Performance of Tense Thin-Film Torsion Bar for Large Rotation and Low-Voltage Driving of Micromirror

In this paper, a micromirror device is developed by realizing the large rotation with the low-voltage driving. The maximum rotation angles observed at 5 V are 8.6deg with hysteresis and 7deg with little hysteresis at the static condition. The thin-film torsion bars contribute to decrease in the torsional spring constant. The tension is included for maintaining the compliance in the rotation of the mirror and for increasing stiffness in other movements. The performance of the torsion bar is investigated. The observed hard-spring effect is significant and this can be explained by the combination of the tension and the vertical displacement of the torsion bar     

Application of HfO2 high-k gate insulator for excimer laser annealed poly-Si TFT

The electrical characteristics of polycrystalline silicon (poly-Si) thin film transistor (TFT) crystallized by excimer laser annealing (ELA) method with high-k gate dielectrics were evaluated. Because a high thermal budget is inevitable for conventional fabricating process of poly-Si TFTs, an amorphous silicon film on a buried oxide was crystallized by annealing with a KrF excimer laser (248) to fabricate a poly-Si film at low temperature. Furthermore, the high permittivity HfO₂ film with a thickness of 20 nm as the gate-insulator was deposited by atomic layer deposition (ALD) to low temperature process. In addition, the solid phase crystallization (SPC) was compared to the ELA method as a crystallization technique of amorphous-silicon film. As a result, the crystallinity and surface roughness of poly-Si crystallized by ELA method was superior to the SPC method. Also, we obtained excellent device characteristics from the poly-Si TFT fabricated by the ELA crystallization method.     

Gate dielectric-breakdown-induced microstructural damage in MOSFETs

Numerous failure mechanisms associated with hard breakdowns (HBD) in ultrathin gate oxides were physically studied with high-resolution transmission electron microscope (TEM). Migration of silicide from silicided gate and source/drain regions, abnormal growth of dielectric-breakdown-induced epitaxy (DBIE), poly-Si gate meltdown and recrystallization, severe damage in Si substrate, and total epitaxy of poly-Si gate and Si substrate of the entire transistor are among the common microstructural damages observed in metal-oxide-semiconductor field-effect transistors (MOSFETs) after HBDs in gate oxides (Gox) were observed electrically. The type of catastrophic failures and its degree of damage were found to be strongly dependent on the allowable current density and total resistance of the breakdown path during the breakdown transient. The physical analysis data from TEM analysis allow us to establish the sequence of the physical damage associated with the Gox HBD in narrow transistors. The proposed model is able to predict the next possible microstructural damage induced by HBD. Such knowledge will allow failure analysts to be able to retro-predict the current and power consumption in a field EOS/ESD failure based on the physical analysis and propose a knowledgeable guess on the potential root cause of the failures.     

$hbox{1}/f$ Noise Characterization of n- and p-Type Polycrystalline-Silicon Thin-Film Transistors

This paper presents a study of low-frequency-noise properties of n- and p-type polycrystalline-silicon (poly-Si) thin-film transistors (TFTs). The $hbox{1}/f$ noise behavior of these devices prompted the use of the carrier number with correlated mobility fluctuation model for data analysis. From this model, trap densities in this study were found to range from $hbox{3.5} times hbox{10}^{16}$ to $hbox{4} times hbox{10}^{17} hbox{states/eV} cdot hbox{cm}^{3}$, which is indicative of a good top surface of the channel and interface between the oxide and poly-Si. The normalized current noise of the p-channel TFTs changes with the inverse of current, independent of the width $(W)$ -to-length $(L)$ ratio of the channel; the normalized current noise of the n-channel TFTs also changes with the inverse of current, but not independent of the $W/L$ ratio. For smaller currents, noise is caused by traps at or near the oxide/semiconductor interface, whereas for larger currents, the larger contribution to the noise is believed to originate from the bulk.      

不同类型电磁加热用磁条材料的成分、结构与性能对比分析

通过电子探针(EPMA)、扫描电镜(SEM)、X射线衍射(XRD)、综合物性测量系统(PPMS)、软磁测量装置(MATS-2010SA、MATS-2010SD),分析并对比了电磁炉厂商使用的不同类型锰锌铁氧体磁条材料在化学成分、显微结构和磁性能上的差异,从材料学的角度揭示了电磁炉能效出现波动的原因。结果表明,不同供应商、不同类型的锰锌铁氧体磁条在化学成分、微观形貌和磁性能上差别较大。不同磁条的Mn与Zn的原子比处在1.21~3.90之间,在二次料生产的磁条中添加了较多的Ca、Si等元素。一次料制备的锰锌铁氧体磁条材料晶粒大小均匀、气孔率低,磁性能明显优于二次料磁条,而一次料磁条之间差别不明显。不同磁条的化学成分和显微结构上的差别导致性能出现波动,从而对电磁炉能效造成影响。     

Laboratory Experiments in the Fabrication of Thick-Film and Thin-Film Integrated Circuits

The thin-film and thick-film technology of fabricating hybrid integrated circuits has become of increasing importance as requirements for precision components, such as in active filters and digital to analog converters, are imposed on present circuit designs. This paper describes a series of experiments used to demonstrate this technology at the undergraduate level. The main objective of these experiments was to allow the undergraduate student to acquire a working knowledge of how the two hybrid integrated circuits were fabricated. A secondary objective was to allow him to evaluate the two techniques in terms of the equipment used and the electrical results obtained. In addition, the equipment and techniques used for monolithic I-C fabrication were introduced by these experiments. The methods used to fabricate photomasks, copper-beryllium evaporation masks, thick-and thin-film conductors, and resistors are described.     

Amorphous silicon-based guided-wave passive and active devices forsilicon integrated optoelectronics

Waveguides and interferometric light amplitude modulators for application at the 1.3- and 1.55-μm fiber communication wavelengths have been fabricated with thin-film hydrogenated amorphous silicon and its related alloys. The technique adopted for the thin-film growth is the plasma- enhanced chemical vapor deposition, which has been shown to give the lowest defect concentration in the film. Consequently the proposed waveguiding structures take advantage of the low optical absorption shown by a-Si:H at photon energies below the energy gap. In addition a good radiation confinement can be obtained thanks to the bandgap tailoring opportunity offered by this simple and inexpensive technology. In particular rib waveguides, based on a a-SiC:H/a-Si:H stack, have been realized on crystal silicon, showing low propagation losses. Recently, however, a new interest as low as 0.7 dB/cm. The same structure has been utilized for the fabrication of thermooptic Fabry-Perot modulators with switching times of 10 μs. Modulators based on the alternative waveguiding configuration ZnO/a-Si:H, giving comparable results, are also presented     

Effects of Thermal-Via Structures on Thin-Film VCSELs for Fully Embedded Board-LevelOptical Interconnection System

The thermal characteristics of a thin-film vertical-cavity surface-emitting laser (VCSEL) are studied both theoretically and experimentally. The thermal resistances of the VCSEL with variable thickness, ranging from 10 to 200$mu$m, have been determined by measuring the output wavelength shift as a function of the dissipated power. The thermal simulation results agree reasonably well with the experimentally measured data. From the thermal management viewpoint, a thinned VCSEL has an exclusive advantage due to the reduction of the thermal resistance. The thermal resistance of a 10-$mu$m-thick VCSEL is 40% lower than that of a 200-$mu$m-thick VCSEL. A theoretical analysis of the thermal-via effects is performed to determine the optimized thickness range of thin-film VCSEL for the fully embedded structure. The thermal resistance of the fully embedded thin-film VCSEL with closed and open thermal-via structures is also evaluated, and the suitable VCSEL thickness is reported.     

太阳电池用Cu-In-Se薄膜的电化学沉积

用CuInSe2制造的太阳电池是仅有的三种产业化的化合物薄膜太阳电池之一。电化学沉积CuInSe2的方法具有价格低、低温成膜、可大面积连续成膜、原材料消耗最少、无污染等特点。但是,电化学沉积中CuInSe2的组成难以控制、工艺参数的变化对组成的影响大,且多数条件上得到的是富铜薄膜。采用电化学沉积方法在钼箔上制备Cu-Se、In-Se和Cu-In-Se薄膜,对电沉积的工艺参数进行了测试,发现Cu-In-Se是一种诱导共沉积,虽然沉积膜不具备化学计量比,但具有一定的光电性能。     

Bottom electrode structures of Pt/Ru and Ru deposited on polycrystalline silicon by MOCVD for DRAM capacitor

Abstract

The electrode structures of Pt/Ru and Ru on polycrystalline silicon (poly-Si) were prepared by metalorganic chemical vapor deposition (MOCVD) for high dielectric constant (Ba, Sr)TiO₃(BST) capacitor integration. The electrode structures of Pt/Ru/poly-Si annealed above 700°C for 1h in oxygen atmosphere showed a smooth surface ·microstructure without any second phases on the platinum. The specific contact resistance of Pt/Ru and poly-Si in Pt/Ru/poly-Si structures annealed at 800°C was about 1.5 × 10^?5 Ω-cm². The step coverage of Ru film deposited at 150°C was 76% and those of Pt film deposited at 300°C on Ru (deposited at 150°C) was about 61.3%.     

Computation of the no-load voltage waveform of laminated salient-pole synchronous generators

This paper presents a combined analytical and finite-element (FE) method for computation of the no-load voltage waveform of laminated salient-pole synchronous generators. The described method takes into account saturation effects as well as the damper bar currents due to the slot pulsation field. The method calculates first the damper bar currents and then includes them in the calculation of the no-load voltage. The combination of magnetostatic two-dimensional (2-D) FE simulations for calculating the magnetic coupling between the machine windings and of an analytical resolution results in a very precise prediction of the no-load voltage. At the same time, simulation time is drastically reduced compared with transient magnetic 2-D FE simulations. The method was verified on several examples, comparing the obtained results (damper bar currents and no-load voltage) with results obtained from transient magnetic FE simulations and, in one case, with the measured no-load voltage.     

Thin-film platinum for appliance temperature control

The accuracy and long-term stability of platinum resistance temperature sensors is now available through thin-film technology at low cost for consumer-appliance applications. The underlying technology and methods of assembly are reviewed, along with the favorable cost basis that has accelerated the expanding application of thin-film platinum. Test data with emphasis on the most demanding application in pyrolytic ovens are presented     

利用有限元法分析单芯光纤复合海缆扭转与光纤应变的关系

利用有限元法建立了海缆扭转模型,对其进行网格划分、施加扭转载荷,模拟海缆不同角速度下的扭转过程,最终提取了铜导体和光单元的应力、应变数据,并对铜导体的径向和轴向应力、应变分布以及扭转速度与铜导体应力、应变的变化关系进行了分析。结果表明,在同一时刻铜导体径向应力、应变由内到外依次增大,轴向应力、应变分布与扭转角度大小有关;海缆以不同角速度扭转时,铜导体的应力、应变的变化与角速度的大小呈现出了一定的规律,整体趋势一致。最后,建立了光纤应变与铜导体应力的关系函数,为利用光纤传感技术监测海缆的扭转状态提供了理论依据。     

An acoustic diagnostic technique for use with electric machineinsulation

Many of the electrical failures of large electric machines have mechanical precursors. This premise has led to the attempts described here to detect mechanical changes, such as groundwall delamination, by acoustic methods as a means of early detection of incipient failure. By optimally launching an ultrasonic wave into a stator bar and using the conductor as a waveguide, it has been shown possible to interrogate the groundwall insulation and the critical interface region adjacent to the conductor. Laboratory studies using an epoxy mica stator bar subjected to thermal cycling have demonstrated that the acoustic signatures obtained with this method are mirrored by conventional corona spectroscopy conducted simultaneously, although earlier damage is clearly discernible. Based on the results of this study, the acoustic technique appears to have substantial promise as an advanced detection tool     

转子断条机理分析与检测准确度研究

随着产业升级、可靠性需求逐渐上升,电动机的故障检测成为当前研究的热点问题。由于电机可检测的信号较少、负载工况复杂、信号处理误差等原因,鼠笼型电机转子断条特征存在较难检测的问题。以电机转子断条（坏条）作为研究对象,经过断条故障有限元仿真建模,通过多种信号处理方法研究对比,提出一种准确率较高、抗干扰性较优的检测方法,达到甄别转子断条（坏条）故障类型及预测故障程度的目标。     

基于Bezier曲线的CIGS薄膜光伏电池I-V曲线简单拟合方法

精准的光伏电池输出数学模型是研究光伏系统的必要条件,然而由于厂家提供的数据有限,铜铟镓硒(CIGS)薄膜光伏电池的输出数学模型是包含若干未知参数的非线性特性曲线.因此提出仅利用厂家提供的有限数据,对CIGS薄膜光伏电池的电流-电压输出特性曲线,即I-V曲线进行拟合.首先利用Bezier曲线选取函数控制点,对CIGS薄膜光伏电池的I-V曲线进行拟合;然后找出Bezier曲线控制点位置与CIGS薄膜光伏电池的填充因子之间的函数关系;最后,利用4种新型CIGS薄膜光伏电池对该函数关系进行验证,并对结果进行了对比分析.分析结果表明,所提方法对4种CIGS薄膜光伏电池的I-V曲线的拟合方法的平均相对误差均小于0.8％,验证了所提方法的有效性.     

Ferroelectric memory FET with Ir/IrO2 electrodes

Abstract

We proposed a MFMIS structure having a floating gate as a bottom electrode between a ferroelectric thin film and the gate SiO₂. Conventional gate SiO₂ can be used and ferroelectric thin films can be grown on bottom electrodes which have a good matching with the ferroelectric materials due to adopt the MFMIS structure. Ir and IrO₂ on poly-Si were used as floating gate. When a IrO₂ layer was formed between PZT and poly-Si, a high-quality PZT thin film was obtained and the PZT films show no fatigue up to 10¹² cycles of switching pulses. From the I_D-V_G characteristics measurement for 1·2 μm P-ch MFMIS FET, the shift in V_th or the memory window for a bias sweep of ±15V was about 3·3V. The difference of I_D-V_D curves which corresponded to I_D-V_G characteristics were found between before and after a programming pulse was applied.     

Imaging breakdown spots in SiO/sub 2/ films and MOS devices with a conductive atomic force microscope

Conductive atomic force microscopy (C-AFM) was used to study the dielectric breakdown of SiO/sub 2/ layers at a nanometric scale. First, bare oxide regions were stressed and broken down using the tip as the metal electrode of a MOS structure. The results show that the initial breakdown is electrically propagated to neighbor regions, affecting their dielectric strength. Moreover, the area affected by the initial breakdown depends on the breakdown hardness. In particular, it is shown that this area is smaller when the current through the structure is limited during the experiments. The effect of the current limitation is analyzed in detail. Based on the results, a qualitative picture of the breakdown process is presented, which accounts for this effect. Finally, for the first time, the breakdown spots in standard MOS devices (with poly-Si gate) are electrically imaged with C-AFM. The areas of the observed spots are in agreement with those obtained on bare oxides.     

基于超高频窄带法的GIS局部放电的研究

为了提高GIS运行的可靠性,笔者简要说明了超高频法检测GIS局部放电的原理,并在实验室以一段220 kV电压等级的GIS母线为试验对象,设计和模拟了GIS中典型的4种局部放电模型,并使用自主研发的超高频窄带检测系统对其局部放电信号进行检测。试验结果表明,该超高频窄带系统能有效测量GIS局部放电信号,同时获得了不同类型缺陷所产生的超高频信号及其对应的特征,为今后GIS局部放电模式识别提供了数值依据。     

薄膜锂电池的研究进展

微电子机械系统(MEMS)和超大规模集成电路(VLSI)技术的发展对能源的微型化、集成化提出了越来越高的要求。全固态薄膜锂电池因其良好的集成兼容性和电化学性能成为MEMS和VLSI能源微型化、集成化的最佳选择。简单介绍了薄膜锂电池的构造,举例说明了薄膜锂电池的工作原理。从阴极膜、固体电解质膜、阳极膜三个方面概述了近年来薄膜锂电池关键材料的研究进展。阴极膜方面LiCoO2依旧是研究的热点,此外对LiNiO2、LiMn2O4、LiNixCo1-xO2、V2O5也有较多的研究;固体电解质膜方面以对LiPON膜的研究为主;阳极膜方面以对锂金属替代物的研究为主,比如锡的氮化物、氧化物以及非晶硅膜,研究多集中在循环效能的提高。在薄膜锂电池结构方面,三维结构将是今后研究的一个重要方向。