Si-SiN界面应力

本文以用 PECVD 法在硅衬底上淀积的氮化硅薄膜为研究对象,研究了薄膜应力与淀积条件之间的相互关系,给出薄膜应力的一种测量方法,并且对薄膜应力的形成机理进行了一些探讨。研究表明:本系统淀积的氮化硅薄膜应力是 Si-SiN 界面应力,它由热应力和本征应力合成。当膜厚达0.2～0.4μm 范围时,应力最小,随膜厚增加,应力形式由压应力转化为张应力,数量级在10~8Pa 左右。     

氮化硅微粉制备技术

就国内外氮化硅粉末合成的研究情况,按照气相合成法、液相合成法和固相合成法的分类,综述了硅粉直接氮化法、碳热还原二氧化硅法、自蔓延法、热分解法、溶胶凝胶(sol-gel)法、高温气相反应法、激光气相反应法和等离子体气相反应法等几种主要的氮化硅粉末制备方法,介绍了各种制备方法的最新研究进展,并从产品质量、成本和生产规模等角度分析比较了各种制备方法的特点,指出了制备氮化硅粉末的主要发展方向。     

用PECVD法(SiH_4-N_2)体系制备氮化硅薄膜的工艺研究

本文对(SiH_4-N_2)混合气体等离子体增强化学气相淀积氮化硅薄膜工艺进行了研究。对PD-300Ⅲ型低溫淀积台的性能进行了大量的试验且对生长的氮化硅薄膜进行了测试,确定出影响氮化硅薄膜性质的各个因数。采用正交实验的方法,找到了该台淀积过程的最佳工艺条件。研究了薄膜参数随工艺参数变化的情况,得到了一组在最佳工艺条件范围内的变化曲线。     

流态床CVD法制氮化硅超微粉过程分析及实验验证

分析了硅烷氨解法制备氮化硅超微粉的化学气相沉积（CVD）过程，讨论了制备氮化硅超微粉体的3个关键工艺要素，并采用立式双温区流态床实验装置实现氮化硅超微粉体的制备，获得粉体合成过程的一些关键控制参数。     

氮化硅—硅界面陷阱的研究

本文对SiH_4-N_2系PECVD氮化硅-硅界面陷阱进行了研究.结果表明:MNS结构的C-V特性有滞后效应,滞后宽度随测试条件而变化;界面陷阱密度随淀积条件变化。     

燃烧合成法制备Si3N4粉体及其相组成影响因素的研究

氮化硅陶瓷材料因具有优异的热、力、电学性能，现已得到广泛应用，其原料制备也更加受到重视.现阶段的几种氮化硅粉体的制备方法存在着很多不足，因此采用燃烧合成工艺制备氮化硅粉体.燃烧合成工艺具有反应速度快、节能、产物纯度高等优点，但很难控制产物的相组成.主要介绍了燃烧合成反应的热力学及动力学；借助x 射线衍射仪和扫描电镜，在采用“归一法”定量计算的基础上探讨了α-Si₃N₄、β-Si₃N₄的形成机理和相组成的影响因素.     

氮化硅陶瓷球的研磨工艺

介绍氮化硅陶瓷球的研磨工艺，论述研磨压力、研磨速度、研磨盘粒度对陶瓷球加工效率及其表面粗糙度的影响关系．根据试验结果探讨氮化硅陶瓷球的研磨机理．     

直拉单晶硅生长过程中碳沾污的主要途径的探讨

碳是无位错直拉硅单晶中一种有害的杂质。晶体生长过程中,碳通过石英坩埚和石墨托埚之间的相互作用产生的 CO 气体被融硅吸收的途径进入到硅晶格中。本文探讨了碳引入硅中的机理和降低直拉无位错硅单晶中碳含量的工艺措施。     

大氢稀释逐层法制备纳米硅薄膜

如何制备高密度、分布可控、尺寸一致的纳米硅量子点,是各种纳米器件研究中首先需要解决的问题。在等离子体增强化学气相沉积系统（PECVD）中,用大氢稀释逐层淀积技术在氮化硅表面上自组装生长高密度、尺寸均匀的硅量子点结构,这种方法充分利用了氢气等离子体在薄膜淀积中诱导晶化作用和对非晶结构的选择刻蚀作用,能够在低衬底温度的条件...     

利用片上超材料构建单芯片太赫兹双频吸波器

利用65 nm互补金属氧化物半导体(CMOS)工艺,设计了一种新的单芯片超材料结构太赫兹吸波器,面积约为0.60 mm×0.65 mm,包含75个吸波单元. 吸波单元图案采用CMOS工艺中顶层铜金属,厚度为3.2μm,设计为正八边形和正方形开口谐振环的组合结构;介质层由无掺杂硅玻璃、碳化硅、氮化硅等组成,厚度为9.02μm;介质层背面短线采用CMOS工艺中的第一层金属,厚度为0.2μm. 仿真结果表明,该吸波器在0.921THz、1.181THz 2个频率处达到最大吸收率,分别为 97.84%和 95.76%. 克服了采用砷化镓、薄膜工艺实现的太赫兹吸波器与CMOS工艺兼容问题,有利于在大规模集成电路中实现.     

Research on the Fe-silicon nitride material self-producing N2 at high temperature

The Fe silicon nitride synthesized by flashing combustion process was studied to determine the reaction temperature between Fe and silicon nitride, the account of N2 given out in the course of the reaction, and the change of the microstructure during calcination. The results showed that at 1127.2℃ the Fe-silicon nitride self-reacts and releases N2 and under 101.3 kPa the volume of N2 given out in the course of the reaction is 20 times more than that of the starting material. N2 is produced quickly, and completes in several decade seconds. With the producing of N2, the structure of Silicon Nitride around Fe becomes loose and porous, or cracks are formed by the reaction between Fe and silicon nitride. So if it is made use of that Fe-silicon nitride self-producing N2 at the high temperature, the performance of the material on a base of Fe-silicon nitride could be greatly improved.     

DC—PCVD法沉积的非晶态氮化硅的显微硬度研究

对用直流等离子体化学气相沉积(DC—PCVD)法得到的非晶态氮化硅薄膜结构与性能进行了研究。对氮化硅薄膜的表面显微硬度和剖面显微硬度进行了测试,并对非晶态氮化硅硬度高于晶态氮化硅硬度的原因进行了探讨。     

影响氮化硅陶瓷内圆磨削加工表面形貌因素分析

目的研究氮化硅陶瓷在内圆磨削时不同的磨削参数：砂轮线速度（vs）、径向进给速度（f）、轴向振荡速度（fa）对表面粗糙度的影响.方法采用树脂结合剂金刚石砂轮对氮化硅陶瓷试件进行内圆加工实验,进行了3因素的均匀实验.建立了氮化硅陶瓷内圆磨削的经验公式,利用Taylor-Hobson Surtroni25型接触式粗糙度仪对加工表面进行测量,得到不同磨削参数下的粗糙度;用日立S-4800冷场发射电子显微镜对加工表面进行观测,得到被磨试件的表面形貌图像.结果加工表面粗糙度随砂轮线速度的增大而减小,随径向进给速度的增大而增大,随轴向振荡速度的增大而减小.砂轮线速度对被加工表面粗糙度影响最大,随着砂轮速度的增大,粗糙度由0.340 1μm下降到0.295 0μm.结论明确了内圆磨削氮化硅陶瓷试件时不同磨削参数对表面粗糙度的影响,通过回归分析,探索出了不同线速度下氮化硅陶瓷材料去除机理对其表面形貌产生的影响.     

Si3N4超微粉体及其制备

Si3N4陶瓷因其优异的力学性能和化学稳定性而在工业生产中广泛使用。Si3N4粉体的合成是制备Si3N4陶瓷的基础。本文在介绍Si3N4陶瓷性能、用途的基础上,详细论述了硅粉直接氮化法、SiO2还原氮化法、热分解法、气相法等Si3N4超微粉体制备技术,并对这4种工艺的优缺点进行对比。     

Si3N4基复合材料的研究与应用进展

评述了Si3N4基复合材料的研究与应用进展,其中重点介绍了Si3N4基复合材料的制备工艺和力学性能;同时分析了我国在该领域的研究现状,并提出了今后的发展前景.     

Pressureless infiltration of Si3N4 preforms with an Al-2wt%Mg alloy

The pressureless infiltration process to synthesize a silicon nitride composite was investigated. An Al-2wt%Mg alloy was infiltrated into silicon nitride preforms in the atmosphere of nitrogen. It is possible to infiltrate the Al-2wt%Mg alloy in silicon nitride preforms, The growth of the composite with useful thickness was facilitated by the presence of magnesium powder at the interface and by flowing nitrogen. The microstructure of the Si3N4-Al composite has been characterized using scanning electron microscope. During the infiltration of Si3N4 preforms, Si3N4 reacted with aluminium to form silicon and AIN. The silicon produced during the growth consumed in the formation of MgSiAIO, MgSiAlN and Al3.27Si0.47 type phases. The growth of the composite was found to proceed in two ways, depending on the oxide content in the initial preforms, First, less oxide content preforms gave rise to MgAlSiO and MgAlSiN type phases after infiltration. Second, more oxide content preforms gave rise to AlN-Al2O3 solid solution phase （AlON）, The AlON phase was only present in the composite, containing 10% aluminium in the silicon nitride preforms before infiltration.     

Effect of counterface materials on friction and wear behavior of double glow glasma discharge surface alloying on Ti22Al25Nb alloy

Samples of surface chromising layer were prepared by the double glow plasma discharge technique. X-ray diffraction and X-ray photoelectron spectroscopy(XPS) analysis of different elements confirmed the formation of chrome in the layer. Their tribological properties were investigated by pin-on-disk tribometer. Silicon nitride, GCr15, and nickel-based alloy were selected as counterface materials. Results indicated that the lowest friction coefficients and wear rate were obtained when substrate and chromising layer against nickel-based alloy, and tribological properties of chromising layer were better than those of substrate. The highest friction and wear rate were samples against silicon nitride alloys. In the case of three rubbing pairs, the unchangeable materials against different hardness counterfaces leaded to different wear mechanisms. Samples against silicon nitride exhibited abrasive mechanism, and when GCr15 and nickel-based alloy were used as counterface, transfer film and glaze layer formed on the contact surface, which played the main role in decreasing friction and wear. Funded by the Natural Science Foundation of Jiangsu Province China(No.BK2005128), and the Scientific Research Foundation of Nanjing University of Information and Technology     

Preparation of silicon carbide nitride films on Si substrate by pulsed high-energy density plasma

Thin films of silicon carbide nitride （SiCN） were prepared on （111） oriented silicon substrates by pulsed high-energy density plasma （PHEDP）. The evolution of the chemical bonding states between silicon, nitrogen and carbon was investigated as a function of discharge voltage using X-ray photoelectron spectroscopy. With an increase in discharge voltage both the C 1s and N 1s spectra shift to lower binding energy due to the formation of C--Si and N--Si bonds. The Si--C--N bonds were observed in the deconvolved C ls and N ls spectra. The X-ray diffractometer （XRD） results show that there were no crystals in the films. The thickness of the films was approximately 1-2 μm with scanning electron microscopy （SEM）.