Ferroelectric capacitors include a support insulating film on an integrated circuit substrate and having a trench therein. A lower electrode is on sidewalls and a bottom surface of the trench. A seed conductive film covers the lower electrode. A ferroelectric film is provided on the support insulating film and the seed conductive film and an upper electrode is provided on the ferroelectric film. The lower electrode may fill the trench and the ferroelectric film may extend over all of the seed conductive film and the support insulating film adjacent the seed conductive film.