Characteristics of metal-insulator-semiconductor capacitors based on high- k HfAlO dielectric films obtained by low-temperature electron-beam gun evaporation

We describe the characteristics of thin HfAlO films deposited at low temperature by electron beam gun evaporation. As-deposited films thinner than 6 nm exhibit an effective dielectric constant ( k eff ) of 9-11.5. The minimum quantum mechanical corrected effective oxide thickness is ∼ 1.45 nm and the leakage currents are very low. Rapid thermal annealing in a N 2 environment improves the leakage further and up to 750°C does not affect k eff . Higher annealing temperatures reduce k eff , but even at 950°C, it has a value of 6.5. These HfAlO films have the potential to serve as a substitute for Si O 2 in small-scale metal-insulator-semiconductor structures.