Individual magnetic antivortices are reliably generated in phi-shaped microstructures using a specific remagnetization sequence of in-plane fields. The process of antivortex creation is understood by means of micromagnetic simulations and is experimentally demonstrated by magnetic force microscopy on multiple microstructures. The probability of antivortex nucleation is optimized by the variation of the structure geometry and the nucleation field strength. The presented method opens the path to radio frequency absorption measurements which rely on the resonant excitation of an ensemble of antivortices.