Fabrication and Electrical Characteristics of Asymmetric Rings Made of HTS YBCO Films Obtained by Pulsed Laser Deposition

Russian Microelectronics - HTS YBCO films 200–400 nm thick are fabricated by pulsed laser deposition, both without filtration and in the regimes of velocity filtration of particles of an...     

AC Loss Characteristics of YBCO Coated Conductors With Varying Magnitude of Critical Current

Three YBCO coated conductors with various critical currents, up to 189 A, were prepared. The magnetization losses without transport current and the total AC losses of the conductors carrying various transport currents in transverse magnetic fields with various orientations were measured electromagnetically to study the AC loss characteristics systematically. The measured total AC losses were compared with the numerical values using a one-dimensional FEM model.     

电极对薄膜体声波谐振器性能的影响

采用有限元分析软件COMSOL Multiphysics仿真了三维结构的谐振器,探讨了不同的顶电极形状对谐振器性能的影响。有效机电耦合系数(k2teff)随电极-压电层厚度比增大而减小,其中电极形状为三角形的谐振器在厚度比为0.05时获得最大k2teff(5.73%)。品质因数Q值变化趋势与k2teff相反,由三角形电极在厚度比为0.25时,获得最大Q值为1 314。不同电极形状的谐振器的优值随电极-压电厚度比先增大后减小,最大值为65.4,由正方形电极在比值为0.15时获得。     

Effect of Colloidal Silver on Optical Transmittance Characteristics of Bulk Cadmium Zinc Telluride Crystals

Colloidal silver is observed to affect the transmittance of p-type Cd_1−y Zn _y Te (CZT) single-crystal substrate material at room temperature. The optical transmittance spectra have been analyzed in the near-infrared (NIR) and mid-infrared (MIR) regions. The transmittance characteristics of CZT showed significant reduction in absorption due to split-off valance band transitions in the NIR region and intervalence band absorption in the MIR region upon coating CZT substrates with silver paste. This reduction in absorption has been explained to be due to the compensation of the acceptor defects (native and foreign). Silver atoms incorporated from the silver coating help in compensation of these defects. A similar effect on transmittance characteristics of mercury cadmium telluride (MCT) epilayers grown on CZT substrates after coating silver paste on the CZT substrate side was also observed. An improvement in the transmittance of CZT substrates after the application of silver paste was observed. A similar improvement in transmittance is usually achieved by annealing the substrates in a Cd/Zn atmosphere. The results are explained by considering the formation of neutral complexes of acceptors (cadmium vacancies) and the interstitial silver. This study also points to the important conclusion that silver paste on CZT should be applied with caution for measurement purposes since it diffuses even at room temperature and modifies the optical characteristics.     

Chemical Solution Deposition of Silver Halide Films

Chemical solution deposition of semiconductor films has been confined almost entirely to chalcogenides. Here, we extend this technique to halide films. Silver halides (AgI, AgBr, and AgCl) were deposited using in‐situ homogeneous hydrolysis of organic haloalcohols to form halide ions that react with silver ions in aqueous solution. Also, a rapid precipitation method is described that gives AgCl films. Structural (XRD), morphological (TEM), and optical (transmission spectra) characterizations of the films are presented. Some preliminary results and ideas on other halide films are presented.     

三沟道体电荷耦合器件在近红外光区光电特性的数值模拟

对三沟道BCCD（bulk charge-coupled device）在近红外光区的光电特性进行了研究．结果表明，锗制的三沟道BCCD不能在近红外光区实现多光谱成像．通过理论分析，找到了一种能保证BCCD在近红外光区工作的衬底材料应满足的吸收曲线．数值模拟结果表明：利用这种新材料制成的三沟道BCCD，其光敏特性曲线可以分别在1.0，1.1和1.26μm处出现最大值．     

Electrical Characteristics of the HfAlON Gate Dielectric With Interfacial UV-Ozone Oxide

In this letter, the electrical properties of a HfAlON dielectric with UV-O₃ interfacial oxide were comprehensively studied and then compared with those of a HfAlON dielectric with interfacial chemical oxide. In the comparison of dielectric characteristics including leakage current density, transconductance, subthreshold swing, saturation drain current, effective electron mobility, and constant voltage stress reliabilities, the results clearly indicate that high-density interfacial UV-O₃ oxide is beneficial in reducing both bulk and interface traps as well as diminishing stress-induced trap generation, and possesses a high potential to be integrated with further high-kappa dielectric applications.     

三沟道体电荷耦合器件在近红外光区光电特性的数值模拟

对三沟道BCCD(bulk charge-coupled device)在近红外光区的光电特性进行了研究.结果表明,锗制的三沟道BCCD不能在近红外光区实现多光谱成像.通过理论分析,找到了一种能保证BCCD在近红外光区工作的衬底材料应满足的吸收曲线.数值模拟结果表明:利用这种新材料制成的三沟道BCCD,其光敏特性曲线可以分别在1.0,1.1和1.26μm处出现最大值.     

Characteristics and Electrical Properties of SiNx：H Films Fabricated by Plasma-Enhanced Chemical Vapor Deposition

SiNx：H films with different N/Si ratios are synthesized by plasma-enhanced chemical vapor deposition （PECVD）. Composition and structure characteristics are detected by Fourier transform infrared spectroscopy （FTIR） and X-ray photoelectron spectroscopy （XPS）. It indicates that Si-N bonds increase with increased NH3/SiH4 ratio. Electrical property investigations by I-V measurements show that the prepared films offer higher resistivity and less leakage current with increased N/Si ratio and exhibit entirely insulating properties when N/Si ratio reaches 0.9, which is ascribed to increased Si-N bonds achieved.     

Characteristics and Electrical Properties of SiNx: H Films Fabricated by Plasma-Enhanced Chemical Vapor Deposition

SiNx:H films with different N/Si ratios are synthesized by plasma-enhanced chemical vapor deposition (PECVD). Composition and structure characteristics are detected by Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS). It indicates that Si-N bonds increase with increased NH3/SiH4 ratio. Electrical property investigations by I-V measurements show that the prepared films offer higher resistivity and less leakage current with increased N/Si ratio and exhibit entirely insulating properties when N/Si ratio reaches 0.9, which is ascribed to increased Si-N bonds achieved.     

Electrical Contact Resistance Degradation of a Hot-Switched Simulated Metal MEMS Contact

Electrical contact resistance testing was performed by hot-switching a simulated gold-platinum metal microelectromechanical systems contact. The experimental objective was to determine the sensitivity of the contact resistance degradation to current level and environment. The contact resistance increased sharply after 100hot-switched cycles in air. Hot-switching at a reduced current and in nitrogen atmosphere curtailed contact resistance degradation by several orders of magnitude. The mechanism responsible for the resistance degradation was found to be arc-induced decomposition of adsorbed surface contaminants     

A Coupled-Simulation-and-Optimization Approach to Nanodevice Fabrication With Minimization of Electrical Characteristics Fluctuation

In this paper, a simulation-based optimization methodology for nanoscale complementary metal-oxide-semiconductor (CMOS) device fabrication is advanced. Fluctuation of electrical characteristics is simultaneously considered and minimized in the optimization procedure. Integration of device and process simulation is implemented to evaluate device performances, where the hybrid intelligent approach enables us to extract optimal recipes which are subject to targeted device specification. Production of CMOS devices now enters the technology node of 65 nm; therefore, random-dopant-induced characteristic fluctuation should be minimized when a set of fabrication parameters is suggested. Verification of the optimization methodology is tested and performed for the 65-nm CMOS device. Compared with realistic fabricated and measured data, this approach can achieve the device characteristics; e.g., for the explored 65-nm n-type MOS field effect transistor, the on-state current > 0.35 mA/mum, the off-state current < 1.5e - 11 A/mum, and the threshold voltage = 0.43 V. Meanwhile, it reduces the threshold voltage fluctuation (sigma_vth ~ 0.017 V). This approach provides an alternative to accelerate the tuning of process parameters and benefits manufacturing of nanoscale CMOS devices.     

基于热力收缩线特征的电接触载荷衰减状态在线评估方法

提出了一种基于红外特征的在役飞机电接触可靠性在线评估方法。在役飞机长期的振动、腐蚀、高温等环境负荷冲击导致电接触载体表面状况恶化,其程度往往难以定量评估。通过模型机理分析发现,斑点化特征引起接触电阻等可靠性指标下降。然后针对某型电接触载体施加一定的扭矩载荷谱,实时获取电接触部位的“热”信息。在低载荷、临近额定载荷状态下,随载荷状态变化而出现的斑点化特征较为明显。由此认为,将热力收缩线区域最高温度、等温线密集程度、连通区域面积及边界模糊化程度等作为表征指标,能够反映电接触表面施加机械载荷状态的实际衰减程度。因此,该方法可用作在役飞机接触电阻恶化程度的有效评估方法。     

钇钡铜氧半导体薄膜的宽光谱响应特性

对以 Si为衬底的钇钡铜氧 (分子式 :Y1 Ba2 Cu3O7-δ　δ≥ 0 .5 ,简称 :YBCO)半导体薄膜的宽光谱响应特性进行了研究 .采用该薄膜作灵敏元的单元测辐射热计分别对红外波段 (1— 15μm)、亚毫米波段 (5个波长 )及毫米波 (3m m )进行光谱响应测试 ,结果表明这种半导体探测器不仅在红外波段 ,而且在亚毫米波甚至毫米波段都有良好的响应特性 .该薄膜是继 VO2 薄膜之后用于非制冷红外焦平面的一种新材料     

钇钡铜氧半导体薄膜的宽光谱响应特性

对以Si为衬底的钇钡铜氧(分子式:Y1Ba2Cu3O7-δδ≥0.5,简称:YBCO)半导体薄膜的宽光谱响应特性进行了研究.采用该薄膜作灵敏元的单元测辐射热计分别对红外波段(1-15μm)、亚毫米波段(5个波长)及毫米波(3mm)进行光谱响应测试,结果表明这种半导体探测器不仅在红外波段,而且在亚毫米波甚至毫米波段都有良好的响应特性.该薄膜是继VO2薄膜之后用于非制冷红外焦平面的一种新材料.     

超细银粉的制备及其导电性研究

用化学还原法在醇水体系中制备出平均颗粒粒径为 0.8~1.2 μm、分散性好的超细球银。讨论了表面活性剂、还原剂的种类、温度、硝酸银含量及 pH 值对球银颗粒粒径和分散性的影响。将所得超细球银在水体系中高效率球磨得分散性好的光亮片状银粉,平均粒径<6 ìm,比表面积 0.7~1.3 m2/g。讨论了吸附在银粉表面的有机物的种类和比表面积对片银导电性能的影响,结果表明:比表面积越大,导电性越好。     

微喷射技术制备的化学镀金属银线微结构

采用一种称为微喷射的新方法制备了微米尺度金属银线。在该方法中,用压电陶瓷驱动器提供的微振动实现微喷嘴内部液柱的均匀破碎和喷射,并通过微喷射系统,把银氨溶液和还原剂溶液喷射到基材表面。采用金属化学沉积技术,在室温下还原出金属银,并沉积在指定的位置。构建的微喷射系统具有脉冲可控和喷射量可控的特征,并且能够实现皮升(picoliter)到飞升(femto-liter)级的微量液体的喷射,因此能够在玻璃基材上获得致密的金属银线,线宽可以按照需要在数微米至数百微米范围内调整。该方法可以在平面或曲面上直写微电路制作微型PCB线路板。由于镀层的可叠加性,该技术还可以用于三维金属微构件的制造。     

激光诱导银纳米颗粒薄膜和微结构

利用可见激光诱导化学沉积方法在玻璃基底上制备纳米银薄膜和微结构。玻璃样品池中装满柠檬酸钠和硝酸银的混合透明溶液,当一束可见连续激光正入射样品池一段时间后,在辐照区域的玻璃内壁上便可以形成一层光亮的银膜。银膜沉积的速度受到激光功率密度、激光波长、辐照时间以及混合溶液的浓度等条件的影响。利用X射线衍射、原子力显微镜和拉曼光谱仪等手段对制备的薄膜的成分、表面形貌和拉曼活性等性质进行了表征和分析。利用此方法制备的银膜具有良好的表面增强拉曼散射活性。同时,利用双光束干涉的方法在玻璃基底上诱导出不同周期的银纳米颗粒光栅。     

An Effective Approach for the Development of Reliable YBCO Bulk Cryomagnets with High Trapped Field Performances

Widespread use of YBa₂Cu₃O_7‐δ (Y123) bulk superconductors as source of strong magnetic fields requires development of high‐performance materials sufficiently reliable with improved thermal transfer ability. An effective approach based primarily on the growth of bulk Y123 single domains comprising a holes‐network to diminish the oxygen diffusion paths is reported here, as well as their progressive annealing at high temperature under oxygen pressure to reduce undue stresses and processing time. Finely, it aims to stimulate the thermal exchange inside the superconductor and compensate for induced magnetic stresses during the field‐trapping process. The approach brings considerable time and energy savings, and turns out to knock down barriers having stymied hitherto the use of Y123 bulk superconductors for engineering applications. Indeed, it enables the achievement of a pore‐free and crack‐free microstructure yielding marked fracture toughness and promoting large size persistent current loops, thereby boosting the trapped field performances. The fostering of the internal thermal exchange leads the maximum trapped field B_max to shift to higher temperatures by up to 14 K. A value B_max of 6.34 T is attained at 17 K on ≈16 mm‐diameter reinforced pellet (disk area s = 1.99 cm²), resulting in an outstanding field density B_max/s=3.19 Tcm^?2.     

Ni、Cu掺杂钛酸锶复合功能陶瓷的电学特性

采用一次烧成工艺制备了NiO、CuO掺杂的SrTiO3复合功能陶瓷，研究了其烧成状况、显微结构、复合功能特性及小电流区的电流－温度关系。研究结果表明，掺NiO样品的晶粒粒度明显大于掺CuO样品；由于在烧成过程中受主杂质的行为有所不同，掺CuO样品具有较高的晶界受主态浓度。这使得在制备条件和掺杂浓度相同的条件下，掺NiO样品和掺CuO样品的复合功能特性之间存在差异。