Growth of highly oriented Pb(Zr,Ti)O-3 films on MgO-buffered oxidized Si substrates and its application to ferroelectric nonvolatile memory field-effect transistors

We have grown highly oriented lead zirconate titanate [Pb(Zr, Ti)O-3 or PZT ] films on oxidized silicon substrates using a thin MgO buffer layer (7-70 nm thick). Ferroelectric nonvolatile memory field-effect transistors (FETs) were successfully fabricated using the metal/PZT/MgO/SiO2/Si structure in conjunction with radio-frequency sputter deposition of PZT and MgO films. T he fabricated devices show excellent performance in ferroelectric polarizat ion switching and memory retention. The results indicate that a thin MgO bu ffer serves well not only as a template layer for the growth of oriented PZ T films on amorphous substrates, but also as a diffusion barrier between a ferroelectric and a substrate during device fabrication, protecting the SiO 2/Si interface and the FET channel region. (C) 1998 American Institute of P hysics. [S0003-6951(98)03652-3].