Atom‐resolved surface chemistry: The early steps of Si(111)‐7×7 oxidation
Atom‐resolved surface chemistry: The early steps of Si(111)‐7×7 oxidation
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DOI：
10.1116/1.585584
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发表时间：
1991-03
影响因子：
1.4
通讯作者：
P. Avouris;I. Lyo;F. Bozsó
中科院分区：
文献类型：
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作者：
P. Avouris;I. Lyo;F. Bozsó
用扫描隧道显微镜、扫描隧道和光电子能谱研究了Si(111)-7×7氧化的早期阶段。已经发现，至少有两个不同的含氧点正在形成。它们不同的表面位置分布和行为随O2-暴露而变化，表明它们是两种不同的早期产物。通过将光谱结果与理论计算的结果相关联，人们能够确定这些产物中的一个涉及O原子与插入其中一个吸附原子背键的第二个O原子连接成一个吸附原子悬挂键，而另一个产物涉及插入到吸附原子背键中的单个O原子。这些产物对7×7晶胞的断层半个晶胞和角吸附原子位的偏好性用与位相关的粘着系数来解释，该粘着系数涉及一个类似于气相“鱼叉”过程的过程。结果表明，大多数分子前驱体都与O2有关。
The early stages of Si(111)‐7×7 oxidation using scanning tunneling microscopy and scanning tunneling and photoemission spectroscopies have been studied. It has been found that there are at least two different oxygen‐containing sites being formed. Their different surface site distributions and behavior as a function of O2‐ exposure show them to be two distinct early products. By correlating the spectroscopic results and the results of theoretical calculations one is able to identify one of these products as involving an O atom tying up an adatom dangling bond with a second O atom inserted in one of the adatom back bonds, while the other involves a single O atom inserted in an adatom back bond. The preference of these products for the faulted half of the 7×7 unit cell and for corner‐adatom sites is explained in terms of a site‐dependent sticking coefficient involving a process analogous to the gas‐phase ‘‘harpooning’’ processes. It is shown that the majority of the resulting molecular precursors involve O2 ...