Characterization of half-metallic L2_1-phase Co_2FeSi full-Heusler alloy films formed by rapid thermal annealing

摘要

The authors developed a preparation technique of Co_2FeSi full-Heusler alloyfilms with the L2_1-ordered structure on silicon-on-insulator (SOI) substrates,employing rapid thermal annealing (RTA). The Co_2FeSi full-Heusler alloy filmswere successfully formed by RTA-induced silicidation reaction between anultrathin SOI (001) layer and Fe/Co layers deposited on it. The highly(110)-oriented L2_1-phase polycrystalline full-Heusler alloy films wereobtained at the RTA temperature of 700 C. Crystallographic and magneticproperties of the RTA-formed full-Heusler alloy films were qualitatively thesame as those of bulk full-Heusler alloy. This technique is compatible withmetal source/drain formation process in advanced CMOS technology and would beapplicable to the fabrication of the half-metallic source/drain of MOSFET typeof spin transistors.