A Processing Window for Fabricating Heavily Doped Silicon Nanowires by Metal-Assisted Chemical Etching

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• 作者：Yangyang Qi ; Zhen Wang ; Mingliang Zhang ; Fuhua Yang ; Xiaodong Wang
• 刊名：Journal of Physical Chemistry C
• 出版年：2013
• 出版时间：November 27, 2013
• 年：2013
• 卷：117
• 期：47
• 页码：25090-25096
• 全文大小：423K
• 年卷期：v.117,no.47(November 27, 2013)
• ISSN：1932-7455

文摘

Heavily doped silicon nanowires (SiNWs) with controllable doping concentrations can be used in many fields because of their unique characteristics. However, it is difficult to fabricate long heavily doped SiNWs. In this article, a systematic study of metal-assisted chemical etching (MACE) of heavily doped silicon wafers is presented. High-quality SiNWs with lengths up to 40 渭m could be achieved. The electron-transfer processes among Si, Ag⁺, Ag nanoparticles, and H₂O₂ were investigated to explain the formation of SiNWs. A chemical etching processing window, considering HF and H₂O₂ concentrations, reaction temperature, and etching time, is proposed. To obtain SiNWs, the etching reaction should occur at room temperature for less than 40 min. The appropriate concentration ranges are 0.2鈥?.4 M for H₂O₂ and 8鈥?0 M for HF. Transmission electron microscopy (TEM) measurements confirmed that the as-prepared nanowires were single-crystalline. Current鈥搗oltage (I鈥?i>V) measurements of an individual nanowire showed a resistance larger than the calculated value based on bulk silicon. This work can provide guidelines for obtaining high-quality heavily doped SiNWs using the MACE method.