Wang Haitao, Zhang Yong, Tian Tian, Xiao Zhongdang
State Key Laboratory of Bioelectronics, Southeast University Nanjing 210096, China.
J Nanosci Nanotechnol. 2009 Aug;9(8):4618-22. doi: 10.1166/jnn.2009.1286.
Negative nanopatterns have been successfully in-situ fabricated on tetradecylated Si(111) surface via bias-dependent atomic force microscopy (AFM) lithography without wet chemical etching procedures. Alkyl self-assembled monolayers (SAMs) made of 1-tetradecene coupled to hydride-terminated Si(111) surface through robust silicon-carbon covalent bonds was employed as a resist layer. The SAM covered silicon substrate was then treated with dilute hydrofluoride, and subsequent used in AFM lithography. By varying the applied bias and pulse duration, both negative and positive patterns can be fabricated via this approach, such as Si pores and oxide dots. The results indicated that the HF-ethanol treatment of SAMs plays an important role in forming negative nanopatterns in situ. In particular, the Si pore structure formation was related to the reaction between F-buried inside the SAM and silicon substrate under the effect of tip electric field. A possible mechanism of Si pore formation based on the reaction of F- ions with silicon induced by the tip bias was proposed.
通过偏压依赖原子力显微镜（AFM）光刻技术，在未进行湿化学蚀刻程序的情况下，已成功在十四烷基化的Si(111)表面原位制备出负性纳米图案。由1-十四碳烯制成的烷基自组装单分子层（SAMs）通过牢固的硅-碳共价键与氢化物端接的Si(111)表面耦合，用作抗蚀剂层。然后用稀氢氟酸处理覆盖有SAMs的硅衬底，并随后用于AFM光刻。通过改变施加的偏压和脉冲持续时间，可通过这种方法制备负性和正性图案，如硅孔和氧化物点。结果表明，SAMs的HF-乙醇处理在原位形成负性纳米图案中起重要作用。特别是，硅孔结构的形成与在尖端电场作用下埋在SAMs内部的F与硅衬底之间的反应有关。提出了基于尖端偏压诱导的F-离子与硅反应的硅孔形成的可能机制。
