Thin film ferroelectric capacitors having improved memory retention through the use of essentially smooth bottom electrode structures

A ferroelectric integrated circuit memory cell comprising:

• a ferroelectric capacitor including
• a bottom electrode having a smooth surface,
• a ferroelectric thin film layered superlattice material contacting said essentially smooth surface and having a thickness ranging from 500 Å to 2300 Å, and
• a top electrode over said ferroelectric thin film layered superlattice material,
• said smooth surface being one in which all surface irregularity features protruding towards said thin film ferroelectric layered superlattice material protrude a distance less than twenty seven percent of a thickness in said ferroelectric thin film layered superlattice material;
• memory read/write means;
• and
• means for operably coupling said memory read/write with said ferroelectric capacitor.

A method of making a ferroelectric capacitor, said method comprising the steps of:

• forming an essentially smooth bottom electrode;
• depositing a liquid precursor on said bottom electrode to provide a precursor film, said precursor film being capable of yielding a ferroelectric layered superlattice material upon drying and annealing of said precursor film;
• drying said precursor film at a temperature less than 400° C. to provide a dried precursor residue;
• soft baking said dried precursor residue using RTP at an RTP temperature ranging from 625° C. to 725° C. for a period of time ranging from thirty seconds to five minutes to provide a soft baked precursor residue;
• and
• annealing said soft baked precursor residue in a diffusion furnace under oxygen at an anneal temperature ranging from 520° C. to 650° C.