Study of the positive charge buildup into buried oxide of SIMOX SOI structure during bias–temperature stress

The buildup of fixed and mobile charge in the buried oxide (BOX) of silicon implanted by oxygen (SIMOX) silicon-on-insulator (SOI) structures during bias–temperature (BT) cycling has been studied by the thermally stimulated polarization (TSP) current technique and C–V measurements. Two polarization processes have been observed: the first process with activation energy of 0.3 eV is likely related to the positively charged ion transport across the BOX, the second process with activation energy about 1.2 eV is associated with space charge polarization. It was found that the ion transport is created simultaneously with the process of lateral positive charge buildup near the BOX/substrate interface when the bias is applied to the structure at temperatures above 280°C.     

Simultaneous Measurement of Liquid Velocity and Oxygen Tension with Catheter-Tip Electrodes?The Dual Cathode Polarographic Method

The application of a dual-cathode catheter system to the simultaneous measurement of oxygen tension (p?) and velocity (V) has been studied under conditions similar to those in human arteries. The catheter tip contained a large silver electrode (16 mm2) and a small silver electrode (0.035 mm2) which were connected to a common polarizing power supply and external silver/silver chloride reference anode (774 mm2). The 2 mm diameter catheter was centered in a 6.4 mm diameter tube through which flow of buffered physiologic saline solution at various oxygen tensions from 154 to 736 torr was metered at velocities of 1-67 cm/s. At a fixed velocity, the limiting current outputs from both the small and large cathodes were linear with p?. Membrane-coated catheters exhibited velocity-insensitive outputs from the small cathode whenever V 5 cm/s. The large cathodes were always flow-sensitive, but the degree of sensitivity depended upon the membrane thickness. Experiments with bare large electrodes indicated that the greatest sensitivity possible with the present cathode geometry is a relative current increase of 124 percent over a velocity range of 5-67 cm/s.     

新型脉冲CO_2激光器参数的测量

采用预电离脉冲群开关技术 ,在一具有独特电极结构的横流CO2 激光器上实现了高功率脉冲激光输出。详细介绍了从预电离到主放电 ,最终到激光输出的整个过程中 ,对电压、电流波形及光波形各参数的测量方法 ,并进行了简要分析 ;提出一种利用光的偏振特性对光进行衰减 ,测量光的方法。     

油气水多相流电容层析成像灵敏场仿真研究

针对准确测量油气水多相流各分相含量的问题,采用了电容层析成像技术完成油气水多相流各分相含量测量。通过仿真分析了采用有限元分析方法的电极间的灵敏度特性,探讨了测量中的"软场"特性;结合灵敏度的分析,对单元滤波图象重建进行了仿真对比,得到单元滤波对图像重建有很大的改善。说明采用电容层析成像技术测量各分相含量的方案是可行的。     

A new semiconductor switching device

A new bipolar-type semiconductor switching device is proposed, fabricated by two diffusion processes and without any isolation technique. The device has an n⁺-diffused small electrode instead of a gate electrode in the MOS transistor structure. This device can have high photo sensitivity in the charge storage mode operation.     

Modeling of optical waveguide poling and thermally stimulated discharge (TSD) charge and current densities for guest/host electro-optic polymers

A charge density and current density model of a waveguide system has been developed to explore the effects of electric field electrode poling. An optical waveguide is modeled during poling by considering the dielectric charge distribution, polarization charge distribution, and conduction charge generated by the poling field. The charge distributions are the source of poling current densities. The model shows that boundary charge current density and polarization current density are the major source of currents measured during poling and thermally stimulated discharge measurements. Charge distributions provide insight into the poling mechanisms and are directly related to E/sub A/ and /spl alpha//sub r/. Initial comparisons with experimental data show excellent correlation to the model results.     

用于工业气体在线测量的VCSEL恒流驱动电路设计

设计了一种应用于工业气体在线测量的垂直腔面发射激光器(vertical cavity surface emitting laser,VCSEL)恒流驱动电路.阐述了该恒流驱动电路的组成和工作原理,设计了延时和调制功能,可以安全稳定驱动VCSEL.以测量氧气的VCSEL为例,结合可调谐二极管激光吸收光谱技术对不同浓度的氧气进行测量,得到了较好的拟合系数,验证了驱动电路对VCSEL输出波长控制的稳定性,因此这种恒流驱动电路具有实际应用到工业气体监测中的潜力.     

A multiscale model for bioimpedance dispersion of liver tissue

Radio-frequency ablation (RFA) has been used in liver surgery to minimize blood loss during tissue division. However, the current RFA tissue division method lacks an effective way of determining the stoppage of blood flow. There is limitation on the current state-of-the-art laser Doppler flow sensor due to its small sensing area. A new technique was proposed to use bioimpedance for blood flow sensing. This paper discusses a new geometrical multiscale model of the liver bioimpedance incorporating blood flow impedance. This model establishes correlation between the physical tissue structure and bioimpedance measurement. The basic Debye structure within a multilevel framework is used in the model to account for bioimpedance dispersion. This dispersion is often explained by the Cole-Cole model that includes a constant phase element without physical explanation. Our model is able to account for reduced blood flow in its output with changes in permittivity in gamma dispersion that is mainly due to the polarization of water molecules. This study demonstrates the potential of a multiscale model in determining the stoppage of blood flow during surgery.     

Linear AC Electrode Polarization Impedance at Smooth Noble Metal Interfaces

The linear A. C. electrode polarization impedance of polished platinum has been analyzed on the basis of the rate determining mechanism of the oxygen electrode. The impedance has been found to follow the frequency dependence predicted by an adsorption of the electroactive species. The effects of D. C. potential and specific adsorption of anions have been studied and their effect on the electrode polarization impedance is in agreement with the adsorption mechanism.     

Determination of trapped oxide charge in flash EPROMs and MOSFETswith thin oxides

A technique for determining the sign and the effective density of the trapped oxide charge near the junction transition region, based on the measurement of the gate-induced drain leakage (GIDL) current, is used to investigate the hot-carrier effects resulting from the erase operation and bit-line stress in flash EPROM devices. While the trapped oxide charge depends on the stress conditions, it has been found that a significant amount of hole trapping is likely when a sufficiently large potential difference exists between the gate and junction for either an abrupt or graded junction     

Vibration of Polarographic Oxygen Electrodes by Piezoelectric Elements: A Method of Reducing Flow Artifacts

A method of reducing fluid flow measurement artifacts associated with polarographic oxygen sensors is described which consists of mounting a miniature polarographic electrode on the end of a vibrating piezoelectric bender element. The electrode sensing area is vibrated at a high speed which causes a reduction in measurement error due to flow eddies in solution as well as greatly increasing the electrode sensitivity.     

Birefringence measurements of single-mode fibers using the polarization shuttle pulse technique

A novel and practical polarization shuttle pulse (PSP) technique has been developed to measure the intrinsic birefringence in short lengths of nominally circular-core low-birefringence single-mode fibers. By adding a linear polarizer, a Soleil-Babinet compensator, and a linear analyzer to the conventional shuttle-pulse arrangement, the length dependence of the phase delay (and hence the birefringence) can be measured nondestructively. An order-of-magnitude improvement in measurement repeatability over the conventional cut-back method has been achieved.     

Measurement of ultralow gate tunneling currents using floating-gate integrator technique

We report for the first time that a gate tunneling current measurement sensitivity better than 3/spl times/10/sup -22/ A has been achieved by using a floating-gate integrator technique. The technique involves monitoring the charge change in the floating-gate integrated with an on-chip op-amp and an on-chip feedback capacitor. We used this technique to study the stress-induced leakage current (SILC) and its cycling dependence of 70 /spl Aring/ oxides in the direct tunneling region at oxide voltage as low as 1.9 V. The technique has been validated through correlation to direct measurement on MOSFET arrays and theoretical calculations. The measured SILC current is modeled with an Inelastic trap-assisted tunneling model.     

Development and Testing of a 2-D Transfer CCD

This paper describes the development, operation, and characterization of charge-coupled devices (CCDs) that feature an electrode structure that allows the transfer of charge both horizontally and vertically through the image area. Such devices have been termed two-dimensional (2-D) transfer CCDs (2DT CCDs), as opposed to the conventional devices, which might be called one-dimensional transfer CCDs, but in other respects are the same as conventional CCD devices. Batches of two different 2DT CCD test devices, featuring different electrode structures but with identical clocking operation in each case, were produced and tested. The methodology of 2-D charge transfer in each of the device types is described, followed by a presentation of test results from the new CCDs. The ability of both 2DT CCD transfer electrode schemes to successfully transfer charge in both horizontal and vertical directions in the image section of the devices has been proven, opening up potential new applications for 2DT CCD use     

溶氧电极新型搅拌装置的设计与实验

膜式溶氧电极作为测量溶液中含氧量的一种重要测量工具,但因其电化学性质受到局限而需要搅拌,针对人工搅拌的不足,提出了将提高测量稳定性的一种由于BOD5动测量的新型溶氧电极搅拌装置,装置采用离心式机械搅拌。通过实验验证,该种搅拌方式有助于稳定测量出培养瓶内溶液的溶氧量。     

Charge-injection imaging: Operating techniques and performances characteristics

The charge-injection device (CID) imaging technique employs intracell transfer and injection to sense photon-generated charge at each sensing site. Sites are addressed by an X-Y coincident-voltage technique that is not restricted to standard scanning. Free-format (random) site selection is possible. An epitaxial structure provides a buried collector to prevent recollection of the injected charge. In sequential injection, the charge is injected into the substrate and the resulting displacement current sensed. In parallel injection, the functions of signal charge detection and injection have been separated. The injection operation is used to reset (empty) the charge storage capacitors after line readout has been completed. Nondestructive readout (NDRO) is possible by deferring the injection operation. Low-loss NDRO operation has been achieved using a cooled imager. High sensitivity, low dark current, high modulation transfer function (MTF), and low blooming are some additional advantages of sensing signal charge levels within the array. Compared to the charge-coupled device (CCD), the CID approach results in a relatively high output capacitance; however, this is not considered to be a performance-limiting factor for most imaging applications.     

Sensitivity and limitations of plasma charging damage measurementsusing MOS capacitors structures

This work investigates the sensitivity and limitation of capacitor testing for measuring potential charging damage to gate oxides after a given plasma step. Ramp breakdown measurements are quick and easy to automate but lack sensitivity. Accelerated charge-to-breakdown measurements offers better sensitivity but with long measurement times. V-t measurements using the slope dV/dt after initial charging are found to be very sensitive to charge damage. The damage sensitivity of this method is high and involves tradeoffs between antenna ratio, testing current and testing time. All of which are critical to damage testing. Leakage measurements offers short measurement times and high sensitivity but are limited by the noise level of the measurement system and by the need to make good probe contact to the gate material     

大功率智能快速充电机

文章以大功率开关电源作为充电电源,利用单片机来调节充电电压和电流、控制充放电脉冲、完成充电电池组的检测和保护,从而实现铅酸蓄电池的快速充电,提高充电效率。充电过程以马斯定律为指导,采用大电流脉冲充电;并利用短时间的停止充电来解决离子扩散速度低于化学反应速度的问题,减小浓差极化;同时脉冲放电可以使积累在正负极板上的电荷迅速消失,电化学极化也得以控制。     

Measurement of very low tunneling current density inSiO2 using the floating-gate technique

The floating-gate technique for measuring extremely low gate currents has been adapted to the measurement of Fowler-Nordheim tunneling currents in metal-oxide-semiconductor (MOS) capacitors. Using a special structure consisting of an MOS capacitor and a monitor transistor sharing a common-gate electrode, it has proved possible to measure tunneling current densities as low as 2×10^-13 A/cm². The Fowler-Nordheim tunneling relationship was found to be obeyed over the entire measurable range of current density     

The resistive gate CTD area-image sensor

The transport of charge in a resistive gate controlled PCCD channel structure is described. With the aid of time analysis it is shown that this structure can be used for column transport in a practical area-image sensor. The operating principles of this type of CTD sensor are discussed, with emphasis on blue sensitivity and antiblooming operation. A 96-element linear test circuit has been built for evaluating the expected sensor performance. Design data and some relevant measured results are presented. Results for charge transport time, modulation transfer function, and spectral responsivity illustrate the feasibility of this new solid-state sensor approach.