Patent ID: 6777287
Filing Date: 2004-08-17
Classification: H01L

Abstract:
A method of fabricating a ferroelectric random access memory comprising the steps of:depositing a ferroelectric film having a perovskite structure on a lower electrode by a sputtering process that uses a target containing therein at least Pb, Zr, Ti, Ca and Sr; annealing said ferroelectric film in a first, inert atmosphere that contains O2 with a reduced partial pressure; annealing said ferroelectric film, after said step of annealing in said first atmosphere, in a second, oxidizing atmosphere; and depositing, after said step of annealing in said second atmosphere, a conductive film having a perovskite structure and containing therein Sr and Ru on said ferroelectric film, said target containing Ca and Sr with respective concentrations, normalized to a sum of Zr and Ti atoms in said target, such that said concentration of Ca does not exceed 3.5 at % and such that said concentration of Sr does not exceed 2.5 at %.