Interfacial and electrical characteristics of Al2O3 gate dielectric on fully depleted SiGe on insulator

The interfacial and electrical characteristics of as-deposited or annealed A2O3 gate dielectric films grown on fully depleted SiGe-on-insulator are investigated. An interfacial layer composed of SiOx and GeOx is observed in the as-grown film. The interfacial silicate formation is effectively suppressed by GeOx formation. However, GeOx is reduced to Ge and extensive silicate formation occurs after annealing. The formation of silicate and disappearance of GeOx after annealing leads to a decrease in the density of the interfacial states.