Amorphous ternary rare-earth gate oxides for future integration in MOSFETs

Abstract

In this contribution we present results on the structural and electrical properties of amorphous REScO 3 ( RE = La, Gd, Tb, Sm) and LaLuO 3 thin films. The study reveals that these oxides are potential candidates for so-called higher- k dielectrics for forthcoming MOSFET generations. High dielectric constants up to 32, low leakage currents and low interface trap densities are determined for amorphous thin films prepared by pulsed-laser deposition, molecular beam deposition and e-gun evaporation. Moreover, we show that LaLuO 3 gate stacks annealed up to 1050 °C maintain low leakage current densities without substantial EOT increase. Finally, promising results for n-MOSFETs with GdScO 3 as gate dielectric processed on strained silicon-on-insulator substrates are also shown.