图案化氧化钨纳米线阵列的低温制备工艺及其场发射特性研究

氧化钨纳米线由于具有长径比较大、导电性好、阈值电场较低、可承受的电流较高等优点,因此在场致电子发射器件中受到人们的广泛关注。但是在氧化钨纳米结构研究发展的过程中,出现了一些技术难题,比如制备温度高(>800℃),制备的氧化钨通常混合多种化学相而导致物性不均匀等,所以束缚了氧化钨纳米线在场发射领域的快速发展。本文采用磁控溅射技术结合化学气相沉积技术在500℃下分别实现了高纯相的WO2和WO3纳米线阵列的定域生长。场发射特性研究结果表明:所制备的WO3纳米线阵列的开启电场低至0.65MV/m,阈值电场约为2.9MV/m,最大电流密度达到18.3A/cm2;WO2纳米线阵列的开启电场低至0.8MV/m,阈值电场为2.46MV/m,最大电流密度达到12.1mA/cm2。这表明在低温下制备的氧化钨纳米线阵列在场致电子发射领域具有非常广阔的应用前景。     

氧化钨纳米线定域制备及其场发射特性研究

冷阴极在X射线源中有重要应用。本文结合微加工技术和磁控溅射镀膜技术,采用直接热氧化法实现了在玻璃衬底上大面积定域制备氧化钨(WO3)纳米线阵列。制备所得的WO3纳米线具有较大的长径比。场发射特性测试表明,该WO3纳米线冷阴极具有良好的场发射特性,开启电场为4.9V/μm,发射均匀性好,有望应用在平板X射线源中。     

铜纳米线的制备及其场发射特性研究

采用水合肼还原硝酸铜的方法制备了高长径比铜纳米线,在此基础上,通过导电双面胶带将铜纳米线转移至阴极表面,基于二极场发射器件结构研究了铜纳米线的场发射特性。结果表明:铜纳米线是一种优良的场发射冷阴极材料,其开启场强为2.18 V/μm,阈值场强为3.69 V/μm,经过2 h老练后具有良好的发射稳定性。     

铜纳米线的制备及其场发射特性研究

采用水合肼还原硝酸铜的方法制备了高长径比铜纳米线,在此基础上,通过导电双面胶带将铜纳米线转移至阴极表面,基于二板场发射器件结构研究了铜纳米线的场发射特性.结果表明:铜纳米线是一种优良的场发射冷阴极材料,其开启场强为2.18 V/μm,阈值场强为3.69 V/μm,经过2h老练后具有良好的发射稳定性.     

ZnO纳米线的快速生长机理及其场发射性能研究

为了快速制备具有优良场发射性能的ZnO纳米线,对ZnO纳米线的生长机理及场发射性能进行研究。首先采用优化的两步法制备出高长径比的ZnO纳米线,其次采用SEM对ZnO的微观形貌进行表征,然后,在分析形貌特点的基础上,说明了强碱体系下ZnO纳米线薄膜的快速生长机理。最后,对典型样品的场发射性能进行了测试。测试果表明,优化后的两步法,只需3h即可获得直径为40~50nm,长度为2.2~2.7μm,长径比高达54的纳米线。薄膜的开启电场为3.6V/μm,阈值场强为9.1V/um,场增强因子β高达3 391。研究表明,高pH值溶液可以加快ZnO纳米线沿C轴方向的择优生长,获得高长径比的ZnO纳米线,进而获得优良的场发射性能。     

大面积超长氮化铝纳米线的制备及场发射特性研究

报道了一种通过直接氮化Al粉合成氮化铝(AlN)纳米线的方法。该方法无需任何催化剂,并且可以获得大面积的单一形貌的AlN纳米线。所制备的AlN纳米线的平均长度超过20μm,直径为30～125nm,是沿着[001]方向生长的单晶六方纤锌矿结构。场发射特性测试结果表明,AlN超长纳米线的开启电场为6.3V/μm,阈值电场为12.2V/μm,最大电流密度达1440μA/cm2。这暗示着AlN超长纳米线是一种很有潜力的冷阴极纳米材料。     

图形化氧化锌纳米线的合成和场发射性能研究

通过简单的热蒸发在ITO电极上合成图形化氧化锌纳米线,利用SEM,XRD,EDX和PL光谱分析氧化锌纳米线的表面形貌、微观结构和光学特性,并测试其场发射性能。SEM表明,ZnO纳米线的直径约为100-200nm,长度大于5um,且均匀长在ITO电极表面。场发射测试表明,图形化ZnO纳米线的开启电场和阈值电场分别为1.6 V/m和4.92 V/m,在电场强度为5.38 V/m时发射电流高达 2.26 mA/cm2,经4.5h场发射测试后发射电流的浮动低于5%。低的开启电场、高的发射电流和好的稳定性表明图形化氧化锌纳米线是一种应用前景广阔的场发射材料。     

ZnO纳米线的气相沉积制备及场发射特性

运用气相沉积方法分别在硅片表面和钨针尖上制备了非取向生长的ZnO纳米线,并通过场发射显微镜研究了纳米线样品的平面场发射特性和针尖场发射特性.结果显示,非取向生长的ZnO纳米线薄膜场发射的开启电压和阈值电压所对应的场强分别为4.7和7.6V/μm,场增强因子达103量级,具有较阵列生长的ZnO纳米线更为优异的场发射能力.非取向生长ZnO纳米线薄膜场发射能力的增强归因于其所具有的稀疏结构避免了强场作用下屏蔽效应的产生,有效地提高了薄膜场发射的电流密度.将ZnO纳米线组装在钨针尖上能够明显地改善针尖的场发射性能,在超高分辨显微探针领域具有良好应用前景.     

ZnO纳米线的气相沉积制备及场发射特性

运用气相沉积方法分别在硅片表面和钨针尖上制备了非取向生长的ZnO纳米线,并通过场发射显微镜研究了纳米线样品的平面场发射特性和针尖场发射特性.结果显示,非取向生长的ZnO纳米线薄膜场发射的开启电压和阈值电压所对应的场强分别为4.7和7.6V/μm,场增强因子达103量级,具有较阵列生长的ZnO纳米线更为优异的场发射能力.非取向生长ZnO纳米线薄膜场发射能力的增强归因于其所具有的稀疏结构避免了强场作用下屏蔽效应的产生,有效地提高了薄膜场发射的电流密度.将ZnO纳米线组装在钨针尖上能够明显地改善针尖的场发射性能,在超高分辨显微探针领域具有良好应用前景.     

GaN纳米线阵列的电子场发射研究

基于HCl辅助热蒸发GaN粉末的方法制备了纯净的一维GaN纳米线垂直阵列,重点研究了不同生长时间对应不同形貌的GaN纳米结构的电子场发射性能,以及氨气氛围下热退火对GaN纳米线阵列场发射性能的影响,并分析了其影响机理.通过对生长时间分别为20 min,60 min(未退火处理)与60 min(退火处理)的三组样品进行对比,结果显示:生长时间为60 min(未退火处理)的样品,电流密度达到1μA/cm2时的开启电场的值为2.1 V/μm,且获得1 mA/cm2的阈值电流密度也只需要4.5 V/μm的电场.     

Resolution Enhancement Technology:Integrated Process Solutions using OPC

DUV lithography, using the 248 nm wavelength, is a viable manufacturing option for devices with features at 130 nm and less. Given the low kl value of the lithography, integrated process development is a necessary method for achieving acceptable process latitude. The application of assist features for rule based OPC requires the simultaneous optimization of the mask, illumination optics and the resist.Described in this paper are the details involved in optimizing each of these aspects for line and space imaging.A reference pitch is first chosen to determine how the optics will be set. The ideal sigma setting is determined by a simple geometrically derived expression. The inner and outer machine settings are determined, in turn,with the simulation of a figure of merit. The maximum value of the response surface of this FOM occurs at the optimal sigma settings. Experimental confirmation of this is shown in the paper.Assist features are used to modify the aerial image of the more isolated images on the mask. The effect that the diffraction of the scattering bars (SBs) has on the image intensity distribution is explained. Rules for determining the size and placement of SBs are also given.Resist is optimized for use with off-axis illumination and assist features. A general explanation of the material' s effect is discussed along with the affect on the through-pitch bias. The paper culminates with the showing of the lithographic results from the fully optimized system.     

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.     

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.     

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.     

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.     

Development of the readout system for waveguide multilayer optical card

Waveguide multilayer optical card （WMOC） is a novel storage device of three-dimensional optical information. An advanced readout system fitting for the WMOC is introduced in this paper. The hardware mainly consists of the light source for reading, WMOC, motorized stages addressing unit, microscope imaging unit, CCD detecting unit and PC controlling ＆ processing unit. The movement of the precision motorized stage is controlled by the computer through Visual Basic （VB） language in software. A control panel is also designed to get the layer address and the page address through which the position of the motorized stages can be changed. The WMOC readout system is easy to manage and the readout result is directly displayed on computer monitor.     

Study of waveguide coupling efficiency in hybrid silicon lasers

This paper presents a new method to increase the waveguide coupling efficiency in hybrid silicon lasers. We find that the propagation constant of the InGaAsP emitting layer can be equal to that of the Si resonant layer through improving the design size of the InP waveguide. The coupling power achieves 42% of the total power in the hybrid lasers when the thickness of the bonding layer is 100 nm. Our result is very close to 50% of the total power reported by Intel when the thickness of the thin bonding layer is less than 5 nm. Therefore, our invariable coupling power technique is simpler than Intel＇s.     

Collinear phase-matching study of terahertz-wave generation via difference frequency mixed in GaAs and Inp

The collinearly phase-matching condition of terahertz-wave generation via difference frequency mixed in GaAs and InP is theoretically studied. In collinear phase-matching, the optimum phase-matching wave hands of these two crystals are calculated. The optimum phase-matching wave bands in GaAs and lnP are 0.95-1.38μm and 0.7-0.96μm respectively. The influence of the wavelength choice of the pump wave on the coherent length in THz-wave tuning is also discussed. The influence of the temperature alteration on the phase-matching and the temperature tuning properties in GaAs crystal are calculated and analyzed. It can serve for the following experiments as a theoretical evidence and a reference as well.     

Effects of the alloy compositions on the phonon-polaritons in ternary mixed crystals

Composition dependence of bulk and surface phonon-polaritons in ternary mixed crystals are studied in the framework of the modified random-element-isodisplacement model and the Bom-Huang approximation. The numerical results for Several Ⅱ - Ⅵ and Ⅲ- Ⅴ compound systems are performed, and the polariton frequencies as functions of the compositions for ternary mixed crystals AlxGa1-xAs, GaPxAS1-x, ZnSxSe1-x, GaAsxSb1-x, GaxIn1-xP, and ZnxCd1-xS as examples are given and discussed. The results show that the dependence of the energies of two branches of bulk phonon-polaritons which have phonon-like characteristics, and surface phonon-polaritons on the compositions of ternary mixed crystals are nonlinear and different from those of the corresponding binary systems.     

New insert layer structure OLEDs

An insert layer structure organic electroluminescent device（OLED） based on a new luminescent material （Zn（salen）） is fabricated. The configuration of the device is ITO/CuPc/NPD/Zn（salen）/Liq/LiF/A1/CuPc/NPD/Zn（salen）/Liq/LiF/A1. Effective insert electrode layers comprising LiF（1nm）/Al（5 nm） are used as a single semitransparent mirror, and bilayer cathode LiF（1 nm）/A1（100 nm） is used as a reflecting mirror. The two mirrors form a Fabry-Perot microcavity and two emissive units. The maximum brightness and luminous efficiency reach 674 cd/m^2 and 2.652 cd/A, respectively, which are 2.1 and 3.7 times higher than the conventional device, respectively. The superior brightness and luminous efficiency over conventional single-unit devices are attributed to microcavity effect.