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Ultra-high vacuum electron microscope study on Micro-processes of surface and crystal growth.

超高真空电子显微镜表面微观过程及晶体生长研究。

基本信息

批准号：
59420048
负责人：
TAKAYANAGI Kunio
金额：
$ 22.98万
依托单位：
Tokyo Institute of Technology
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (A)
财政年份：
1984
资助国家：
日本
起止时间：
1984 至 1986
项目状态：
已结题

项目摘要

A new high resolution UHV (ultra-high vacuum ) electron microscope has been developed for in-situ surface study at atomic level resolution. The microscope has the vacuum of <10^(-8)> level after baking at 100 ゜ C and the resolution of 0.22 nm. With deposition facilities, metals and semiconductor materials were deposited on substrate surfaces places at the specimen position in-situ in the microscope. Surface processes, then, are imaged in transmission and reflection electron microscopy and diffraction.We performed in-situ surface studies for Si(111)7x7 reconstruction and the phase transition, for metal adsorption on Si surface and for metal cluster. By transmission electron diffraction, the reconstructed Si(111)7x7 surface was found to have dimer adatom stacking-fault (DAS) structure. Adsorption processes of Ag, Au, Cu and Al on the 7x7 surface were observed by reflection electron microscopy. Surface steps were found to work as the nucleation site. Phase transition of Si(111)7x7 process was observed by high resolution reflection microscopy, 2.3 nm spaced superlattice fringes being resolved. The phase boundary between the 7x7 and "1x1" structure was found to be vary narrow throughout the transition process. In addition to these studies, structures and dynamical behavior of clusters consisting a few to several tens of Au atoms were seen at atomic level.The high resolution UHV electron microscopy, thus, is useful for basic and applied surface science.

研制了一种新的高分辨超高真空电子显微镜，用于原子级分辨率的原位表面研究。显微镜经100 ℃烘烤后真空度达到<10^（-8）>级，分辨率为0.22 nm。与沉积设施，金属和半导体材料沉积在基板表面上的地方在试样位置原位在显微镜。利用透射、反射电子显微镜和衍射技术对Si（111）7 x7重构和相变、金属在Si表面的吸附和金属团簇进行了原位表面研究。通过透射电子衍射分析，发现重构的Si（111）7 x7表面具有二聚体吸附原子层错（DAS）结构。用反射电镜观察了Ag、Au、Cu和Al在7 × 7表面的吸附过程。发现表面台阶作为成核位点。用高分辨反射显微镜观察了Si（111）7 × 7过程的相变，分辨出2.3nm间距的超晶格条纹。在整个转变过程中，发现7 x7和“1x 1”结构之间的相边界变窄。除此之外，还可以在原子水平上观察到由几个到几十个Au原子组成的团簇的结构和动力学行为，因此，高分辨UHV电子显微术在基础和应用表面科学中具有重要意义。