负性液晶材料电压保持率的研究

电压保持率(VHR)是表征液晶材料信赖性特性的重要参数之一,液晶材料的线残像特性与VHR相关。本文着重探讨了负性液晶材料在搭配不同PI材料,在不同电压、不同温度时VHR的表现。通过使用由不同PI材料制备的测试盒测量液晶材料在不同电压和温度下的VHR,从而得出负性液晶材料在不同条件下VHR的变化趋势。实验结果表明,测试盒的VHR值受到液晶材料和PI材料的共同影响。|Δε|较大的液晶材料VHR相对较低。在常温时,伴随充电电压升高,测试盒VHR呈下降趋势;而在高温时趋势相反,伴随充电电压升高,VHR呈上升趋势。|Δε|较高的液晶材料含有较多极性成分,易出现相对较低的VHR。常温时,离子运动较慢,伴随充电电压升高测试盒离子析出持续增加,离子析出增加会使测试盒VHR呈下降趋势。而高温时,离子活性较强,测试盒会析出大量离子,而大量离子不纯物的存在会使液晶盒在充电放时产生直流电残留,伴随充电电压升高,直流电残留电会更加严重,因此导致测试盒伴随VHR呈上升趋势。     

高可靠性Cu BCE a-IGZO TFTs的制作

背沟道刻蚀型（BCE）非晶氧化铟镓锌薄膜晶体管（a-IGZO TFT）具有工艺简单、寄生电容小以及开口率高等优点,但BCE IGZO器件背沟道易受酸液和等离子体损伤,进而引起TFT均匀性和稳定性等方面问题,随着GOA技术的导入,对TFT器件电学性能的均匀性和稳定性提升的要求也日益迫切,因此开发高信赖性BCE IGZO TFT是技术和市场的迫切要求。本文主要分析了基于IGZO的背沟道刻蚀型薄膜晶体管电学性质,通过优化钝化层材料,色阻材料以及GOA TFT结构等削弱因背沟道水汽吸附引起的器件劣化,偏压温度应力测试结果显示优化后的TFT展现了良好的稳定性——在80℃,栅极30 V负向偏压条件下,2 000 s的ΔV_th小于1 V。最终,利用优化的IGZO TFT制作了215.9 mm（85 in）8K4K 120 Hz液晶显示器。     

一种含氟液晶材料及其掉氟杂质的质谱分析

烷基双环己基三氟苯类液晶是TFT和高档第一极小TN混合液晶中常用的液晶单体,在生产过程中不可避免地会产生掉氟杂质,对这类单体和掉氟杂质的质谱分析有助于生产中对掉氟杂质的控制和液晶单体纯度的提高。通过比较丙基双环己基-3,5-二氟苯和丙基双环己基-3,4-二氟苯的质谱图发现,m/z为127和140的丰度比在两张质谱图上存在明显差别,比较了它们的共振形式,为最终确定掉氟杂质提供了可靠的依据。     

高可靠性Cu BCE a-IGZO TFTs的制作（英文）

背沟道刻蚀型(BCE)非晶氧化铟镓锌薄膜晶体管(a~-IGZO TFT)具有工艺简单、寄生电容小以及开口率高等优点,但BCE IGZO器件背沟道易受酸液和等离子体损伤,进而引起TFT均匀性和稳定性等方面问题,随着GOA技术的导入,对TFT器件电学性能的均匀性和稳定性提升的要求也日益迫切,因此开发高信赖性BCE IGZO TFT是技术和市场的迫切要求。本文主要分析了基于IGZO的背沟道刻蚀型薄膜晶体管电学性质,通过优化钝化层材料,色阻材料以及GOA TFT结构等削弱因背沟道水汽吸附引起的器件劣化,偏压温度应力测试结果显示优化后的TFT展现了良好的稳定性——在80℃,栅极30V负向偏压条件下,2 000s的ΔV_(th)小于1V。最终,利用优化的IGZO TFT制作了215.9mm(85in)8K4K120Hz液晶显示器。     

环境湿度对非晶铟镓锌氧薄膜晶体管负偏压光照稳定性的影响

为了探究环境湿度对非晶铟镓锌氧薄膜晶体管(a-IGZO TFT)的负偏压光照(NBIS)稳定性的影响,本文使用非密闭腔室进行不同波长光照射下以及不同相对湿度下的TFT负偏压测试。介绍了a-IGZO TFT的基本结构以及实验所用I-V测试系统。测试了不同波长光照条件下a-IGZO TFT的转移特性曲线以及相同波长光照射下不同相对湿度的转移特性曲线。实验结果表明:a-IGZO TFT的转移特性曲线随着电压偏置时间的增加而发生负偏;随着光照波长的减小,器件阈值电压负漂越明显。随着相对湿度增加,a-IGZO TFT的NBIS不稳定性逐渐降低,但其电学特性发生了严重的劣化。在相对湿度为50%,光照波长为400nm时,a-IGZO TFT的NBIS电学特性最好,其在负偏压时间为1 500s时的阈值电压偏移为15V。     

液晶微棱镜阵列工艺结构研究

本文对液晶微棱镜阵列的设计与工艺的基本问题进行了讨论。针对TFT的优势,试制了激光晶化底栅结构的poly-SiTFT为构造核心的液晶微棱镜,对其工艺结构和液晶的光学性能进行了探讨。实验表明,尽管TFT液晶微棱镜工艺复杂,但具有一定的优点值得深入研究。     

环己烷苯类单体液晶的检测方法研究

环己烷苯类液晶是TFT液晶、高档第一极小TN和STN类混晶中常用的单体,杂质的存在对混合液晶电阻率、清亮点、低温性能有很大的影响。文章用不同极性的色谱柱对环己烷苯类液晶中的顺反产物进行分离,寻找到最佳的检测柱和最佳检测方法,并结合GC-MS手段对产品顺式定性。     

通过改进TFT-LCD生产工艺提高光透过率降低生产成本和能耗

很多人都把注意力集中在TFT液晶显示器的面板技术上,例如LED背光源、120/240Hz帧频、宽视角以及其它一些能提高显示性能的技术。在这个背景下,通过不断改进TFT液晶显示器的制造工艺,提高了生产效率,降低了成本,同时亦提高了能源利用率。最新的技术进展涉及滤光片、液晶配向、TFT设计等方面。     

通过改进TFT-LCD生产工艺提高光透过率降低生产成本和能耗

很多人都把注意力集中在TFT液晶显示器的面板技术上,例如LED背光源、120/240Hz帧频、宽视角以及其它一些能提高显示性能的技术。在这个背景下,通过不断改进TFT液晶显示器的制造工艺,提高了生产效率,降低了成本,同时亦提高了能源利用率。最新的技术进展涉及滤光片、液晶配向、TFT设计等方面。     

大屏幕TFT液晶显示器栅极/源极显示驱动解决方案

本文首先对TFT液晶显示技术进行了简要的介绍,随后对大屏幕TFT液晶栅极/源极显示驱动技术进行了详细的解析,最后对典型的大屏幕TFT液晶显示系统给出了完整的栅极/源极显示驱动芯片解决方案.     

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.