Impact of High Pressure O2 Annealing on Amorphous LaLuO3/Ge MIS Capacitors

Amorphous LaLuO3/Ge MIS capacitors were fabricated and dielectric properties were investigated. LaLuO3 has a high dielectric constant (k similar to 23) and an amorphous structure after annealed at 600 degrees C. Its energy band-gap is reasonably large (5.5 similar to 5.8 eV). The C-V characteristics annealed in a small amount of O-2 ambient were quite good and showed a high saturated capacitance thanks to a negligible interface layer formation. Furthermore, it has been demonstrated that the hysteresis in C-V curves was reduced by high pressure O-2 annealing. Although an optimization of the trade-off between EOT increase and hysteresis reduction will be the next challenge for LaLuO3 on Ge, the high pressure O-2 annealing will make a strong combination with amorphous LaLuO3.