利用CF4等离子体制作高开口率TFT-LCD

为了获得高的开口率,有必要优化设计参数和工艺容差。通常的过孔刻蚀工艺采用SF6基气体进行刻蚀,但是这种方法在金属和钝化层之间的选择性太小,因此,必须增加过孔的尺寸才行。为了克服上述问题,在本研究中用CF4气体代替SF6气体进行刻蚀,结果在FFS 5 .16(2 .03 in)像素结构中,开口率提高了60 %。     

On Stability of Constrained Receding Horizon Control with Finite Terminal Weighting Matrix

In this paper, a new stabilizing receding horizon control, based on a finite input and state horizon cost with a finite terminal weighting matrix, is proposed for time-varying discrete linear systems with constraints. We propose matrix inequality conditions on the terminal weighting matrix under which closed-loop stability is guaranteed for both cases of unconstrained and constrained systems with input and state constraints. We show that such a terminal weighting matrix can be obtained by solving a linear matrix inequality (LMI). In the case of constrained time-invariant systems, an artificial invariant ellipsoid constraint is introduced in order to relax the conventional terminal equality constraint and to handle constraints. Using the invariant ellipsoid constraints, a feasibility condition of the optimization problem is presented and a region of attraction is characterized for constrained systems with the proposed receding horizon control.     

Dream of standalone CAE and its vision

CAE （Computer Aided Engineering） began in late 1960s in accordance with the rapid development of computer H/W and S/W industries. Until now, engineering designs are depended mostly on experiences and analytical methods in many aspects. Many scientists in United States and Europe had realized that computer technologies would have been the key of engineering design technology in the future, and their expectations turn out correct. Now, what are they predicting in the future from now on？ What can be the dream or vision of CAE？ Where will CAE product move on？ There has been quite long questions and discussions in CAE community and those related. Let＇ s see the history of CAE first, then it could be more clear where it is moving to.     

Exponential slow crack growth of glass and advanced ceramics—dynamic fatigue

The life prediction analysis based on an exponential crack‐velocity formulation was made and examined using a variety of experimental data on glass and advanced structural ceramics in constant stress‐rate (‘dynamic fatigue’) loading at ambient and elevated temperatures. The data fit to the relation of strength versus ln (stress rate) was very reasonable for most of the materials. The major limitation in the exponential crack‐velocity formulation, however, was that the inert strength of a material must be known a priori to evaluate the important SCG parameter, n, a significant drawback as compared with the conventional power‐law crack‐velocity formulation.     

Development of high performance casting analysis software by coupled parallel computation

Up to now, so much casting analysis software has been continuing to develop the new access way to real casting processes. Those include the melt flow analysis, heat transfer analysis for solidification calculation,mechanical property predictions and microstructure predictions. These trials were successful to obtain the ideal results comparing with real situations, so that CAE technologies became inevitable to design or develop new casting processes. But for manufacturing fields, CAE technologies are not so frequently being used because of their difficulties in using the software or insufficient computing performances. To introduce CAE technologies to manufacturing field,the high performance analysis is essential to shorten the gap between product designing time and prototyping time.The software code optimization can be helpful, but it is not enough, because the codes developed by software experts are already optimized enough. As an alternative proposal for high performance computations, the parallel computation technologies are eagerly being applied to CAE technologies to make the analysis time shorter. In this research, SMP (Shared Memory Processing) and MPI (Message Passing Interface) (1) methods for parallelization were applied to commercial software "Z-Cast" to calculate the casting processes. In the code parallelizing processes,the network stabilization, core optimization were also carried out under Microsoft Windows platform and their performances and results were compared with those of normal linear analysis codes.     

Plasma density measurement and downstream etching of silicon and silicon oxide in Ar/NF3 mixture remote plasma source

In this study, plasma density measurements were performed near the plume region of the remote plasma source (RPS) in Ar/ NF₃ gas mixtures using a microwave cutoff probe. The measured plasma density is in the range of 10 ¹⁰ –10 ¹¹ cm ⁻³ in the discharge conditions with RPS powers of 2–4 kW and gas pressures of 0.87–4 Torr. The plasma density decreased with increasing gas pressures and RPS powers under various Ar/ NF₃ mixing ratios. This decrease in the plasma density measured at the fixed measurement position (plume region) can be understood by the reduction of the electron energy relaxation length with increases in the gas pressures and mixing ratio of NF₃/(Ar / NF₃). We also performed downstream etching of silicon and silicon oxide films in this system. The etch rate of the silicon films significantly increases while the silicon oxide is slightly etched with the gas pressures and powers. It was also found that the etch rate strongly depends on the wafer position on the processing chamber electrode, and that the etch selectivity reached 96–131 in the discharge conditions of RF powers (3730–4180 W) and gas pressures (3.6–4 Torr).     

动态电压恢复器研究综述

动态电压恢复器（DVR）作为一种重要的用户电力装置,受到国内外研究者的广泛关注。首先介绍DVR的工作原理和基本结构,然后从拓扑结构、补偿策略以及控制方法几个方面对现有文献进行综述。最后对DVR的研究发展进行了探讨。     

Effects of alloying elements on the electrochemical characteristics of iron aluminides

Effects of alloying elements on the electrochemical characteristics of iron aluminides in the H2SO4, H2SO4+KSCN and HCl solutions were investigated using electrochemical tests. The corrosion morphologies in iron aluminides were analysed by utilising optical microscopy. It was found that the addition of Cr and Mo to iron aluminides increased the corrosion potential, pitting potential and repassivation potential. The active current density, passive current density and reactivation current density decreased as Cr and Mo were added. In the case of Mo addition, the passive current density was slightly higher in the H2SO4 solution than in solutions containing SCN- and Cl-. When B was added to samples, the corrosion potential and repassivation potential decreased, whereas the active current density, passive current density, reactivation current density and pitting potential increased. Iron aluminides containing Mo and Cr showed remarkably improved intergranular and pitting corrosion resistance to SCN- and Cl- solution. On the other hand, B addition accelerated granular and intergranular corrosion by precipitation of borides. This revised version was published online in November 2006 with corrections to the Cover Date.     

Silver-palladium alloy deposited by DC magnetron sputtering method as lubricant for high temperature application

The silver-palladium(Ag-Pd) alloy coating as a solid lubricant was investigated for its application to the high temperature stud bolts used in nuclear power plants. A hex bolt sample was prepared in the following steps: 1) bolt surface treatment using alumina grit blasting for cleaning and increasing the surface area; 2) nickel(Ni) film coating as a glue layer on the surface of the bolt; and 3) Ag-Pd alloy coating on the Ni film. The films were deposited by using a direct current(DC) magnetron sputtering system. The thickness and composition of the Ag-Pd alloy film have effect on the friction coefficient, which was determined using axial force measurement. A 500 nm-thick Ag-Pd (80:20, molar ratio) alloy film has the lowest friction coefficient of 0.109. A cyclic test was conducted to evaluate the durability of bolts coated with either the Ag-Pd (80:20) alloy film or N-5000 oil. In a cycle, the bolts were inserted into a block using a torque wrench, which was followed by heating and disassembling. After only one cycle, it was not possible to remove the bolts coated with the N-5000 oil from the block. However, the bolts coated with the Ag-Pd (80:20) alloy could be easily removed up until 15 cycles.     

Application of artificial neural network for predicting plain strain fracture toughness using tensile test results

A back‐propagation neural network was applied to predicting the K_IC values using tensile material data and investigating the effects of crack plane orientation and temperature. The 595 K_IC data of structural steels were used for training and testing the neural network model. In the trained neural network model, yield stress has relatively the most effect on K_IC value among tensile material properties and K_IC value was more sensitive to K_IC test temperature than to crack plane orientation valid in the range of material data covered in this study. The performance of the trained artificial neural network (ANN) was evaluated by comparing output of the ANN with results of a conventional least squares fit to an assumed shape. The conventional linear or nonlinear least squares fitting methods gave very poor fitting results but the results predicted by the trained neural network were considerably satisfactory. This study shows that the neural network can be a good tool to predict K_IC values according to the variation of the temperature and the crack plane orientation using tensile test results.