Electrical properties of HfO2 deposited via atomic layer deposition using Hf(NO3)4 and H2O

We report on the electrical properties of ${\mathrm{HfO}}_2$ deposited via atomic layer deposition using $\mathrm{Hf}({\mathrm{NO}}_3{)}_4$ precursor for metal/oxide/semiconductor gate dielectric applications. Thin films, with less than 1% variation in accumulation capacitance over a 150 mm wafer, have been deposited directly on hydrogen-terminated Si wafers. The effective dielectric constant of thin $\text{(<10\hspace{0.17em}}\mathrm{nm})$ films was in the range of ${\kappa }_{\mathrm{eff}}\text{=10–12,}$ the breakdown voltage was about 6–9 MV/cm, and the leakage current was between 3–6 orders of magnitude lower than that of ${\mathrm{SiO}}_2.$ The relative benefit of lower leakage current of ${\mathrm{HfO}}_2$ over ${\mathrm{SiO}}_2$ decreased with decreasing effective thickness. Electron trapping was observed under constant voltage stressing.