2003 Fiscal Year Final Research Report Summary
Theoretical study of thin film deposition processes of cubic boron nitride
| Project/Area Number |
13450020
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
表面界面物性
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| Research Institution | The University of Tokyo |
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Principal Investigator |
WATANABE Satoshi The University of Tokyo, School of Engineering, Professor, 大学院・工学系研究科, 教授 (00292772)
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| Co-Investigator(Kenkyū-buntansha) |
KOGA Hiroaki The University of Tokyo, School of Engineering, JSPS Research Fellowship (DC1), 大学院・工学系研究科, 特別研究員(DC1)
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| Project Period (FY) |
2001 – 2003
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| Keywords | Cubic boron nitride / Thin film deposition / Molecular dynamics / Density functional theory / High-energy particle / Charging effect / Migration-enhanced epitaxy |
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| Research Abstract |
Cubic boron nitride (cBN) has many remarkable properties, and is ideal for wide variety of applications. However, methods to obtain cBN thin films having both good quality and sufficient thickness are yet to be developed. Though the importance of microscopic understanding of elementary processes during thin film deposition for this purpose is well recognized recently, no theoretical studies in this direction considering recent experimental findings have been performed. In this study, we tried to clarify microscopic mechanism of elementary processes during cBN thin film deposition, using molecular dynamics and first-principles calculations. We also aimed at deriving guiding principles to obtain good quality cBN thin films.
First, we examined injection of high-energy E and N particles in graphitic BN (gBN) substrates using classical molecular dynamics, and found formation of sp3-bonded defect structures and that of cBN nuclei as clusters of the defect structures. On the basis of these findings, we proposed a microscopic model for cBN crystal growth. Second, we examined the effects of charged states caused by injected charged particles on gBN-cBN phase transition by density functional calculation, and found that the charging may promote the phase transition from gBN to cBN. Third, we examined possibility of migration-enhanced epitaxy, and found this method is promising for cBN thin film growth of good quality.
In addition, our study produced several by-products. For example, we found that the phase transition from gBN to cBN can be understood in terms of repulsion-induced order formation (Alder-type mechanism).
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