1996 Fiscal Year Final Research Report Summary
Fabrication of Long-Life Laser Diodes in GaAs films on Si formed by annealing under ultrahigh pressure
| Project/Area Number |
07555003
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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 | 試験 |
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| Research Field |
Applied materials science/Crystal engineering
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| Research Institution | Tokyo Institute of Technology |
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Principal Investigator |
ISHIWARA Hiroshi Tokyo Institute of Technology Precision and Intelligence Laboratory, Professor, 精密工学研究所, 教授 (60016657)
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| Co-Investigator(Kenkyū-buntansha) |
KATAHAMA Hisasi Sumitomo Metal Industries, LTD Research & Development Division, Research Enginee, 未来技術研究所, 主任研究員
AIAWA Kouji Tokyo Institute of Technology Precision and Intelligence Laboratory, Research As, 精密工学研究所, 助手 (40222450)
TOKUMITSU Eisuke Tokyo Institute of Technology Precision and Intelligence Laboratory, Associate P, 精密工学研究所, 助教授 (10197882)
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| Project Period (FY) |
1995 – 1996
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| Keywords | ultrahigh pressure / thermal expansion coefficient / GaAs-on-Si / elastic strain / annealing / photoluminescence / strain-free |
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| Research Abstract |
In order to fabricate long-life laser diodes, strain-free GaAs films on Si substrates which were formed by annealing under ultrahigh pressure, were first characterized using X-ray diffraction (XRD) analysis and photoluminescence (PL) measurement. In the annealing method under ultrahigh pressure, the difference of the thermal expansion coefficient between a GaAs film and a Si substrate is expected to be compensated by that of the elastic strain generated by hydrostatic pressure.
It was found that a strain-free GaAs film was formed on a Si substrate without serious degradation of the optical and crystallographical proterties of the film.It was also found that no additional strain or defects were generated during PL measuremet at 77 K.Next, the strain-free GaAs-on-Si structure was reannealed at atmospheric pressure, and variation of the strain was investigated. It was found in this experiment that the strain in the GaAs film increased rapidly in the first 5 min of reannealing but within 20 to 30 min it reached to a constant value which was determined by the reannealing temperature. Finally, both XRD and PL data were compared and an interesting result on the depth distribution of strain in a GaAs film was derived.
Based on the above characterization, the residual strain in light emitting diodes with a (In, Ga)P/GaAs/Si structure was reduced by applying an appropriate pressure to the diodes, and the photo-and electoluminescence measurements were conducted. It was found from XRD analysis that the residual strain in the GaAs film was completely relaxd. PL measurements showed that the strain in the (In, Ga)P film was also relaxd partially. We conclude from these results that the annealing method under ultrahigh pressre is good enough for fabrication of oprical devices in heteroepitaxial structures.
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