Electrical and Structural Properties of Ternary Rare-Earth Oxides on Si and Higher Mobility Substrates and their Integration as High-k Gate Dielectrics in MOSFET Devices

The continuous downscaling in metal-oxide-semiconductor field effect transistors is approaching fundamental limits. Allied to new device architectures, novel materials are needed in order to continue the evolution of complementary metal-oxide-semiconductor technologies. The combination of high dielectric constant (k) oxides with silicon and other semiconductors having a higher charge carrier mobility (ex.: germanium) is currently a fundamental technologic issue that requires extensive investigation on materials science. The search for high-k oxides (with k > 20) that can offer stable interfaces combined with a low density of electrically active defects is a topic of major interest. In this contribution, we will review some of our results on the structural and electrical properties of REScO3 (RE = La, Gd, Tb, Sm) and LaLuO3 amorphous films on Si as well as on high mobility substrates, showing their potential as high-k dielectrics for future CMOS applications.