Real‐time observation of oxygen and hydrogen adsorption on silicon surfaces by scanning tunneling microscopy
Real‐time observation of oxygen and hydrogen adsorption on silicon surfaces by scanning tunneling microscopy
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扫描隧道显微镜实时观察硅表面氧和氢的吸附
DOI：
10.1116/1.577079
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发表时间：
1990
期刊：
影响因子：
--
通讯作者：
K. Kajimura
中科院分区：
文献类型：
--
作者：
H. Tokumoto;K. Miki;H. Murakami;H. Bando;M. Ono;K. Kajimura
利用超高真空扫描隧道显微镜（UHV STM），在室温下对Si（111）-7×7表面上氧和氢吸附过程的初始阶段进行了真实的研究.我们发现了每个过程的几个具体特征。(1)[112]步骤对氧或氢暴露相对不敏感：对氢的耐受性比对氧的耐受性更强。(2)吸附原子之间的化学反应性不同：在7×7晶胞的有缺陷的一半中的吸附原子比无缺陷的一半中的吸附原子更活跃;在每一半中的中心吸附原子更活跃，其次是角吸附原子;在7×7晶胞中的角孔的活性较低，表明即使在相当高的覆盖率下，7×7结构仍然存在。(3)在吸附的初始阶段，氧被吸附在表面吸附原子的顶位形成Si-O，然后在桥位形成Si-O-Si，这导致图像中的无序，而氢被吸附在顶位形成Si-O-Si。
The initial stages of the adsorption processes of oxygen and hydrogen on the Si(111)‐7×7 surface were studied at room temperature in real time using a ultrahigh vacuum scanning tunneling microscopy (UHV STM). We have found several specific features for each process. (1) the [112] steps are relatively insensitive to oxygen or hydrogen exposure: more resistant to hydrogen than to oxygen. (2) The adsorption proceeds with different chemical reactivities among the adatoms: the adatoms in the faulted half of the 7×7 unit cell are more active than the unfaulted half; the center adatoms in each half are more active and the corner adatoms are the next; the corner holes in the 7×7 unit cell are less active indicating that the 7×7 structure still exists even for fairly high coverages. (3) At initial stages of adsorption, oxygen is adsorbed in the on‐top site of the surface adatom forming Si–O and then in the bridge site forming Si–O–Si which causes the disorder in the image, whereas hydrogen is adsorbed in the on‐...