HIYAMIZU Satoshi Osaka University, Faculty of Engineering Science, Professor, 基礎工学部, 教授 (50201728)
TERAUCHI Hikaru Kwansei Gakuin University, School of Science, Professor, 理学部, 教授 (00079667)
|Budget Amount *help
¥6,400,000 (Direct Cost : ¥6,400,000)
Fiscal Year 1991 : ¥500,000 (Direct Cost : ¥500,000)
Fiscal Year 1990 : ¥900,000 (Direct Cost : ¥900,000)
Fiscal Year 1989 : ¥5,000,000 (Direct Cost : ¥5,000,000)
High quality NiAl epitaxial thin films on(AI, Ga)As(001)successfully grown at high temperature by means of molecular beam epitaxy(MBE). Ni and AI fluxes were obtained by heating the each Knudsen cell. The Knudsen cell for Ni is a special one that has very low outgas pressure at 1400ﾟC.
It was found that there existed there characteristic temperature regions in the crystal growth. Below 300ﾟC, the in situ formation of NiAl failed. Above 300ﾟC, NiAl was formed in situ, while other Ni-AI intermetallic compounds(Ni_3AI_2, NiAl_3, Ni_3AI)also appeared. Above 400'C, remarkable improvements of the crystallinity, epitaxyf and monocrystallinity were found. The best NiAl film was obtained at 600'C, where no-interfacial disorder attributed to the interdiffusion and no film discontinuity due to balling up were observed. The epitaxial relationship between AlAs and NiAl is clarified as (100)_<NiAl>//(1OO)_<AlAs> and _<NiAl>// _<AlAs>.
In the early epitaxial-growth stage of NiAl on AlAs at 52
0ﾟC, the formation of the pseudo-ID single-crystal island and its self-arrangement along the _<AlGa> direction are found. There appeares the quasiperiodic array of NiAl wires over a few mu m long with mesoscopic(110)crosssectional areas running along thedirection at the coverage rheta =0.4 on AlAs. The results indicate that the growth behavior is dominated by a strong repulsive interaction among islands in a wide rheta range. Recent works have endeavored to exploit the nucleation behavior to create and control the 1D lateral structure on a nanometer scale. There it can lead to new physical phenomena and devices based on quasi-lo electron gas in the ultrafine wires. We propose that the present system is a good candidate for the attainment of well-controlled 1D lateral structure.