红外探测器背景抑制读出结构设计研究

长波红外焦平面探测器一般工作在高背景下，信号电流小于背景电流，器件本身暗电流也较大，信号读出时积分电容极易饱和，这都不利于获得理想的信噪比。通过在读出电路输入级中增加电流抑制结构，可有效提高积分时间，改善动态范围和对比度。本文介绍了红外焦平面读出电路中几种典型的背景电流及暗电流抑制技术，依次叙述不同结构背景及暗电流抑制的实现原理，并比较各个结构的优缺点，针对不同电路结构的特点，通过典型电路仿真分析，确定了它们在各种红外焦平面读出电路输入级中的应用范围。     

红外探测器背景抑制读出结构设计研究

长波红外焦平面探测器一般工作在高背景下,信号电流小于背景电流,器件本身暗电流也较大,信号读出时积分电容极易饱和,这都不利于获得理想的信噪比.通过在读出电路输入级中增加电流抑制结构,可有效提高积分时间,改善动态范围和对比度.本文介绍了红外焦平面读出电路中几种典型的背景电流及暗电流抑制技术,依次叙述不同结构背景及暗电流抑制的实现原理,并比较各个结构的优缺点,针对不同电路结构的特点,通过典型电路仿真分析,确定了它们在各种红外焦平面读出电路输入级中的应用范围.     

基于门控多周期积分的背景抑制读出电路

在空间遥感领域,波长在3?m～5?m的中红外焦平面探测器大都工作在高背景环境下,信号电流远小于背景电流。为解决当前信号淹没于背景这一突出问题,设计了一种采用门控多周期积分结构实现的背景抑制功能的读出电路。该电路在抑制背景电流(包括暗电流)的同时能有效降低噪声,提高有效积分时间,增大输出信号动态范围。经Spectre仿真软件验证了电路设计的正确性。背景电流输入范围为0 nA～110 nA,能够有效读出2.5 nA～25 nA之间的信号电流,电路输出摆幅大于2 V。该电路的设计不仅能解决当前工程中的关键问题,还对今后高性能大面阵红外焦平面高背景弱信号探测具有重要的指导意义。     

具有背景抑制功能的长波红外读出电路

为了提高红外焦平面检测目标的灵敏度，目标辐射产生的载流子应尽可能长时间保持，同时应尽可能减少热激发和背景辐射激发的比例。高背景条件下长波红外读出电路的积分电容较快饱和，且长波红外探测器暗电流的非均匀性会影响焦平面的固定图形噪声。基于共模背景抑制结构以及长波碲镉汞探测器暗电流分析的基础上，设计了具有非均匀性矫正的背景抑制电路。传统的背景抑制电路采用单一共模背景抑制或差模背景抑制。差模背景抑制模块的高精度背景记忆一般在小范围区间内。本文背景抑制结构采用共模背景抑制与差模背景抑制相结合，可以在较大的背景噪声范围内有效地降低固定图形噪声以及增大动态范围。该背景抑制结构中共模背景抑制采用电压-电流转换法，差模背景抑制采用电流存储型背景抑制结构。差模背景抑制通过背景记忆时信号放大，背景抑制时信号缩小来提高背景抑制精度。电路采用标准CMOS工艺流片。测试结果表明:读出电路的FPN值为2.08 mV。未开启背景抑制时，焦平面FPN值为48.25 mV。开启背景抑制后，焦平面FPN值降至5.8 mV。基于探测器的暗电流非均匀分布，计算其理论FPN值为40.9 mV。长波红外焦平面输出信号的RMS噪声在0.6 mV左右。     

背景暗电流抑制的红外探测器读出电路输入级设计

主要研究红外探测器读出电路的输入级设计,针对短波红外信号,电容反馈互导放大器型(CTIA)读出电路具有高注入效率的特点。本文设计了一种带有背景暗电流抑制的CTIA型读出电路输入级结构,该结构在77 K低温环境,大于300μs的长积分时间工作。探测器接收短波小信号,注入电流0~800 pA,与传统的CTIA型读出电路输入级相比,有效实现对背景暗电流的抑制作用,提供探测器偏压的稳定度提高93.2%,同时,积分线性度达到99.97%,具有良好的积分均匀性、灵敏度和动态范围。     

BDI 型甚长波IRFPA 读出电路研究与设计

针对甚长波红外（VLWIR）探测器动态结阻抗过低、暗电流较大,且工作在高背景环境下等特点,设计了一种具有记忆功能背景抑制的3232甚长波红外焦平面（IRFPA）读出电路。该电路采用基于高增益负反馈运放的缓冲直接注入级（BDI）结构作为输入级,大幅降低了输入阻抗,提高了注入效率,并使探测器处于稳定偏压状态。同时,该电路采用具有记忆功能的背景抑制电路,有效提高了积分时间和红外焦平面的信噪比（SNR）,改善了动态范围和对比度。基于HHNECCZ6H0.35m1P4M标准CMOS工艺,完成了电路的流片制造。实测结果表明:50K低温下电路功能正常,输出范围大于2V,读出速率达到2.5MHz,RMS噪声小于0.3mV,线性度优于99%,功耗小于100mW。     

大周长面积比延伸波长InGaAs红外焦平面噪声

在理论上分析了红外焦平面组件中光敏元、读出电路以及两者耦合的总噪声特性,对大周长面积比(38×500μm2)延伸波长InGaAs组件的噪声与温度、积分时间的关系进行了实验和分析.实验结果指出,在一定条件下组件噪声与积分时间的根号并不成正比.测量了不同温度下的组件暗信号、噪声,得到组件噪声与暗电流的关系,分析表明,该种组件噪声主要来自于1/f噪声及读出电路输入级电流噪声.     

320×256大电荷容量的长波红外读出电路结构设计

长波红外探测器存在暗电流大、背景高的特点,需要设计大电荷容量的读出电路。采用分时共享积分电容的电路结构,在面阵焦平面的有限单元面积中设计了一种高读出效率、大电荷容量的320256长波红外焦平面读出电路。电路输入级采用电容反馈跨阻放大器（CTIA）结构,具有注入效率高、噪声低、线性度好的特点。基于CSMC 0.35 m标准CMOS工艺模型进行了模拟仿真以及版图设计完成后的后端仿真,电路输出电压范围大于2 V,非线性小于1%,帧频为100 f/s,采用分时共享积分电容电路结构后,像元有效电荷容量达到57.5 Me-/像元。     

基于分时共享方案的640×512红外读出电路设计

大规模、高集成度的红外焦平面器件是实现高空间分辨率红外成像的核心。针对高集成度的红外焦平面技术发展,文中设计了一款15 m中心距640512的红外焦平面读出电路。为提升器件信噪比和积分时间,提出了一种22四个像元分时复用积分电容共享技术方案,单元采用直接注入（DI）结构作为输入级,使得读出电路最大电荷容量可达20 Me-/像元。电路有两档电荷容量可选,可满足不同光电流信号的读出要求。为了减小噪声的注入及提高缓冲器偏置电流的精度,为信号传输链路设计了相应的偏置电路。电路仿真结果表明,电路帧频108 Hz,功耗低于110 mW,线性度可高达99.99%。电路采用了CSMC 0.18 m 1P4M 3.3 V工艺加工流片,常温测试结果显示电路工作电流正常,偏置开关可控,功能正常。     

基于电流镜的同步积分模式双色读出结构设计

文章对N^＋ PPN结构的MW／LW双色红外焦平面信号电流同步积分的工作模式，提出了一种双色读出电路输入级的新结构，即在栅调制注入输入级的基础上加以设计改进，采用电流镜对一个独立波段（LW）的信号电流进行两路精确复制，分别用于此波段的信号电流积分、与混合波段信号电流的相减，解决了探测器输出端混合波段信号电流的分离问题，达到了两个波段信号电流同步独立积分的目的。本文就双色电路的输入级结构和工作原理进行了详细的阐述，电路模拟验证的结果表明该电路适用于信号电流大于10nA的双色器件（MW／LW，MW1／MW2，LW1／LW2双色器件），有较高的精确度（误差〈2％）和良好的性能。     

Technology innovation and process integrations for sub-100nm gate patterning

This paper presents a brief overview of the Applied Centura(R)DPS(R)system,configured with silicon etch DPS Ⅱ chamber, with emphasis on discussing tuning capability for CD uniformity control. It also presents the studies of etch process chemistry and film integration impact for an overall successful gate patterning development. Discussions will focus on resolutions to key issues, such as CD uniformity, line-edge roughness, and multilayer film etching integration.     

White organic light-emitting devices based on fac tris（2- phenylpyridine） iridium sensitized 5,6,11,12-tetraphenylnap -hthacene

We have fabricated the white organic light-emitting devices （WOLEDs） based on 4,4＇ -bis（2,2 -diphenyl vinyl）-1,1＇ - biphenyl （DPVBi） and phosphorescence sensitized 5,6,11,12,-tetraphenylnaphthacene （rubrene）. The device structure is ITO/2T-NATA （20 nm）/NPBX （20 nm）/CBP： x%Ir（ppy）3：0.5% rubrene （8 nm）/NPBX （5 nm）/DPVBi （30 nm）/Alq（30 nm）/LiF（0.5 nm）/A1. In the devices, DPVBi acts as a blue light-emitting layer, the rubrene is sensitized by a phosphorescent material, fac tris （2-phenylpyridine） iridium [Ir（ppy）3], acts as a yellow light-emitting layer, and N,N＇ -bis- （1-naphthyl）- N,N＇ -diphenyl -1, 1＇ -biphenyl-4,4＇ -diamine （NPBX） acts as a hole transporting and exciton blocker layer, respectively. When the concentration of Ir （PPY）3 is 6wt%, the maximum luminance is 24960 cd/m^2 at an applied voltage of 15 V, and the maximum luminous efficiency is 5.17 cd/A at an applied voltage of 8 V.     

Complete approach to automatic identification and subpixel center location for ellipse feature

To meet the need of automatic image features extraction with high precision in visual inspection, a complete approach to automatic identification and sub-pixel center location for similar-ellipse feature is proposed. In the method, the feature area is identified automatically based on the edge attribute, and the sub-pixel center location is accomplished with the leastsquare algorithm. It shows that the method is valid, practical, and has high precision by experiment. Meanwhile this method can meet the need of instrumentation of visual inspection because of easy realization and without man-machine interaction.     

小角度扩展相关性近似算法分析

本论文提出一种在多天线MIMO信道相关性建模中小角度扩展近似理论算法,并应用于分析MIMO系统性能。分析中分别对三种不同角能量分布情况下的空间相关性研发快速近似计算法,并同时提出双模(Bi-Modal)角能量分布情况下的近似运算。通过分析这些新方法的近似效率,可以得到计算简单、复杂度低、而且符合实际的MIMO相关信道矩阵,对系统级的快速高效计算法的研究和系统级的评估以及误差分析具有重要的意义。     

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.     

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.     

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.     

A Versatile Mixed-Signal Pin Approach for Cost-Effective Test of Automotive ICs

Integrated circuits (ICs) intended for increasingly sophisticated automotive applications bring unique test demands. Advanced ICs for applications such as highly integrated automatic braking system (ABS) and airbag controllers combine high voltage digital channels, significant VI demands and precise timing capability. Along with continued missioncritical reliability concerns, the trend toward higher voltage operation and increased device integration requires specialized test capabilities able to extend across the wide operating ranges found in automotive applications. Among these capabilities, automotive test requirements increasingly dictate a need for a cost-effective versatile mixed-signal pin electronics with very high data rates reaching up to 50MHz with a voltage swing of-2 V to +28 V.     

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.     

Optical vibration and deviation measurement of rotating machine parts

It is of interest to get appropriate information about the dynamic behaviour of rotating machinery parts in service. This paper presents an approach of optical vibration and deviation measurement of such parts. Essential of this method is an image derotator combined with a high speed camera or a laser doppler vibrometer （LDV）.