[9p-W933-1~11] New trend of multinary compound research ~ control of physical properties, new application~

[9p-W933-8] Magnetic tunnel junctions with a chalcopyrite Cu(In,Ga)Se₂ tunneling barrier

〇Shinya Kasai¹ (1.NIMS)

Keywords:spintronics, magnetic tunnel junction, semiconductor

Magnetic tunnel junction (MTJ) is a most important key block to establish spintronics applications. MgO is a major material used for the tunneling barrier, which can achieve the huge magnetoresistance (MR) ratio because of the spin filtering effect. However, it’s very difficult to reduce resistance area product (RA) due to the large bandgap as an oxide insulator. In this talk, we demonstrate the potential of chalcopyrite Cu(In,Ga)Se₂ (CIGS) as alternative to MgO tunneling barrier. CIGS can be epitaxially grown on the ferromagnetic metals by magnetron sputtering. MTJs with CIGS show relatively large MR ratio over 40 % at room temperature and more than 100 % at low temperature with small RA between 0.1 -1 Ωμm². Further enhancement of MR properties is available by tuning the composition of CIGS.