Annealing characteristics of ultra-thin high-K HfO₂ gate dielectrics

Ultra-thin HfO₂ gate-dielectric films were fabricated by ion-beam sputtering a sintered HfO₂ target and subsequently annealed at different temperatures and atmospheres. We have studied the capacitance-voltage, current-voltage, and breakdown characteristics of the gate dielectrics. The results show that electrical characteristics of HfO₂ gate dielectric are related to the annealing temperature. With increase annealing temperature, the largest value of capacitance decreases, the equivalent oxide thickness increases, the leakage current reduces, and the breakdown voltage decreases.