Effects of vacancy structural defects on the thermal conductivity of silicon thin films

Vacancy structural defect effects on the lattice thermal conductivity of silicon thin films have been investigated with non-equilibrium molecular dynamics simulation.The lattice thermal conductivities decrease with increasing vacancy concentration at all temperatures from 300 to 700 K.Vacancy defects decrease the sample thermal conductivity,and the temperature dependence of thermal conductivity becomes less significant as the temperature increases.The molecular dynamics result is in good agreement with the theoretical analysis values obtained based on the Boltzmann equation.In addition,theoretical analysis indicates that the reduction in the lattice thermal conductivity with vacancy defects can be explained by the enhanced point-defect scattering due to lattice strain.     

太钢高炉降硅冶炼技术

通过对太钢高炉降硅冶炼进行大量的理论分析与实验研究,得出了铁水硅质量分数的影响因素,找到了降硅冶炼的有效途径,达到铁水低硅冶炼的目的,铁水质量有了明显的提高。     

基于低温直接键合的血细胞计数芯片结构制备

研究了一种新颖的微流管道血细胞计数器的结构及其工作原理,采用流体动力学对其液体分层流动特性进行了仿真分析,结合图形制备和低温直接键合工艺制作了硅基微流体管道血细胞计数器结构,并采用红外透射方法对微流体管道结构进行了检测.对封闭管道的流通性及结构的键合强度也进行了测量.研究分析表明,采用上述工艺制备的微流体芯片结构与电子器件兼容性好,具有良好的化学惰性和热稳定性,而且管道结构规则,精度高,键合界面层薄,具有较好的应用前景.     

Silicon Pick-up of Interstitial-Free Steel From MgO-SiC Refractories

The silicon pick-up of interstitial-free steel （IF steel） from resin bonded MgO-SiC refractories is studied via a medium frequency induction furnace. Samples of IF steel were heated in MgO-SiC crucibles with mould flux cover at 1 600 ℃ for 180 min. The silicon contents of IF steel samples taken from the molten steel in every 30 min were examined and the refractories after heating were investigated by electron probe microanalysis （EPMA） with energy dispersive spectrometer （EDS）. The silicon content of steel rapidly increased in the first 90 min of beating, and then decreased because of the formation of liquid layer on the refractory. Liquid layer separated the liquid steel from the bulk refractory and stopped the pick-up of silicon. At the same time, desilication via oxygen through the liquid layer and flux started to reduce the silicon content of the liquid steel     

改进的BP算法在中小型高炉炉温预测上的应用

本研究应用人工神经网络方法对高炉炉温进行预测,确定了三层前向网络结构。针对基于梯度下降法的BP网络存在的学习效率低、收敛速度慢、易陷于局部极小状态、网络的泛化及适应能力较差等缺陷,采用了附加动量法及自适应学习率、合理选择激励函数等策略对算法中的缺陷给出了改进措施,取得了较好的应用效果。     

一种亚微米垂直硅墙的刻蚀方法

亚微米垂直硅墙的制备是垂直硅薄膜耦合约瑟夫逊结的关键工艺.本文作者在普通光刻设备基础上,开发了一种在〈100〉硅片上制备亚微米硅墙的刻蚀方法:首先用普通光刻手段刻出较宽的墙区;其次,对非墙区进行迭加注入掺杂;第三,杂质高温横向扩散,第四,掺杂选择性刻蚀;第五,高温氧化减薄.实验结果表明,这种方法可以获得墙宽为0.29μm,墙高为1μm左右的硅墙,而且还有一定的改进潜力.     

X射线荧光光谱熔片分析的校准曲线与玻璃片质量校正

在铁合金和铁矿石的X射线荧光光谱(XRF)熔片分析中,存在着样品直接灼烧和熔融质量变化不同产生的误差,常用的稀释比校正无法校正这种误差。实验提出在固定质量(体积)的熔剂中熔入系列被测组分的氧化物制备出质量(体积)相同的玻璃片标准系列,建立X射线荧光强度与玻璃片中被测组分体积浓度的函数曲线,使用样品玻璃片质量与校准曲线玻璃片的质量比校准分析结果,即质量校正代替稀释比校正。以纯物质(SiO₂、CaCO₃、Al₂O₃和Fe₂O₃)为标准,用选定的仪器工作条件,建立了硅钙合金分析用Si、Ca、Fe、Al质量分数对荧光强度的校准曲线,其线性相关系数分别为0.9990、0.9993、0.9994、0.9995。用标准样品考察了校准曲线的准确度。t检验结果表明,当玻璃片的质量变化较大时,不使用质量校正测量结果偏差较大,正确度差。     

硅片处理预对准系统的研究

介绍了所研制的12 in硅片预对准系统．首先,根据硅片预对准系统的任务和流程设计了系统的结构．其次,设计了预对准检测算法,采用最小二乘圆法对硅片圆心进行定位;提出了检测硅片缺口的边缘变化率法和计算缺口基准点的曲线拟合法．对预对准系统进行了误差分析．最后,采用光学式预对准方法,对12 in硅片进行了预对准实验研究．实验结果表明硅片缺口的重复定位精度小于48 μm,预对准时间为23 s,满足设计要求．     

低温电沉积硅工艺研究进展

半导体硅的传统制备工艺主要有直拉法、区熔法及气相沉积法等,这些制备工艺都需要在高温下进行,且涉及到大型设备,制备成本较高,操作较为复杂。采用低温电沉积法制备硅具有简单可控、低成本的特点,因而受到了研究者青睐。主要从电极、溶剂的选取及电沉积方法等方面阐述了低温电沉积硅工艺研究现状,同时对低温电沉积硅存在的问题和发展趋势进行了讨论。     

Study on Microstructure and Mechanical Properties of Hot Rolled Low Silicon Containing Phosphorus TRIP Steel

The effects of final air cooling temperature on the microstructure and mechanical properties of hot rolled 0.2C-1.9Mn-0.5Si-0.08P TRIP steel were studied by utilizing OM, SEM, TEM and tensile tests. Experimental results showed that in the multiphase microstructure of the investigated steel when the finish rolling temperature was about 820 ℃ and the final air cooling temperature was in the range of 630-700 ℃, the grain size of most of ferrite was finer (about 4 μm) and which had higher dislocation density, t...