Physical properties of Co2MnSi for the material of Si-based Spin transistor

초록

Das-Datta spin transistor(1) has attracted a lot of attention for the possible application as a next-generation switching device in the field of spintronics because it has the same architecture as the conventional field effect transistor with an electric field controlling spin degree of freedom for switching. Main obstacle to realize the spin transistor is, however, the difficulty associated with the efficient injection of spin-polarized carriers into semiconductor channel. One of the desirable device scheme is the MOSFET(Metal-Oxide-Semiconductor Field-Effect Transistor) with the source electrode made of ferromagnetic material and with a clean interface at the Schottky junction. For this purpose, we have performed to prepare Co2MnSi films on SOI(Silicon-On-Insulator) by the salicide(self-aligned silicide) process because it is half-metallic to be a perfect spin-injector into silicon and this approach is a viable option for silicon-based technology. The rapid thermal annealing at 650 ℃ for 3 minutes after deposition of Co/Mn multilayers on SOI produced Co2MnSi films for which the homogeneity was confirmed by TEM with compositional analysis. We also measured the physical properties of the Co2MnSi film and found a high saturated magnetization amounting to 1.6 μB/Co-atom with a strong correlation between the magnetic and transport properties.