Stress-induced nano-oxidation of silicon by diamond-tip in moisture environment: A hybrid quantum-classical simulation study
Stress-induced nano-oxidation of silicon by diamond-tip in moisture environment: A hybrid quantum-classical simulation study
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DOI：
10.1063/1.3481451
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发表时间：
2010-09
影响因子：
3.2
通讯作者：
S. Ogata;Yuya Abe;N. Ohba;R. Kobayashi
中科院分区：
文献类型：
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作者：
S. Ogata;Yuya Abe;N. Ohba;R. Kobayashi
采用数值模拟的方法研究了纳米水滴插入到H-端Si（001）表面和纳米H-端金刚石针尖之间的化学反应。混合量子-经典模拟方法，其中的量子区域描述的密度泛函理论嵌入在整个系统的经典原子，是用来执行模拟运行在现实的设置。添加了在运行期间自适应地选择量子区域的功能，以跟踪尖端和表面的接触面积的时间演化。当尖端推动水滴时，而Si表面与水分子弱相互作用，尖端将水分子从水滴中吸引到靠近尖端末端的独特亚稳态。当针尖在硅表面进一步滑动或被推向硅表面时，处于亚稳态的水分子由于在接触处集中的高应力而分解。
This paper reports a numerical simulation study about the chemical reactions of a nanosized water droplet inserted between H-terminated Si(001) surface and a nanosized, H-terminated diamond-tip when the tip is either slid on or pushed to the surface. The hybrid quantum-classical simulation method, in which the quantum region described with the density-functional theory is embedded in the total system of classical atoms, is used to perform the simulation runs in realistic settings. A feature to select the quantum region adaptively during the run is added to trace the time evolution of the contact area of the tip and surface. When the tip pushes the water droplet, while the Si surface interacts weakly with the water molecule, the tip draws a water molecule from the droplet into a unique metastable state in close proximity to the end of the tip. When the tip is further slid on or pushed to the Si surface, the water molecule in the metastable state decomposes due to high stresses concentrated at the contact a...