Thin films of zirconia have been deposited by an Inductively Coupled Plasma Assisted CVD (ICP-PACVD) reactor from tetra (tert-butoxy)-zircon precursor diluted in Ar and O2 gas mixture. An independent RF generator is used to control carefully the substrate negative bias voltage during the deposition. Zirconia thin films, with thickness up to 10 microns were deposited on Si (100) polished wafers under different plasma conditions. Correlation between deposition parameters, and microstructure has been established showing that the ion bombardment has a large influence on the coating characteristics. In particular, the possibility of tailoring mechanical properties of the films by controlling the applied DC bias voltage is discussed.