Surface Orientation and Temperature Effects on the Interaction of Silicon with Water: Molecular Dynamics Simulations Using ReaxFF Reactive Force Field

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• 作者：Jialin Wen ; Tianbao Ma ; Weiwei Zhang ; Adri C. T. van Duin ; Xinchun Lu
• 刊名：Journal of Physical Chemistry A
• 出版年：2017
• 出版时间：January 26, 2017
• 年：2017
• 卷：121
• 期：3
• 页码：587-594
• 全文大小：778K
• ISSN：1520-5215

文摘

In this work, we use ReaxFF molecular dynamics simulations to investigate the interaction between water molecules and silicon surfaces with different orientations under ambient temperatures of 300 and 500 K. We studied the water adsorption and dissociation processes as well as the silicon oxidation process on the Si (100), (110), and (111) surfaces. The simulation results indicate that water can adsorb on the Si surfaces in the forms of molecular adsorption and dissociative adsorption, making the surfaces terminated by H₂O, OH, and H species. The molecular adsorption of H₂O dominates the (100) and (110) surfaces, whereas the dissociative adsorption dominates the (111) surface. Besides, the adsorbed hydroxyl oxygen can insert into the Si–Si bond of the substrate to make the surface oxidized, forming the Si–O–Si bonds. Our simulation results also indicate that the (100) surface is mostly terminated by H whereas (111) is mostly terminated by OH. The higher temperature causes more H₂O to dissociate and also make all these surfaces more oxidized. Our results are consistent with most experiments. This study sheds lights on the wet oxidation process of Si and Si surface structure evolution in microelectromechanical systems as well as the Si chemical mechanical polishing process.