一种新的MoSi2基复合材料显微结构及其对力学性能的影响

本文研究了原位生成的ＴｉＣ／ＴｉＢ２／ＭｏＳｉ２三相复合材料的一种新的显微结构及其对力学性能的影响,结果表明,当热压金属Ｔｉ,Ｂ４Ｃ和ＭｏＳｉ２的混合粉末时,在ＭｏＳｉ２的基体内生成由ＴｉＣ和ＴｉＢ２组成的空心粒子。     

TiO_2在MCM-41内表面单层及双层分散的结构表征

首次以有机物钛酸丁酯为前驱体,合成了ＴｉＯ２呈单层分散状态（Ｔｉ／Ｓｉ＝０.２０）或双层分散状态（Ｔｉ／Ｓｉ＝０．３９）的介孔分子筛ＭＣＭ－４１（Ｓｉ／Ａｌ＝３５）,并以 ＸＲＤ,ＦＴＩＲ,Ｎ２吸附－脱附,固体ＵＶ－ｖｉｓ 漫反射等表征手段对其结构特征和氧化钛分散状态进行了研究．结果表明： ＴｉＯ２在介孔分子筛ＭＣＭ－４１孔道中分散, ＭＣＭ－４１骨架结构结晶度降低,但是附着二层ＴｉＯ２后,仍能保持长程有序结构; ＴｉＯ２与ＭＣＭ－４１孔道表面的ＳｉＯ２以化学键连接,生成Ｓｉ－Ｏ—Ｔｉ键;无论是单层还是双层分散的 ＴｉＯ２在 ＭＣＭ－４１内孔壁均匀分散;且由于ＴｉＯ２粒子的减小使其对紫外光的吸收发生明显的蓝移现象．     

金刚石薄膜与基材之间过渡层技术的研究

通过ＴＥＭ观察发现在金刚石膜与单晶硅片，金刚石膜与ＡｌＮ陶瓷之间存在一层过渡层，过渡层的存在为金刚石的形核及生长提供了有利的条件，受此启发，为了改善金刚民基材的结合强度，采用磁控溅射，空心离子镀，真空蒸镀等方法在Ｍｏ片上沉积ＴｉＣ，ＴｉＣＮ（Ｃ／Ｎ＝１／２）ＴｉＣＮ（Ｃ／Ｎ＝１／１０）等薄膜，研究了它们对金刚石膜与基材的结合强度的影响。     

硅藻上一莫来石陶瓷负载SiO2膜的制备与表征

将液晶模板技术与溶胶－凝胶法相结合,制备了硅藻土－莫来石陶瓷（Ｋ－Ｍ）负载型ＳｉＯ２膜。表征实验结果表明：ＳｉＯ２膜层与ＴｉＯ２过渡膜层间通过Ｓｉ－Ｏ－Ｔｉ键的价联方式形成了紧密、稳定的伦合型复合膜;ＳｉＯ２膜孔径集中在４～５ｎｍ,孔分布较为均匀;Ｋ－Ｍ负载ＳｉＯ２膜管对气体具有较强的渗透能力,并有较好的气体分离作用根据实验结果探讨了模板剂的性质及用量对ＳｉＯ２膜孔结构的决定性作用。     

一种新的MoSi2基复合材料显微结构及其对力学性能的影响

本文研究了原位生成的ＴｉＣ／ＴｉＢ_２／ＭｏＳｉ_２三相复合材料的一种新的显微结构及其对力学性能的影响,结果表明,当热压金属Ｔｉ,Ｂ_４Ｃ和ＭｏＳｉ_２的混合粉末时,在ＭｏＳｉ_２的基体内生成由ＴｉＣ和ＴｉＢ_２组成的空心粒子．其中的ＴｉＣ和ＴｉＢ_２粒子均为纳米粒子．具有此新显微结构的复合材料,强度达到４８０ＭＰａ,断裂韧性为５．２ＭＰａ·ｍ^１／２,较单相ＭｏＳｉ_２材料的力学性能有大幅度提高．     

TiB2和SiCW对Al2O3陶瓷材料高温摩擦磨损特性的影响

研究了Ａｌ２Ｏ３、Ａｌ２ｏ３／ＴｉＢ２和Ａｌ２Ｏ３／ＴｉＢ２／ＳｉＣＷ三处陶瓷材料在不同条件下的擦靡损特性。结果表明：三种陶瓷材料与硬质合金摩擦副的摩擦系数随温度温度的增加有不同的变化规律，摩擦表面的Ｘ射线衍射分析表明，摩擦系数的变化与陶瓷物膜的和结构有关，在高温下Ａｌ２Ｏ３／ＴｉＢ２陶瓷材料摩擦表面形成了具有优良的高温润性的ＴｉＯ２氧化膜，因而ＴｉＢ２的加入明显改善了Ａｌ２Ｏ３陶瓷材料 摩擦磨损     

试样参数对划痕试验临界载荷的影响

本文有摩擦力监测的划痕法研究了试样参数（基体硬度、膜厚、基体表面粗糙度等）对硬质摩膜（或软膜）的临界载荷Ｌｃ的影响．样品基材是Ｗ６Ｍｏ５Ｃｒ４Ｖ２、５ＣｒＭｎＭｏ、４５钢、Ａ３钢和不锈钢．膜层为磁控溅射离子镀ＴｉＮ膜和Ｔｉ膜、化学镀ＮｉＰＣＵ膜，以及在Ｓｉ３Ｎ４上溅射镀Ａｌ膜．结果发现离子度ＴｉＮ膜和Ｔｉ膜与ＮｉＰＣｕ膜规律不同，ＴｉＮ膜和Ｔｉ膜的临界载荷Ｌｃ随基体硬度的提高而提高，但当基体硬度接近和超过膜层硬度时，Ｌｃ变化不大；基体粗糙度增加时Ｌｃ下降；随膜厚的增加Ｌｃ提高．而化学镀ＮｉＰＣｕ膜的临界载荷Ｌｃ随基体硬度的提高而下降，随基体表面粗糙度的提高而增加．以Ｗ６Ｍｏ５Ｃｒ４Ｖ２为基体的ＮｉＰＣｕ膜，随膜厚的增加Ｌｃ变化不大．本文对上述规律的实质进行了初步探讨，并对目前生产中正在推广的工具钢磁控溅射离子镀ＴｉＮ膜的划痕法标准提出建议．     

Si作过渡层的Co／Cu／Co三明治膜中高灵敏度巨磁电阻效应？…

用高真空电子束蒸发方向制备了以半导体材料Ｓｉ为过渡层的Ｃｏ／Ｃｕ／Ｃｏ三明治膜并研究了其巨磁电阻效应。当Ｓｉ过渡层厚度达到０．９ｎｍ时,三明治膜中开始出现较强的平面内磁各是性。在Ｓｉ １５ｎｍｍ／ｃｏ５ｎｍ／Ｃｕ３ｎｍ／Ｃｏ５ｎｍ结构中,在其易轴上得到了５．５％的巨磁电阻值和０．９％／Ｏｅ的高磁场灵敏度。研究了过渡层Ｓｉ／Ｃｏ界面之间的相互扩散,发现在过渡层Ｓｉ与Ｃｏ层间形成了Ｃｏ－Ｓｉ化合物。这     

Mo／α—Al2O3界面的二次离子质谱研究

采用电子束蒸发方法，在２００℃的抛光（１１０２）取向的蓝宝石（α－Ａｌ２Ｏ３）单晶衬底上淀积厚度为３００ｎｍ的Ｍｏ膜。经８７０℃下不同真空退火时间处理后，运用ＭＣｓ＾＋－ＳＩＭＳ技术进行了深度剖析，并结合ＸＲＤ物相分析，对Ｍｏ／Ａｌ２Ｏ３界面问题进行了探讨。结果表明，在Ｍｏ／Ａｌ２Ｏ３界面处存在原子相互扩散形成的过渡层。退火处理后，过渡层展宽，有ＭｏＯ２生成。延长退火时间，过渡层变化不大。     

Ti—Mo—N三元多层膜的结构与性能

采用Ｔｉ／Ｍｏ复合靶,用多弧离子镀技术沉积了Ｔｉ－Ｍｏ－Ｎ多元多层膜,并对其组织结构与性能进行了研究,结果表明：在本试验条件下多元膜的结构形式为（Ｔｉ,Ｍｏ）２Ｎ,最佳多层膜的结构形式为基体／Ｔｉ／ＴｉＮ／（ＴｉｙＭｏ１－７）Ｎ／（Ｔｉ,Ｍｏ）２Ｎ,并具有较高的显微硬度、耐磨性和极低的孔隙率,在８００℃具有很好的抗氧化性能。在沉积过程中存在着多元合金膜层与合靶的成分离析现象,这与靶材的结构有关。     

Diffusion barrier property of TiN and TiN/Al/TiN films deposited with FMCVD for Cu interconnection in ULSI

Flow modulation chemical vapor deposition (FMCVD) with titanium tetrachloride (TiCl₄) and ammonia (NH₃) is effective for depositing titanium nitride (TiN) films with conformal morphology, good step coverage, low electrical resistivity, and low chlorine residual contamination. It means that FMCVD TiN film is a good candidate of diffusion barriers for copper interconnection technology in ULSI. But the diffusion barrier property of FMCVD TiN film against Cu diffusion has not been confirmed. So, firstly, we deposited Cu (100 nm)/FMCVD TiN (25 nm)/Si multilayer films and investigated the thermal stability of Cu/TiN/Si structure. Vacuum annealing was done at 400, 500, 550 and 600 °C. For films annealed for 30 min at 400 °C, Cu diffused through the TiN layer and formed copper silicides on the surface of Si substrates. Therefore, FMCVD films formed under such conditions are unsatisfactory diffusion barriers. To enhance the diffusion barrier property of FMCVD TiN films, we used sequential deposition to introduce a monolayer of Al atoms between two TiN films. Etch-pit tests showed that for TiN films with Al interlayer, Cu diffusion through the barrier occurred at 500 °C and that is 100 °C higher than TiN film without Al interlayer. Al atoms formed AlO_x with oxygen atoms present in the TiN films as impurities, and fill up the grain boundaries of TiN film, thereby blocking the diffusion of Cu atoms.     

Optimization of Ti/TiN/Mo back contact properties for Cu(In,Ga)Se2 solar cells on polyimide foils

Molybdenum is conventionally used as electrical back contact for Cu(In,Ga)Se₂ (CIGS) solar cells. In this work, a multifunctional stack of Ti/TiN/Mo is introduced as back contact for flexible CIGS solar cells. The multilayer back contact was deposited on 25 μm thick polyimide foil by means of DC reactive sputtering.To optimize electrical conductivity and film stress of the alternative back contact sputter parameters such as total gas pressure, sputtering power, substrate temperature and RF substrate bias have been varied. XRD measurements and quantitative analysis of foil curvature revealed that the film stress is significantly influenced by the argon gas pressure and sputtering power. The electrical conductivity was improved by applying higher sputtering power or RF substrate bias. Analysis of the film microstructure with SEM shows that applied substrate bias influences the density of the sputtered film. The solar cells processed on Ti/TiN/Mo as well as on a conventional Mo bilayer back contact have been compared using standard current density to voltage (J-V) measurements and external quantum efficiency measurements. Conversion efficiencies of 13.4% for the alternative and 14.9% for the conventional design have been obtained.     

Improvement of heavy dopant doped Ni-silicide using ytterbium interlayer for nano-scale MOSFETS with an ultra shallow junction

In this paper, a novel Ni silicide with Yb interlayer (Yb/Ni/TiN) on a boron cluster (B18H22) implanted source/drain junction is proposed for the first time, and its thermal stability characteristics are analyzed in depth. The proposed Ni-silicide exhibits a wider RTP temperature window for uniform sheet resistance, surface roughness and better thermal stability than the conventional structure (Ni/TiN). In addition, the cross-sectional profile of the proposed Ni-silicide showed less agglomeration despite the high temperature post-silicidation annealing, and it can be said that the proposed structure was little dependence on the temperature post-silicidation annealing. The improvement of Ni silicide properties is analyzed and found to be due to the formation of the rare earth metal--NiSi (YbNi2Si2), whose peaks were confirmed by XRD. The junction leakage current of the p + -n junction with Yb/Ni/TiN and B18H22 implantation is smaller than that with Ni/TiN by almost one order of magnitude as well as improving the thermal stability of ultra shallow junction.     

Initial growth of TiN on different phases of high speed steel

High speed steel is a complex substrate material consisting of various phases including metal carbides such as MC and M₆C. The MC carbides, which mainly consists of VC_0.8, have the same crystal structure as TiN (NaCl B1) and a similar lattice parameter (4.16 Å) to that (4.24 Å) for TiN. Different nucleation and growth modes can thus be expected on the various phases during growth of TiN thin films. For example, on the MC carbides a local epitaxial growth can be expected. Deposition of TiN layers 40–60 nm thick by d.c. magnetron sputtering was carried out onto electrolytically thinned steel substrates for transmission electron microscopy examination. The substrate temperature was varied between 310 and 920 K. Air-exposed substrates were deposited with and without sputter etching. Examination of the as-deposited films shows fine equiaxed grains of TiN on the substrate that was not sputter etched. On the sputter-etched substrate, TiN grew epitaxially on the MC carbides and with fine equiaxed grains on the surrounding steel matrix. The size and number of TiN grains per unit area were the same for the non-sputter-etched substrates and for the steel matrix in the sputter-etched substrates. The carbide grains are randomly oriented and distributed in the steel matrix. Epitaxial growth of TiN is observed on the six most densely packed lattice planes of the MC carbides.     

新型铁电薄膜底电极TiN的结构与电性能研究

自制了导电的TiN薄膜底电极,并在其上制备了铁电钽酸锂薄膜,测试了TiN薄膜电阻随热处理温度变化的关系,以及TiN底电极上钽酸锂薄膜的介电和漏电特性.实验结果表明,当热处理温度低于700℃时,TiN薄膜的电阻率小于0.004QΩ·cm,具有良好的导电性,可用作钽酸锂薄膜底电极;TiN底电极上钽酸锂薄膜的漏电电流大于Pt衬底上钽酸锂薄膜的漏电电流;N2气氛下在TiN底电极上结晶的钽酸锂薄膜的介电损耗远大于O2气氛下结晶的钽酸锂薄膜的介电损耗;氧缺位是TiN底电极上钽酸锂薄膜介电损耗大和漏电大的主要原因.     

Thermal Stress in Free-standing Diamond Films with Cr Interlayer Destroyed

Thermal stress in large area free-standing diamond films was remarkable during the post-deposition cooling of direct current (DC) arc plasma jet chemical vapor deposition (CVD) process.In this research,the stress release caused by delamination of Cr interlayer was of great importance to ensure the integrity of free-standing diamond film.The effects of Cr interlayer on Mo substrate,namely composite substrate,on thermal stress were investigated.Thermo-mechanical coupling analysis of the thermal stress was app...     

Preparation and mechanical properties of laminated zirconium diboride/molybdenum composites sintered by spark plasma sintering

Laminated ZrB₂/Mo composites, alternately consisting of matrix layers of 80 vol.% ZrB₂ + 10 vol.% nano-SiC whiskers + 10 vol.% SiC particles and Mo interlayers, with the addition of Si and B as interlayer adjusting agent, were prepared by roll-compaction and spark plasma sintering (at 1600°C) process. XRD and SEM techniques were used to characterize the phases and microstructure of the obtained composites. The results showed that without the addition of Si and B in the interlayer, interfacial debonding between the matrix layer and interlayer often occurred due to the thermal mismatch between the two kinds of layers. However, the interfacial mismatch could be effectively inhibited by the addition of Si and B to the Mo interlayers. The laminated ZrB₂/Mo composites with 6 at.% Si and 4 at.% B in the interlayers showed the highest bending strength at (451±20) MPa and the highest fracture toughness at (7.52±0.12) MPa·m^?. MoB, ZrB and Mo5SiB2 were formed by the reactions among ZrB₂, Mo and the additions.     

Preparation and properties of TiN and AlN films from alkoxide solution by thermal plasma CVD method

Single phase TiN and AlN films were prepared on a Si wafer from titanium tetra-etoxide and aluminum tri-butoxide solutions dissolved in ethanol and toluene, respectively, using an Ar/N₂/H₂ radio-frequency (r.f.) inductive thermal plasma chemical vapor deposition (CVD) method. The films were characterized by X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscopy, measurement of electrical resistivity and Vickers microhardness. Factors affecting the formation of the films (lattice parameter, chemical composition, oxygen/carbon content, and deposition rate of the films) were examined in terms of the N₂ flow rate (2.5–4.5 slm), substrate temperature (300–700°C), feed rate of the solution (0.025–0.3 ml/min), and the mole ratio of the alkoxide solution (1:1–1:3). The optimum conditions for preparation of TiN films produced a film 0.2–3 μm thick with an oxygen content of 8 at.% and a free carbon content of 4 at.%, showing an electrical resistivity of 370 μΩ cm. The optimum conditions for AlN films produced a film 0.3 μm thick containing 14 at.% oxygen and 8 wt.% carbon. The deposition rate of the TiN film was determined to be 30–35 nm/min. The Vickers microhardness of the TiN and AlN films was found to be 10±1 and 13±3 GPa, respectively.     

Effects of Ti- and Zr-based interlayer coatings on the hot filament chemical vapour deposition of diamond on high speed steel

The prospect of obtaining good adhesion of diamond films onto steel substrates is highly exciting because the achievement of this objective will open up applications in the cutting and drilling industry. However, a major problem with depositing diamond onto steel is high diffusion of carbon into steel at chemical vapour deposition (CVD) temperatures leading to very low nucleation density and cementite (Fe₃C) formation. Therefore, the study of the nucleation and growth processes is timely and will yield data that can be utilised to get a better understanding of how adhesion can be improved. This work focuses on investigating the adhesion of thin diamond films on high speed steel previously coated with various interlayers such as ZrN, ZrC, TiC and TiC/Ti(C,N)/TiN. The role of seeding on nucleation density and the effect of diamond film thickness on stress development and adhesion has been investigated using SEM, XRD and Raman spectroscopy.The main emphasis in this study is the TiC interlayer which for the first time proved to be a suitable layer for diamond CVD on high speed steel (HSS). In contrast from other interlayer materials investigated here, no delamination was observed even after 3 h of CVD at 650 °C only when TiC was employed. Nevertheless, the increase of diamond film thickness on TiC coated HSS substrates led to the delamination of small areas in various regions of the substrate. This occurrence suggests that there was a distribution of adhesive toughness values at the diamond/TiC interface with stress development being dependent on film thickness.     

M2高速钢离子渗氮与离子镀TiN复合工艺

在改进后的DLKD800型离子镀膜机中，对M2高速钢基体材料施以离子修氮与离子镀TiN复合工艺。研究表明离子渗镀复合处理后，可使高速钢W6Mo5CR4v2（即M2）试样TiN膜硬度的测试情、基体表面硬度值（渗氮层部分）、膜基间的复合强度都有明显地提高。高速钻头经离子渗镀复合工艺后，使用寿命有显著提高。