Partial-SOI high voltage laterally double-diffused MOS with a partially buried n~+-layer

A novel partial silicon-on-insulator laterally double-diffused metal-oxide-semiconductor transistor （PSOI LDMOS） with a thin buried oxide layer is proposed in this paper. The key structure feature of the device is an n＋-layer, which is partially buried on the bottom interface of the top silicon layer （PBNL PSOI LDMOS）. The undepleted interface n＋-layer leads to plenty of positive charges accumulated on the interface, which will modulate the distributions of the lateral and vertical electric fields for the device, resulting in a high breakdown voltage （BV）. With the same thickness values of the top silicon layer （10 p.m） and buried oxide layer （0.375 μm）, the BV of the PBNL PSOI LDMOS increases to 432 V from 285 V of the conventional PSOI LDMOS, which is improved by 51.6%.     

Experimental evaluation of the forming process of virgin HfO2 memory cells by capacitance–voltage measurements

In this Letter, we evaluate the so‐called forming process of virgin HfO₂ cells under ac and dc stress by capacitance–voltage measurements. It is found that the ac nonlinearity is higher than the dc one. This is related to the dispersive nature of hopping conduction according to the electrode polarization model. Under short stress times, both capacitance and current are unaffected. However, after longer stress times, no recovery is observed. Consequently, the current increases and a plateau appears in the capacitance. The observed degradation is consistent with the RRAMs‐forming process. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Influence of additives blended with motor base oils on the braking torque under an auxiliary external DC electric field

The paper presents the results of experiments upon the influence of tribocharging of PAO and PAG synthetic motor base oils blended with different additives—friction modifiers (FM) and antiwear agents (AW)—and the effect of an external DC electric field on the braking torque. The experiments are carried out in a rotating shaft–oil–lip seal system which represents a specially built experimental facility to be a simplified model of an engine crankcase in the interior of which a metal shaft rotates. The research is especially aimed at the braking torque of a rotating shaft sealed with a lip seal and a possibility of reduction in the torque under external DC electric fields. DC voltage is applied between the stiffening ring of lip seal and a rotating, earthed shaft. The braking torque of rotating shaft is measured as a function of the oil–additive blend's temperature, the shaft's angular velocity, and the absolute value of the external DC voltage. In general, it is found that an external DC electric field causes the braking torque to change with the increasing DC voltage. The change depends on the additives and base oils used in their blends which in turn causes the torque to increase in the case of the PAO–additive blends or to decrease for the PAG–additive blends.     

低压驱动液晶透镜设计的研究

探讨了低压液晶透镜设计的规律. 由五种液晶材料的Δn_eff随驱动电压变化的规律可知: 如果液晶材料归一化Δn_eff控制在 95%以下, 驱动电压可控制在10 V以下; 在能满足透镜性能和制备工艺允许的前提下, 设计液晶透镜时选取的归一化Δn_eff越小, 获得的液晶透镜驱动电压越低. 该规律可为高性能液晶透镜的设计与制备提供指导. 关键词： 液晶透镜 设计 低压驱动 n_eff')" href="#">归一化Δn_eff     

Polymeric Multimode Interference Mach–Zehnder Interferometer Electro-Optic Switch Using Embedded Coplanar Waveguide Electrode: Theory,Design, and Analysis

Abstract

The self-imaging theory is improved for designing a polymer multimode interference Mach–Zehnder interferometer electro-optic switch. The electro-optic overlap factor is enhanced from 0.6510 to 0.9658 through adopting an embedded coplanar waveguide electrode. Considering the mode dispersion effect, formulations of time-domain response are derived, and switching characteristics are analyzed. The total device length is about 7.175 mm, the switching voltage is 2.622 V, and the switching time is 29.90 ps. The lightwave 3-dB bandwidth is 20 nm, the insertion loss is less than 2.70 dB, and the crosstalk under cross and bar states are less than ?55 dB and ?45 dB, respectively.     

基于金属氧化物半导体晶体管Colpitts混沌振荡电路及其同步研究

用金属氧化物半导体(MOS)晶体管模型取代传统Colpitts混沌振荡电路中的三极管模型, 提出了一种基于MOS管的Colpitts混沌振荡电路. 通过合适的归一化方法, 得到了与基于三极管电路类似的状态模型. 平衡点的指标说明两种结构产生混沌的机理并不相同. 然后, 通过参数反演, 得到了详细的电路参数, 并用Pspice软件仿真得到了混沌吸引子和混沌信号的频谱图, 说明了此结构可在低电压下工作并且能产生高频率的混沌信号. 最后, 用误差反馈的方法实现了这种结构的同步. 关键词： Colpitts混沌 金属氧化物半导体晶体管 低电压 误差反馈同步     

基于P掺杂SiO2为栅介质的超低压侧栅薄膜晶体管

在室温下利用等离子体增强化学气相沉积法(PECVD)制备的颗粒膜P掺杂SiO₂为栅介质, 使用磁控溅射方法利用一步掩模法制备出一种新型结构的侧栅薄膜晶体管. 由于侧栅薄膜晶体管具有独特的结构, 在射频磁控溅射过程中, 仅仅利用一块镍掩模板, 无需复杂的光刻步骤, 就可同时沉积出氧化铟锡(ITO)源、漏、栅电极和沟道, 因此, 这种方法极大地简化了制备流程, 降低了工艺成本. 实验结果表明, 在P掺杂SiO₂栅介质层与沟道层界面处形成了超大的双电层电容(8 μF/cm²), 这使得这类晶体管具有超低的工作电压1 V, 小的亚阈值摆幅82 mV/dec、高的迁移率18.35 cm²/V·s和大的开关电流比1.1×10⁶. 因此, 这种P掺杂SiO₂双电层超低压薄膜晶体管将有望应用于低能耗便携式电子产品以及新型传感器领域. 关键词： 2')" href="#">P掺杂SiO₂ 侧栅薄膜晶体管 双电层(EDL) 超低压     

金属Pt薄膜上二氧化钒的制备及其电致相变性能研究

通过引入SiO₂氧化物缓冲层, 在金属Pt电极上利用射频磁控溅射技术成功制备出高质量的VO₂薄膜. 详细研究了SiO₂厚度对VO₂薄膜的晶体结构、微观形貌和绝缘体–金属相变(MIT)性能的影响. 结果表明厚度0.2 μm以上的SiO₂缓冲层能够有效 消除VO₂薄膜与金属薄膜之间的巨大应力, 制备出具有明显相变特性的VO₂薄膜. 当缓冲层达到0.7 μm以上, 获得的薄膜具有明显的(011)晶面择优取向, 表面平整致密, 相变前后电阻率变化达到3个数量级以上. 基于该技术制备了Pt-SiO₂/VO₂-Au三明治结构, 通过在垂直膜面方向施加很小的驱动电压, 观察到明显的阶梯电流跳跃, 证实实现了电致绝缘体–金属相变过程. 该薄膜制备工艺简单, 性能稳定, 器件结构灵活可应用于集成式电控功能器件. 关键词： 二氧化钒薄膜 相变特性 电致相变 阈值电压     

Energy-saving seawater electrolysis for hydrogen production

The change in the polarization potentials of anode and cathode due to pH change on electrode surfaces during galvanostatic polarization was examined in 0.5 M NaCl solutions of different pH. On the basis of these results, feeding of the anolyte after oxygen evolution to the cathode compartment for hydrogen production was examined for energy-saving seawater electrolysis. This was assumed to prevent the occurrence of a large pH difference on cathode and anode in electrolysis of neutral solution if sufficient H⁺ is permeated through the membrane. The cell performance was examined using Nafion 115 or Selemion HSF membranes for separation of anode and cathode compartments. The permeation fraction of H⁺ with Nafion 115 was 45–65% in 0.5 M NaCl and was about 90% in 0.25 M Na₂SO₄. These values were smaller than 97% necessary for prevention of the occurrence of pH difference on cathode and anode. The permeation fraction of H⁺ with Selemion HSF became more than 97% during electrolysis of 0.025 M Na₂SO₄, and the cell voltage was kept at low values. These results indicate the effectiveness of our seawater feeding system if the 97% H⁺ permeation fraction through the membrane is attained. Contribution to the Fall Meeting of the European Materials Research Society, Symposium D: 9th International Symposium on Electrochemical/Chemical Reactivity of Metastable, Warsaw, 17th-21st September, 2007.     

Sensing method based on impedance variation of minicolumn packed with cation-exchanger under electric field

Voltage-induced impedance variation of the minicolumn (i.d. 0.53 mm, length 2 mm) packed with cation exchanger was investigated to develop a sensing method. An aqueous sample solution containing the metal cations was continuously supplied to the minicolumn during the impedance measurement with the simultaneous application of both alternating current voltage (amplitude, 1.0 V; frequency, 200 kHz to 6 Hz) and direct current (DC) offset voltage (0.1 to 1.0 V). On a complex plane plot, the profile of the column impedance consisted of a semicircle (200 kHz to 100 Hz) and a straight line (<100 Hz), of which slope varied with the magnitude of the applied DC offset voltage (V _DC). The slope–V _DC relation depended on the kind of the metal cation and its concentration; in particular, the slope–V _DC relations of monovalent cations (Na⁺ and K⁺) and divalent ones (Mg²⁺ and Ca²⁺) were significantly different. With the change in the concentration of minor divalent salt of MgCl₂ or CaCl₂ (60 to 140 μM) in the sample solution containing 10 mM NaCl, the slopes showed almost linear relationships between those with application of V _DC = 0.1 V and 1.0 V both for magnesium and calcium additions. In the case of plural addition of both MgCl₂ and CaCl₂ to the solution, the data points in the slope_{0.1  V}–slope_{1.0  V} plot were located between the two proportional lines for single additions of magnesium and calcium, reflecting both the mixing ratio and net concentrations of the divalent cations. Thus, simulations determination of Mg²⁺ and Ca²⁺ can be attained on the basis of the slope_{0.1  V}–slope_{1.0  V} relation obtained by the impedance measurements of the minicolumn. Actually, the contents of both magnesium and calcium cations in the bottled mineral waters determined simultaneously using the proposed method were almost equivalent to those obtained by the atomic absorption spectrometric measurement.