Low imprint ferroelectric material for long retention memory and method of making the same

摘要

A liquid precursor for forming a thin film of ferroelectric metal oxide in an integrated circuit contains metal oxides in excess of the stoichiometrically balanced amount. When the precursor comprises strontium, bismuth, tantalum and niobium for forming strontium bismuth tantalum niobate, the precursor contains excess amounts of at least one of tantalum and niobium. Capacitors containing thin films of layered superlattice material made from a precursor containing excess tantalum and niobium show good polarizability and low percentage imprint after 10¹⁰ negative polarization switching pulses at 75 C., and after 10⁹ negative polarization switching pulses at 125 C.