Epitaxial diamond-hexagonal silicon nano-ribbon growth on (001) silicon.
Epitaxial diamond-hexagonal silicon nano-ribbon growth on (001) silicon.
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DOI：
10.1038/srep12692
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发表时间：
2015-08-04
影响因子：
4.6
通讯作者：
Vandervorst W
中科院分区：
文献类型：
--
作者：
Qiu Y;Bender H;Richard O;Kim MS;Van Besien E;Vos I;de Potter de ten Broeck M;Mocuta D;Vandervorst W
硅结晶在金刚石立方相，并仅显示在1.1 eV的弱发射。然而，金刚石-六方晶硅具有1.5 eV的间接带隙，因此具有在光电器件中应用的潜力。在这里，我们讨论了一种基于先进的硅器件工艺形成金刚石-六边形硅纳米带的方法。通过施加适当的温度退火以使硅鳍之间的氧化物填充物致密化，施加在夹在宽氧化物窗口和窄氧化物窗口之间的鳍上的横向向外应力可以导致在这些鳍的基部处从金刚石立方到金刚石六方Si的相变。金刚石-六边形板通常为5-8 nm厚，并且可以在鳍的整个宽度和长度上延伸，即，沿着鳍沿着具有纳米带形状。虽然六方硅是一种亚稳相，但一旦形成，它在随后的高温处理过程中，甚至在高达1050 ºC的工艺步骤中也是稳定的。
Silicon crystallizes in the diamond-cubic phase and shows only a weak emission at 1.1 eV. Diamond-hexagonal silicon however has an indirect bandgap at 1.5 eV and has therefore potential for application in opto-electronic devices. Here we discuss a method based on advanced silicon device processing to form diamond-hexagonal silicon nano-ribbons. With an appropriate temperature anneal applied to densify the oxide fillings between silicon fins, the lateral outward stress exerted on fins sandwiched between wide and narrow oxide windows can result in a phase transition from diamond-cubic to diamond-hexagonal Si at the base of these fins. The diamond-hexagonal slabs are generally 5–8 nm thick and can extend over the full width and length of the fins, i.e. have a nano-ribbon shape along the fins. Although hexagonal silicon is a metastable phase, once formed it is found being stable during subsequent high temperature treatments even during process steps up to 1050 ºC.