ZrO₂film prepared by atomic layer deposition using less viscous cocktail CpZr[N(CH₃)₂]₃/C₇H₈precursor and ozone

The precursor consists of a mixture of CpZr(NMe₂)₃(Cp = C₅H₅, Me = CH₃) and cycloheptatriene (C₇H₈), CpZr(NMe₂)₃/C₇H₈, is introduced as a precursor in the atomic layer deposition (ALD) of zirconium oxide (ZrO₂). The cocktail CpZr(NMe₂)₃/C₇H₈chemical exhibits a higher vapor pressure of 1.2 torr and a lower viscosity of 7.0 cP at 100 °C than the pure CpZr(NMe₂)₃. In the ALD of ZrO₂films, CpZr(NMe₂)₃/C₇H₈and O₃act as the metal precursor and oxidant, respectively. Self-limited growth of ZrO₂films occurs after a 2 s pulse of CpZr(NMe₂)₃/C₇H₈, and a growth rate of 0.8–0.9 Å/cycle is obtained over a wide temperature range of 250–400 °C. ZrO₂film formed at 300 °C is stoichiometric with a lower impurity level of carbon and shows a tetragonal polycrystalline phase dominantly. The fabricated TiN/ZrO₂/TiN capacitors exhibit compatible capacitance and leakage current properties with a quadratic voltage coefficient, inversely proportional to the dielectric film thickness (t) according to α∼t^−1.8.