2019 Fiscal Year Final Research Report
Growth processes and low-dimensional physical properties on ultrathin high-k materials film fabricated on concave-convex Si surface by spectroscopic observation
| Project/Area Number |
17K06030
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Multi-year Fund |
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| Section | 一般 |
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| Research Field |
Device related chemistry
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| Research Institution | Ehime University |
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Principal Investigator |
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| Project Period (FY) |
2017-04-01 – 2020-03-31
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| Keywords | 金属半導体ヘテロ界面 / Si半導体 / 高誘電体材料 / 光電子分光 / コインシデンス分光法 / シンクロトロン放射光 / 酸化反応ダイナミクス / 表面界面反応 |
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| Outline of Final Research Achievements |
In this study, we have succeeded to prepare ultrathin hafnium (Hf) films on clean Si semiconductor surfaces (Hf/Si), which are grown by a lever rule, by using electron beam heating. There some different chemical states of silicide species were observed at Hf/Si interface; such as HfSi, HfSi_2, and HfSi_4. Each of them shows individual reactivity with O_2 molecules. Therefore, the chemical states at the interface of the ultrathin Hf/Si films depend on a plane orientation, a thickness, temperature of substrate, and so on. On the other hand, metallic Hf component at surface shows high O_2 reactivity with barrier-less. Moreover, we have succeeded to reveal the different local valence electronic states at SiO_2 interface between HfO_2/SiO_2/Si and HfSi_2/SiO_2/Si samples by Auger-photoelectron coincidence spectroscopy. Our new findings will be very useful for preparing well-defined interfaces and surface structures for obtaining next generation nano materials.
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| Free Research Field |
表面界面科学
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| Academic Significance and Societal Importance of the Research Achievements |
Si半導体基板上の金属超薄膜成長を理解することは、原子混合、局所状態、反応特性、等々を解明するだけでなく、その表面界面で示す低次元物性やその応用を創生できるため非常に重要である。特に、周期表第４族に属するチタン、ジルコニウム、およびハフニウムは僅かな組成の違いによって光触媒、半導体素子、記憶媒体、セラミック、原子炉、超高真空材料などに応用される興味深い元素である。各分野で要求される特異な機能をこれらの混合試料からナノデザインできるようになれば、持続可能なエネルギー源の調達、省エネ化、デバイスの小型設計、紫外線による除菌など、緊急に解決すべき課題にブレークスルーを起こすことができる。
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