1997 Fiscal Year Final Research Report Summary
High-quality Si thin film growth on single-crystalline Al203 films
| Project/Area Number |
08455144
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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 |
Electronic materials/Electric materials
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| Research Institution | TOYOHASHI UNIVERSITY OF TECHNOLOGY |
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Principal Investigator |
ISHIDA Makoto TOYOHASHI UNIVERSITY OF TECHNOLOGY,FACULTY OF ENGINEERING,PROFESSOR, 工学部, 教授 (30126924)
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| Project Period (FY) |
1996 – 1997
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| Keywords | SOI structures / Si epitaxial growth / Insulator substrates / MBE method / Buffer layrs / single-crystalline insulator films / Substrate surface control |
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| Research Abstract |
Heteroepitaxial growth of insulating layrs on Si and the successive growth of a single crystalline Si on those insulating layrs are of great interest in the formation of silicon-on-insulator (SOI) structures. We have proposed gamma-Al_2O_3 films as an insulator material and obtained high quality on layrs of gamma-Al_2O_3 Si substrates. Epitaxially grown Si/Al_2O_3/Si stacked structures have not only the features of silicon-on-sapphire (SOS) but also other advantages for sensor devices using micro machining technology. However, for device applications of the Si/y-Al_2O_3/Si stacked structure, it is necessary to improve the crystalline quality and surface flatness of grown films. In this research, we report the high crystalline quality epitaxial growth of Si films using thin Al layr deposited onto gamma-Al_2O_3 (111) /Si (111) substrates at room temperature, prior to the growth of Si films by gas source MBE.Before the epitaxial growth of Si, Al was evaporated from Knudsen cell at a rate
… More
of 1A^^ﾟ/sec on the gamma-Al_2O_3 (111) /Si substrate at room temperature. The Al films were grown epitaxially at room temperature. High crystalline quality gamma-Al_2O_3 films were epitaxially grown on Si (111) substrates at growth temperatures from 650 at 900ﾟC by Al solid source and N_2O gas molecular beam epitaxy. The substrates were exposed to a Si_2H_6 flow of lsccm. The grown rate of Si films was 400A^^ﾟ/min. Very flat epitaxial Si (111) films with high crystalline quality were grown using thin Al layrs deposited onto Al_2O_3 (111) /Si (111) substrates at room temperature, prior to the growth of Si films by Si_2H_6 gas source molecular beam epitaxy. The epitaxial Si had a significantly improved crystalline quality and surface morphology comparable to that grown without the Al predeposition layr. For an Al thickness of 10A^^ﾟ, the optimum Al thickness for a high quality Si film, the Al deposited surface was changed to an Al-O surface (rather than a metallic Al layr) just before Si growth at 800ﾟC.However, Al-Al bonds remain for an 25-A^^ﾟ-thick Al predeposition layr. It is believed that a modification of the Al_2O_3 surface occur, which results in improved crystalline quality of Si films grown on the Al_2O_3. Less
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