Thermal oxidation of silicon nanocrystals in O2 and NO ambient
Thermal oxidation of silicon nanocrystals in O2 and NO ambient
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O2 和 NO 环境中硅纳米晶的热氧化
DOI：
10.1063/1.1565172
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发表时间：
2003
期刊：
影响因子：
--
通讯作者：
B. White
中科院分区：
文献类型：
--
作者：
K. Scheer;R. Rao;R. Muralidhar;S. Bagchi;J. Conner;L. Lozano;C. Perez;M. Sadd;B. White
我们已经研究了作为氧化环境，温度，时间和初始尺寸的函数的Si纳米晶体的氧化，使用X射线光电子能谱，透射电子显微镜，和能量过滤透射电子显微镜。与NO气氛相比，O2气氛中的氧化获得更厚的氧化物壳。在O2中的氧化被观察到在低于SiO2的粘弹性温度的温度下是自限性的，因为垂直于SiO2/Si界面的压缩应力，这阻碍了表面氧化速率。由于在Si/SiOx界面处并入N，NO中的氧化也导致自限制氧化。该富N界面层充当对抗氧化剂扩散的有效屏障，并且还阻挡Si表面上的反应位点。因此，NO氧化在减缓Si芯的进一步氧化方面是成功的，甚至在诸如1050 °C下的O2的严重氧化环境中也是如此。
We have studied the oxidation of Si nanocrystals as a function of oxidizing ambient, temperature, time, and initial nanocrystal size using x-ray photoelectron spectroscopy, transmission electron microscopy, and energy-filtered transmission electron microscopy. Thicker oxide shells are obtained by oxidation in O2 ambient compared with NO ambient. Oxidation in O2 is observed to be self-limiting at temperatures below the viscoelastic temperature of SiO2 because of compressive stress normal to the SiO2/Si interface, which retards the surface oxidation rate. Oxidation in NO also results in self-limiting oxidation due to the incorporation of N at the Si/SiOx interface. This N-rich interfacial layer acts as an effective barrier against oxidant diffusion and also blocks the reaction sites on the Si surface. Therefore, NO oxidation is successful in slowing further oxidation of Si cores, even in a severe oxidizing ambient such as O2 at 1050 °C.