Epitaxy of rare-earth oxides on Si

Oxides have various applications as insulators in integrated circuits for information processing applications. In particular, one of the major obstacles in the further miniaturization of CMOS devices lies in shrinking the thickness of the gate oxide, leading to tunneling current losses that can dominate the thermal dissipation of the entire integrated circuit.
We investigate rare earth oxides with high dielectric constant to solve this problem. Gate stacks incorporating these materials electrically behave like very thin layers, while at the same being physically thicker, thereby avoiding the tunneling current losses. Using newly developed high-temperature effusion sources, we sublimate rare earth oxides such as Gd₂O₃ directly on Si and investigate their structural quality and interface structure with the Si substrate.