【作者】 苑士登； 张恒； 苑世领；

【Author】 Shideng Yuan;Heng Zhang;Shiling Yuan;Department of Chemistry,University of Shandong University;

【机构】 山东大学化学与化工学院；

【摘要】 氢终止的硅表面在金属氧化物半导体(MOS)等半导体器件的制造以及表面有机分子自组装过程中有着重要应用。但是在实验中发现,即使在室温下,该表面暴露于空气中也会形成自然氧化物,该自然氧化物含有大量缺陷,对半导体的性能及自组装过程造成不良影响。实验上通过不同手段对氧化过程进行了研究。然而该氧化过程缺乏在分子层面上的理论研究。本文通过基于ReaxFF反应力场的分子动力学模拟,研究了不同环境(水环境以及空气环境)以及温度(300K及500K)下H-Si(100)表面的氧化行为。研究结果表明,H-Si(100)表面在氧化过程中,氧化剂物质是以过氧化物结构扩散的,这一结论与实验得出的相符。而且,相较于低温而言,高温使更多的氧气发生反应,同时也使更多的Si原子被氧化,氧化速率也随之增加。同时,水分子的存在也会促进表面的氧化过程。此外,本文还就水分子对氧化的促进也进行了一定的研究,结果显示,水分子的加入会使体系中具有过氧化物结构的物质增多,进而促进了表面的氧化。更多还原

【Abstract】 Hydrogen-terminated silicon surfaces have important applications in the fabrication of semiconductor devices such as metal oxide semiconductors(MOS) and in the self-assembly of surface organic molecules. However, it has been found in experiments that even at room temperature, the surface is exposed to air to form a natural oxide which contains a large number of defects which adversely affect the performance and self-assembly process of the semiconductor. The oxidation process was studied experimentally by different means. However, this oxidation process lacks theoretical studies at the molecular level. In this paper, the oxidation behavior of H-Si(100) surface in different environments(water environment and air environment) and temperature(300 K and 500 K) was studied by molecular dynamics simulation based on ReaxFF reaction field. The results show that the oxidant species diffuses in the peroxide structure during the oxidation process of H-Si(100). This conclusion is consistent with the experimental results. Moreover, compared to the low temperature, the high temperature causes more oxygen to react, and at the same time, more Si atoms are oxidized, and the oxidation rate also increases. At the same time, the presence of water molecules also promotes the oxidation process of the surface. In addition, the paper also carried out some research on the promotion of oxidation of water molecules. The results show that the addition of water molecules will increase the number of substances with peroxide structure in the system, which promotes the oxidation of the surface.更多还原