In this paper, we report on high-k composite oxides that are formed by depositing multiple layers of HfO 2 and La 2 O 3 on In 0.53 Ga 0.47 As for MOS device application. Both multilayer HfO 2 (0.8 nm)/La 2 O 3 (0.8 nm)/In 0.53 Ga 0.47 As and La 2 O 3 (0.8 nm)/HfO 2 (0.8 nm)/In 0.53 Ga 0.47 As MOS structures were investigated. The effects of oxide thickness and postdeposition annealing (PDA) temperature on the interface properties of the composite oxide MOS capacitors were studied. It was found that a low CET of 1.41 nm at 1 kHz was achieved using three-layer composite oxides. On the other hand, a small frequency dispersion of 2.8% and an excellent D it of 7.0 ' 10 11 cm %2 &eV %1 can be achieved using multiple layers of La 2 O 3 (0.8 nm) and HfO 2 (0.8 nm) on the In 0.53 Ga 0.47 As MOS capacitor with optimum thermal treatment and layer thickness.

The use of a high k composite dielectric composed of La 2 O 3 and HfO 2 layers as the gate dielectric for In 0.53 Ga 0.47 As MOS application is proposed. Two multi-layer structures of La 2 O 3 (1 nm)/HfO 2 (1 nm) and La 2 O 3 (0.5 nm)/HfO 2 (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 × 10 12 cm −2 eV −1 was achieved for six layers of an La 2 O 3 (0.5 nm)/HfO 2 (0.5 nm) composite oxide structure on an In 0.53 Ga 0.47 As MOS capacitor with a post-deposition annealing temperature of 450°C.