Formation of size-controlled silicon nanocrystals in plasma enhanced chemical vapor deposition grown SiOxNy/SiO2 superlattices
Formation of size-controlled silicon nanocrystals in plasma enhanced chemical vapor deposition grown SiOxNy/SiO2 superlattices
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DOI：
10.1016/j.tsf.2011.06.084
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发表时间：
2011-10-31
期刊：
影响因子：
2.1
通讯作者：
Zacharias, M.
中科院分区：
文献类型：
--
作者：
Hartel, A. M.;Hiller, D.;Zacharias, M.
采用等离子体增强化学气相沉积法在氮氧化硅基体中制备了尺寸可控的硅纳米晶。通过热退火处理沉积的超晶格（SL）和相应的体膜。通过选择足够低的加热斜坡，在加热过程中进行氢渗出。在高达1150摄氏度的温度下，研究了层相分离成SiNC和周围的氮氧化物基质。采用变角椭圆偏振光谱、光致发光光谱、X射线光电子能谱、傅里叶变换红外光谱和透射电子显微镜研究了不同SiOxNy层厚度下退火温度对SiOxNy/SiO2 -SL的影响。退火前FTIR研究表明，除了预期的Si-O键，还形成了氮和氢相关的键。退火后Si-O-Si伸缩振动向更高波数的移动表明相分离。氢相关键的消失指示氢渗出。随着退火温度的升高，PL信号显著上升，并且PL值也随之升高。由于量子限制效应，峰位置与SiOxNy子层的厚度密切相关。TEM研究证实了氮氧化物基质中SiNCs的尺寸控制生长。结合氮和氢的作用进行了讨论。(C)2011 Elsevier B. V.保留所有权利。
Size controlled silicon nanocrystals (SiNC) in silicon oxynitride matrix were prepared using plasma enhanced chemical vapor deposition. The as-deposited superlattices (SLs) and the corresponding bulk films were treated by thermal annealing. Hydrogen effusion was performed during the heating up by choosing a sufficiently low heating ramp. The phase separation of the layers into SiNCs and surrounding oxynitride matrix was studied at temperatures of up to 1150 degrees C. The influence of the annealing temperature on SiOxNy/SiO2 - SLs with varying SiOxNy layer thickness was investigated by several analytical techniques including variable angle spectroscopic ellipsometry, photoluminescence (PL) spectroscopy, x-ray photoelectron spectroscopy, Fourier transform infrared spectrometry (FTIR) and transmission electron microscopy (TEM). Before annealing FTIR investigations show in addition to the expected Si-O bonds also the formation of nitrogen and hydrogen related bonds. The shift of the Si-O-Si stretching vibration to higher wave numbers after annealing indicates phase separation. The disappearance of the hydrogen related bonds indicates the hydrogen effusion. The PL signal is rising significantly with increasing annealing temperature and the PL. peak position is strongly related to the thickness of the SiOxNy sublayers due to quantum confinement effects. TEM investigations confirm the size-controlled growth of SiNCs within the oxynitride matrix. The role of incorporated nitrogen and hydrogen is discussed. (C) 2011 Elsevier B.V. All rights reserved.