2000 Fiscal Year Final Research Report Summary
Development of combined FIM/STM system and investigation of the mechanism of thin-film growth on the atomic level
| Project/Area Number |
11305044
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| Research Category |
Grant-in-Aid for Scientific Research (A).
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Physical properties of metals
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| Research Institution | University of Tokyo |
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Principal Investigator |
YAMAMOTO Ryoichi University of Tokyo, Center for Collaborative Research, professor, 国際・産学共同研究センター, 教授 (10107550)
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| Co-Investigator(Kenkyū-buntansha) |
KYUNO Kentaro University of Tokyo, Faculty of Engineering, lecturer, 工学部, 講師 (40251467)
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| Project Period (FY) |
1999 – 2000
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| Keywords | Field ion microscope / Scanning tunneling-microscope / Crystal growth / Surface diffusion / Dissociation / Nucleation / Cluster / Diffusivity |
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| Research Abstract |
Although surface diffusion is an important process in thin film growth, because of the difficulty in observing the diffusion process of an atom directly without disturbing its motion, only a limited amount of work using field ion microscope (FIM) have been reported. This is because the application of FIM is restricted to a few metals like tungsten, platinum and so on. We have tried to develop a method to observe surface diffusion by a scanning tunneling microscope (STM) which is useful for observing the surface of a wide range of materials. We succeeded to control the sample temperature and got a nice of image of Si (111) and Si (100) between 30K and 320K.We also fabricated an evaporator for the deposition of silicon in ultra-high vacuum. We tried to observe the motion of an atom without affecting its motion by scanning only at the sample temperature of 30K where the position of the atom is frozen and letting the atom diffuse freely at a higher temperature without scanning. But it is found that because of thermal drift, it is very difficult to look at the same position constantly. This suggests some sort of a marker should be necessary to always find the same position. The sharp top of a tip created by FIM might be a possibility.
We also investigated the effect of surface diffusion and cluster stability on thin-film growth by rate equation and kinetic Monte Carlo simulation using the directly measured data for Pt and Ir for the first time. Although the importance of cluster diffusion has been claimed by some groups based on a qualitative argument, it is found for the first time using experimental diffusion data that the cluster stability is much more important for growth compared to cluster diffusion.
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