US Patent 7696549 Bismuth ferrite films and devices grown on silicon

A functional perovskite cell formed on a silicon substrate layer and including a functional layer of bismuth ferrite (BiFeO3 or BFO) sandwiched between two electrode layers. An optional intermediate template layer, for example, of strontium titanate allows the bismuth ferrite layer to be crystallographically aligned with the silicon substrate layer. Other barrier layers of platinum or an intermetallic alloy produce a polycrystalline BFO layer. The cell may be configured as a non-volatile memory cell or a MEMS structure respectively depending upon the ferroelectric and piezoelectric character of BFO. Lanthanum substitution in the BFO increases ferroelectric performance. The films may be grown by MOCVD using a heated vaporizer.