STM Observation of the Si(111) - (7×7) Reconstructed Surface Modified by Excess Phosphorus Doping
STM Observation of the Si(111) - (7×7) Reconstructed Surface Modified by Excess Phosphorus Doping
复制标题
过量磷掺杂修饰的Si(111)-(7×7)重构表面的STM观察
DOI：
10.11591/ijece.v7i6.pp2993-3001
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发表时间：
2017
影响因子：
--
通讯作者：
Masaru Shimomura
中科院分区：
文献类型：
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作者：
Hirulak D. Siriwardena;Toru Yamashita;Masaru Shimomura
通过控制掺杂剂浓度来改变载流子密度，半导体表面的电子特性容易发生变化。此外，过量的掺杂原子可以施加电场，影响分子的吸附过程，可以用来操纵受限制分子的动态运动。可以建立一种机制来控制掺杂剂在修饰半导体表面上的分子动态运动，从而改变电场对活性分子的影响。本研究采用热扩散法在Si（111）表面过量掺磷。然后在UHV条件下加热将表面重建为7x7结构，然后通过STM和STS技术进行研究。由于孤电子对的作用，表面和亚表面P原子的突起显得更亮。由于高表面应变导致P端（6√3× 6√3）R30º重构，在Si-adatom浓度达到临界P取代后，7× 7重构会不稳定。
The electronic properties of semiconductor surfaces change readily upon changing the carrier densities by controlling the dopant concentration. Additionally, excess dopant atoms can exert electric field which would affect the molecular adsorption process and could be used to manipulate the dynamic movement of confined molecules. A mechanism can be developed to control the molecular dynamic movement on modified semiconductor surface by dopants thus changing the effect of the electric field on the active molecules. In this study, the Si (111) surface was doped with phosphorus excessively using thermal diffusion process. The surface was then reconstructed to the 7× 7 configuration via heating under UHV conditions and then studied through STM and STS techniques. The protrusions due to surface and subsurface P atoms appear brighter due to the lone electron pair. The 7× 7 reconstruction would be destabilized after a critical P substitution of Si-adatom concentration due to high surface strain result in P-terminated (6√ 3× 6√ 3) R30º reconstruction.