高稳定电源虚拟测试系统

为了测试电子显微镜高稳定线圈恒流电源的稳定度,设计了一种基于虚拟仪器技术的在线测试系统。该系统硬件平台基于GPIB总线,以8位半数字多用表为高精度电压采集设备,软件系统以LabVIEW为开发平台,可以实时采集处理线圈电流反馈的电压信号。应用该系统测试了稳定度为2 ppm/min的物镜线圈电源。结果表明,该测试系统精度高,反应快,使用方便,满足自动测试高稳定电源的需求。     

高稳定度电子束透镜系统电源的研制技术综述

本文介绍了为我室新型电子束主机研制的高稳定度透镜系统电源。该透镜系统电源在关键技术的处理上,采用了精密稳压管零温度系数工作电流的检测方法、研制出温度互补的基准电压发生器,使用了高增益、低漂移的运算放大器功能块,并应用热管技术研制出精密取样电阻器及整机采用了屏蔽浮地措施等,使该透镜系统电源取得了较高的技术指标,特别是系统的Ⅲ物镜电源的长时间稳定度达到7×10~(-6)/8小时的指标。 该系统电源的长时间稳定度指标优于英国剑桥科仪公司1981年研制的EBMF—6.5型电子束机的物镜电源指标。     

亚微米电子束曝光机数控电流源系统

对于亚微米级的电子束曝光机而言,电子光柱体电流源系统的自动化程度及各路电流源尤其是物镜电源的稳定度,对束斑的影响极大。为突破0.1μm的束斑,特研制了一种电流源系统,集高稳定度、高精度、高抗干扰性、大电流、低噪声、多路输出、计算机控制于一体,它的研制成功为亚微米电子束曝光机的自动化调机奠定了基础,并可推广用于其它需要高稳定度数控电源的领域。 系统构成 该系统在结构上抛弃了传统的开环控制方式,首次将电压/频率转换器(VFC)用于连续可调的电源。整个电流源系统由23个模块组成,其中20块电源板输出20路独立的电流;一块8255板作为IBM主机     

亚微米电子束曝光机数控电流源系统

本文介绍了亚微米电子束曝光机电流源系统。该系统在国内首次使用计算机实现了自动化调节,系统内关键部位使用了大量先进器件,多达20路独立可调的电流输出,稳定度均达到2×10~(-5)/1小时。其中对稳定度要求最高的物镜电源,由于首次将电压/频率转换器(VFC)用于连续可调的电源系统,形成了一个闭环反馈控制电路,使它达到5×10~(-6)/4小时的稳定度。该系统还具有很强的抗干扰能力,纹波<1×10~(-5)V_(P-P)。这些指标保证了0.1μm束斑的精度要求,它的研制成功为电子束曝光机的自动化调机奠定了基础。     

高分辨率透射电子显微镜试制中的几个问题

本文简要介绍了DXB2-12型电子显微镜成象系统的光路计算数据,并与实际仪器进行比较。说明采用了强激励物镜的一些特点。再叙述了加速电源获得高稳定度的措施,介绍了关键元件——高压反馈电阻进行老化筛选的方法。     

电子显微镜加速高压稳定度的测量

欲使电子显微镜获得高分辨本领的象,条件之一是必须具有高度稳定的电源.理论分析指出:电子加速电压U及物镜励磁电流I的任一变动都将引起象差,其模糊圆半径为下式确定:     

利用法拉第筒测试环形强流电子束束流

通过优化设计法拉第筒的响应电阻和分布电感,在“TPG700”平台上对无箔二极管阴极发射的环形电子束束流进行轴向测试。结果表明,无波二极管工作在低磁场(<1 T)条件下,在二极管电压较低时,优化后的法拉第筒测试获得的电子束束流前沿较慢,随着二极管电压的升高,电子束束流前沿明显变快;在强磁场(>2 T)条件下,法拉第筒测试结果与罗果夫斯基线圈测试结果一致。该结果表明,相比于罗果夫斯基线圈,法拉第筒更能准确地测试出无箔二极管的前向电子束束流。     

智能PID算法在恒流源纹波抑制中的应用

降低恒流电源的纹波是提高恒流源精度和稳定度的重要技术手段。在实际工作中,电路结构复杂,形成电源纹波的因素众多,用传统的线性传递方法难以详尽地分析。为此,尝试用智能PID算法进行电路分析和数字模拟,利用Matlab的Simulink仿真功能匹配出符合系统要求的电路参数,获得更为理想的系统输出,使系统的动态性能得到改善。     

场发射电子枪第一阳极电源的研制

用场发射电子枪作为高分辨率扫描透射电子显微镜的电子源有亮度高、束斑小、能散度低等优点。本文的工作就是研制用于扫描透射电子显微镜的场发射电子枪的第一阳极电源V_i,对此我们做了以下工作。1.电源V_i控制着场发射电子枪的场致发射电子束流的大小。本文根据电子显微镜实际运用要求,从场发射理论出发。计算了电源V_i的各项指标,得出其输出电压为500→5000伏,输出电流为0→200微安,稳定度应优于9×10~(-4)。2.电源V_i为置于第二阳极电源V_0(-50kV)之上的一正高压直流电源。为了能在低压端调节置于高压V_0上的电源V_1的输出电压,并使之达到所需的稳定度,本文对现有资料文献进行了归纳和分析,根据差     

美陆军数字设备电源分系统的交流—直流电源变换模型

已经研制成了28V/100A的交流一直流电源变换器,作为美陆军电子司令部数字设备电源分系统的标准一次电源模型。该模型将可控硅LC串联谐振逆变器制成彼此间有相移的四个功率级结构形式,功率级的开关半导体器件中流过正弦电流,因此减小了开关损耗,在不正常负载期间提供了固有的电流限制,且由于整个工作频率较高,减小了输入/输出滤波。这个多级系统采用了双环控制系统,使直流输出具有精密的稳定度和良好的动态响应。     

Preparation and Characterization of TaN ALD Precursors

High purity organic-tantalum precursors for thin film ALD TaN were synthesized and characterized.Vapor pressure and thermal stability of these precursors were studied.From the vapor pressure analysis,it was found that TBTEMT has a higher vapor pressure than any other published liquid TaN precursor,including TBTDET,TAITMATA,and IPTDET.Thermal stability of the alkyl groups on the precursors was investigated using a 1H NMR technique.The results indicated that the tertbutylimino group is the most stable group on TBTDET and TBTEMT as compared to the dialkylamido groups.Thermal stability of TaN precursors decreased in the following order:TBTDET ＞ PDMAT ＞ TBTEMT.In conclusion,precursor vapor pressure and thermal stability were tuned by making slight variations in the ligand sphere around the metal center.     

Curved crystal spectrometer for the measurement of X-ray lines from laser-produced plasmas

In order to diagnose the laser-produced plasmas, a focusing curved crystal spectrometer has been developed for measuring the X-ray lines radiated from a laser-produced plasmas. The design is based on the fact that the ray emitted from a source located at one focus of an ellipse will converge on the other focus by the reflection of the elliptical surface. The focal length and the eccentricity of the ellipse are 1350 mm and 0.9586, respectively. The spectrometer can be used to measure the X- ray lines in the wavelength range of 0.2-0.37 nm, and a LiF crystal （200） （2d = 0.4027 nm） is used as dispersive element covering Bragg angle from 30° to 67.5°. The spectrometer was tested on Shengnang- Ⅱ which can deliver laser energy of 60-80 J/pulse and the laser wavelength is 0.35 μm. Photographs of spectra including the 1 s2p ^1P1-1s^2 ^1S0 resonance line（w）, the 1s2p ^3P2-1s^2 1S0 magnetic quadrupole line（x）, the 1s2p ^3P1-1 s^2 ^1S0 intercombination lines（y）, the 1 s2p ^3S~1-1 s^2 ^1S0 forbidden line（z） in helium-like Ti Ⅹ Ⅺ and the 1 s2s2p ^2P3/2-1 s622s ^2S1/2 line（q） in lithium-like Ti Ⅹ Ⅹhave been recorded with a X-ray CCD camera. The experimental result shows that the wavelength resolution（λ/△ 2） is above 1000 and the elliptical crystal spectrometer is suitable for X-ray spectroscopy.     

Cost-effective test solutions for smart card and other integrated flash applications

From its emergence in the late 1980s as a lower cost alternative to early EEPROM technologies, flash memory has evolved to higher densities and speedsand rapidly growing acceptance in mobile applications.In the process, flash memory devices have placed increased test requirements on manufacturers. Today, as flash device test grows in importance in China, manufacturers face growing pressure for reduced cost-oftest, increased throughput and greater return on investment for test equipment. At the same time, the move to integrated flash packages for contactless smart card applications adds a significant further challenge to manufacturers seeking rapid, low-cost test.     

An improved parallel thinning algorithm with two subiterations

The parallel thinning algorithm with two subiterations is improved in this paper. By analyzing the notions of connected components and passes, a conclusion is drawn that the number of passes and the number of eight-connected components are equal. Then the expression of the number of eight-connected components is obtained which replaces the old one in the algorithm. And a reserving condition is proposed by experiments, which alleviates the excess deletion where a diagonal line and a beeline intersect. The experimental results demonstrate that the thinned curve is almost located in the middle of the original curve connectivelv with single pixel width and the processing speed is high.     

Theoretical analysis of the relationship between the Brillouin gain coefficient and the strain in the optical-fiber sensors

The relation between the power of the Brillouin signal and the strain is one of the bases of the distributed fiber sensors of temperature and strain. The coefficient of the Bfillouin gain can be changed by the temperature and the strain that will affect the power of the Brillouin scattering. The relation between the change of the Brillouin gain coefficient and the strain is thought to be linear by many researchers. However, it is not always linear based on the theoretical analysis and numerical simulation. Therefore, errors will be caused if the relation between the change of the Brillouin gain coefficient and the strain is regarded as to be linear approximately for measuring the temperature and the strain. For this reason, the influence of the parameters on the Brillouin gain coefficient is proposed through theoretical analysis and numerical simulation.     

Novel fiber-optical interferometer with miniaturized probe for in-hole measurements

Today, micro-system technology and the development of new MEMS （Micro-Electro-Mechanical Systems） are emerging rapidly. In order for this development to become a success in the long run, measurement systems have to ensure product quality. Most often, MEMS have to be tested by means of functionality or destructive tests. One reason for this is that there are no suitable systems or sensing probes available which can be used for the measurement of quasi inaccessible features like small holes or cavities. We present a measurement system that could be used for these kinds of measurements. The system combines a fiber optical, miniaturized sensing probe with low-coherence interferometry, so that absolute distance measurements with nanometer accuracy are possible.     

Electronic Structure of Semiconductor Nanocrystals

This paper reviews our recent development of the use of the large-scale pseudopotential method to calculate the electronic structure of semiconductor nanocrystals, such as quantum dots and wires, which often contain tens of thousands of atoms. The calculated size-dependent exciton energies and absorption spectra of quantum dots and wires are in good agreement with experiments. We show that the electronic structure of a nanocrystal can be tuned not only by its size,but also by its shape. Finally,we show that defect properties in quantum dots can be significantly different from those in bulk semiconductors.     

Critical Stage Rule-Based Real Time Dispatch（RTD）System in Highly-Mixed-Products （HMP） FAB

An improving utilization and efficiency of critical equipments in semiconductor wafer fabrication facilities are concerned. Semiconductor manufacturing FAB is one of the most complicated and cost sensitive environments. A good dispatching tool will make big difference in equipment utilization and FAB output as a whole. The equipment in this paper is In-Line DUV Scanner. There are many factors impacting utilization and output on this equipment group. In HMP environment one of the issues is changing of reticule in this area and idle counts due to load unbalance between equipments. Here we'll introduce a rule-based RTD system which aiming at decreasing the number of recipe change and idle counts among a group of scanner equipment in a high-mixed-products FAB.     

GaAsSb/InAlAs PA DHBTs Grown by Production MBE

The epi material growth of GaAsSb based DHBTs with InAlAs emitters are investigated using a 4 × 100mm multi-wafer production Riber 49 MBE reactor fully equipped with real-time in-situ sensors including an absorption band edge spectroscope and an optical-based flux monitor. The state-of-the-art hole mobilities are obtained from 100nm thick carbon-doped GaAsSb. A Sb composition variation of less than ± 0.1 atomic percent across a 4 × 100mm platen configuration has been achieved. The large area InAlAs/GaAsSb/InP DHBT device demonstrates excellent DC characteristics,such as BVCEO＞6V and a DC current gain of 45 at 1kA/cm2 for an emitter size of 50μm × 50μm. The devices have a 40nm thick GaAsSb base with p-doping of 4. 5 × 1019cm-3 . Devices with an emitter size of 4μm × 30μm have a current gain variation less than 2% across the fully processed 100mm wafer. ft and fmax are over 50GHz,with a power efficiency of 50% ,which are comparable to standard power GaAs HBT results. These results demonstrate the potential application of GaAsSb/InP DHBT for power amplifiers and the feasibility of multi-wafer MBE for mass production of GaAsSb-based HBTs.     

Teleportation of an arbitrary unknown N-qubit entangled state under the controlling of M controllers

A new quantum protocol to teleport an arbitrary unknown N-qubit entangled state from a sender to a fixed receiver under M controllers(M < N) is proposed. The quantum resources required are M non-maximally entangled Greenberger-Home-Zeilinger (GHZ) state and N-M non-maximally entangled Einstein-Podolsky-Rosen (EPR) pairs. The sender performs N generalized Bell-state measurements on the 2N particles. Controllers take M single-particle measurement along x-axis, and the receiver needs to introduce one auxiliary two-level particle to extract quantum information probabilistically with the fidelity unit if controllers cooperate with it.