Ferroelectric capacitors are provided that include an integrated circuit substrate and a supporting insulation layer on the integrated circuit substrate having a face and a trench in the face. An oxidation barrier conductive layer is provided in the trench and a lower electrode is provided on the oxidation barrier conductive layer. A ferroelectric layer is provided on the lower electrode and an upper electrode is provided on the ferroelectric layer. Related methods of fabricating ferroelectric capacitors are also provided.