20 research outputs found
Characterization of half-metallic L2_1-phase Co_2FeSi full-Heusler alloy films formed by rapid thermal annealing
The authors developed a preparation technique of Co_2FeSi full-Heusler alloy
films with the L2_1-ordered structure on silicon-on-insulator (SOI) substrates,
employing rapid thermal annealing (RTA). The Co_2FeSi full-Heusler alloy films
were successfully formed by RTA-induced silicidation reaction between an
ultrathin SOI (001) layer and Fe/Co layers deposited on it. The highly
(110)-oriented L2_1-phase polycrystalline full-Heusler alloy films were
obtained at the RTA temperature of 700 C. Crystallographic and magnetic
properties of the RTA-formed full-Heusler alloy films were qualitatively the
same as those of bulk full-Heusler alloy. This technique is compatible with
metal source/drain formation process in advanced CMOS technology and would be
applicable to the fabrication of the half-metallic source/drain of MOSFET type
of spin transistors.Comment: 18 pages, 5 figure
Electron spin transport in a metal-oxide-semiconductor Si two-dimensional inversion channel: Effect of hydrogen annealing on spin scattering mechanism and spin lifetime
Department of Electrical Engineering and Information Systems, The University
of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan Center for Spintronics
Research Network (CSRN), The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo
113-8656, JapanComment: 26 pages, 5 figures, 1 tabl
Carrier transport properties of the Group-IV ferromagnetic semiconductor Ge1-xFex with and without boron doping
We have investigated the transport and magnetic properties of group-IV
ferromagnetic semiconductor Ge1-xFex films (x = 1.0 and 2.3 %) with and without
boron doping grown by molecular beam epitaxy (MBE). In order to accurately
measure the transport properties of 100-nm-thick Ge1-xFex films, (001)-oriented
silicon-on-insulator (SOI) wafers with an ultra-thin Si body layer (~5 nm) were
used as substrates. Owing to the low Fe content, the hole concentration and
mobility in the Ge1-xFex films were exactly estimated by Hall measurements
because the anomalous Hall effect in these films was found to be negligibly
small. By boron doping, we increased the hole concentration in Ge1-xFex from
~1018 cm-3 to ~1020 cm-3 (x = 1.0%) and to ~1019 cm-3 (x = 2.3%), but no
correlation was observed between the hole concentration and magnetic
properties. This result presents a contrast to the hole-induced ferromagnetism
in III-V ferromagnetic semiconductors