) for organic thin film transistors (OTFTs) is demonstrated. To study the effect of the ZrO₂ content on the properties of the dielectric layer, a series of PZn films (n = 0, 2, 5, 8, 10, 12, and 15, which are the weight percentage of ZrO₂ in the film) were prepared. The results showed that all of the prepared hybrid films had a high transmittance of 96–99%. The nondestructive Zr K-edge XANES analysis revealed that the absorption intensity was proportional to the ZrO₂ content. EXAFS analysis indicated that the ZrO₂ formed bigger clusters in the film than in the solution state. Water and diiodomethane contact angle analysis found that the PZ12 film had the largest contact angles, lowest surface energy, and lowest water absorbance, which results in the least structural defects and highest carrier mobility. Electrical property analysis indicated that the dielectric constant of the films increased from 4.04 for the PZ0 film to 8.10 for the PZ12 film, but then dropped for the PZ15 film. All current leakages (−2 MV/cm) were less than 10⁻⁹ A/cm. The carrier mobility in the PZ0 film was 2.78 × 10⁻¹, up to 4.15 × 10⁻¹ for the PZ12 film, but down to 3.34 × 10⁻¹ for the PZ15 film. The I_on/I_off ratio was 2.3 × 10³ for PZ0, up to 1.4 × 10⁵ for PZ12, but down to 1.8 × 10⁴ for PZ15. The hybrid dielectric devices showed better performance. This work reveals great potential for hybrid dielectric materials for OTFT applications.