Scaling of ferroelectric properties in thin films

A fundamental issue in ferroic systems (ferromagnetic and ferroelectric) is the scaling of the order parameter (magnetization or polarization) with si ze. Specifically, in ferroelectric thin films, deviations in the polarizati on can occur due to: (i) competition between thermal vibrations and the cor relation energy (which aligns the dipoles) and (ii) damage during fabricati on. These deviations will have a profound impact on the performance of the next generation of high-density nonvolatile memories based on the spontaneo us polarization. We have combined approaches, namely, focused ion-beam mill ing to define submicron capacitors and scanning force microscopy to examine the scaling of the fundamental ferroelectric response of these capacitors. We find that the capacitors exhibit ferroelectric properties for lateral d imensions down to at least 100 nm, suggesting that memories with densities in the range of 4-16 Gbits can be successfully fabricated. (C) 1999 America n Institute of Physics. [S0003-6951(99)02729-1].