基于机械—化学方法硅表面芳香烃重氮盐单层膜的制备

Mechanochemical Method to Prepare Aryl Diazonium Salts Monolayer on Silicon Surfaces

基于金刚石刀具建立能在溶液中加工微小结构的微加工系统,在一端为硝基的四氟化硼芳烃重氮盐溶液(NO2C6H4N2BF4)中用该系统切削硅片,利用机械与化学结合的方法使得芳香烃分子和切削过的硅片之间以共价键连接,实现硅表面的"成形并功能化"的一步完成,为纳米尺度功能化结构的构筑提供一定的试验基础。用扫描电子显微镜(Scanning electronic microscopy,SEM)表征不同切削力下的微结构表面形貌图,为下一步在溶液中"成形并功能化"硅表面提供好的基底。用X射线光电子能谱(X-ray photoelectron spectroscopy,XPS)和原子力显微镜(Atomic force microscopy,AFM)分别研究组装时间和切削速度对切削处生成自组装单层膜(Self-assembly monolayer,SAMs)质量的影响,总结出本试验条件下切削力为20mN,组装时间为12h左右,切削速度为500nm/s的时候组装膜表面质量较好。并用AFM对自组装膜的纳米摩擦性能进行检测,证明组装前后硅基底表面的化学组成发生了变化,组装后SAMs表面的摩擦力较大。

A micromachining system based on diamond tool is built, which can process micro structure in solution. The system is used to scribe the silicon surface in aryldiazonium salt solution （NO2 C6H4N2BF4）. Arenes can be connected with silicon atom with covalent bonds. Functionalizing and patterning silicon surface are realized simultaneously. This approach will be employed to build nano-scale functional structures. To obtain microstructures with better quality which will act as a good substrate for the following functionalizing and patterning processes, scanning electron microscopy （SEM） is used to characterize the surface morphology with different cutting force. X-ray photoelectron spectroscopy （XPS） as well as atomic force microscopy （AFM） are used to verify the self-assembly monolayers. Effects of the scribed speed and assembly time on the quality of self-assembled monolayer （SAMs） are discussed, which results in suitable testing parameters （20 mN cutting force, 12 h assembly time and 500 nm/s scribing speed） to produce better films. Atomic force microscopy （AFM） is used to characterize the surface frictional performance. The chemical composition of silicon surface changes after self-assembly, and the friction force of SAMs surface becomes greater.