宽温度范围高精度带隙基准电压源的设计

为了满足市场对宽温度范围、高精度带隙基准电压源的需求,本文设计制作了一种新型带隙基准电压电路。设计采用多点曲率补偿技术,在温度较低时采用指数频率补偿,高温时采用亚阈值指数曲率补偿。采用电压-电流转换器对分段补偿电流在输出端进行整合,进而在-55~150℃的温度范围内进行补偿,得到低温度系数的基准电压。设计的电路采用CSMC 0.5μm CMOS工艺验证,结果表明:5V电源电压下,输出1.25V的基准电压;在-55~150℃的温度范围内温度系数为2.5×10~(-6)/℃,在低频时,PSRR为-66dB。带隙基准电压源芯片面积为0.40mm×0.45mm。     

一种二阶曲率补偿的带隙电压基准

设计一种二阶曲率补偿的带隙电压基准。基于一阶曲率补偿的基准电路,利用二极管正向导通附近电流I与电压V的非线性关系,将补偿电流注入PTAT电流来补偿Vbe的二阶项。运用0.35μm工艺的器件模型Cadence工具下进行了仿真,在-50-＋120℃温度范围内,一阶曲率补偿带隙电压基准的温度系数为16.6 ppm/℃,经过二阶曲率补偿的带隙电压基准的温度系数减小到约为3.07 ppm/℃,带隙电压基准的温度特性得到了很大改善。整个补偿电路使用器件少、占用面积小、实用性强。     

一种用于非致冷红外焦平面读出电路的带隙基准源

设计了一种用于新型非致冷红外焦平面阵列读出电路的低温漂低压带隙基准电路.提出了同时产生带隙基准电压源和基准电流源的技术.通过改进带隙基准电路中的带隙负载结构及基准核心电路,可以分别对基准电压和基准电流进行温度补偿.在0.5μm CMOS N阱工艺条件下,采用Spectre软件进行了模拟验证.仿真结果表明,在3.3 V条...     

一种新型电流模式带隙基准源的设计

提出了一种新型电流模式的带隙基准电压源结构,与传统带隙基准源不同,通过电流模式高阶曲率补偿技术,消除了高阶温度系数对基准电压的影响,得到一个与温度相关性较小的基准电压.电路采用Chartered 0.35μm工艺进行设计,仿真验证结果表明,在-40℃～125℃温度范围内,温度系数为7.25×10-6/℃,基准电压平均值为1.114 V,电源抑制比为-89.28 dB.     

基于新型非制冷IRFPA读出电路的带隙基准源

设计了一种用于新型非制冷IRFPA读出电路的低温漂的低压带隙基准电路.提出了同时产生带隙基准电压源和基准电流源的技术,通过改进带隙基准电路中的带隙负载结构以及基准核心电路,基准电压和基准电流可以分别进行温度补偿.在0.5 μm CMOS N阱工艺条件下,采用spectre进行模拟验证.仿真结果表明,在3.3 V条件下,...     

一种低温度漂移曲率补偿带隙基准源设计

针对传统带隙基准源无法补偿高阶温度项导致温度系数较差的问题,提出了一种高阶曲率补偿电路。电路利用VBE线性补偿原理,使用特定的电路结构产生与双极型晶体管基极-发射极电压开口曲率相反方向的补偿电压,达到降低基准电压高阶温度项的目的。电路基于SMIC 0.18μm MS and BCD工艺进行流片验证,测试结果表明,温度由-40℃变化到125℃时,使用曲率补偿后带隙基准电压的温度系数由14.3ppm/℃降低到了3.18ppm/℃。     

一个1.2 V,9 ppm/℃的CMOS带隙电压基准源

基于传统CMOS带隙电压基准源电路的分析,结合曲率补偿技术设计了一种带衬底驱动运算放大器的低电源电压的电压基准源电路,主体电路采用电流模式基准源结构,并结合所采用的衬底驱动运放作为基准源的负反馈运放。整个电路采用0.5μm标准CMOS工艺实现,在电源电压1.2 V的条件下用HSpice进行仿真,仿真结果表明输出基准电压在-40~120℃范围内温度系数为9 ppm/℃。     

一种具有高电源抑制比的带隙基准电压源

根据带隙基准电压源理论,在传统CMOS带隙电压源电路结构的基础上,采用曲率补偿技术,对一阶温度补偿电路进行高阶补偿,获得了一种结构简单,电源抑制比和温度系数等性能都较好的带隙电压基准源.该电路采用CSMC 0.5 μm标准CMOS工艺实现,用Spectre进行仿真.结果表明,在3.3 V电源电压下,在-30 ℃～125 ℃范围内,温度系数为3.2×10-6 /℃;在27 ℃下,10 Hz时电源抑制比(PSRR)高达118 dB,1 kHz时(PSRR)达到86 dB.     

一种曲率补偿的高精度带隙基准源设计

基于CSMC 0.5μm CMOS工艺,设计了一种带曲率补偿的低温漂带隙基准源。采用折叠式共源共栅放大器反馈结构带隙基准源,利用晶体管的VBE与IC的温度特性产生T1n T补偿量,对传统的带隙基准进行曲率补偿。仿真结果表明,在5 V供电电压下,-40~125℃温度范围内,基准电压的波动范围为1.2715~1.2720 V,温漂为3.0×10~(-6)/℃,低频时电路电源抑制比为-86 d B。     

CMOS带隙基准电压源中的曲率校正方法

基准电压源是集成电路系统中一个非常重要的构成单元。结合近年来的设计经验,首先给出了带隙基准源曲率产生的主要原因,而后介绍了在高性能CMOS带隙基准电压源中所广泛采用的几种曲率校正方法。给出并分析了一些近年来采用曲率校正方法的CMOS带隙基准电压源核心电路以及他们的设计原理、理论推导、参考电路和特点。最后,对于所讨论的基准源电路进行了性能比较和优缺点分析。     

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.     

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.