测试环境对亚毫开红外探测器测试结果的影响研究

红外探测器是红外系统的核心器件。近年来,高灵敏度、低噪声成为红外探测器技术的研究热点之一。对于噪声等效温差(Noise Equivalent Temperature Difference, NETD)值小于1 mK的低噪声红外探测器,环境因素对其性能的影响不可忽视。从黑体控温精度、测试环境温度、测试环境中的气流扰动等方面,分析了测试环境对亚毫开红外探测器测试结果的影响,并对低噪声红外探测器的测试方法进行了探究。实验结果表明,黑体控温精度对高灵敏度红外探测器的NETD值有直接影响,测试环境温度与气流扰动会影响黑体控温稳定性,从而间接影响NETD测量的准确度。     

二极管型红外焦平面阵列的噪声分析及结构优化设计

二极管非制冷红外焦平面阵列(IRFPA)探测器具有广阔的前景,然而它的性能受噪声源的制约,为了得到高性能的探测器,必须研究噪声源并减小其影响。概述了探测器噪声源,量化并研究了不同噪声对探测器的影响,最后得到了二极管IRFPA的性能极限,此外,计算得到了最优的结构参数。理论研究表明温度起伏噪声对应的最小噪声等效温差(NETD)为2.36K,此时探测器热导为辐射热导,其值为2.06nW/K。当单元尺寸为25μm×25μm的探测器的正向偏置电流为33μA,占空比为54%时可得到最优NETD为46.5mK。     

热成像系统的噪声

要评估热成像系统的性能、噪声模型是很重要的，噪声的存在使得探测器的分辨能力下降，并限制了系统的动态性能，热成像系统通常通过限制背景噪声获得最佳灵敏度，此时主要的噪声源与光子到达的随意性有关，在没有其它噪声源的情况下，探测器输出振幅也有白噪声也有白噪声，可通过采样，过滤数字化等手段消除。阐述了几种噪声源以及这些噪声源与背景噪声的共同作用，同时分析了这些噪声对噪声等效温差（NETD）和最小可分辨温差（MRTD）的影响。     

红外探测器用偏置电压源的设计及其低频噪声测量

红外成像系统利用光学系统和红外探测器接收目标物体的红外辐射,并将红外辐射分布图以人眼可观测的方式显示出来。成像处理电路功能包括为探测器提供电源、偏置电压和驱动信号使探测器能够正常工作。偏置电压源的噪声将给探测器的输出引入噪声,增大系统的NETD,降低系统性能。在设计低噪声偏置电压源的基础上,采用经典噪声测量电路对偏置电压源的噪声进行了测量。为测量偏压源的低频噪声,噪声测量电路分为前置放大电路和0.1~10 Hz滤波电路。对红外探测器用偏置电压源各级电压进行噪声测量后,得出了噪声值最小的红外探测器用偏置电压源的设计方案。     

二极管型红外焦平面阵列的噪声分析及结构优化设计（英文）

二极管非制冷红外焦平面阵列(IRFPA)探测器具有广阔的前景,然而它的性能受噪声源的制约,为了得到高性能的探测器,必须研究噪声源并减小其影响.概述了探测器噪声源,量化并研究了不同噪声对探测器的影响,最后得到了二极管IRFPA的性能极限,此外,计算得到了最优的结构参数.理论研究表明温度起伏噪声对应的最小噪声等效温差(NETD)为2.36mK,此时探测器热导为辐射热导,其值为2.06 nW/K.当单元尺寸为25μm×25μm的探测器的正向偏置电流为33μA,占空比为54%时可得到最优NETD为46.5 mK.     

甚高灵敏度红外探测器读出电路实现方法研究

随着红外焦平面技术的不断发展,红外焦平面探测器应用领域越来越广泛,这对红外焦平面探测器灵敏度提出更高的要求。本文首先分析了传统TDI型读出电路的降噪原理,通过仿真、测试及理论分析论述了传统TDI型读出电路提高红外探测器灵敏度的局限性,并计算出传统TDI型红外探测器所能实现的最优NETD值为4.19 mK。随后分析了像素级数字化TDI型读出电路的噪声来源及如何降低各类噪声,通过仿真结果结合理论计算得出像素级数字化TDI型红外探测器在应用32级TDI时NETD可达到亚毫K级,能够实现甚高灵敏度红外探测器的需求。     

低温背景下红外焦平面阵列的噪声分析

对红外探测器在低温背景下的噪声模型及特性进行了分析与实验研究。利用探测器噪声四参数法计算模型与方法;搭建实验平台对红外探测器在不同低温背景温度下的性能进行测试,得到红外探测器的低频时间噪声,高频时间噪声,低频空间噪声各自与温度、积分时间的关系。实验表明:在一定温度区间内,低频时间噪声表现出较强的温度相关性,低频空间噪声表现出较明显非线性响应特性,高频空间噪声表现出积分时间相关性。     

红外热像仪时间噪声测量技术研究

在对红外热像仪的测量中,噪声是评价红外热像仪性能的主要参数。噪声参数包括时间域噪声和空间域噪声,时间域噪声可分为高频时间噪声和低频时间噪声(即1/f噪声);空间域噪声可分为高频空间噪声(即固定模式噪声FPN)和低频空间噪声(非均匀性噪声)。对高频时间噪声和低频时间噪声进行了严格的区分和定义;给出了在短时间内忽略低频时间噪声时高频噪声NETD的计算模型;在不忽略低频时间噪声时计算高频噪声等效温差的数学计算模型和测量方法;对高频时间域NETD测量结果进行了不确定度分析与评价。     

利用NETD和探测器测试数据计算红外成像系统的噪声等效带宽

因为涉及参数较多,红外成像系统的噪声等效带宽有时不易计算或确定.△fn与噪声等效温差(NETD)有关.利用NETD的理论公式以及探测器的测试结果,例如相对光谱响应、黑体探测率等,可以导出一个新的△fn表达式,其中的光谱积分项容易利用MATLAB提供的样条函数命令做数值积分求解.该表达式可用作噪声等效带宽△fn的一种间接测试方法.     

非制冷微测辐射热计探测器工作温度特性研究

根据非制冷红外热成像技术的基本原理,通过对α-Si微测辐射热计探测器响应性能及功耗特性的分析,得到了探测器噪声等效温差NETD、探测率及功耗与工作温度之间的关系.提出了在环境温度变化范围较大的情况下改善探测器低温环境工作性能的方法——采用多个工作温度点.并对探测器采用0℃和30℃双工作温度点工作进行了实验,实验结果表明,该方法切实有效,可以显著扩展非制冷微侧辐射热计探测器的环境温度适用范围.     

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.