深亚微米同步辐射x射线光刻技术

报道了我们制作深亚微米 x射线掩模的工艺和同步辐射 x射线曝光工艺 ,并报道了我们在北京同步辐射装置 (BSRF) 3B1 A光刻束线所获得的深亚微米 x射线光刻图形的实验结果     

同步辐射x射线光刻制作深亚微米T形栅

x射线光刻非常适合用于深亚微米T形栅的制作,这是因为它的高分辨率、大的曝光视场和高的生产效率足以满足MMIC制造工艺的要求。本文中我们首先对我们的x射线掩模制造工艺进行介绍,然后论述了一种用于制造深亚微米T形栅的两层胶工艺,介绍了所取得的一些研究结果,最后对国内的深亚微米光刻现状进行了简要分析。     

A controlled radiation source and electron/X-ray flux ratios in an electron beam metal evaporator

The use of ionizing radiation (X-rays, electrons and ions) in semiconductor processes is becoming more pervasive as device dimensions decrease. One such source of ionizing radiation is an electron beam (EB) metal evaporator. It has, in fact, been used earlier as a mixed X-ray/electron source to simulate ionizing radiation processes in device fab-rication sequences. In those studies, it was not known, however, what fraction of the energy striking a specimen was due to electrons, and what fraction was due to X-rays. In the present paper, application of an electron beam evaporator as a controlled, essen-tially monochromatic ionizing radiation source is described. Using a 0.5 mil thick Be foil, and knowing its mass absorption coefficient for X-rays at the wavelengths involved, the percentage electron and X-ray fluxes as a function of hearth beam current for a set of accelerating voltages was estimated. In addition, the absorption coefficient of an in-expensive, expendable, polymeric foil (pellicle) used in place of Be for actual experi-mental studies was evaluated. The 2.85 μm thick pellicle was found to transmit 87% of the incident Al K_α radiation, and to exhibit a mass absorption coefficient of 303 cm²/ g. The electron flux percentage from an aluminum hearth at a distance of 205 mm, was found to be 26% for a range of hearth electron beam currents between 2.5 x 10^-2A and 7.5 x 10^-2A, at an accelerating voltage of 6 kV. For a 10 kV accelerating voltage the electron percentage was found to be 35% between 2.5 x 10^-2A and 7.5 x 10^-2A. X-ray fractions were 74% and 65%, respectively. The radiation system can be used to pro-vide exposures in the 5 x 10⁴ rad(SiO₂) to the 2 x 10⁸ rad(SiO₂) range for Insulated Gate Field Effect transistors, in about an hour-long experiment.     

纳米器件的一种新制造工艺——纳米压印术

纳米压印术可以用于大批量重复性地制备纳米图形结构。此项技术具有操作简单、分辨率高、重复性好、费时少,成本费用极低等优点。本文介绍了较早出现的软刻印术的两种方法———微接触印刷法和毛细管微模制法。详细讲述了纳米压印术(主要指热压雕版压印法)的各步工序———压模制备、压印过程和图形转移,以及用于压印的设备、纳米图案所达到的精确度等,还简述了纳米压印术的另一方法———步进-闪光压印法。最后,通过范例介绍了纳米压印术在制作电子器件、CD存储器和磁存储器、光电器件和光学器件、生物芯片和微流体器件等方面的应用。     

基于MEMS工艺的硅基红外辐射源研制

利用微机电系统( MEMS)制造工艺制备出了一种硅基红外辐射源.该辐射源采用单晶硅为衬底,通过直流溅射沉积Pt/Ti薄膜,并利用深反应离子刻蚀与湿法腐蚀工艺制备隔离槽和释放支撑层.研究了支撑层厚度对红外辐射源辐射特性的影响.结果表明,随着支撑层厚度的减小,红外辐射源的调制驱动电压会降低.当支撑层厚度为1μm时,辐射源调...     

冰点槽空腔黑体辐射源实验研究

使用铜圆柱圆锥形黑体辐射源空腔 ,F500型高精 密温度测温仪和TRTⅡ辐射温度计,搭建冰点槽黑体辐射源及性能测试系统,完成冰点黑体 辐射源空腔温度 的均匀性和稳定性实验。实验验证了冰点条件下黑体辐射源空腔用于红外辐射温度计校准, 利用冰点开展 量值传递的可行性。实验测得冰点槽黑体辐射源空腔温场环境稳定性在0.001min, 均匀性不超过 0.001℃,黑体辐射源空腔腔底稳定性为0.03min,均匀性优于0.024℃,验证了 在给定的气压条件下, 可利用基于冰点作为冰点槽黑体辐射源固定点,其性能良好,可用于红外辐射温度计在冰点 的稳定性测试和校准。     

A novel printing technique for highly integrated organic devices

A new printing technology is described, which is capable of printing metallic electrodes onto organic layers. Electrodes are defined on top of a sacrificial layer by optical or nano-imprint lithography. To increase the stability of the process the electrodes are coated with several backing layers. The metallic features are released from the sacrificial layer by immersion in water and subsequently transferred onto the target substrate. By the use of nano-imprint lithography, feature sizes below 100 nm are achieved. The strengths of the printing technology are high integration density, versatility and reproducibility.     

一种基于方向特性识别电磁辐射源的新方法

通过获取电磁辐射源周围空间的电场强度分布,从而确定辐射源的方向特性,利用方向特性这种辨识度高的特性参数,基于支持向量机对电磁辐射源进行了准确的区分识别.文中分析了三个基本的天线辐射模型,在相同位置建立正方体接收阵获取其远区场强值,并采用支持向量机方法对数据进行处理,建立评判模型对识别准确率进行了分析.结果表明提出的方法具有很高的识别准确率.最后从抗噪性能、数据归一化方法和F1值三个方面综合分析了方法的合理性.     

柱弥散光源内部辐照组织的Monte-Carlo模拟和实验研究

为无损获取组织中光剂量分布信息,本文构建 了弥散光源内部辐照柱状组织的光学模型,利用Monte-Carlo模拟方法实现了 组织内光分布信息的无损预测, 有关模拟结果与实验测量结果基本一致。提出的模型模拟方法对于由弥散光源在组织内部实 施光辐照的临床医用中光剂量的无损确定和治疗方案的优化设计有实际价值。     

Linear x-ray detector array made on bulk CdZnTe for 30∼100 keV energy

A CdZnTe detector grown by the high pressure Bridgman (HPB) growth technique was tested using high energy x-rays (30∼100 keV), and the performance was compared with a commercially available Nal scintillating detector of 5 cm thickness. The charge collection efficiency of a CdZnTe detector is as high as 90% at relatively low electric field, 600 V/cm. At high x-ray photon energies, the detection efficiency is reduced due to the thickness of the CdZnTe. A 32 channel linear array was fabricated on 1.2∼1.7 mm thick CdZnTe, of which the detector area was 175 × 800 μm² and the pitch size 250 μm. The measured dark current for the 16 element detector was as low as 0.1 pA at 800 V/cm with an excellent uniformity. Energy spectra were measured using a Co⁵⁷ radiation source. A small pixel effect and charge sharing were observed. The energy resolution was improved and compared with the large area detector. The array detector gave an average 5.8% full-width-half-maximum (FWHM) at 122 keV photopeak. The large area detector of the same material before fabrication exhibited a low energy tail at the photopeak, which limits the photopeak FWHM to 8%.     

集成电路光刻镜扫描控制系统

用同步辐射光源进行大规模集成电路和微器件光刻是现阶段的一项高新技术。本文介绍同步辐射光刻的镜扫描控制系统。它的设计思想,所采用的方法以及最优控制等都具有科技应用和经济价值。     

A study of etch pit density and x-ray rocking curves for GaAs substrate evaluation

The relationship of structural defects to the electrical properties of semiconductor materials is discussed. Etch pit density (EPD) measurements are normally used to evaluate dislocation density. A nondestructive, quantitative method for evaluation of substrate defect populations is needed for quality assurance. In this study, double crystal x-ray diffraction rocking curves are investigated for this purpose. Rocking curve widths are determined experimentally for a set of GaAs substrated with a range of EPD. The experimentally determined values are also compared with those calculated from simulated rocking curves based on x-ray diffraction theory. Limited correlation between rocking curve widths and EPD is observed. Formerly of Spectrum Technology Inc., Holliston, MA     

面向MEMS红外光源的辐射增强结构设计

针对常规TO封装下红外光源辐射量在一定光程下严重衰减的不足,基于自研的MEMS红外光源结构,提出了用于红外辐射增强的反射镜及用于光束准直的透镜封装结构,以期大幅提高光源有效辐射效率。本文基于Zemax软件对红外光源在光路中的辐射特性进行了模拟仿真。仿真结果表明:红外光源放置于9.52 mm口径、9.41 mm深度的抛物面反射镜的焦点位置,辐射能量提高了15.5倍;采用2.2 mm厚的BaF2材料的双凸曲面辐射透镜,红外光线呈准直收敛辐射,辐射效率最大可以达到27.42%。本工作研究成果为红外光学气体传感器光源提供了合理的红外辐射增强结构尺寸参数,有效提高了系统的稳定性和光源的辐射效率。     

线阵非成像式激光辐射源定向方法

探测报知激光威胁源的方向是激光告警必不可少的一项技术指标.从激光告警技术发展的角度,提出了一种采用线阵探测器利用非成像方式测定激光辐射源方向的方法.通过将多个线阵探测器在接收系统中进行布局,首先获得激光源在多个不同一维坐标方向上的角度信息;然后利用坐标转换将这些一维角度信息合成相对于接收系统的二维角度信息,最后根据激光...     

一种新的多信号卷积混合信号盲分离算法

对于含噪声情况下多个源信号卷积混合盲分离,由于混合矩阵比较复杂,分离算法会出现迭代次数增加、收敛速度变慢等问题.在对多信号卷积混合进行合理简化的基础上,提出一种以四阶累积量为独立准则的多信号卷积混合的新的时域盲源分离算法.由于采用高阶累积量为独立准则,该算法对高斯噪声具有良好的抑制作用,改善了信噪比.其次,算法也建立了步长因子的选取与二次残差之间的非线性函数关系,使得算法既获得了较快的收敛速度,也得到较高的分离精度.仿真数据表明提出的算法对于多个源信号卷积混合具有良好的分离效果.     

Equivalent radiation source of 3D package for electromagnetic characteristics analysis

An equivalent radiation source method is proposed to characterize electromagnetic emission and interference of complex three dimensional integrated circuits (IC) in this paper. The method utilizes amplitude-only near-field scanning data to reconstruct an equivalent magnetic dipole array, and the differential evolution optimization algorithm is proposed to extract the locations, orientation and moments of those dipoles. By importing the equivalent dipoles model into a 3D full-wave simulator together with the victim circuit model, the electromagnetic interference issues in mixed RF/digital systems can be well predicted. A commercial IC is used to validate the accuracy and efficiency of this proposed method. The coupled power at the victim antenna port calculated by the equivalent radiation source is compared with the measured data. Good consistency is obtained which confirms the validity and efficiency of the method.     

用于抽运XeF(C-A)激光的分段表面放电辐射源

研制了用于抽运激光的分段表面放电辐射源。辐射源采用分段表面滑闪放电诱导长距离、线性等离子体通道大电流放电 ,实现了高亮度真空紫外辐射 (140～ 170nm) ,且各段总的放电分散时间小于 10 0ns。用该辐射源解离XeF2 获得了XeF (C A)激光输出     

基于稀疏分解的非相干分布式信号源DOA估计

论文提出了一种基于稀疏分解的非相干分布源的DOA估计算法。根据非相干分布源协方差矩阵的结构特点,提取协方差矩阵的相位信息并对其进行重构。然后对重构矩阵向量化,建立稀疏表示模型进行分布源DOA估计。该算法无需已知角功率密度函数,受快拍数影响较小,在信噪比与角度扩展较大时具有较好地DOA估计精度,并且具有较高地分辨能力。计算机仿真验证了算法的性能。     

A joint source and channel coding algorithm for error-resilient SPIHT-coded video bitstreams

We propose an analytical rate-distortion optimized joint source and channel coding algorithm for error-resilient scalable encoded video for lossy transmission. A video is encoded into multiple independent substreams to avoid error propagation and is assigned forward error correction (FEC) codes and source bits using Lagrange optimization. Our method separates video coding and packetization into different tiers which can be easily incorporated into any coding structure that generates a set of independent compressed bit-streams. To demonstrate the performance, we use the 2-state Markov model to describe the burst loss channel and Reed-Solomon codes as forward error correction codes. Simulation results show that the proposed channel incorporated rate-distortion optimization approach have better performance.     

用于尾流探测的新型片光源

尾流气泡幕图像的像质取决于水下光电探测系统的效率,而光源是影响整个成像系统品质的重要原因。针对这个问题设计了适用于实际水下复杂工作环境的新型激光片光源系统,分析和验证了该片光源的能量利用率及可行性。试验结果表明,该片光源系统解决了成像系统照明问题的同时,避免了在光学系统景深范围内太多的图像层叠。在实验室条件下可以获得较清晰的图像,为后续的气泡幕物理参数的精确获取创造了重要的条件。这种光源的独特优势使其在水下小视场光学系统中得到很好的应用。