Time-resolved radial uniformity of pulse-modulated inductively coupled O_2/Ar plasmas

Time-resolved radial uniformity of pulse-modulated inductively coupled O_2/Ar plasma has been investigated by means of a Langmuir probe as well as an optical probe in this paper. The radial uniformity of plasma has been discussed through analyzing the nonuniformity factor β(calculated by the measured n_e, lower β means higher plasma radial uniformity). The results show that during the active-glow period, the radial distribution of ne exhibits an almost flat profile at the beginning phase, but it converts into a parabola-like profile during the steady state. The consequent evolution for β is that when the power is turned on, it declines to a minimum at first, and then it increases to a maximum, after that, it decays until it keeps constant. This phenomenon can be explained by the fact that the ionization gradually becomes stronger at the plasma center and meanwhile the rebuilt electric field(plasma potential and ambipolar potential) will confine the electrons at the plasma center as well. Besides, the mean electron energy( ε_(on)) at the pulse beginning decreases with the increasing duty cycle. This will postpone the plasma ignition after the power is turned on. This phenomenon has been verified by the emission intensity of Ar(λ = 750.4 nm). During the after-glow period, it is interesting to find that the electrons have a large depletion rate at the plasma center. Consequently, ne forms a hollow distribution in the radial direction at the late stage of after-glow. Therefore, β exhibits a maximum at the same time. This can be attributed to the formation of negative oxygen ion(O~-) at the plasma center when the power has been turned off.     

0.5μm分步光刻机关键参数测量与分析

主要对 0 5 μm分步光刻机的几个代表性参数即 :投影镜头分辨率、照明均匀性、套刻精度、工作台步进精度、镜头畸变等引起误差的原因 ,测量和计算方法以及采取的相应措施作了一些归纳性总结 ,在解释问题的同时 ,也提出了相应的解决办法 ,为下一代光刻机的研制打下一定的基础。     

离子注入剂量的均匀性检测和校正

介绍了离子注入机中注入剂量的均匀性检测和校正,着重阐述了均匀性的检测原理、均匀性计算公式、均匀性检测和校正流程及算法。     

高功率固体激光放大器中增益均匀化研究

针对高功率固体激光放大器中增益分布不均匀的现象,为获得较为均匀的增益分布,提出了分布式泵浦的方法.相对于均匀泵浦,分布式泵浦就是通过设计使得泵浦场具有一定的分布.在总体泵浦功率相同的情况下,分别对均匀泵浦和一定分布的分布式泵浦条件下产生的增益分布进行了模拟计算.结果表明,与均匀泵浦相比,使用分布式泵浦方法获得了较为均匀...     

基于无缝平凹透镜阵列的LCD背光模组设计

针对大尺寸LCD直下式背光模组的均匀性问题提出了一种无缝平凹透镜阵列,用以代替常用的扩散膜。模拟了106.68mm(42in)LED背光源的光学分布,得到了合适的透镜半径、结构以及LED阵列间距,分析了平凹透镜阵列半径和平凹透镜阵列与光源的相对位置对匀光作用的影响。结果表明:半径为1mm、厚度为2mm的无缝平凹透镜阵列较好地起到了匀光的效果,接收面的照度均匀性为88.61%。     

一种新的OLED亮度均匀度测试方法

根据CCD的成像特点,建立了CCD感光像素与OLED显示像素亮度的关系,从而提出了一种由CCD采集图像分析OLED显示设备亮度均匀度的理论方法。给出了一种基于CCD摄像器件的测试平台与软件系统,阐述了测试平台的主要组成、工作流程以及设计要点等。给出了OLED样板的测试评估结果,表明了这种基于CCD的测试平台与评估理论的方法是快捷而有效的。     

变测度的积分-水平集确定性算法

提出了一个求总极值的变测度确定性算法,对不同的箱子采用不同的测度,结合确定性数论方法选取一致分布佳点集来代替Monte-Carlo随机投点,使水平值充分地下降,更快地到达全局最小,从而提高算法的计算效率.在文中给出了算法的收敛性证明,并通过数值算例验证了它的有效性.     

液相外延用碲镉汞母液晶锭的组分均匀性

开展了液相外延用碲镉汞母液晶锭的合成工艺优化研究.通过优化合成温度、合成时间、摇炉速率和淬火工艺,有效提高了碲镉汞晶锭的纵向组分均匀性.用改进工艺后合成的碲镉汞母液晶锭生长了28个外延薄膜样品,其组分平均偏差为0.95%,满足第二代红外焦平面探测器研制对探测器材料组分均匀性的要求.     

高强混凝土动态压缩试验分析

准确测量混凝土动态压缩性能及其应变率强化效应一直是冲击动力学研究领域的重点和难点之一。针对混凝土大口径SHPB实验,分析探讨了其中几个主要问题:应力均匀性问题、恒应变率问题和端面接触问题。研究表明:对于此次试验中混凝土试件而言,应力均匀性假设限制试验最大应变率小于166 s^-1;杆和试件端面接触不平和接触不良使得测算出的杨氏模量和屈服强度明显小于实际值;在此基础上,给出了五步测试法和预应力法;利用复合整形技术实现了近似恒应变率加载。利用以上所发展和改进的技术得到了C110混凝土动静态应力应变曲线,结果显示,在试验范围内混凝土杨氏模量并没有应变率效应,其单轴压缩屈服强度与应变率对数呈线性正比关系,其唯象应变率强化因子为0.10。理论分析表明,大口径SHPB试验所得混凝土应变率效应是一种唯象效应,对于混凝土类压力敏感屈服材料而言,应该根据其屈服面方程对其进行校正,从而得到其本构方程中材料的应变率强化因子,分别利用Tresca屈服准则和K&C本构中屈服面方程对其进行校正,得到C110材料的真实应变率强化因子分别为0.015和0.038。     

Influence of Thermal Treatments on In-depth Compositional Uniformity of CuIn(S,Se)2 Thin Films

CuIn(S,Se)₂ thin films were prepared by thermal crystallization of co-sputtered Cu-In alloy precursors in S/Se atmosphere. In-depth compositional uniformity is an important prereq-uisite for obtaining device-quality CuIn(S,Se)₂ absorber thin films. In order to figure out the influence of heat treatments on in-depth composition uniformity of CuIn(S,Se)₂ thin films, two kinds of reaction temperature profiles were investigated. One process is "one step profile", referring to formation of CuIn(S,Se)₂ thin films just at elevated temperature (e.g. 500 oC). The other is "two step profile", which allows for slow diffusion of S and Se elements into the alloy precursors at a low temperature before the formation and re-crystallization of CuIn(S,Se)₂ thin films at higher temperature (e.g. first 250 oC then 500 oC). X-ray diffrac-tion studies reveal that there is a discrepancy in the shape of (112) peak. Samples annealed with "one step profile" have splits on (112) peaks, while samples annealed with "two step profile" have relatively symmetrical (112) peaks. Grazing incident X-ray diffraction and en-ergy dispersive spectrum measurements of samples successively etched in bromine methanol show that CuIn(S,Se)₂ thin films have better in-depth composition uniformity after "twostep profile" annealing. The reaction mechanism during the two thermal processing was also investigated by X-ray diffraction and Raman spectra.