The calibration of CERL-Planer capacitance strain gauges

CEGB-Planer capacitance strain gauges are used extensively for monitoring the deformation of components operating in the creep range. However, there are significant differences between the way the gauges are installed for use and the way they are installed for calibration. This paper describes the various types of calibrations that have been carried out to identify the errors associated with these differences and the results show that, providing the manufacturers' recommendations are adhered to, the errors are acceptably small.     

电容器容量损耗自动分类机的优化改进

快速检测自动分类机,主要应用于片式半导体陶瓷电容器生产线中,对电容器电容量、损耗进行检测,并由此对电容器进行分类.我们引用先进的机电器件,优化改进设备结构,最终完成机电一体化,设计出符合IEC(International electrotechnical commission)标准的自动测试分类机.该设备采用双通道测试系统,分类快速精确,工作稳定,测试速度可达300只/min,为以往同类分类机测试速度的5倍,且稳定性和可靠性都大有提高.目前该设备已在成都宏明电子科大新材料有限公司的半导体陶瓷电容器生产线上使用,并发挥了重要作用.     

Capacitance fluctuations in bulk MOSFETs due to random discrete dopants

Accuracy of timing in circuits and systems using nanoscale transistors is crucial and is dependent, to first order, on the capacitances of the load transistors. It is accepted that variation in parameters will be intrinsic to such devices due to, among other factors, the discrete nature of the doping. It is likely that one such parameter exhibiting variation will be capacitance. Here we investigate, using 3-dimensional simulation, the fluctuation in gate and drain capacitance in a 30 nm MOSFET due to random discrete doping.     

A Spindleless Instrument for the Roundness Measurement of Precision Spheres

This paper presents an automated instrument for high-precision roundness measurement of spheres. Instead of a rotating spindle, the surface of the sphere itself is used as a geometrical reference. The measurement method is based on the well-established three-point method. In our design, two points are realized as mechanical contacting points and one as a capacitive gauge that directly faces the surface of the sphere. By this simple design—without any moving parts involved in the probing process—we measured the roundness of 1-inch steel spheres with nanometer resolution. After a short introduction into the basic mathematics of the three-point method, the design of the instrument is presented, including the automation of the measuring process and the means used to minimize environmental effects in an industrial environment. Results are presented that prove the outstanding repeatability and accuracy of the instrument. In a comparison with conventional methods, the advantages and limitation of the method are discussed.     

Capacitance theory of open quantum systems with classical contacts

We consider semiconductor devices composed of a small quantum structure as the active device region and two classical environments constituting the source- and the drain contact. The contacts are taken as free electron gases with infinite conductivity defining the chemical potentials in the contacts. The transport through the quantum structure is described in the Landauer–Büttiker formalism using electronic scattering wave functions which determine the electron density in the quantum system. In our Hartree approximation these charges and the induced charges in the contacts are the sources of the self-consistent Coulomb field. As a particular quantum structure we study a GaAs heterostructure device consisting of a two-dimensional electron gas sandwiched between a gate contact and an AlGaAs blocking barrier [see V.T. Dolgopolov et al., Phys. Low-Dim. Struct. 6 (1996) 1]. We demonstrate the quantitative agreement of our theory with the experimental results.     

Decay of capacitance on ceasing formation of anodic oxide films on tantalum

The decrease with time in the capacitance of anodic oxide films on tantalum after ceasing film growth by reducing the field in the oxide was investigated. No dependence was observed of the amount and rate of change in relative dielectric permittivity on the initial current density. The kinetics of this effect are therefore different from those for the decay of the latent ionic conductivity.     

Evaluating k-values for low-k materials after damascene integration: Method and results

This work discusses a method for measuring k-values of low-k films after integration in damascene structures. The experimental results are obtained from 90 nm ½ pitch single damascene structures on low-k materials with intrinsic k-values ranging between 2.2 and 3. The measurement technique is discussed in detail with a focus on the accuracy, limitation of the method, impact of low-k damage and applicability for smaller dimensions.     

液柱式压力计的使用和误差

主要介绍了液术一压力计的正确使用方法和误差分析，给出了U型管压力计和双管差压计的测量精度。     

Capacitance effect on Co-layer dissolution during pulse potentiostatic deposition of Co-Cu/Cu multilayers

Electrodepositon of Co-Cu/Cu multilayer was carried out employing two-pulse potentiostatic method from a sulphate based single solution electrolyte. Dissolution characteristics of thin Co-layer preceding a Cu-layer, were investigated using chronoamperometry, chronocolumetry and electrochemical quartz crystal microbalance (EQCM) techniques. Both galvanic displacement due to Cu²⁺ ions and cell capacitance effect were found to be responsible for the dissolution of Co-layer during pulse switchover from Co to Cu-discharge. Competitive effect of these two factors on Co-dissolution was found to depend solely on the choice of discharge potential pair of Cu and Co. Co-layer dissolution could be prevented on application of Cu-discharge potential very close to the point of onset of Co-reduction potential. An effort has been made to understand the thickness loss due to capacitance effect by adopting a double layer model. It was also seen that the Cu-layer formed due to galvanic displacement reaction was porous in nature, and allows the Co-layer underneath to corrode for several nanometers upon allowance.