ELECTRODE STRUCTURE AND METHOD OF MAKING FOR FERROELECTRIC CAPACITOR INTEGRATED ON SILICON

摘要

A ferroelectric capacitor structure and its method of making in which a ferroelectric stack of two metal-oxide electrodes (46, 52) sandwiching a ferroelectric layer (50) is fabricated on a silicon substrate (40) with an intervening barrier layer, preferably of TiN (42). In one embodiment, a platinum layer (44) is grown between the TiN and the lower metal-oxide electrode at a sufficiently high temperature that provides crystallographically ordered growth of the ferroelectric stack. In another embodiment, the platinum layer was completely eliminated with the lower electrode (46) being grown directly on the TiN (42). Although the conventional conductive metal-oxide used in the electrode is lanthanum strontium cobalt oxide (LSCO), lanthanum nickel oxide provides good electrical and lifetime characteristics in a ferroelectric cell. Alternatively, the electrodes can be formed of the rock-salt metal oxides, such as neodymium oxide (NdO).