共查询到20条相似文献,搜索用时 156 毫秒
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基于能量平衡条件,结合低温硅(LT-Si)剪切模量小于SiGe的实验结果,从螺位错形成模型出发,给出了基于LT-Si技术的赝晶SiGe应变弛豫机理.该机理指出,赝晶SiGe薄膜厚度小于位错形成临界厚度,可通过LT-Si缓冲层中形成位错释放应变;等于与大于临界厚度,位错在LT-Si层中优先形成,和文献报道中已观察到的实验结果相符合.同时,实验制备了基于LT-Si技术的弛豫Si0.8Ge0.2虚拟衬底材料.结果显示,位错被限制在LT-Si缓冲层中,弛豫度达到了85.09%,且在Si0.8Ge0.2中未观察到穿透位错,实验结果证实了赝晶Si0.8Ge0.2是通过在LT-Si缓冲层形成位错来释放应变的弛豫机理.
关键词:
低温硅
赝晶锗硅
弛豫机理
位错理论 相似文献
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从固体模型理论的结果出发,计算了生长于Si(100)衬底上x值小于085的Si1-xGex合金材料(能带结构为类Si结构)的间接带隙与应变的关系,结 果表明,应变的S iGe材料的带隙和完全弛豫状态下材料的带隙之差与应变呈线性关系.基于这一结果,提出了 用测量带隙来间接测定SiGe/Si应变状态的方法.用带隙法和x射线双晶衍射法测量了不同应 变状态下的SiGe/Si多量子阱材料的应变弛豫度,两者可以较好的符合,表明带隙法测量SiG e应变弛豫度是可行的.
关键词:
SiGe合金
应变
带隙 相似文献
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UHV/CVD硅锗膜的Raman光谱分析 总被引:6,自引:0,他引:6
本文提出一种用Raman光谱测量SiGe合金膜中的锗组分及应变的方法,方法是非破坏的。并用这一方法测量了几种不同锗组分和膜厚度的SiGe合金样品,它们都是用UHV/CVD设备生长的,其中两个样品还与X-射线双晶衍射的结果作了比较,两种方法的结果十分一致,这说明本文提出的方法是准确可靠的,这些样品用于制作SiGe/Si异质结PMOSFET,对0.5um 沟长器件,跨导达112ms.mm^-1。 相似文献
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硅锗异质结双极晶体管(SiGe HBT)一般以重掺硼(B)的应变SiGe层作为基区.精确表征SiGe材料能带结构对SiGe HBT的设计具有重要的意义.在应变SiGe材料中,B的重掺杂一方面会因为重掺杂效应使带隙收缩,另一方面,B的引入还会部分补偿Ge引起的应变,从而改变应变引起的带隙变化.在重掺B的应变SiGe能带结构研究中,采用半经验方法,考虑了B的应变补偿作用对能带的影响,对Jain-Roulston模型进行修正,并分析了重掺杂引起的带隙收缩在导带和价带的分布. 相似文献
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硅基锗薄膜的异质外延生长及其在光电子器件中的应用 总被引:1,自引:0,他引:1
准直接带隙的锗,其禁带宽度小,吸收系数大,迁移率高,更重要的是,它能与硅微电子工艺兼容,在硅基光电集成中得到了广泛的研究和应用.文章综述了硅基锗薄膜的异质外延生长及其在光电子器件(特别是长波长光电探测器和激光器)应用上的进展;介绍了在硅衬底上异质外延生长锗薄膜的缓冲层技术,如组分变化的SiGe缓冲层技术、选区外延技术和低温技术;讨论了硅基锗薄膜光电探测器的性能与结构的关系以及发展趋势;分析了张应变和n型掺杂对锗光电性质的影响;展望了硅基锗薄膜单片集成和电抽运激光器的前景. 相似文献
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用等离子体增强化学气相淀积(PECVD)生长了200nm的SiGe薄膜,然后将C离子注入SiGe层,经两步热退火处理制备了Si1-x-yGexCy三元合金半导体薄膜.应用卢瑟福背散射(RBS),傅里叶变换红外光谱(FTIR)和高分辨率x射线衍射(HRXRD)研究了薄膜的结构和外延特性.发现C原子基本处于替代位置,C原子的掺入缓解了SiGe层的压应变
关键词:
Si1-x-yGexCy薄膜
离子注入
固相外延 相似文献
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针对国产锗硅异质结双极晶体管(SiGe HBTs), 采用半导体器件模拟工具, 建立SiGe HBT单粒子效应三维损伤模型, 研究影响SiGe HBT单粒子效应电荷收集的关键因素. 分析比较重离子在不同位置入射器件时, 各电极的电流变化和感生电荷收集情况, 确定SiGe HBT电荷收集的敏感区域. 结果表明, 集电极/衬底结内及附近区域为集电极和衬底收集电荷的敏感区域, 浅槽隔离内的区域为基极收集电荷的敏感区域, 发射极收集的电荷可以忽略. 此项工作的开展为下一步采用设计加固的方法提高器件的抗辐射性能打下了良好的基础.
关键词:
锗硅异质结双极晶体管
单粒子效应
电荷收集
三维数值仿真 相似文献
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According to the dimer theory on semiconductor surface and chemical vapor deposition(CVD) growth characteristics of Si1-xGex, two mechanisms of rate decomposition and discrete flow density are proposed. Based on these two mechanisms, the Grove theory and Fick’s first law, a CVD growth kinetics model of Si1-xGex alloy is established. In order to make the model more accurate, two growth control mechanisms of vapor transport and surface reaction are taken into account. The paper also considers the influence of the dimer structure on the growth rate. The results show that the model calculated value is consistent with the experimental values at different temperatures. 相似文献
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By means of first-principles calculations we studied the decomposition pathways of SiH? on Ge(100) and of GeH? on Si(100), of interest for the growth of crystalline SiGe alloys and Si/Ge heterostructures by plasma-enhanced chemical vapor deposition. We also investigated H desorption via reaction of two adsorbed SiH?/GeH? species (β? reaction) or via Eley-Rideal abstraction of surface H atoms from the impinging SiH? and GeH? species. The calculated activation energies for the different processes suggest that the rate-limiting step for the growth of Si/Ge systems is still the β? reaction of two SiH? as in the growth of crystalline Si. 相似文献
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Qi-Yue Shao Ai-Dong Li Jin-Bo Cheng Hui-Qin Ling Di Wu Zhi-Guo Liu Yong-Jun Bao Mu Wang Nai-Ben Ming Cathy Wang Hong-Wei Zhou Bich-Yen Nguyen 《Applied Surface Science》2005,250(1-4):14-20
LaAlO3 (LAO) is explored in this work to replace SiO2 as the gate dielectric material in metal–oxide–semiconductor field effect transistor. Amorphous LAO gate dielectric films were deposited on Si (0 0 1) substrates by low pressure metalorganic chemical vapor deposition using La(dpm)3 and Al(acac)3 sources. The effect of processing parameters such as deposition temperature and precursor vapor flux on growth, structure, morphology, and composition of LAO films has been investigated by various analytical methods deeply. The film growth mechanism on Si is reaction limiting instead of mass transport control. The reaction is thermally activated with activation energy of 37 kJ/mol. In the initial growth stage, Al element is deficient due to higher nucleation barrier on Si. The LAO films show a smooth surface and good thermal stability and remain amorphous up to a high temperature of 850 °C. The electrical properties of amorphous LAO ultrathin films on Si have also been evaluated, indicating LAO is suitable for high k gate dielectric applications. 相似文献
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采用低压化学汽相沉积(LPCVD)方法,依靠纯SiH4气体分子的表面热分解反应, 在由Si—O—Si键和由Si—OH键终端的两种SiO2表面上,自组织生长了Si纳米量子点. 实 验研究了所形成的Si纳米量子点密度随SiO2表面的反应活性位置数、沉积温度以及反应气 压的变化关系. 依据LPCVD的表面热力学过程,定性地分析了Si纳米量子点的形成机理.研究结果对具有密度分布均匀和晶粒尺寸可控的Si纳米量子点的自组织生长,以及Si基新型量子电子器
关键词:
Si纳米量子点
LPCVD
自组织化形成
生长机理 相似文献
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We report results of a scanning tunneling microscopy and X-ray photoelectron spectroscopy study on the interaction of tetraethoxysilane (TEOS), a precursor for chemical vapor deposition of silicon dioxide, with Si(111)-(7×7) at room temperature. Under these conditions the interaction of TEOS with the surface is predominantly dissociative. The main adsorption products are ethyl- and triethoxysiloxane groups, which probably evolve in a four-center reaction of TEOS with two neighboring surface dangling bonds. Adsorption of the dissociation products is highly site-selective: triethoxysiloxane groups adsorb on the Si adatoms while ethyl groups react with the rest-atom dangling bonds. Center adatoms are over three times more reactive towards this reaction than corner adatoms. This two-fold selectivity is explained within the concept of local electron donor/acceptor properties. 相似文献
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Surface saturation control on the formation of wurtzite polytypes in zinc blende SiC nanofilms grown on Si-(100) substrates
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We investigate the formations of wurtzite (WZ) SiC nano polytypes in zinc blende (ZB) SiC nanofilms hetero-grown on Si-(100) substrates via low pressure chemical vapor deposition (LPCVD) by adjusting the Si/C ratio of the introduced precursors. Through SEM, TEM, and Raman characterizations, we find that the nanofilms consist of discrete WZ SiC nano polytypes and ZB SiC polytypes composed of WZ polytypes (WZ + ZB) and disordered ZB SiC polytypes, respectively, according to Si/C ratios of 0.5, 1.5, and 3. We attribute the WZ polytype formation to being due to a kinetic mechanism based on the Si/C surface saturation control. 相似文献
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讨论在热解碳化学气相沉积过程中出现的多重定态和非平衡相变这一典型的非平衡物理现象的机理和发展趋势.通过理论分析和实验结果的分析发现热解碳化学气相沉积的化学反应是一个典型的非平衡化学反应,其中在沉积过程中出现的生成碳黑的过程是一个典型的非平衡相变.在这一非平衡化学反应中,自由基的反应模型符合Schlogl模型.在这一非平衡化学反应中,有线性区和非线性区,线性区的产物是热解碳,而非线性区是碳黑.在线性区,反应速率方程是唯一的、线性的,而在非线性区,反应速率方程是多重的、非线性的.
关键词:
非平衡化学反应
非平衡相变
化学气相沉积
Schlogl模型
热解碳 相似文献
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A. V. Zdoroveishchev N. V. Baidus’ B. N. Zvonkov P. B. Demina 《Bulletin of the Russian Academy of Sciences: Physics》2011,75(1):25-27
This work examines the possibility of controlling the parameters of InAs/GaAs quantum dot arrays obtained by metal-organic
chemical vapor deposition (MOCVD) at atmospheric pressure with using antimony as a surfactant. The possibility of controlling
the parameters and optical properties of InAs quantum dot arrays by varying the surface concentration of Sb atoms in a GaAs
buffer layer surface is demonstrated. A model of quantum dot array formation in the presence of Sb atoms is proposed. 相似文献
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在自行设计、建立的MOCVD系统上,以Cu(hfac)2为反应前驱物在单晶硅上进行铜薄膜的化学气相沉积,并用AFM、SEM对铜核的成长机理进行了研究.结果表明,反应初期,单晶硅上铜核的成长为岛状,反应后期为先层状后岛状.利用XPS对铜薄膜成长的反应机理进行了探讨,由薄膜的Cu2p、Ols、Fls、Si2p谱可推论出,XPS谱中所出现的C=O、OH及CF3/CF2可能为Cu(hfac),当Cu(hfac)2在高温下分解成Cu(hfac)及hfac后,H2还原表面的hfac生成OH基,反应进行一段时间,OH基浓度大到一定的程度后,与Cu(hfac)2热裂解产生的hfac作用生成HO-hfac并脱附,使表面的铜的氧化物被还原以及发生Cu(hfac)2与H2的氧化还原反应. 相似文献