  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.
