| Project/Area Number |
14550302
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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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 | Kagawa University |
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Principal Investigator |
KOSHINA Shyun Kagawa University, Faculty of Engineering, Professor, 工学部, 教授 (80314904)
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| Co-Investigator(Kenkyū-buntansha) |
NAKANISHI Shunnsuke Kagawa University, Faculty of Engineering, Professor, 工学部, 教授 (30155767)
ITOH Hiroshi Kagawa University, Faculty of Engineering, Professor, 工学部, 教授 (60112249)
SAKAKI Hiroyuki Univ.of Tokyo, IIS, Professor, 生産技術研究所, 教授 (90013226)
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| Project Period (FY) |
2002 – 2003
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| Project Status |
Completed (Fiscal Year 2003)
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| Budget Amount *help |
¥3,700,000 (Direct Cost: ¥3,700,000)
Fiscal Year 2003: ¥700,000 (Direct Cost: ¥700,000)
Fiscal Year 2002: ¥3,000,000 (Direct Cost: ¥3,000,000)
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| Keywords | Molecular Beam Epitaxy / Nano Structure / Self Formation Mechanism / Vicinal Surface / Optical Property / Super Lattice / Ridge Quantum Wire / リッジ構造 / ステップバンチング |
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| Research Abstract |
We have investigated the mechanisms of self assembled nano structures and obtained following results ;
1.We have calculated the wave functions for the modeled ridge QWR structures with mirror symmetry as well as the asymmetric structures, and discussed the polarization dependence of the optical transition. The polarization dependence of the ridge QWR is proved be vertical due to dependence on the special distribution of envelope wave functions of holes, and tilted by the existence of asymmetry caused by fluctuation in the QWR structure.
2.The MBE grown semiconductor corrugated structure on a (757)B plane is closely investigated by scanning transmission electron microscope (STEM). The cross section of the AlAs/GaAs SL and InGaAs layer on (757)B shows asymmetric corrugated structures, which is not observed in layers on (001). A strong corrugation of approximately 55 nm in lateral period and 5nm in height was observed in the upper side interface of InGaAs layer, which is stronger than of the lower side. This means InGaAs stronger tendency to corrugation, and stronger potential modulation in InGaAs channel, than in GaAs. On the other hand, AlAs/GaAs SL layers on the GaAs layer show smoothing, in which the height of corrugation reduces gradually, as the growth of the AlAs and the GaAs layers proceeds, although each AlAs layer seems traces exactly the morphology of the GaAs surface underneath.
3.Digital alloy, which replace the alloy by the short period super lattice (SL), was investigated to control nano structures. The AlAs/GaAs super lattices of various periods which equivalent to Al_xGa_<1-x> As alloy of x= 0.3, were prepared by MBE and characterized by XRD and PL. Optical properties such as PL energies and FWHMs show anomalous behavior when the SL has period of few MLs. Discussion by Kronig-Penney model differentiates MQW like SLs from alloy like SLs by their periods.
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