实噪声参激一类余维2分叉系统的最大Lyapunov指数(Ⅰ)

对于三维中心流形上实噪声参激的一类余维2分叉系统,为使模型更具有一般性,取系统的参激实噪声为一线性滤波系统的输出-零均值的平稳高斯扩散过程,并满足细致平衡条件.并在此基础上首次使用Arnold的渐近方法以及Fokker-Planck算子的特征谱展式,求解不变测度以及最大的Lyapunov指数的e_max的渐近展式.     

Upgrading design of the 3B1A beamline for x-ray nanometre lithography of microelectronic devices at BSRF

Beijing Synchrotron Radiation Facility is a partly dedicated synchrotron radiation source operated in either parasitic or dedicated mode. The 3B1A beamline, extracted from a bending magnet, was originally designed as a soft x-ray beamline for submicro x-ray lithography with critical lateral size just below 1μm in 1988 and no change has been made since it was built. But later the required resolution of x-ray lithography has changed from sub-micrometre to the nanometre in the critical lateral size. This beamline can longer more meet the requirement for x-ray nano lithography and has to be modified to fit the purpose. To upgrade the design of the 3B1A beamline for x-ray nano lithography, a mirror is used to reflect and scan the x-ray beam for the nano lithography station, but the mirror's grazing angle is changed to 27.9mrad in the vertical direction, and the convex curve needs to be modified to fit the change; the tiny change of mirror scanning angle is firstly considered to improve the uniformity of the x-ray spot on the wafer by controlling the convex curve.     

光学读出微梁阵列红外成像性能分析与优化

系统响应率是光学读出微梁焦平面阵列(Focal Plane Array,FPA)红外成像的关键性能参数。在刀口滤波光学读出技术中,系统响应率的主要组成部分——光学读出灵敏度与微梁反光板的长度密切相关,并受到反光板弯曲变形的严重影响。由于残余应力在制作过程中不可避免地存在,微梁反光板都有弯曲变形,膜厚相同的反光板具有相同的变形曲率半径。本文利用傅里叶光学分析了反光板长度和弯曲变形对光学读出灵敏度的影响,构建并实验验证光学读出灵敏度理论模型。根据该模型,分析了系统响应率与反光板长度之间关系,理论分析与实验结果相符。结果表明,通过减薄SiNx厚度并使反光板处于该厚度下的最优长度,不仅能提高红外成像的系统响应率,而且能同时提高红外成像的空间分辨率。     

A novel anti-shock silicon etching apparatus for solving diaphragm release problems

This paper presents a novel anti-shock bulk silicon etching apparatus for solving a universal problem which occurs when releasing the diaphragm (e.g.\ SiNx), that the diaphragm tends to be probably cracked by the impact of heating-induced bubbles, the swirling of heating-induced etchant, dithering of the hand and imbalanced etchant pressure during the wafer being taken out. Through finite element methods, the causes of the diaphragm cracking are analysed. The impact of heating-induced bubbles could be the main factor which results in the failure stress of the SiNx diaphragm and the rupture of it. In order to reduce the four potential effects on the cracking of the released diaphragm, an anti-shock bulk silicon etching apparatus is proposed for using during the last etching process of the diaphragm release. That is, the silicon wafer is first put into the regular constant temperature etching apparatus or ultrasonic plus, and when the residual bulk silicon to be etched reaches near the interface of the silicon and SiNx diaphragm, within a distance of 50--80~\mu m (the exact value is determined by the thickness, surface area and intensity of the released diaphragm), the wafer is taken out carefully and put into the said anti-shock silicon etching apparatus. The wafer's position is at the geometrical centre, also the centre of gravity of the etching vessel. An etchant outlet is built at the bottom. The wafer is etched continuously, and at the same time the etchant flows out of the vessel. Optionally, two symmetrically placed low-power heating resistors are put in the anti-shock silicon etching apparatus to quicken the etching process. The heating resistors' power should be low enough to avoid the swirling of the heating-induced etchant and the impact of the heating-induced bubbles on the released diaphragm. According to the experimental results, the released SiNx diaphragm thus treated is unbroken, which proves the practicality of the said anti-shock bulk silicon etching apparatus.     

电活性超支化聚合物的合成与性质

通过分子设计, 利用A2+B3反应合成了一种新型电活性超支化聚合物材料. 该材料在保持聚苯胺的电活性基础上, 还具有超支化聚合物特有的低黏度(其特性黏度为0.33 dL/g)、低结晶性及良好的溶解性. 利用紫外-可见光谱对聚合物的氧化过程进行了监测. 热失重分析显示, 该材料具有较好的热稳定性, 失重10%时的温度高达517 ℃. 该材料具有较高的介电常数, 有望成为一种具有实际应用价值的高介电材料.     

四边形单元h－收敛误差估计的探讨*

本文证明了四边形单元的h-收敛性,给出了相应的引理和定理,讨论了误差估计问题,为四边形单元h-收敛自适应有限元分析准备了基础。     

SiH2Cl2-NH3配比对a-SiNx:H薄膜PL峰的影响

低压化学气相沉积制备的纳米硅镶嵌结构的a-SiNx：H薄膜,在3．75eV的激光激发下,室温下发射1～3个高强度的可见荧光。在相同的沉积温度下（900℃）,选择不同的SiH2Cl2和NH3气体配比时,所得薄膜表现出不同的荧光属性,荧光峰的峰位和数目有着显著的变化。通过TEM、IR、XPS等分析手段对其原因进行了研究分析,认为不同配比下,生成的薄膜中缺陷态的种类和密度有所不同,这影响了其PL峰个数及其各峰的相对强弱。     

翡翠B货的拉曼光谱鉴别

与传统宝石鉴定相比 ,拉曼光谱在漂白或注胶翡翠 (B货翡翠 )的鉴别中是一种快速、无损、微区分析方法 ,特别对于宝石中的包体和填充物尤其有效[1 ] 。翡翠中经常充填各种油、蜡、胶 (如石蜡、石蜡油、AB胶、环氧树脂等 )来增强其透明度[2 ] ,由于它们化学成分、化学结构的不同 ,在拉曼光谱中显示不同的峰位特征。环氧树脂的特征峰主要属于苯环的 :1 60 9和 1 1 1 6cm- 1 两个C—C伸缩振动 ,3 0 69cm- 1 C—H的伸缩振动以及 1 1 89cm- 1 C—H的面内弯曲振动 ,而用于翡翠抛光处理的石蜡不具有苯环的特征峰 ,据此可作为鉴别B货翡翠的依据。     

制作深亚微米T型栅的X射线光刻技术

T型栅结构已经广泛应用于赝配高电子迁移晶体管(PHEMT)的制作中去,因为这种结构可以有效地减少由于栅寄生电阻而引起的晶体管噪声.X射线光刻具有工艺宽容度大、成品率高、景深大、曝光视场大、成本低等诸多优点,更为重要的是,其技术已经比较成熟,它是最好的制作深亚微米T型栅技术手段.本文首先简要介绍我们自行研发的X射线掩模工艺,并对模糊对光刻胶表面的光强分布的影响进行了分析,最后对制作深亚微米T型栅的三层胶方法和在北京同步辐射装置上取得的75nm T型栅图形结果进行了介绍.     

红外热成像无损检测技术现状及发展

红外热成像是近年来发展起来的一种快速有效的无损检测技术,通过主动热激励使物体内部的异性结构以表面温场变化的差异形式表现出来,实现缺陷的定位、识别和定量测量;它是一门跨学科的技术,它的研究和应用,提高了多种军、民用工业设备的安全性可靠性;综述了红外热成像无损检测技术的基本概念、关键技术原理和系统组成,比对分析了光脉冲、超声、锁相、太赫兹等各种热激励方式的技术特点,介绍了国内外相应的发展状况和进展,并给出了一些典型应用案例,最后总结了该技术的发展趋势。