Experimental and numerical studies of interfacial stress between dissimilar materials in a nano-scale area
| Project/Area Number |
17K06059
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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 |
Materials/Mechanics of materials
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| Research Institution | Kagoshima University |
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Principal Investigator |
Ikeda Toru 鹿児島大学, 理工学域工学系, 教授 (40243894)
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| Project Period (FY) |
2017-04-01 – 2020-03-31
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| Project Status |
Completed (Fiscal Year 2019)
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| Budget Amount *help |
¥4,810,000 (Direct Cost: ¥3,700,000、Indirect Cost: ¥1,110,000)
Fiscal Year 2019: ¥650,000 (Direct Cost: ¥500,000、Indirect Cost: ¥150,000)
Fiscal Year 2018: ¥1,430,000 (Direct Cost: ¥1,100,000、Indirect Cost: ¥330,000)
Fiscal Year 2017: ¥2,730,000 (Direct Cost: ¥2,100,000、Indirect Cost: ¥630,000)
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| Keywords | ミスフィット転位 / 特異応力場 / 異方性異種材界面角部 / ひずみシリコン / 限界薄膜厚さ / ミスフット転位 / 分子静力学 / 分子動力学 / 異方性弾性論 / 双晶 / エピタキシャル成長薄膜 / 界面応力 / 界面 / 超薄膜 / ナノ材料 / 分子シミュレーション |
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| Outline of Final Research Achievements |
Misfit dislocation is spontaneously introduced on the interface between dissimilar crystals which have different lattice constants to reduce the stress along the interface. Stress field around the misfit dislocation has 1/r stress singularity (r is the distance from a dislocation). We calculated the stress intensity factor of the singular stress around the misfit dislocation to investigate the strength of the stress singularity quantitatively.
We investigated the effect of the thickness of the thin film crystals on the singular stress field around the misfit dislocations for interfaces of Si-Ge and Si-SiGe using the molecular statics. In the case of Si-SiGe, the stress intensity factor of the singular stress around the misfit dislocation reduced with the decrease of the thickness of SiGe thin film when the thickness was less than 50 Angstrom.
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| Academic Significance and Societal Importance of the Research Achievements |
Siなどの基板の上に異種結晶をCVDなどで堆積して，この薄膜結晶を電子デバイスとして使用することや，薄膜結晶によって基板結晶に引っ張り応力を加えて，電子移動度を加速するなど，異種材薄膜結晶の形成は多くの電子デバイスで利用されている．しかし，薄膜結晶と基板結晶の格子定数の違いから，異種結晶界面に大きな応力が発生し，薄膜結晶を破壊することが大きな問題になっている．本研究は，異種結晶間に生じるミスフィット転位周りの特異応力の厳しさを定量的に解析し，薄膜結晶の破壊限界を定量的に明らかにすることにより，薄膜結晶の破壊を防ぐことで，これらのデバイスの信頼性を向上させることが期待できる．
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Report
(4 results)
Research Products
(24 results)
