Presenter: Mark D.
Advisor(s): Jon-Paul Maria
Author(s): Mark D. Losego and Jon-Paul Maria
Graduate Program: Materials Science and Engineering
Title: Achieving compatibility between lead-containing ferroelectric oxide thin films and base metal substrates
Abstract: Ferroelectric oxide thin films are attractive for various devices including non-volatile memory, piezoelectric MEMS, and pyroelectric sensors. Typical device structures utilize bottom electrodes, like noble metals or conductive oxides, that resist oxidation/reaction during crystallization of the overlying ferroelectric ceramic film. Replacing these substrates with base metal bottom electrodes, like copper or nickel, would lower device production costs and possibly enhance functionality through the use of ferromagnetic or shape memory alloys. Compatibility with base metals has been achieved for the BaTiO3 family of ferroelectrics through an equilibrium processing approach. Unfortunately, fundamental materials differences (equilibrium stability, constituent volatility) make equilibrium processing of Pb-based ferroelectrics impractical. In this work, a new methodology is developed for achieving compatibility between chemical solution deposited (CSD) lead zirconate titanate (PZT) thin films and copper foil substrates. This new approach relies on kinetically avoiding substrate oxidation while maintaining device-quality PZT thin films through a careful design of solution chemistry and processing variables.