高介电(1–x)Ca_(0.7)Nd_(0.2)TiO_(3-x)Ba_(0.4)Sr_(0.6)TiO_3陶瓷微波介电特性

采用固相反应法制备了具有钙钛矿结构的(1–x)Ca_(0.7)Nd_(0.2)TiO_(3-x)Ba_(0.4)Sr_(0.6)TiO_3(0.05≤x≤0.5)陶瓷,并对其烧结行为、相组成、显微结构及微波介电性能进行了研究。结果表明:随着(Ba0.4Sr0.6)2+含量的增加,(1–x)Ca_(0.7)Nd_(0.2)TiO_(3-x)Ba_(0.4)Sr_(0.6)TiO_3(0.05≤x≤0.5)陶瓷的品质因数(Q·f)及谐振频率温度系数(τf)单调递减,而相对介电常数(εr)先升后小幅降低。当x=0.2,且烧结温度为1 450℃时,该介质陶瓷的微波介电性能为:εr=151.3,Q·f=5 900 GHz,τf=399.4×10–6/℃。与CaTiO_3(εr=160,Q·f=6 800 GHz,τf=850×10–6/℃)相比,Q·f和εr略微降低,τf有较大程度的减少,故此陶瓷体系有望替代CaTiO_3成为新一类高介电性微波陶瓷。     

添加TiO_2对0.94 ZnTiNb_2O_8-0.06 BaCu(B_2O_5)材料的物相组成及介电性能的影响

采用传统固相反应法制备了(1–x)(0.94ZnTiNb_2O_8-0.06Ba Cu(B_2O_5))-xTiO_2(0.038≤x≤0.091)微波介质陶瓷,研究了不同含量TiO_2添加对0.94ZnTiNb_2O_8-0.06BaCu(B_2O_5)(0.94ZTN-0.06BCB)陶瓷烧结特性、相结构、微观形貌以及微波介电性能的影响。结果表明:(1–x)(0.94ZTN-0.06BCB)-x TiO_2陶瓷均由ZnTiNb_2O_8和Zn_(0.17)Ti_(0.5)Nb_(0.33)O_2相组成,随着TiO_2含量的增加,陶瓷的烧结温度、εr和τf增加,ρ和Q·f降低。烧结温度为880℃时,0.926(0.94ZTN-0.06BCB)-0.074TiO_2陶瓷表现出了优良的综合性能:εr=40.25,Q·f=32 000 GHz(5.89 GHz),τf=–3.86×10–6℃–1。且在此温度下介质材料与Ag电极兼容性良好,表明该材料是制备LTCC器件的备选材料。     

低温烧结(1–x)Ba_3(VO_4)_(2-x)Li_2WO_4微波介质陶瓷的研究

为了获得低温烧结的陶瓷材料,用固相反应制备了(1–x)Ba3(VO4)2-x Li2WO4(0.05≤x≤0.20)微波介质陶瓷。实验结果表明:随着添加剂Li2WO4的增加,复合陶瓷的相对体密度、相对介电常数εr和品质因数Q·f都呈现出先增加随后又降低的趋势,而谐振频率温度系数τf呈线性降低。添加了摩尔分数0.15Li2WO4的微波介质陶瓷在850℃烧结2 h达到约96.8%的致密度,并获得最佳的微波介电性能:εr=13.7,Q·f=97000 GHz,τf=1.8×10–6/℃。     

温度稳定型Li_2(Zn_(1–x)Co_x)_2Mo_3O_(12)陶瓷的微波介电性能研究

采用固相反应法制备了Li_2(Zn_(1–x)Co_x)_2Mo_3O_(12)陶瓷,研究了Co~(2+)取代对其相结构和微波介电性能的影响,并通过添加Ti O_2调节了该陶瓷的τ_f值。结果表明:不同Co~(2+)取代的Li_2(Zn_(1–x)Co_x)_2Mo_3O_(12)陶瓷均显示出单相钒铁铜矿结构。随着Co~(2+)取代量的增加,陶瓷的致密化温度显著降低,相对密度和Q·f值均呈现先增大后减小的趋势。当x=0.1时,陶瓷具有相对较好的微波介电性能:ε_r=10.85,Q·f=65 031 GHz,τ_f=–73×10~(–6)/℃。添加Ti O_2能够有效调节Li_2Zn_2Mo_3O_(12)陶瓷的τ_f值向正值方向移动,0.4Li_2(Zn_(0.9)Co_(0.1))_2Mo_3O_(12)-0.6Ti O_2陶瓷的介电性能较佳:ε_r=15.80,Q·f=22 991 GHz,τ_f=–4.5×10~(–6)/℃。     

CNT对BST陶瓷微波介电性能的影响

采用XRD及SEM研究(Ca0.61Nd0.26)TiO3对微波介质陶瓷Ba4Sm9.33Ti18O54的结构和微波介电性能的影响。获得了一些性能较好的微波介质陶瓷(1–x)Ba4Sm9.33Ti18O54-x(Ca0.61Nd0.26)TiO3,其微波介电性能如下:εr=75,Q·f为8985GHz,τf为–8.2×10–6℃–1(x?=0);εr为75,Q·f为9552GHz,τf为–14.4×10–6℃–1(x?=0.2)。     

非化学计量比Li_(2+x)ZnTi_3O_(8+0.5x)微波介质陶瓷的性质研究

采用传统固相反应法制备Li2+xZnTi3O8+0.5x微波介质陶瓷,研究了A位Li的非化学计量比对Li2+xZnTi3O8+0.5x陶瓷的烧结特性、相结构及微波介电性能的影响。结果表明:随着Li2+xZnTi3O8+0.5x(x=–0.2～+0.2)陶瓷中Li含量的逐渐增加,TiO2相逐渐消失,陶瓷的致密度逐渐升高,介电常数逐渐降低,Q.f值先上升再下降,谐振频率温度系数逐渐降低,然后保持不变。当x=–0.05时,Li1.95ZnTi3O7.975陶瓷取得最佳的综合微波介电性能:εr=26.41,Q.f=65 200 GHz,τf=–4.16×10–6/℃。     

钙钛矿锰氧化物Ca_(0.5)Nd_(0.5)(Mn_(0.7)Fe_(0.3))O_3掺杂对Ca_(0.61)Nd_(0.26)TiO_3微波介电性能的影响

研究了传统固相反应法制备所得xCa_(0.5)Nd_(0.5)(Mn_(0.7)Fe_(0.3))O_3-(1–x)Ca_(0.61)Nd_(0.26)TiO_3(0.1≤x≤0.25,CNMFT_x)多晶陶瓷相组成、显微结构、烧结性能与微波介电性能之间的影响关系。X射线衍射研究表明,在研究组分范围内CNMFT_x样品均为单一正交钙钛矿结构;当烧结条件为1 400℃/4 h,x=0.1~0.2时,Fe~(3+)/Mn~(3+,4+)替代Ca_(0.61)Nd_(0.26)TiO_3中Ti~(4+)后,相对介电常数(εr为88.5~77.5)、品质因子(Q·f为7 010~9 370 GHz)和谐振频率温度系数(τf为207.4×10~(–6)/℃~149.1×10~(–6)/℃)逐渐降低,而当x=0.25时,εr(73.4)与τf值(119.6×10~(–6)/℃)仍按规律降低,虽然此时样品晶粒尺寸更为均匀,但Q·f值(5 100 GHz)降幅增加。因此,对于ABO3型钙钛矿结构的微波介质陶瓷,当具有铁磁效应离子的添加量较小时,微波介电性能的变化符合预期规律;但当置换量达到一定比例时,铁磁性增加,导电性增强,巨磁电阻效应减小,致使微波陶瓷介电损耗增加。     

CaTiO3-（La,Nd）AlO3微波介质陶瓷的研究与应用

为了降低材料成本,研究了(1–x)CaTiO3–x(La1–yNdy)AlO3微波介质陶瓷的性能与组成之间的关系。采用固相法制备粉料,在1 400℃下烧结,用XRD和SEM分析陶瓷的晶相组成和显微结构,采用闭腔法测量其微波介电性能。研究结果表明该陶瓷形成单一晶相固溶体,当x=0.35,y=0.286时,εr=43,Q.f=30 000 GHz,τf=5×10–6/℃。用该陶瓷制作了基站用环形介质谐振器,其性能如下:f0=2.122 0 GHz,Q=12 436,fs/f0=1.220,与仿真结果非常吻合。     

CaWO_4-Mg_2SiO_4陶瓷的微波介电性能与应用

为了使微波介电陶瓷在厘米波段获得应用,采用固相法制备了低εr、高Q·f值的(1–x)CaWO4-xMg2SiO4(x=0～1.0)介电陶瓷,并添加质量分数为5%的TiO2调节其τf。研究了其晶相结构和微波介电性能。结果表明,x≤0.2时,Mg2SiO4和CaWO4形成不完全固溶体;x=0.2时,在1300℃烧结2h所制得的陶瓷具有优良的微波介电性能:εr=9.58,Q·f=56400GHz,τf=–8.2×10–6/℃,并采用该材料制作了f0=5.4909GHz,插入损耗小于1.1dB,外形尺寸为5.0mm×2.5mm×4.0mm的两级片式介质带通滤波器。     

中温制备钛酸钕钙-钛酸钕锂系高介微波陶瓷

将温度系数相反的钛酸钕钙(CNT)和钛酸钕锂(LNT)进行复合,中温下(1200℃)烧结获得了εr>100的CNT-LNT微波介质陶瓷。该陶瓷为斜方结构的CaTiO3基固溶体单相。介电常数随x增加先增加后减小,在x=0.5处最大。Q.f值和谐振频率温度系数随LNT含量增加而线性下降。中温下制备了性能良好的CNT-LNT系微波介质陶瓷,如x=0.6时微波性能为:εr=123.9,Q.f=1500GHz,τf=12.0×10–6℃–1。     

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.     

Nanoimprint Lithography -A Next Generation High Volume Lithography Technique

IntroductionNanoimprint Lithography is a well-acknowl-edged low cost, high resolution, large area pattern-ing process. It includes the most promising methods,high-pressure hot embossing lithography (HEL) [2],UV-cured imprinting (UV-NIL) [3] and micro contactprinting (m-CP, MCP) [4]. Curing of the imprintedstructures is either done by subsequent UV-lightexposure in the case of UV-NIL or by cooling downbelow the glass transition temperature of the ther-moplastic material in case of HEL…     

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.     

Influence of PVK ： NPB hole transporting layer on the characteristics of organic light-emitting devices

A doping system consisting of NPB and PVK is employed as a composite hole transporting layer （CHTL）. By adjusting the component ratio of the doping system, a series of devices with different concentration proportion of PVK ： NPB are constracted. The result shows that doping concentration of NPB enhances the competence of hole transporting ability, and modifies the recombination region of charge as well as affects the surface morphology of doped film. Optimum device with a maximum brightness of 7852 cd/m^2 and a power efficiency of 1.75 lm/W has been obtained by choosing a concentration proportion of PVK ： NPB at 1：3.     

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.     

Analysis of error performance on Turbo coded FDPIM

Due to variable symbol length of digital pulse interval modulation（DPIM）, it is difficult to analyze the error performances of Turbo coded DPIM. To solve this problem, a fixed-length digital pulse interval modulation（FDPIM） method is provided. The FDPIM modulation structure is introduced. The packet error rates of uncoded FDPIM are analyzed and compared with that of DPIM. Bit error rates of Turbo coded FDPIM are simulated based on three kinds of analytical models under weak turbulence channel. The results show that packet error rate of uncoded FDPIM is inferior to that of uncoded DPIM. However, FDPIM is easy to be implemented and easy to be combined, with Turbo code for soft-decision because of its fixed length. Besides, the introduction of Turbo code in this modulation can decrease the average power about 10 dBm, which means that it can improve the error performance of the system effectively.     

A method for calculating the center position of collimated light

It is a key problem to accurately calculate beam spots＇ center of measuring the warp by using a collimated laser. A new method, named double geometrical center method （DGCM）, is put forward for the first time. In this method, a plane wave perpendicularly irradiates an aperture stop, and a charge couple device （CCD） is employed to receive the diffraction-beam spots, then the geometrical centers of the fast and the second diffraction-beam spots are calculated respectively, and their mean value is regarded as the center of datum beam. In face of such adverse instances as laser intension distributing defectively, part of the image being saturated, this method can still work well. What＇s more, this method can detect whether an unacceptable error exits in the courses of image receiving, processing and calculating. The experimental results indicate the precision of this method is high.     

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.