退火温度对铁电薄膜钛酸锶钡的影响

用醋酸盐和钛酸酯为原料，采用改进的Sol—gel工艺在Pt／Ti／SiO2／Si基片上制备出Ba0.6Sr0.4TiO3(BST)铁电薄膜，然后进一步对薄膜进行退火实验：对(110)方向生长BST薄膜在550～750℃进行恒温退火。X射线衍射分析表明：退火温度在650℃以上时，BST薄膜转变为较为完整的ABO3型钙钛矿晶体结构，更高的退火温度将提高晶体的取向度。     

退火工艺对钛酸锶钡薄膜结构的影响

采用射频磁控溅射在Pt/Ti/SiO2/Si(100)衬底上制备Ba0.6Sr0.4TiO3(BST)铁电薄膜,在500~750℃之间对薄膜快速退火。XRD分析表明:500℃时BST薄膜开始晶化为ABO3型钙钛矿结构,温度越高结晶越完整,晶粒越大。理论计算表明,薄膜在低温退火后无择优取向,高温退火后在(111)、(210)晶面有择优取向。退火气氛、保温时间、循环次数等因素对薄膜晶粒大小无明显影响,但对表面粗糙度和结晶程度影响较大。     

磁控溅射法制备BST铁电薄膜的实验研究

采用射频磁控溅射法在Si和Pt/TiOx/SiO2/Si衬底上沉积了(Ba0.65Sr0.35)TiO3铁电薄膜,研究了BST铁电薄膜微观结构和介电性能。实验结果表明:衬底温度在550℃,工作气压为2.0 Pa的溅射条件下沉积的BST薄膜,经750℃退火处理30 min后,形成了完整的钙钛矿相;与Si衬底相比,在Pt衬底上制备的BST薄膜晶粒更均匀、表面平整无裂纹。在室温、频率为100 kHz条件下薄膜的介电常数ε=353.8,介电损耗tanδ=0.012 8。介电温谱结果表明制备的(Ba0.65Sr0.35)TiO3铁电薄膜居里温度在5.0℃左右。     

倒筒式射频溅射频偏压对Ba0.65Sr0.35TiO3热释电薄膜结构及性能的影响

采用倒筒式射频溅射方法,在Pt、Ti/SiO2/Si基片上制备了Ba0.65Sr0.35TiO3(简称BST)薄膜.研究了自偏压对BST薄膜结构及电学性能的影响.在较高自偏压下制备的BST薄膜具有高度的(100)择优取向,且结晶性好,表面平整,耐压能力强.在25℃时薄膜的热释电系数高达6.73×10-7C.cM-2.K-7.研究结果表明,利用倒筒式射频溅射方法适当提高自偏压,可以制备出热释电性能优良的BST薄膜.     

快速退火对Pt/BST/Pt电容器结构和性能的影响

采用脉冲激光沉积(PLD)法在Pt/Ti/SiO2/Si(001)基片上制备了Ba0.6Sr0.4TiO3(BST)薄膜,对Pt/BST/Pt电容器在空气中进行400℃快速退火(RTA)处理,研究了快速退火对Pt/BST/Pt电容器的结构和性能的影响。结果表明:快速退火虽然对BST薄膜的结晶质量影响较小,但却极大改善了Pt/BST/Pt电容器的电学性能。当测试频率为100kHz、直流偏压为0V时,介电损耗从快速退火前的0.07减小到0.03,介电常数和调谐率略有增加。快速退火后负向漏电流过大现象得到了明显抑制,正负向漏电流趋于对称,在300×103V/cm电场强度下,漏电流密度为4.83×10–5A/cm2。     

BST/LSCO异质结构的研究

利用脉冲激光沉积法在STO(001)基片上外延生长了La0.5Sr0.5CoO3(LSCO)导电氧化物薄膜,研究了基片温度对LSCO薄膜结构和电性能的影响,并制备了Ni-Cr/BST/LSCO多层膜结构。XRD谱发现,沉积温度在450~700℃均能得到高度(00 l)取向的LSCO薄膜,LSCO(002)峰的半高峰宽FWHM=0.1°~0.2°;在LSCO薄膜上制备的BST介质膜具有良好的c轴取向和较高的表面平整度,其εr约为470,tgδ为0.036~0.060。     

应用于DRAM的BST薄膜制备与性能研究

BaxSr1-xTiO3(BST)是动态随机存取存储器(DRAM)中常规电容介质SiO2的替代材料。用溶胶-凝胶(Sol-Gel)法在Si及Pt/Ti/SiO2/Si基片上制备出了较高品质的BST薄膜。系统地研究了在不同退火条件下薄膜的结晶情况、微结构和电学性能。在室温100kHz下,薄膜的介电常数为230。在3V的偏压下,薄膜的漏电流密度为1.6×10-7A/cm2。利用HCl/HF刻蚀溶液成功获得了分辨率达到微米量级的BST薄膜微图形。     

温度对飞秒激光沉积ZnO/Si薄膜的结构和性能的影响

通过飞秒脉冲激光(50 fs,800 nm,1 kHz,2 mJ)沉积技术在n型Si(100)单晶基片上制备了ZnO薄膜.详细研究了基片温度变化以及退火处理对ZnO薄膜的结构、表面形貌及光学性质的影响.X射线衍射(XRD)结果表明,不同温度下(20~350℃)生长的ZnO薄膜具有纤锌矿结构,并且呈c轴择优取向;当基片温度为80℃时,薄膜沿(002)晶面高度择优生长;当基片温度为500℃时薄膜沿(103)晶面择优生长,场发射扫描电子显微镜(FEEM)结果表明薄膜呈纳米晶结构,并观察到了ZnO的六方结构.进一步通过透射光谱的测量讨论了基片温度及退火处理对ZnO薄膜光学透射率的影响,结果表明退火后薄膜的透射率增大.     

氧气氛退火对BST薄膜电阻热敏特性的影响

利用氩离子束镀膜技术在 SiO2/Si 衬底上淀积 BST 薄膜,研究了氧气氛下退火对 BST 薄膜热敏特性的影响。结果表明,当退火温度不太高时(≤600℃),薄膜热敏特性随退火温度升高而变差;但当退火温度较高时(>600℃),薄膜热敏特性随退火温度升高而得到改善。在室温至 200℃范围内 BST 薄膜具有较好的热敏特性,其温度系数最大值为–5.3 %℃–1。并利用 SEM 和 AES 分析了退火条件对薄膜电阻热敏特性的影响机理。     

退火温度对ZnO/PZT薄膜结构及电阻率的影响

采用射频反应磁控溅射法在Pb(Zr0.52Ti0.48)O3(PZT)/Pt/Ti/SiO2/Si基片上制备了ZnO薄膜,利用X线衍射仪(XRD)、原子力显微镜(AFM)、霍尔效应测试系统等对不同退火温度下制备薄膜的结构、形貌及电阻率等进行了分析表征。结果表明,退火温度600℃的ZnO薄膜(002)择优取向较好,晶粒大小均匀,表面平整致密。随着退火温度的增大,电阻率先下降后升高,600℃时ZnO薄膜电阻率达最小。     

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.     

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.     

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.     

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.     

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.     

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.     

Diode-end-pumped Nd:YVO4/LBO lasers with 4.2W continuous-wave output at 457 nm

A continuous-wave (CW) 457 nm blue laser operating at the power of 4.2 W is demonstrated by using a fiber coupled laser diode module pumped Nd: YVO4 and using LBO as the intra-cavity SHG crystal With the optimization of laser cavity and crystal parameters, the laser operates at a very high efficiency. When the pumping power is about 31 W, the output at 457nm reaches 4.2 W, and the optical to optical conversion efficiency is about 13.5% accordingly. The stability of the out putpower is better than 1.2% for 8 h continuously working.