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An experimentally verified analytical model for pulsed dc reactive sputtering of tantalum oxide films is described. The influences of important process variables, like oxygen flow rate and sputtering ion current, on the oxygen partial pressure in the chamber, deposition rate, as well as film breakdown and leakage characteristics, are predicted using this model. The experimentally established existence of multiple oxygen partial pressures at a given oxygen flow rate (hysteresis loop) is theoretically explained using steady state analysis. The partial pressure of oxygen during deposition can be used to correlate and predict the critical oxygen flow rate required to achieve insulating dielectric films (with no metallic tantalum) for a specified sputtering ion current. The experimental results suggest that in order to ensure the electrical reliability of tantalum oxide films, deposition should be done at oxygen flow rates more than that required to go beyond the hysteresis region in partial pressure versus flow rate curve. In addition, the observed hystereses in breakdown field and leakage current density of tantalum oxide films closely follow the hystereses in the oxygen partial pressure curve with oxygen flow rate. The stabilities of different steady state operating points with respect to fluctuations in flow rate are discussed. © 2003 American Institute of Physics.