半化学法制备钨镁酸铅-钛酸铅陶瓷

采用半化学法制备了纯钙钛矿结构的0.50 Pb(Mg1/2W1/2)O3-0.50 PbTiO3 (0.50 PMW-0.50 PT)陶瓷。以醋酸镁代替传统氧化物混合法中的MgO,提高了MgO的分散性和反应活性,能够有效地促进钙钛矿相0.50 PMW-0.50 PT的形成和抑制钨酸铅的存在。随着预烧温度的提高,0.50 PMW-0.5 0PT粉体的钙钛矿相含量增加,当预烧温度为850℃和保温时间为2 h时其钙钛矿含量达到100%;随着烧结温度的提高,0.50PMW-50PT陶瓷的晶粒尺寸增大,而陶瓷的介电常数先增大后减小,介电损耗先减小后稍微增大。0.50 PMW-0.50 PT陶瓷的最佳烧结条件为1 050℃,2 h,最大相对介电常数为7 606。     

B位取代对钛酸锌相结构及介电性能的影响

通过固相烧结法结合半化学法制备了ZnO-(1-x)TiO2-xSnO2(x=0.04~0.20)陶瓷,掺杂1.0%3V2O5(质量分数)-B2O3降低陶瓷的烧结温度,研究了B位取代对ZnTiO3相结构及介电性能的影响。结果表明,Sn的加入促进了六方相分解,形成了立方尖晶石结构的固溶相Zn2(Ti1-xSnx)O4;随烧结温度升高,Sn的固溶量增加,900℃时,最大固溶量为0.08 mol。900℃烧结试样,随x增加,其介电常数ε先增大后减小,而介电损耗tanδ恰好相反,先减小后增大,当x=0.12时,得到ε的最大值(ε=29)和tanδ的最小值(tanδ=9.86×10-5)。900℃烧结的具有优良介电性能的ZnO-(1-x)TiO2-xSnO2(x=0.04~0.20)陶瓷有很好的实际应用前景。     

钛酸钡纳米粉体的共沉淀法合成与研究

采用TiCl4和BaCl2·2H2O原料,以正丁醇为分散剂,NH4HCO3和NH3·H2O作为沉淀剂合成钛酸钡前驱体,在900 ℃煅烧制备分散性良好的钛酸钡纳米粉体.利用XRD、透射电镜(TEM)和 SEM等手段分析了反应温度、TiCl4浓度、分散剂掺杂量等反应参数对粉体的晶相组成、晶粒度、形貌等的影响,并且测试了相应陶瓷烧结体的介电常数.结果表明,反应温度为900 ℃,TiCl4浓度为0.6 mol/L,分散剂用量为3‰条件下,保温2 h可制备高分散性的纳米级粉体.用以上方法制备的粉体烧结而成的陶瓷片介电常数约为3 400.     

锰掺杂对钠过量K0.5Na0.7NbO3无铅陶瓷结构及介电性能影响

采用一种新颖的混合钙钛矿结构法制备了锰掺杂钠过量K_(0.5)Na_(0.7)NbO_3-xMnO_2陶瓷,研究了不同锰掺杂量和烧结温度对该系列陶瓷微观结构、形貌和介电性能的影响。研究表明,锰掺杂改善了该系列陶瓷的烧结特性;陶瓷样品中均形成了正交钙钛矿结构,但同时都存在少量第二相物质;随着烧结温度的升高,陶瓷样品中第二相物质的含量逐渐减少;在不同锰掺杂量陶瓷样品的SEM分析中可以看出,掺少量锰的陶瓷样品出现晶粒异常长大且大小不均匀现象;1100℃烧结的锰掺杂量为摩尔分数1.5%的陶瓷中含有最少的第二相物质和最优的综合介电性能,即具有均匀的晶粒大小、最大的相对介电常数和较小的介电损耗,该陶瓷样品由正交向四方的相转变温度为176℃、居里温度为403℃。     

MgO-Y_2O_3对热压烧结Al_2O_3性能的影响

以高纯的硫酸铝氨分解的无定形Al2O3为原料,MgO-Y2O3为烧结助剂,在N2气氛下热压烧结制备Al2O3陶瓷。研究了烧结助剂掺量对Al2O3材料的相组成、显微结构、烧结性能、力学性能、热导率和介电性能的影响。结果表明:所制Al2O3陶瓷具有细晶的显微结构特征和超高的抗弯强度。随着MgO-Y2O3掺量的增加,晶粒尺寸、抗弯强度和热导率先增大后减小,而介电损耗则呈现先减小后增大的变化规律。当MgO和Y2O3掺量均为质量分数2%时,Al2O3陶瓷呈现为较佳的综合性能:抗弯强度达最大值为603 MPa,热导率为36.47 W.m–1.K–1,介电损耗低至6.32×10–4。     

熔盐法制备Bi4Ti3O12的研究

采用NaCl-KCl熔盐法制备了各向异性的Bi4Ti3O12粉体和陶瓷，研究了熔盐含量对粉体尺寸、形貌以及陶瓷的显微组织结构和介电性能的影响。结果表明采用熔盐法可制备出纯Bi4Ti3O12相的粉体和陶瓷，随熔盐含量增加，钛酸铋粉体尺寸及各向异性的程度明显增大；烧结后的Bi4Ti3O12陶瓷晶粒呈片状，且随熔盐含量的增加，钛酸铋陶瓷产生织构；对陶瓷介电性能的研究表明随熔盐含量增加，钛酸铋陶瓷的绝缘电阻率和介电常数增大，介电损耗减小．     

稀土掺杂BTO基纳米陶瓷的制备及介电性能

采用"连续有序可控爆发式成核"纳米粉体制备技术,以BaCl2、SrCl2.6H2O、TiCl4为原料制备了BaxSr1–xTiO3及BaxSr1–x–yGdyTiO3纳米粉体和陶瓷,研究了所制粉体和陶瓷的微观结构及性能。结果表明:所制纳米粉体分散性好,粒径分布范围窄,平均粒径小于40nm;BaxSr1–xTiO3介电常数随锶掺杂量的增加有增大的趋势,在1 325℃烧结得到的Ba0.7Sr0.3TiO3陶瓷的介电常数最大,达到30 000 F/m。BaxSr1–x–yGdyTiO3介电常数随Gd掺杂量的增加趋于减小,在1 325℃烧结得到的Ba0.8Sr0.18Gd0.02TiO3的介电常数最大,达到近25 000 F/m。     

锰掺杂对钠过量K0.5Na0.7NbO3无铅陶瓷结构及介电性能影响北大核心CSCD

采用一种新颖的混合钙钛矿结构法制备了锰掺杂钠过量K0.5Na0.7NbO3-xMnO2陶瓷,研究了不同锰掺杂量和烧结温度对该系列陶瓷微观结构、形貌和介电性能的影响。研究表明,锰掺杂改善了该系列陶瓷的烧结特性;陶瓷样品中均形成了正交钙钛矿结构,但同时都存在少量第二相物质;随着烧结温度的升高,陶瓷样品中第二相物质的含量逐渐减少;在不同锰掺杂量陶瓷样品的SEM分析中可以看出,掺少量锰的陶瓷样品出现晶粒异常长大且大小不均匀现象;1100℃烧结的锰掺杂量为摩尔分数1.5%的陶瓷中含有最少的第二相物质和最优的综合介电性能,即具有均匀的晶粒大小、最大的相对介电常数和较小的介电损耗,该陶瓷样品由正交向四方的相转变温度为176℃、居里温度为403℃。     

CuO掺杂Ba_(0.6)Sr_(0.4)TiO_3陶瓷的结构与性能

采用传统陶瓷制备工艺,以容差因子为依据进行CuO掺杂,制备了可在较低温度烧结成瓷的Ba_(0.6)Sr_(0.4)TiO_3(BSTO)基陶瓷.结果表明,w(CuO)=0.5%～4.0%的BSTO基陶瓷可在1 200 ℃烧结成瓷,且不会引入杂相.介电性能测试表明,在室温低频下,随CuO掺杂量的增加,BSTO陶瓷的介电常数增加,而介电损耗降低;在微波频段下,BSTO基陶瓷的介电常数和介电损耗均随CuO掺杂量的增加而增大.可调性测试表明,在1 kV/mm的直流偏压下,各BSTO基陶瓷掺杂样的可调性均大于10%,其中,试样w(CuO)=1%的可调性达到13.2%.     

BST陶瓷制备及介电性能研究

采用微波水热法合成了纳米晶钛酸锶钡(Ba0.6Sr0.4TiO3,简称BST)粉体,并将粉体烧结成陶瓷,对样品的介电性能进行了测试,研究分析了材料的介电性能,并与传统制备工艺获得的样品进行了性能上的对比,实验结果表明:微波水热法获得的BST粉体较细,其合成温度和烧结成瓷温度较传统制备工艺大幅降低,分别为195℃和1 230℃,可以获得晶粒尺寸在3μm以下的陶瓷。随着晶粒的减小,BST陶瓷的相对介电常数和介电损耗降低,尤其是介电损耗因子有较大幅度降低。     

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.     

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.     

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.     

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.