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

摘要

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 similar to1.45 nm and the leakage currents are very low. Rapid thermal annealing in a N-2 environment improves the leakage further and up to 750 degreesC does not affect k(eff). Higher annealing temperatures reduce k(eff), but even at 950 degreesC, it has a value of 6.5. These HfAlO films have the potential to serve as a substitute for SiO2 in small-scale metal-insulator-semiconductor structures. (C) 2004 American Institute of Physics.