Study of Atomic Layer Deposited Zirconium Oxide Thin Films by Using Mono-Cyclopentadienyl Based Precursors

The electrical characterization of ZrO₂-based MIS structures fabricated by ALD on SiO₂/Si substrates with monocyclopentadienyls of zirconium, ZrCp(NMe₂)₃, as precursors was carried out. These precursors combine the beneficial properties related to the high thermal stability of the Cp compounds with the high growth rate and tendency of forming high permittivity cubic or tetragonal ZrO₂ phases of the alkylamido compounds. Interfacial state densities of annealed samples reached values as low as 1 times 10¹¹ Cm^-2 eV^-1, and leakage current was essentially bulk driven, with similar values to those obtained when precursors contained two cyclopentadienyl groups. The hysteresis of C-V curves, as well as the amplitude of conductance and flat-band voltage transients had moderate values, indicating the good quality of the films.