慢波结构色散测量中的探针引入误差分析

提出了一种微波器件色散测量中探针引入误差分析方法。该方法将探针对器件微扰的各种参数分离,便于对复杂结构进行分析,可以直接带人相关参数计算。提出分解微扰引人的误差省略其中的极小值,简化了计算。在此基础上,分析了不同探针对电磁带隙波导色散测量的误差,给出了探针器件位于不同位置以及不同探针半径所引入的误差相对值。计算结果表明,探针半径变化对测量误差的影响远大于探针位置变化对测量误差的影响。     

扫描探针制备技术的研究现状及发展

探讨了近几年来探针制备技术的发展和趋势,分别就探针检测性能的改进、探针结构、探针检测功能拓展及多通道信息采集组合探针等几方面,对相关制备技术的方法、特点以及相应检测条件、适用环境展开讨论,这些方面反映探针制备技术正朝着尖锐化、多样化、功能化和组合方向发展。     

扫描隧道显微镜图像重建的研究

在扫描隧道显微镜轮廓测量过程中,探针自身的几何形状会混入测量结果中,从而造成相应的测量误差。本文提出了根据对标准样品的测量结果,反算出探针的几何形状的算法,并应用于实没图像示解出探针的几何形状。在求得探针的几何形状后,文中推导了去除探针几何形状造成的误差,对扫描隧道显微镜图像进行重建的算法,并对实测样品进行了处理。结果表明上术坷有效地减少小探针自形状造成的测量误差。     

波导的探针激励研究

本文主要用等效电路法推导了单探针激励矩形波导和圆波导时，探针输入阻抗的表达式。同时，利用反应的概念，探讨了双探针激励波导时，探针间的互阻抗问题，以及在进行多探针激励同一波导时，输入阻抗对功率合成的影响。     

接触式轮廓仪探针状态检查图形样块的研制

针对接触式轮廓仪存在的探针沾污、探针缺陷、扫描位置不准的问题,采用半导体工艺技术在硅晶圆片上制备出探针状态检查样块。该样块具有探针沾污及缺陷检查图形和探针扫描位置检查图形,可实现探针针尖10个位置沾污和缺陷的检查以及偏移量为-150～150μm内探针扫描位置的检查。使用探针状态检查样块对一台型号为P-6的接触式轮廓仪进行了检查,实验结果表明:该样块能够准确判断出轮廓仪存在探针缺陷和扫描位置不准的问题,进而有助于接触式轮廓仪探针的故障检查和维修。     

全光纤型侧向OCT探针的设计与鲁棒性分析

全光纤型侧向光学相干层析(OCT)探针由于兼具尺寸小和三维全周成像的优点,近年来受到了学术、工业界的广泛关注。文章通过对全光纤型侧向OCT探针的聚焦性能进行数值仿真,优化了探针的结构参数。基于优化的探针结构,针对反射器与GRIN光纤间随机横向位移引发的光功率衰落,进一步数值分析了探针套管尺寸及反射器位置对于探针鲁棒性的影响。     

利用图像中的探针信息获取探针形貌的方法

扫描探针显微技术已在纳米甚至原子级的形貌获取中得到了广泛地应用。其分辨本领在很大程度上依赖于探针的形貌尺寸。传统的检测探针的方法大多对针尖的损伤很大或需要复杂的仪器,这就使这些方法带有一定局限性。本文提出利用扫描图像中反映的探针信息数值求解探针形貌的方法,利用探针扫描不同样品所得到的扫描图像还原探针的形貌,结果显示用此算法能够还原出原针尖的形貌。为了更好地与实际结果对比,用原子力显微镜扫描图像来验证此方法的正确性,结果显示反构造的探针形貌结果与MI公司所提供的探针尺寸吻合很好。     

射频／微波波段的测试探针

薄膜探针九十年代前,半导体芯片、圆片等未封装器件的直接测试,都是通过机械探针作触点来进行的。随着频率的增加,探针的尺寸也越来越小巧。虽然输入输出都用同轴线传输并且端接有匹配阻抗,但机械探针的杂散电感(nH)和杂散电容(pF),对1GHz以上的频率测试必然带来显著失真,机械探针的尖端对芯片上的触点有     

SPM探针制造技术的研究和发展

探针是扫描探针显微镜的核心部分,结构及针尖的表面状态会影响此类仪器的操作性、可控制性、工作稳定性、可靠性以及其它性能的发挥。探针及其相关技术的研究进展成为人们十分关注的问题。探针对表面物理信息的检测是一个针尖与试样表面相互作用的过程,包含物理、几何关系,还包含表面微观化学作用及其它微观因素的影响。本文探讨探针与表面相互作用关系,并就近些年探针技术发展讨论探针性能、针尖及相应结构的改进,探针功能的拓展以及功能的组合,讨论相关制备技术方法、特点和相应检测条件、适用环境等。     

管腐蚀法制作纳米光纤探针

根据优质探针的理论模型,利用管腐蚀法制作了可用于光纤生物传感器的纳米光纤探针,该制作方法操作方便,成本低廉,易于批量生产,且受环境的影响较小,制作的光纤探针具有较高的重复率。所获探针锥径小于50nm,锥角为45°。最后讨论了在管腐蚀实验中不良因素对光纤探针形貌的影响。     

基于HTc rf SQUID的通信传感器技术

超导量子干涉仪(Superconducting Quantum Interference Devices,简记为SQUID)是迄今为止灵敏度最高的磁场传感器,高温超导射频量子干涉仪(HTc rf SQUID)更以其良好的实用性而备受业界关注。将HTc rf SQUID技术引入到低频段通信中,可以有效解决目前低频段通信中收信天线设备笨重、灵敏度不高的问题。文中分析了超导技术发展现状和HTc rf SQUID技术原理,总结了该技术的特点和应用于低频段通信的优势,结合CSAMT试验方法验证了应用HTc rf SQUID进行低频段收信的可行性,提出了HTc rf SQUID实用化的技术途径。     

二分量BEC原子数密度在射频场作用下的崩塌与复苏现象

研究射频场频率对二分量玻色-爱因斯坦凝聚体(BEC)原子数密度长时间演化特性的影响,研究结果显示当射频场频率较小而时间较长时BEC第二分量原子数密度的演化呈现出量子力学中典型的崩塌与复苏现象;原子数密度在更长时间的动力学行为中,若射频场频率增大,则呈现出崩塌与复苏现象的原子数密度震荡曲线整体逐渐下降.     

ZnO films deposited on GaAs substrates with a SiO2 thin buffer layer

Sputter deposition of ZnO films on GaAs substrates has been investigated. ZnO films were radio frequency (rf)-magnetron sputter deposited on GaAs substrates with or without SiO₂ thin buffer layers. Deposition parameters such as rf power, substrate-target distance, and gas composition/pressure were optimized to obtain highly c-axis oriented and highly resistive films. Deposited films were characterized by x-ray diffraction, scanning electron microscopy (SEM), capacitance, and resistivity measurements. Thermal stability of sputter-deposited ZnO films (0.5–2.0 μm thick) was tested with a post-deposition heat treatment at 430°C for 10 min, which is similar to a standard ohmic contact alloying condition for GaAs. The ZnO/SiO₂/GaAs films tolerated the heat treatment well while the ZnO/GaAs films disintegrated. The resistivity (10¹¹ Ω-cm) of the ZnO films on SiO₂-buffered GaAs substrates remained high during the heat treatment. The post-deposition anneal treatment also enhances c-axis orientation of the ZnO films dramatically and relieves intrinsic stress almost completely. These improvements are attributed to a reduction of grain boundaries and voids with the anneal treatment as supported by SEM and x-ray diffraction measurement results.     

硅基镓浓度对GaN晶体膜质量的影响

采用射频磁控溅射工艺在扩镓硅基上溅射Ga2O3薄膜，再氮化反应组装GaN晶体膜，并对其生长条件进行了研究。用傅里叶红外谱仪(FTIR)、X射线衍射(XRD)、扫描电镜(SEM)、选区电子衍射(SAED)和光致发光(PL)谱对样品进行结构、形貌和发光特性的分析。测试结果表明，采用此方法可得到六方纤锌矿结构的GaN晶体膜。镓浓度在影响膜层质量方面起着不可忽视的作用，随着扩镓浓度的增加，薄膜的晶化程度和发光特性明显提高。     

The role of ion characteristics in determining the structural and electrical quality of InN grown by metalorganic molecular beam epitaxy

The effects of growth temperature and nitrogen plasma biasing on the electrical and structural properties of InN grown using electron cyclotron resonance metalorganic molecular beam epitaxy (ECR MOMBE) have been investigated. These results are compared to those found from InN grown using a higher energy radio frequency (rf) plasma source (rf MOMBE). By varying the bias of the nitrogen plasma or the growth temperature, it is possible to achieve smooth surface morphologies. However, biasing can also be used to increase the mobility by a factor of two while the growth temperature has only a small effect. By contrast, use of an rf plasma improves mobility by nearly a factor of ten. None of the growth conditions investigated were found to significantly alter the electron concentration, which was measured to be 1−5 × 10²⁰ cm⁻³.     

The effect of N2 plasma damage on AlGaAs/InGaAs/GaAs high electron mobility transistors. I. DC characteristics

0.25 μm gate length AlGaAs/InGaAs/GaAs pseudomorphic high electron mobility transistors were exposed to inductively coupled plasma (ICP) N₂ discharges at varied source power and rf chuck power. The plasma damage was characterized by evaluating device extrinsic transconductance and saturated drain–source current, as well as Schottky gate ideality factor and reverse breakdown voltage as a function of both ICP source power and rf chuck power. Auger and atomic force microscopy were also used to characterize the atomic ratio and roughness of plasma damaged surface, respectively. At a lower range of ICP source power (between 100 and 300 W) with a constant rf power of 10 W, the device performance was barely changed. But at higher ICP source power (greater than 400 W) and rf power (greater than 20 W), device characteristics including gate ideality factor, reverse breakdown voltage and saturated drain–source current were seriously degraded. In this plasma damage study, two device degradation mechanisms were identified. The first was ion bombardment induced lattice disorder that created generation–recombination centers and reduced the free carrier concentration. The second was preferential loss of As from GaAs surface and this also created deep level states, which gave rise to gate leakage current.     

Reactive ion etching of dielectrics and silicon for photovoltaic applications

This paper investigates the reactive ion etching of SiO₂, Si₃N₄, and Si using CHF₃/O₂ plasma. In particular, we have characterized the time and rf power dependence of the carrier lifetimes in n‐ and p‐type FZ Si. The time dependence of reactive ion etching (RIE) at different rf powers provide insight into the two competing processes of damage accumulation and damage removal in the near‐surface region of the Si during plasma etching. The carrier lifetime, measured using the quasi‐steady‐state photoconductance (QSSPC) technique, has a quadratic dependence on the rf power, which can be related to changes in the dc self‐bias generated by the plasma at different rf powers. The change in carrier lifetime is similar in both n‐ and p‐type Si of the same doping concentration. Using this fact, together with the electronic properties of defects obtained by deep level transient spectroscopy (DLTS), we have modeled the injection‐dependence of the measured carrier lifetimes using the Shockley–Read–Hall model. The isochronal annealing behavior of plasma etched Si has also been studied. Copyright © 2006 John Wiley & Sons, Ltd.     

溅射工艺参数对BST薄膜介电常数的影响

采用射频磁控溅射法在ITO玻璃基片上制备了约700nm的Ba0.5Sr0.5Ti03(BST)薄膜。研究了溅射功率、气压、ψ[O2/(Ar+O2)]比和基片温度对εr的影响,获得各种溅射条件下的薄膜的εr为250~310。提出了较优的工艺,即本底真空1.5×10–3Pa、靶基距6.2cm、功率300W、气压1.8Pa、ψ[O2/(Ar+O2)]为30%和衬底温度500℃,并研究了薄膜的晶相、组成和形貌。     

α—Si TFT矩阵等离子体刻蚀技术的研究

本文介绍了α-Si TFT有源矩阵的CF_4等离子体刻蚀技术。分析了CF_4等离子体刻蚀α-Si:H和α-SiN_x的机理,对α-Si TFT的有源层与绝缘层之间刻蚀选择性和均匀性进行了研究,讨论了等离子体刻蚀速率与射频功率、反应室压力及衬底温度的依赖关系。根据实验结果总结了CF_4等离子体刻蚀速率随射频功率、反应室压力和衬底温度的增加而增大的规律,通过控制合适的工艺条件,成功地实现了选择性刻蚀并改善了刻蚀的均匀性。     

Nitridation of silicon in a multiwafer plasma system

Silicon wafers were nitrided in a multiwafer plasma system at low temperatures (< 850°C). An argon plasma (400 kHz rf plasma) was used to which small quantities (approximately 2–8 %) of NH3, N₂ or mixtures of N₂ and H₂ were added. As the rf power was increased, the film thickness as well as the etch rate (in buffered HF) increased. The rate of film growth was found to be slower than that for oxidation in a similar type of plasma system. The effects of variation of power and gas composition on film composition and etch rate are discussed.