Fabrication of ferroelectric SrBi2Ta2O9 capacitor films using plasma-assisted metalorganic chemical vapor deposition and their electrical properties

The fabrication of SrBi2Ta2O9 (SBT) films using plasma-assisted metalorgani c chemical vapor deposition (P-MOCVD) has been investigated. Optimizing the process conditions under plasma environment, amorphous SBT films were succ essfully deposited at a substrate temperature below 300 degreesC, suggestin g that the P-MOCVD process effectively utilizes plasma energy to promote th e reaction and decomposition of metal organic source molecules. The amorpho us SBT films were crystallized to the bilayered perovskite SBT films by a p ostannealing at 725 degreesC. Thin SBT capacitors fabricated using P-MOCVD showed a good step coverage and the excellent ferroelectric properties incl uding endurance. Low voltage operation below 1.5 V was successfully achieve d using a 75 nm SBT capacitor, in which the signal level derived from the h ysteresis curve suggests the feasibility of application to a 64 Mbit ferroe lectric random access memories. (C) 2001 American Institute of Physics.