嵌入式微纳光纤环形腔的海水盐度传感研究

通过将Loop型谐振腔嵌入在具有正热光系数的MgF2中,设计了海水中温度弱敏感的盐度传感器来实现海水盐度测量。利用COMSOL软件建立海水盐度传感模型,结合Matlab对盐度传感器的特征参量进行数值研究。结果表明:传感器的温度特性依赖于微纳光纤的半径,温度弱敏感的光纤半径随探测波长的减小而减小;盐度灵敏度随镀膜厚度和光纤半径的增大而减小;探测极限随镀膜厚度的增加而增大,随波长的减小而减小。通过优化,传感器盐度灵敏度可达0.025 nm/(mg/mL),探测极限可达到0.15 mg/mL。     

一种交叉式圆形MEMS热电堆红外探测器

微电子机械系统(MEMS)热电堆红外探测器是非接触测温仪、光谱仪、气体传感器等现代信息探测系统的核心工作器件。研制了一种交叉式排布的圆形热电堆结构,其热偶条形状由传统矩形调整为直角梯形以降低探测器电阻,热端通过交叉式排布延伸至中心温度集中区,同时增大冷端欧姆接触面积并覆盖反射层以降低冷端温度,有效地增大了冷热端温度梯度。测试结果显示,优化后的交叉式圆形MEMS热电堆探测器距黑体辐射面3 cm处响应电压为22.673 mV,响应率为47.5 V/W,探测率为■,相对于传统圆形热电堆探测器的18.649 mV、39.1 V/W和■分别提升了21.57%、21.48%和18.5%。给出了热电堆探测器结构设计、仿真结果、制作工艺以及测试结果,为热电堆红外探测器的优化设计提供了参考。     

热电式微波功率传感器的优化设计

提出了一种热电式微波功率传感器的二维热分布解析模型,通过分析传感器的各种结构参数对热分布的影响,给出了热电式微波功率传感器的优化设计.为了获得高灵敏度,给出了设计膜的厚度、匹配电阻与热电堆热端的距离、热电堆悬浮部分的长度等结构参数的原则,并利用Ansys模拟结果和解析结果进行对比验证,结果显示两者吻合较好,说明了解析模型的适用性,可在设计该类传感器时参考.     

热电式微波功率传感器的优化设计

提出了一种热电式微波功率传感器的二维热分布解析模型,通过分析传感器的各种结构参数对热分布的影响,给出了热电式微波功率传感器的优化设计.为了获得高灵敏度,给出了设计膜的厚度、匹配电阻与热电堆热端的距离、热电堆悬浮部分的长度等结构参数的原则,并利用Ansys模拟结果和解析结果进行对比验证,结果显示两者吻合较好,说明了解析模型的适用性,可在设计该类传感器时参考.     

光纤研磨纸粒度对侧边研磨塑料光纤传感器灵敏度的影响

为了提高侧边研磨型(D形)塑料光纤倏逝波传感器的灵敏度,采用不同粒度的光纤研磨纸对塑料裸光纤进行侧边研磨,制备了不同直径及不同表面粗糙度的D形塑料光纤倏逝波传感器。实验观测了D区表面形貌、D区直径与表面粗粗度对传感器光传输性能及灵敏度的影响。实验研究发现:D形敏感区域直径及表面粗糙度对传感器光传输及灵敏度影响显著;传感器灵敏度随着D区直径的减小先增大后减小,当D区直径为1200μm时,传感器对葡萄糖溶液的响应灵敏度达到最大值:-0.0032(mg/L)-1;当采用粒度为9μm的光纤研磨纸对光纤进行研磨时,传感器的灵敏度将进一步提升至-0.0045(mg/L)-1,是未经研磨塑料光纤传感器灵敏度的11.25倍。     

近红外空间碎片激光测距探测成功概率影响因素的研究

基于激光雷达方程和天空背景噪声估算公式推导出近红外空间碎片激光测距探测成功概率的计算公式,仿真研究了该公式中大气透过率和天空背景噪声的影响因素,经数据拟合,得到空间碎片激光测距探测成功概率的归一化表达式。在此基础上,仿真分析了太阳高度角、目标天顶角、目标轨道距离和目标横截面积对目标探测成功概率的影响。结果表明：目标探测成功概率随太阳高度角升高而减小,随目标轨道距离的增加而减小,随目标天顶角的增大而减小,当目标天顶角增加到70°时,目标探测成功概率开始急剧下降;目标轨道距离固定的情况下,目标探测成功概率随目标横截面积的增大而增大。该研究对提高空间碎片的观测效率具有一定的应用价值。     

PbTiO3系热电薄膜的高性能红外传感器

1. 前言热电型红外传感器因其灵敏度与波长无关,并具有在室温下可工作的特性,广泛应用于自动装置,环境监视,温度控制,防灾防盗等领域。特别是在长波波段,灵敏度也很高,可作室温附近物体的热探测用。通常,用作红外传感器的热电材料,其性能指数以F_v=γ/cv·ε_r和F_m=γ/cv√ε_r ttanδ表征。F_v为表征电压灵敏度R_v 的性能参数、F_m 为表征噪声的性能参数,主要为tanδ噪声时的探测率D~*,γ是热电系数,c_v 是体积比热,ε_r 是介电常数,t 是材料厚度。因而要求γ大,c_v,ε_r,tanδ小。另外,就D~*而言薄的材料是有利的。作为热电     

硅基红外热堆中热电偶尺寸和对数对探测性能的影响

分析了多晶硅-金集成热堆中热电偶的尺寸和对数对热堆性能的影响,对非接触红外测温的实用型热堆提出了设计和改进的思路.随着热电偶对数的增加,时间常数减小,响应率增大,探测率出现最大值.减小热电偶的长度可以减小热堆内阻和时间常数.多晶硅横截面积和金横截面积的比值接近最佳比值时,探测率呈最大值3×10scm@Hz1/2@W-1.     

基于表面等离子体共振的椭圆侧芯光子晶体光纤传感器研究

设计出一种高灵敏度的新型椭圆侧芯光子晶体光纤传感器模型。圆形孔和3种不同大小椭圆孔构成该椭圆侧芯光子晶体光纤空气孔，其中椭圆孔的椭圆率分别为e、e1、e2，在椭圆率为e的左侧椭圆孔内涂敷金纳米薄膜。通过有限元分析软件COMSOL对传感器的传感特性进行数值分析。研究发现：表面等离子体共振的共振峰对待测液体折射率的变化有很高的传感灵敏度；光子晶体光纤传感器的灵敏度会随着椭圆率e、e1以及金纳米薄膜的厚度而变化。折射率在1.40～1.42范围内，传感器灵敏度随着e1的增大而增大；折射率在1.42～1.43范围内，传感器灵敏度随着e1的增大先减小再增大。当椭圆率e1=1.2、折射率为1.43时，灵敏度高达31800 nm/RIU（折射率单元）。折射率在1.38～1.43范围内，传感器灵敏度随着椭圆率e的增大而增大，当椭圆率e=2.3时，灵敏度高达33200 nm/RIU。折射率在1.42～1.43范围内，传感器灵敏度随着金纳米薄膜厚度的增大而减小，在折射率为1.43、金纳米薄膜厚度为40 nm时，传感器灵敏度高达34600 nm/RIU。     

硅基红外热堆中热电偶尺寸和对数对探测性能的影响

分析了多晶硅 -金集成热堆中热电偶的尺寸和对数对热堆性能的影响 ,对非接触红外测温的实用型热堆提出了设计和改进的思路 .随着热电偶对数的增加 ,时间常数减小 ,响应率增大 ,探测率出现最大值 .减小热电偶的长度可以减小热堆内阻和时间常数 .多晶硅横截面积和金横截面积的比值接近最佳比值时 ,探测率呈最大值 3× 10 8cm· Hz1 / 2· W- 1 .     

Effects of alumina substrate surface defects on thin-film interconnect patterns

An investigation was made into the occurrence of substrate surface defects, such as surface pits, low-density regions and burrs, and their effect on fine-line thin-film conductor patterns fabricated on the substrate. Substrate surface quality was characterized through examination of fine-line thin-film test patterns (50-µm lines on 100-µm centers). The results of these observations are summarized in terms of N^-, the substrate surface defect density, and f, the frequency of resultant conductor-line imperfections greater in width than some critical size δ. The parameter f is directly related to the expected yield Y for a thin-film interconnect circuit with fine-line conductor length L. A quantitative model is developed which accurately relates N and f to N^-(x), the size distribution of surface voids; δ, the critical extent of defect overlap on a conductor line; and D, the width of the conductor line. Application of the model to prediction of the dependence of f and Y on various parameters led to the conclusion that it is important to establish objective criteria as to what constitutes a conductor-line imperfection. A change in definition from the extent to which a conductor line appeared to be open to the overlap of a substrate defect on a conductor line resulted in a tenfold increase in f. This change would result in a fourfold decrease in Y for the case of an interconnect pattern with 500 cm of 50-µm lines. A change in δ from D/3 to 2D/3 resulted in a sixfold decrease in f and a corresponding increase in yield from 20 to 80 percent for the same interconnect circuit.     

基于尺寸效应的Cu/CuNi薄膜热电偶灵敏度研究

采用磁控溅射法在镀有SiO2阻挡层的基底上制备了一系列的Cu/CuNi薄膜热电偶,其厚度分别为0.5,1.0,1.5和2.0 μm,测得四种Cu/CuNi薄膜热电偶的灵敏度,分别为46.47,45.23,44.32和43.98 μV/℃,通过实验和理论研究了薄膜热电偶灵敏度S与厚度δ之间的关系.结果表明:Cu/CuNi...     

Spectroscopic detection of gastrointestinal dysplasia using optical microsensors

The detection of dysplasia in the gastrointestinal tract can be performed using optical microsensors based on thin-film optical filters and silicon photodiodes. This paper describes two optical microsensors that can be used for spectroscopy data collection in two different spectral bands (one in the violet/blue region and the other in the green region) for which two optical filters were designed and fabricated. An empirical analysis of gastrointestinal spectroscopic data using these specific spectral bands is performed. The obtained results show that it is possible to accurately differentiate dysplastic lesions from normal tissue, with a sensitivity and specificity of 77.8% and 97.6%, respectively. Therefore, the developed filters can be used as a tool to aid in diagnosis. The small size of the optical microsensors can enable, in the future, integration in endoscopic capsules.     

金电极薄膜微应力对InSb芯片性能的影响研究

基于锑化铟(InSb)红外探测器的大批量生产,发现电极薄膜微应力会引起 器件性能劣化。通过实验设计验证了金电极薄膜微应力对InSb芯片探测率、灵敏度和可靠性的 影响。研究了电极薄膜微应力的可恢复性及其作用机理,并提出了控制和优化电极微应力的途径,为 从工艺结构上提高红外探测器的性能和可靠性奠定了理论参考和实验基础。     

遥感用硅PIN二极管

本工作研制适合于在0.5～1.1μm和0.55～0.75μm波段内工作的硅PIN光电二极管。叙述了器件的设计考虑和制造,分别采用双面扩散和高阻外延片单面扩散两种方法制造该器件,达到了预期的要求。文中给出了器件的光谱响应、暗电流、探测率,响应速度及响应均匀性等结果,并进行了讨论。研制出的器件性能良好,探测率D*为7×10~(12)cmHz~(1/2)/w左右。     

接触效应对小型半导体温差发电器性能的影响

针对小型半导体温差(TEG)发电器中接触热阻和接触电阻的影响进行了分析研究.结果表明,接触热阻和接触电阻只在2mm以内的电偶臂长度内有明显影响;在电偶臂长度小于1mm时,输出功率和热电效率均有一个急剧上升的变化阶段;当长度超过5mm后,输出功率和热电效率均趋于定值;在冷热端温度分别为283和383K,Z=0.0024K-1、电偶臂长为2mm、接触热阻比0.2和接触电阻比0.1条件下,热电功率约为4mW/mm2,热电效率约为3.5%,而理想无接触热阻和电阻的热电效率约为4.2%.由此可知,半导体温差发电器中接触热阻和接触电阻的影响不可忽视.     

Short-channel metal-gate TFTs with modified Schottky-barrier source/drain

A thin active layer, a fully silicided source/drain (S/D), a modified Schottky-barrier, a high dielectric constant (high-/spl kappa/) gate dielectric, and a metal gate are integrated to realize high-performance thin-film transistors (TFTs). Devices with 0.1-/spl mu/m gate length were fabricated successfully. Low threshold voltage, low subthreshold swing, high transconductance, low S/D resistance, high on/off current ratio, and negligible threshold voltage rolloff are demonstrated. It is thus suggested for the first time that the short-channel modified Schottky-barrier TFT is a solution to carrier out three-dimension integrated circuits and system-on-panel.     

Limitations on the Size of Miniature Electric-Field Probes

The miniature dipole probe is a useful tool for measuring the electric field at high radio and microwave frequencies. A common design for the probe consists of an electically-short antenna with a diode across its terminaIy a resistive, parallel-wire transmission line transmits the detected signal from the diode to the monitoring instrumentation. Small dipoles are desirable because they provide high spatial resolution of the field, and because they permit a frequency-independent response at higher microwave frequencies. Recent efforts have produced probes with dipole half lengths h less than one millimeter. With the advances occuring in microelectronics and thin-film technology, the construction of even smaller probes may be possible. In this paper, the limitations imposed on the sensitivity of the probe by a reduction in its physical size are determined. A model that contains noise sources for the diode and the resistive transmission Iife is used to obtain the signal-to-noise ratio for the probe, and this is examined as a function of the parameters that describe the dipole, diode, resistive transmission line, and amplifier. When the physical dimensions of the probe are reduced by the scale factor k/sub l/ (k/sub l/ < 1), the signal-to-noise ratio is found to decrease by approximately the factor k/sup 4//sub l/, and the minimum-detectable incident electric field for a fixed signal-to-noise ratio is found to increase by approximately the factor k/sub l//sup -2/. A numerical estimate is made for the sensitivity of miniature probes with dipole half lengths in the range 10 µm <= h <= 1 cm.     

Improved p- and n-type thin-film microstructures for thermoelectricity

Improved microstructures based on thin-films of n-type bismuth telluride (Bi_{2Te3) and p-type antimony telluride (Sb2Te3) to convert temperature differences in electricity are presented. The microstructures are obtained by thin-film deposition, applying the co-evaporation method to the bismuth/antimony and telluride materials. Measurements demonstrated the superior thermoelectric features of the obtained films when compared with the most recent thermoelectric thin-film deposition. Measurements show that the deposited films present thermoelectric properties comparable to those reported for the same materials in bulk form, as is the case of the materials used in conventional macro-scale Peltier modules. The absolute values of the Seebeck coefficient are in the range 150?250 μVK^-1 and the in-plane electrical resistivity is in the 7-15 μΩm range. Measurements for the Bi2Te3 and Sb2Te3 films also show figures of merit at room temperatures of 0.84 and 0.5, and power factors of 4.87 and 2.81 mWK^-2 m^-1, respectively. These microstructures are used for the fabrication of thermoelectric microgenerators to supply stand-alone microsystems with power consumption that ranges from cents of μW to a few mW.}     

Source/drain contact resistance of silicided thin-film SOI MOSFET's

We developed a source/drain contact (S/D) resistance model for silicided thin-film SOI MOSFET's, and analyzed its dependence on device parameters considering the variation in the thickness of the silicide and residual SOI layers due to silicidation. The S/D resistance is insensitive to the silicide thickness over a wide range of thicknesses; however, it increases significantly when the silicide thickness is less than one hundredth of initial SOI thickness, and when almost all the SOI layer is silicided. To obtain a low S/D resistance, the specific contact resistance must be reduced, that is, the doping concentration at the silicide-SOI interface must be more than 10²⁰ cm^-3