A method includes: providing a bottom layer; forming a first transistor over a substrate; forming a bottom electrode over the transistor; depositing a first seed layer over the bottom electrode; performing a surface treatment on the first seed layer, wherein after the surface treatment the first seed layer includes at least one of a tetragonal crystal phase and an orthorhombic crystal phase; depositing a dielectric layer over the bottom layer adjacent to the first seed layer, the dielectric layer including an amorphous crystal phase; depositing an upper layer over the dielectric layer; performing a thermal operation on the dielectric layer to thereby convert the dielectric layer into a ferroelectric layer.