Demonstrating 1 nm-oxide-equivalent-thickness La2O3 and HfO2 multi-layer composite oxides on In0.53Ga0.47As MOS capacitor

The use of a high k composite dielectric composed of La2O3 and HfO2 layers as the gate dielectric for In0.53Ga0.47As MOS application is proposed. Two multi-layer structures of La2O3 (1 nm)/HfO2 (1 nm) and La2O3 (0.5 nm)/HfO2 (0.5 nm) were deposited and annealed at 450 and 500°C for device performance comparison. X-ray photoelectron spectroscopy, TEM and C–V measurements were used for the interface analysis between the oxide and the semiconductor. Finally, a 1 nm equivalent-oxide-thickness dielectric with small hysteresis of 88 mV and D it of 1.9 × 1012 cm−2 eV−1 was achieved for six layers of an La2O3 (0.5 nm)/HfO2 (0.5 nm) composite oxide structure on an In0.53Ga0.47As MOS capacitor with a post-deposition annealing temperature of 450°C.