Methods of depositing thin films of hafnium oxide possessing strong ferroelectric properties are described. A hafnium oxide monolayer is formed in a first process cycle comprising sequential exposure of a substrate to a hafnium precursor, purge gas, first oxidant and purge gas. A doped hafnium oxide monolayer is formed in a second process cycle comprising sequential exposure of the substrate to a hafnium precursor, purge gas, dopant precursor, purge gas, second oxidant and purge gas. Thin films of hafnium oxide are also described.