Monolayers of n-Alkanethiols onto Oxide-Free Silicon (100) Surface

Yu-Xun Chen^1,2*, Lo-Yueh Chang^2,3, Yen-Chien Kuo², Jenh-Yih Juang¹, Chia-Hao Chen²

¹Department of Electrophysics, National Chiao Tung University, Hsinchu, Taiwan
²National Synchrotron Radiation Research Center, Hsinchu, Taiwan
³Soochow University-Western University Centre for Synchrotron Radiation Research, Institute of Functional Nano and Soft Material (FUNSOM), Soochow University, Suzhou, China

* Presenter:Yu-Xun Chen, email:yxchen.ep05g@g2.nctu.edu.tw

Since the first report of Si-C bound organic monolayers on oxide-free Si almost two decades ago, a substantial amount of research has focused on studying the fundamental mechanical and electronic properties of these self-assembled monolayers (SAMs)/Si surfaces and interfaces. However, alkanethiols (AT) grown on semiconductor surfaces was less systematically studied, especially on bare silicon surface, despite their prospective applications. Hence, the AT derived SAMs on silicon are of great interest to bridge inorganic and organic materials.
The commercially available alkanethiols solution were employed, which reacted with hydrogen-terminated Si (100) surface through ultraviolet assisted chemical reaction in ambient condition. Self-assembled monolayers have been characterized in detail by water contact angle measurement, synchrotron radiation based X-ray photoemission spectroscopy (XPS), polarization dependent near-edge X-ray absorption fine structure (NEXAFS). The spectroscopy results indicate the n-alkanethiols were directly attached on Si surface through Si-S bond formation and the molecules formed ordered organic monolayer. Preliminary data to probe the electronic and chemical structures of the hybrid system and the molecular orientation of the SAMs will be presented in the meeting.

Keywords: Self-assembled monolayers, Alkanethiols, X-ray photoemission spectroscopy, Polarization dependent near-edge X-ray absorption fine structure, SAMs/Si(100)