High speed, nondestructive readout from thin-film ferroelectric memory

Abstract

High speed, polarization direction dependent photoresponse from ferroelectric lead zirconate titanate (PbZr0.53Ti0.47O3) thin films, sandwiched between conducting electrodes to form a memory capacitor, is reported. Laser pulses with a full width at half maximum of ∼10 ns at 532 nm wavelength are utilized to readout the photoresponse signal from individual polarized elements. Such readout is repeated over a million times, with no detectable degradation in the photoresponse or the remanent polarization, suggesting its potential as a nondestructive readout (NDRO) of nonvolatile polarization state in thin-film ferroelectric memories. In principle, both electronic as well as thermal mechanisms could be triggered by such photon exposure of ferroelectric thin films. A comparison of the photoresponse from capacitors with semitransparent and opaque top electrodes suggests that the observed NDRO signal is primarily due to thermally triggered mechanisms.