Electrical characterization of directly deposited La-Sc oxides complex for gate insulator application

This study reports the electrical characteristics of La-Sc oxides complex and effect of nitrogen incorporation for applications to high-k gate stack. We found that Vfb can be controlled by the ScO concentration. Moreover, large bumps in C-V curves, which indicate high interfacial state density, can be suppressed with large ScO concentration. nMOSFETs using the La-Sc oxides complex in the gate stack are fabricated. In addition, nitrogen incorporation into the La-Sc oxide films was fond to be useful to suppress the EOT growth during annealing at high temperatures.