Interface control of Y2O3 thin film with Si(100) in a metal-(ferroelectric)-insulator-semiconductor structure

Y-metal deposition on chemical oxide of Si and vacuum annealing was adopted to control the interface for the formation of Y2O3. Free interfacial SiO2 state and Y-silicate with small amount of Y2O3 on top was obtained through vacuum annealing of Y-metal on the chemical oxide system. Furthermore, an effective suppression of interfacial SiO2 formation was also observed during the formation of Y2O3 on the interface-controlled system and an improvement of electrical properties was achieved. When compared with Y2O3 on a HF-cleaned Si system, a small positive shift of flatband voltage in capacitance-voltage characteristic was observed with Y2O3 on the interface-controlled system with Y-silicate. A smaller leakage-current behavior of 1 similar to 2 orders was obtained with the controlled system than with Y2O3 on a HF-cleaned Si system, with 2.5 V higher breakdown voltage.