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UHV/CVD生长SiGe/Si材料分析及应用研究 总被引:1,自引:1,他引:0
以Si2H6和GeH4为生长气源,采用UHV/CVD系统在Si(100)衬底上生长了Sil—xGex合金和Sil—xGex/Si多量子阱结构。采用X射线双晶衍射仪、扫描电子显微镜和原子力显微镜等仪器设备对样品的组份、界面和表面形貌等晶体质量进行了研究。SiGe合金中Si和Ge摩尔分数的比值随着Si2H6和GeH4流量比的增加按比例线性增加,比例因子为2.57。生长的Si0.88Ge0.12合金样品的界面清晰,表面平整,平均粗糙度仅为0.4nm,位错密度低于104/cm2。六周期Si0.88Ge0.12/Si多量子阱的X射线双晶衍射摇摆曲线中存在多级卫星峰和Pendellosung条纹。这些结果表明SiGe合金和SiGe/Si多量子阱均具有很好的晶体质量。 相似文献
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王玉萍 《天津成人高等学校联合学报》2014,(8):109-113
教学环境对于学生的学业成就和智力发展有着至关重要的影响。教学环境可分为教育环境与学习环境。本文将从教育心理学针对教学环境的新进展入手,探讨教育环境、教学环境对学生学业成就、学业自我概念的影响,以针对课堂情感氛围和Marsh的I\E模型与大鱼小池效应的组合模型为重点,探讨其对于教与学的启示。 相似文献
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从PBL的定义、特征、作用,以其在国外ESL\EFL教学中的实施等方面,对PBL研究现状进行了系统地梳理和分析,旨在为我国英语教师实施PBL提供参考。 相似文献
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The conventional fault analysis method based on symmetrical components supposes that the three-phase parameters of un-transposed transmission line are symmetrical in case of fault. The errors caused by the method with the symmetrical distributed parameter circuit model as the equivalent circuit of the un-transposed ultra high voltage (UHV) transmission line were studied under both normal operation and fault, and the corresponding problems arising were pointed out. By contrast with electromagnetic transient and power electronics (EMTPE) simulation results with the asymmetrical distributed parameter circuit model of un-transposed line, it is shown that the conventional method cannot show the existence of negative and zero sequences before fault happening and there are many errors on voltage and current after fault happening which are different with fault types. The error ranges of voltage and current are 2.13%-81.13% and -7.82%-86.15%, respectively. 相似文献
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Huang Jing-yun Ye Zhi-zhen Lu Huan-ming Zhao Bing-hui Wang Lei Que Duan-lin 《浙江大学学报(A卷英文版)》2000,1(4):427-430
An ultrahigh vacuum chemical vapor deposition (UHV/CVD) system with reflection high energy electron diffraction (RHEED) was
introduced. The Si epilayers and SiGe strained-layers on three-inch Si (100) substrates were grown in this UHV/CVD system.
The substrate temperature during growth was from 550°C to 780°C. The properties of epilayers were characterized by high-resolution
cross-sectional transmission electron microscopy (TEM), double crystal X-ray diffraction (DCXRD), and spreading resistance
(SPR). A B-doped SiGe epilayer with uniform resistivity distribution was grown.
Project supported by NSFC and Science Commission Program of Zhejiang Province of China. 相似文献
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1 Introduction Becauseofthecombinationofanumberoffavorableproperties,suchashighhardness,highcarriermobilityandbreakdownvoltage,largebandgap ,lowdielectricconstant,andtransparencytovisiblelight,IRlightandmicrowaves,etc.[1] ,diamondfilmhasbeenconsider ablyprom… 相似文献
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本文主要对化学气相沉积法制备(类)金刚石薄膜专利申请中专利申请的年度变化趋势、专利申请国家/地区布局、制备方法、申请人类型、专利技术改进方向、国内外主要申请人技术演进和发展等方面进行分析。研究表明,日本、美国等在该领域处于绝对领先地位,近年来国内的研究已取得了重大的进展,正在逐渐缩小与国外技术差距,切削加工和耐磨部件等应用领域是申请热点。 相似文献